Search

Background/aims: Support vector machine-based automated grading (known as iGradingM) has been shown to be safe, cost-effective and robust in the diabetic retinopathy (DR) screening (DES) programme in Scotland. It triages screening episodes as gradable with no DR versus manual grading required. The study aim was to develop a deep learning-based autograder using images and gradings from DES and to compare its performance with that of iGradingM., Methods: Retinal images, quality assurance (QA) data and routine DR grades were obtained from national datasets in 179 944 patients for years 2006-2016. QA grades were available for 744 images. We developed a deep learning-based algorithm to detect whether either eye contained ungradable images or any DR. The sensitivity and specificity were evaluated against consensus QA grades and routine grades., Results: Images used in QA which were ungradable or with DR were detected by deep learning with better specificity compared with manual graders (p<0.001) and with iGradingM (p<0.001) at the same sensitivities. Any DR according to the DES final grade was detected with 89.19% (270 392/303 154) sensitivity and 77.41% (500 945/647 158) specificity. Observable disease and referable disease were detected with sensitivities of 96.58% (16 613/17 201) and 98.48% (22 600/22 948), respectively. Overall, 43.84% of screening episodes would require manual grading., Conclusion: A deep learning-based system for DR grading was evaluated in QA data and images from 11 years in 50% of people attending a national DR screening programme. The system could reduce the manual grading workload at the same sensitivity compared with the current automated grading system., Competing Interests: Competing interests: HMC is the principal investigator on the JDRF UK grant. The employment of ADF and JM was with this funding. HMC and PMM have declared stock options in Bayer AG and Roche Pharmaceuticals. HMC has received grants from AstraZeneca LP, Regeneron, Pfizer, Novo Nordisk and Eli Lilly and Company, and is on the advisory panels or boards of Novo Nordisk, Eli Lilly and Company, Regeneron, Novartis Pharmaceuticals, Bayer AG and Sanofi-Aventis. HMC has received payments for speakers bureaus and honoraria from Eli Lilly and Company, Regeneron and Novartis Pharmaceuticals., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Purpose: To determine associations between deprivation using the Index of Multiple Deprivation (IMD and individual IMD subdomains) with incident referable diabetic retinopathy/maculopathy (termed rDR)., Methods: Anonymised demographic and screening data collected by the South-East London Diabetic Eye Screening Programme were extracted from September 2013 to December 2019. Multivariable Cox proportional models were used to explore the association between the IMD, IMD subdomains and rDR., Results: From 118 508 people with diabetes who attended during the study period, 88 910 (75%) were eligible. The mean (± SD) age was 59.6 (±14.7) years; 53.94% were male, 52.58% identified as white, 94.28% had type 2 diabetes and the average duration of diabetes was 5.81 (±6.9) years; rDR occurred in 7113 patients (8.00%). Known risk factors of younger age, Black ethnicity, type 2 diabetes, more severe baseline DR and diabetes duration conferred a higher risk of incident rDR. After adjusting for these known risk factors, the multivariable analysis did not show a significant association between IMD (decile 1 vs decile 10) and rDR (HR: 1.08, 95% CI: 0.87 to 1.34, p=0.511). However, high deprivation (decile 1) in three IMD subdomains was associated with rDR, namely living environment (HR: 1.64, 95% CI: 1.12 to 2.41, p=0.011), education skills (HR: 1.64, 95% CI: 1.12 to 2.41, p=0.011) and income (HR: 1.19, 95% CI: 1.02 to 1.38, p=0.024)., Conclusion: IMD subdomains allow for the detection of associations between aspects of deprivation and rDR, which may be missed when using the aggregate IMD. The generalisation of these findings outside the UK population requires corroboration internationally., Competing Interests: Competing interests: PG, PN, JMNdR, LW, SM, DH, MJC, MM and CB has no conflicts of interest to declare. TLJ’ employer (King’s College Hospital) receives funding for participants enrolled on commercial clinical trials of diabetic retinopathy including THR149-002 (sponsor: OXURION), NEON NPDR (sponsor: BAYER), RHONE-X (sponsor: ROCHE) and ALTIMETER (sponsor: ROCHE). He is a paid advisor to solicitors acting for REGENERON and has received conference support from ROCHE., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Background/aims: Deep learning systems (DLSs) for diabetic retinopathy (DR) detection show promising results but can underperform in racial and ethnic minority groups, therefore external validation within these populations is critical for health equity. This study evaluates the performance of a DLS for DR detection among Indigenous Australians, an understudied ethnic group who suffer disproportionately from DR-related blindness., Methods: We performed a retrospective external validation study comparing the performance of a DLS against a retinal specialist for the detection of more-than-mild DR (mtmDR), vision-threatening DR (vtDR) and all-cause referable DR. The validation set consisted of 1682 consecutive, single-field, macula-centred retinal photographs from 864 patients with diabetes (mean age 54.9 years, 52.4% women) at an Indigenous primary care service in Perth, Australia. Three-person adjudication by a panel of specialists served as the reference standard., Results: For mtmDR detection, sensitivity of the DLS was superior to the retina specialist (98.0% (95% CI, 96.5 to 99.4) vs 87.1% (95% CI, 83.6 to 90.6), McNemar's test p<0.001) with a small reduction in specificity (95.1% (95% CI, 93.6 to 96.4) vs 97.0% (95% CI, 95.9 to 98.0), p=0.006). For vtDR, the DLS's sensitivity was again superior to the human grader (96.2% (95% CI, 93.4 to 98.6) vs 84.4% (95% CI, 79.7 to 89.2), p<0.001) with a slight drop in specificity (95.8% (95% CI, 94.6 to 96.9) vs 97.8% (95% CI, 96.9 to 98.6), p=0.002). For all-cause referable DR, there was a substantial increase in sensitivity (93.7% (95% CI, 91.8 to 95.5) vs 74.4% (95% CI, 71.1 to 77.5), p<0.001) and a smaller reduction in specificity (91.7% (95% CI, 90.0 to 93.3) vs 96.3% (95% CI, 95.2 to 97.4), p<0.001)., Conclusion: The DLS showed improved sensitivity and similar specificity compared with a retina specialist for DR detection. This demonstrates its potential to support DR screening among Indigenous Australians, an underserved population with a high burden of diabetic eye disease., Competing Interests: Competing interests: PAK has acted as a consultant for DeepMind, Roche, Novartis and Apellis and is an equity owner in Big Picture Medical. He has received speaker fees from Heidelberg Engineering, Topcon, Allergan and Bayer. FH, RS, PB and RT are employees of Google LLC and own Alphabet stock., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY. Published by BMJ.)

Aims: To analyse the prevalence of visual impairment (VI), compare it to certification of visual impairment (CVI) and analyse VI associations in patients with diabetic retinopathy (DR)., Methods: Retrospective cohort study, which included 8007 patients with DR referred from the English diabetic eye screening programme to a tertiary referral eye hospital. Main outcome measure was VI, defined as vision in the best eye of <6/24. We conducted a multivariable logistic regression for VI as primary outcome of interest, controlling for age, sex, type of diabetes, baseline DR grade, ethnicity and index of multiple deprivation (IMD)., Results: Mean age was 64.5 (SD 13.6) years; 61% of patients were men; and 31% of South Asian ethnicity. There were 68 patients with CVI during the study period, and 84% (272/325) of patients with VI did not have CVI after a mean follow-up of 1.87 (SD ±0.86) years. Older age showed a positive association with VI (OR per decade rise 1.88, 95% CI 1.70 to 2.08; p=1.8×10 -34 ). Men had a lower risk of VI (OR 0.62, 95% CI 0.50 to 0.79, p=6.0×10 -5 ), and less deprivation had a graded inverse association with VI (OR per IMD category increase 0.83, 95% CI 0.74 to 0.93, p value for linear trend 0.002)., Conclusion: The majority of people with vision impairment are not registered at the point of care, which could translate to underestimation of diabetes-related VI and all-cause VI at a national level if replicated at other centres. Further work is needed to explore rates of VI and uptake of registration., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2023. No commercial re-use. See rights and permissions. Published by BMJ.)

Background/aims: The English Diabetic Eye Screening Programme (DESP) offers people living with diabetes (PLD) annual screening. Less frequent screening has been advocated among PLD without diabetic retinopathy (DR), but evidence for each ethnic group is limited. We examined the potential effect of biennial versus annual screening on the detection of sight-threatening diabetic retinopathy (STDR) and proliferative diabetic retinopathy (PDR) among PLD without DR from a large urban multi-ethnic English DESP., Methods: PLD in North-East London DESP (January 2012 to December 2021) with no DR on two prior consecutive screening visits with up to 8 years of follow-up were examined. Annual STDR and PDR incidence rates, overall and by ethnicity, were quantified. Delays in identification of STDR and PDR events had 2-year screening intervals been used were determined., Findings: Among 82 782 PLD (37% white, 36% South Asian, and 16% black people), there were 1788 incident STDR cases over mean (SD) 4.3 (2.4) years (STDR rate 0.51, 95% CI 0.47 to 0.55 per 100-person-years). STDR incidence rates per 100-person-years by ethnicity were 0.55 (95% CI 0.48 to 0.62) for South Asian, 0.34 (95% CI 0.29 to 0.40) for white, and 0.77 (95% CI 0.65 to 0.90) for black people. Biennial screening would have delayed diagnosis by 1 year for 56.3% (1007/1788) with STDR and 43.6% (45/103) with PDR. Standardised cumulative rates of delayed STDR per 100 000 persons for each ethnic group were 1904 (95% CI 1683 to 2154) for black people, 1276 (95% CI 1153 to 1412) for South Asian people, and 844 (95% CI 745 to 955) for white people., Interpretation: Biennial screening would have delayed detection of some STDR and PDR by 1 year, especially among those of black ethnic origin, leading to healthcare inequalities., Competing Interests: Competing interests: AYL: has received fees from Santen, Genetech, FDA, Johnson and Johnson, Carl Zeiss Meditec, Gyroscope, Regeneron, and has a non-remunerative relation with Microsoft. CE: has received fees from Heidelberg Engineering, Inozyme Pharma. AT: has received fees from Annexon, Apellis, Bayer, Genentech, Iveric Bio, Novartis, Oxurion, and Roche., (© Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY. Published by BMJ.)

Aims: To investigate the associations of ocular biometric parameters with incident diabetic retinopathy (DR), incident vision-threatening DR (VTDR) and DR progression., Methods: This community-based prospective cohort study recruited participants with type 2 diabetes aged 35-80 years from 2017 to 2019 in Guangzhou, China. Refractive error and ocular biometric parameters were measured at baseline, including axial length (AL), axial length-to-corneal radius (AL/CR) ratio, corneal curvature (CC), lens thickness (LT), anterior chamber depth (ACD), lens power and corneal diameter (CD)., Results: A total of 1370 participants with a mean age of 64.3±8.1 years were followed up for two consecutive years. During the follow-up period, 342 out of 1195 (28.6%) participants without DR at baseline had incident DR, 15 out of 175 (8.57%) participants with baseline DR had DR progression and 11 of them progressed to VTDR. After multiple adjustments, a longer AL (OR=0.76; 95% CI, 0.66 to 0.86; p<0.001) and a larger AL/CR ratio (OR=0.20; 95% CI, 0.07 to 0.55; p=0.002) were associated with significantly reduced risks of incident DR but were not associated with incident VTDR or DR progression. Refractive status and other ocular biometric parameters investigated, including ACD, CC, CD, lens power and LT were not associated with any of the DR outcomes (all p>0.05)., Conclusions: A longer AL and a larger AL/CR ratio are protective against incident DR. These parameters may be incorporated into future DR risk prediction models to individualise the frequency of DR screening and prevention measures., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2023. No commercial re-use. See rights and permissions. Published by BMJ.)

Aim: To provide contemporary longitudinal data on the incidence and progression of diabetic retinopathy (DR) in a multi-ethnic population of whites, African Americans, Chinese and Hispanics in the United States., Methods: A prospective, multi-region, multi-ethnic population-based cohort study that included 498 participants with diabetes, aged 45-84 years at baseline, from the Multi-Ethnic Study of Atherosclerosis with retinal images obtained twice, on average 8 years apart. Presence and severity of DR were graded from these retinal images according to the modified Airlie House classification system. Main outcome measures were 8-year incidence, progression and improvement of DR, and their associated risk factors., Results: Over the 8 years, the cumulative rates were 19.2% for incident DR, 17.3% for DR progression, 23.3% for DR improvement, 2.7% for incident vision-threatening DR, 1.8% for incident proliferative DR and 2.2% for incident macular oedema. In multivariate analysis, significant risk factors associated with incident DR were higher glycosylated haemoglobin (relative risk (RR) 1.28; 95% CI: 1.16 to 1.41) and higher systolic blood pressure (RR 1.14; 95% CI: 1.04 to 1.25). Significant factors associated with DR progression were higher glycosylated haemoglobin (RR 1.20; 95% CI: 1.00 to 1.43) and higher low-density lipoprotein cholesterol (RR 1.01; 95% CI: 1.00 to 1.03)., Conclusion: Over an 8-year period, approximately one in five participants with diabetes developed DR, while almost a quarter of those with DR at baseline showed improvement, possibly reflecting the positive impact of clinical and public health efforts in improving diabetes care in the United States over the last two decades., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2022. No commercial re-use. See rights and permissions. Published by BMJ.)

Background/aims: Obesity is a well-known risk factor for diabetes, but its association with diabetic retinopathy (DR) is inconclusive, in particular in Asians. We aimed to assess whether body mass index (BMI) is associated with the presence and severity of DR in Asian populations with diabetes., Methods: Pooled analysis of individual-level cross-sectional data from 10 010 adults with diabetes who participated in 12 population-based studies conducted in China, India, Japan, Russia (Asian), Singapore and South Korea that were part of the Asian Eye Epidemiology Consortium (AEEC). BMI was calculated as weight in kilograms divided by height in square metres and categorised into normal (<25 kg/m 2 , reference), overweight (25-29.9 kg/m 2 ) and obese (≥30 kg/m 2 ). Any-DR (n=1669) and vision-threatening DR (VTDR, n=489) were assessed from digital retinal photographs and graded according to standard protocols. Each study was analysed separately using multivariable logistic regression models adjusted for age, sex, haemoglobin A1c%, systolic blood pressure and diabetes duration, and the estimated odds ratios (ORs) and 95% confidence interval (CIs) from all studies were then combined using random-effects models., Results: In multivariable models, obesity showed a significant inverse association with any-DR (pooled OR (95% CI) =0.74 (0.59 to 0.91)) and VTDR (0.75 (0.60 to 0.93)). Similarly, in continuous analysis, BMI showed a significant inverse association with both any-DR (0.93 (0.87 to 0.99)) and VTDR (0.79 (0.68 to 0.92) per SD increase). Overweight did not show a significant association with any-DR., Conclusions: Among Asian adults with diabetes, both BMI and obesity showed an inverse association with DR. These findings warrant confirmation in further longitudinal studies., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2022. No commercial re-use. See rights and permissions. Published by BMJ.)

Purpose: We described the 6-year incidence and changes of retinopathy, and their associated risk factors in a multi-ethnic Asian population without diabetes., Methods: We included 4374 participants with non-diabetes from a population-based cohort, the Singapore Epidemiology of Eye Disease Study, with gradable retinal photographs at baseline and 6-year follow-up visit. Retinopathy was assessed according to the modified Airlie House classification system., Results: Over the 6-year period, the cumulative rates were 2.5% (106/4279) for retinopathy incidence, 1.0% (1/95) for retinopathy progression and 68.4% (65/95) for retinopathy regression. In multivariable analysis, higher diastolic blood pressure (DBP) (risk ratio (RR)=1.02; 95% CI: 1.00 to 1.04; per 10 mm Hg increase in DBP) and wider retinal arteriolar calibre (RR=1.36; 95% CI: 1.13 to 1.63; per SD increase in central retinal artery equivalent) were associated with higher risk of incident retinopathy, while higher level of high-density lipoprotein (HDL) was associated with lower risk of incident retinopathy (RR=0.56; 95% CI: 0.32 to 0.99; per mmol/L increase in HDL). Compared with Chinese, Malays were more likely to have retinopathy regression (RR=1.63; 95% CI: 1.20 to 2.22), while overweight (RR=0.47; 95% CI: 0.26 to 0.84) and higher glycosylated haemoglobin (HbA1c) level (RR=0.58; 95% CI: 0.37 to 0.93; per per cent increase in HbA1c) were associated with lower likelihood of retinopathy regression., Conclusion: Risk of developing retinopathy in Asians without diabetes is generally low. However, regression of retinopathy over time is common, suggesting that these retinopathy signs may reflect subclinical reversible microvascular dysfunction. Several metabolic risk factors are associated with incidence or regression of retinopathy, suggesting that good metabolic control may still be important in the management of non-diabetic retinopathy., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2022. No commercial re-use. See rights and permissions. Published by BMJ.)

Purpose: To investigate the associations between body mass index (BMI) with diabetes mellitus (DM) and vision-threatening diabetic retinopathy (VTDR)., Methods: This was a longitudinal study which included DM-free participants aged ≥40 years from the Lingtou Eye Cohort Study at baseline (2008-2010). Physical and ocular examinations were performed at baseline and annual follow-ups under standardised protocol. Two 45° non-mydriatic colour digital retinal photographs were obtained for each eye at all study visits, and presence of VTDR at the 2016 follow-up was graded by a deep-learning algorithm (LableMe) with proved high accuracy for detection of VTDR., Results: A total of 2934 participants were included with a mean (SD) age of 59.5 (7.3) years (58.3% men). Participants with incident DM (441/2934, 15%) were significantly older (p<0.001), had higher obesity levels (p<0.001), higher systolic blood pressure (SBP) (p<0.001), diastolic blood pressure (p<0.001), fasting plasma glucose (FPG) (p<0.001), triglycerides (p=0.002) and high-density lipoprotein cholesterol (p<0.001), as compared with those without. Participants with incident VTDR (48/2934, 1.63%) were also older (p<0.001), had higher SBP (p=0.013) and FPG (p<0.001), but did not differ in baseline BMI, comparing with those without. Regression analysis showed that higher baseline BMI was significantly related to incident DM (p<0.005), but not incident VTDR, during the follow-up. Subgroup analysis among participants with incident DM also revealed no association between BMI and VTDR., Conclusions: Higher baseline BMI increased the risk of incident DM, but was not related to the risk of VTDR in this adult Chinese population., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2022. No commercial re-use. See rights and permissions. Published by BMJ.)

Objective: To study the uptake of annual diabetic retinopathy screening and study the 5-year trends in the detection of screen-positive diabetic retinopathy and non-diabetes-related eye disease in a cohort of annually screened individuals., Design: Retrospective retinopathy screening attendance and retinopathy grading analysis., Setting: Community-based retinopathy screening centres for the Diabetic RetinaScreen Programme., Participants: 171 557 were identified by the screening programme to be eligible for annual diabetic retinopathy screening. 120 048 individuals over the age of 12 consented to and attended at least one screening appointment between February 2013 to December 2018., Main Outcome Measures: Detection rate per 100 000 of any retinopathy, screen-positive referrable retinopathy and nondiabetic eye disease., Results: Uptake of screening had reached 67.2% in the fifth round of screening. Detection rate of screen-positive retinopathy reduced from 13 229 to 4237 per 100 000 screened over five rounds. Detection of proliferative disease had reduced from 2898 to 713 per 100 000 screened. Non-diabetic eye disease detection and referral to treatment centres increased almost eightfold from 393 in round 1 to 3225 per 100 000 screened. The majority of individuals referred to treatment centres for ophthalmologist assessment are over the age of 50 years., Conclusions: Screening programme has seen a reduced detection rate both screen-positive retinopathy referral in Ireland over five rounds of screening. Management of nondiabetic eye diseases poses a significant challenge in improving visual outcomes of people living with diabetes in Ireland., Competing Interests: Competing interests: MC is a beneficial owner of Global Vision (Dublin, Ireland)., (© Author(s) (or their employer(s)) 2022. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Aims: To use machine learning (ML) to determine the relative contributions of modifiable and non-modifiable clinical, metabolic, genetic, lifestyle and socioeconomic factors on the risk of major eye diseases., Methods: We conducted analyses in a cross-sectional multi-ethnic population-based study (n=10 033 participants) and determined a range of modifiable and non-modifiable risk factors of common eye diseases, including diabetic retinopathy (DR), non-diabetic-related retinopathy (NDR); early and late age-related macular degeneration (AMD); nuclear, cortical and posterior subcapsular (PSC) cataract; and primary open-angle (POAG) and primary angle-closure glaucoma (PACG). Risk factors included individual characteristics, metabolic profiles, genetic background, lifestyle patterns and socioeconomic status (n~100 risk factors). We used gradient boosting machine to estimate the relative influence (RI) of each risk factor., Results: Among the range of risk factors studied, the highest contributions were duration of diabetes for DR (RI=22.1%), and alcohol consumption for NDR (RI=6.4%). For early and late AMD, genetic background (RI~20%) and age (RI~15%) contributed the most. Axial length was the main risk factor of PSC (RI=30.8%). For PACG, socioeconomic factor (mainly educational level) had the highest influence (20%). POAG was the disease with the highest contribution of modifiable risk factors (cumulative RI~35%), followed by PACG (cumulative RI ~30%), retinopathy (cumulative RI between 20% and 30%) and late AMD (cumulative RI ~20%)., Conclusion: This study illustrates the utility of ML in identifying factors with the highest contributions. Risk factors possibly amenable to interventions were intraocular pressure (IOP) and Body Mass Index (BMI) for glaucoma, alcohol consumption for NDR and levels of HbA1c for DR., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2022. No commercial re-use. See rights and permissions. Published by BMJ.)

Background/aim: To validate a previously developed model for prediction of diabetic retinopathy (DR) for personalised retinopathy screening in persons with type 1 diabetes., Methods: Retrospective medical data of persons with type 1 diabetes treated in an academic hospital setting were used for analysis. Sight-threatening retinopathy (STR) was defined as the presence of severe non-proliferative DR, proliferative DR or macular oedema. The presence and grade of retinopathy, onset of diabetes, systolic blood pressure, and levels of haemoglobin A 1c were used to calculate an individual risk estimate and personalised screening interval. In persons with STR, the occurrence was compared with the calculated date of screening. The model's predictive performance was measured using calibration and discrimination techniques., Results: Of the 268 persons included in our study, 24 (9.0%) developed STR during a mean follow-up of 4.6 years. All incidences of STR occurred after the calculated screening date. By applying the model, the mean calculated screening interval was 30.5 months, which is a reduction in screening frequency of 61% compared with annual screening and 21% compared with biennial screening. The discriminatory ability was good (Harrell's C-statistic=0.82, 95% CI 0.74 to 0.90), and calibration showed an overestimation of risk in persons who were assigned to a higher risk for STR., Conclusion: This validation study suggests that a screening programme based on the previously developed prediction model is safe and efficient. The use of a personalised screening frequency could improve cost-effectiveness of diabetic eye care., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2021. No commercial re-use. See rights and permissions. Published by BMJ.)

Background/aims: The purpose of this study was to estimate the total healthcare cost associated with diabetic retinopathy (DR) in the population aged 18 years and older in Hungary, and its projection for the year 2045., Methods: A cost model was developed based on the standardised rapid assessment of avoidable blindness with the diabetic retinopathy module (RAAB+DRM) methodology and recently reported prevalent-based cost of illness model. Projection for 2045 was made based on the estimation for increasing diabetes mellitus (DM) prevalence of the International Diabetes Federation. Costs were analysed from the perspective of the healthcare system and the patients. Our DR cost model was constructed according to the Scottish DR grading scale and based on the DR severity stadium., Results: The total DR-associated healthcare cost was US$145.8 million in 2016 and will increase to US$169.0 million by 2045. The two major cost drivers were intravitreal antivascular endothelial growth factor injections and vitrectomies in this study (US$126.4 million in 2016 and US$146.5 million in 2045); they amounted to 86.7% of the total treatment cost of DR. The DR-related cost per patient was US$180.5 in Hungary., Conclusions: The cost per patient for treating DR was lower in Hungary than in other countries. Due to the increasing socioeconomic burden of proliferative DR and diabetes-related blindness, it would be important to invest in DR screening, prevention and early treatment. Our new RAAB-based cost of DR model may facilitate comparisons of DR treatment costs across countries., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2021. No commercial re-use. See rights and permissions. Published by BMJ.)

Aims: To assess knowledge of diabetes and acceptance of eye care among people with diabetes in rural China, to improve service uptake., Methods: Population-based study of people in Guangdong, China, with glycosylated haemoglobin A1c≥6.5% and/or known history of diabetes. Between August and November 2014, participants answered a questionnaire (based on Delphi process/previous focus groups) on medical history, demographic characteristics, self-rated health and vision, knowledge about diabetes and diabetic retinopathy, quality of local healthcare, barriers to treatment, likely acceptance of eye exams and treatment, and interventions rated most likely to improve service uptake. Presenting visual acuity was assessed, fundus photography performed and images graded by trained graders. Potential predictors of accepting care were evaluated and confounders adjusted for using logistic regression., Results: A total of 562 people (9.6% (256/5825), mean age 66.2±9.84 years, 207 (36.8%) men) had diabetes, 118 (22.3%) previously diagnosed. 'Very likely' or 'likely' acceptance of laser treatment (140/530=26.4%) was lower than for eye exams (317/530=59.8%, p<0.001). Predictors of accepting both exams and laser included younger age (p<.001) and prior awareness of diabetes diagnosis (p=0.004 and p=0.035, respectively). The leading barrier to receiving diabetes treatment was unawareness of diagnosis (409/454, 97.2%), while interventions rated most likely to improve acceptance of eye exams included reimbursement of travel costs (387/562, 73.0%), video or other health education (359/562, 67.7%) and phone call reminders (346/562, 65.3%)., Conclusions: Improving diagnosis of diabetes, along with incentives, education and communication strategies, is most likely to enhance poor acceptance of diabetic eye care in this setting., Competing Interests: Competing interests: NC works as the Director of Research for Orbis International, a non-governmental organization which carries out programs I eye health, including diabetic retinopathy, in China., (© Author(s) (or their employer(s)) 2021. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: We investigated the incidence and causes of sight-threatening diabetes-related eye disease in children living with diabetes in the UK, to inform the national eye screening programme and enable monitoring of trends., Methods: We undertook a prospective active national surveillance via the British Ophthalmic Surveillance Unit. Eligible cases were children aged 18 years or younger, with type 1 or 2 diabetes, newly diagnosed between January 2015 and February 2017 with sight-threatening diabetic eye disease., Results: Eight children were reported. The annual incidence of all sight-threatening diabetes-related eye disease requiring referral to an ophthalmologist among children living with diabetes (n=8) in the UK was 1.21 per 10 000 person-years (95% CI 0.52 to 2.39) and was largely attributable to cataract (n=5) 0.76 per 10 000 person-years (95% CI 0.25 to 1.77). The incidence of sight-threatening diabetic retinopathy (n=3) among those eligible for screening (12 to 18 year-olds living with diabetes) was 1.18 per 10 000 person-years (95% CI 0.24 to 3.46). No subjects eligible for certification as visually impaired or blind were reported., Conclusions: Secondary prevention of visual disability due to retinopathy is currently the sole purpose of national eye screening programmes globally. However, the rarity of treatment-requiring retinopathy in children/young people living with diabetes, alongside growing concerns about suboptimal screening uptake, merit new consideration of the utility of screening for primary prevention of diabetes-related morbidity by using the screening event and findings as a catalyst for better diabetes self-management., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2021. No commercial re-use. See rights and permissions. Published by BMJ.)

Purpose: We examined the longitudinal association of baseline alcohol intake and frequency with the 6-year incidence and progression of diabetic retinopathy (DR) in a population-based cohort of Singaporean Indians., Methods: We included 656 participants with diabetes mellitus, gradable retinal photographs from baseline (2007-2009) and follow-up (2013-2015) examinations, information on alcohol intake and other relevant data from the Singapore Indian Eye Study were included. Incident DR was defined using the Modified Airlie House Classification as no DR at baseline and at least minimal non-proliferative DR at follow-up; and DR progression as at least a one-step worsening in DR at follow-up from minimal or worse status at baseline, excluding those with proliferative DR., Results: The mean age (SD) of our participants (n=656) was 58.8 (9.2) years, and 54.4% were male. At follow-up, 82 of 510 (16%) participants developed DR, and 45 of 146 (30.8%) had DR progression. 65 (12.7%) and 28 (19.1%) participants consumed alcohol in incident DR and progression categories, respectively. In multivariable analyses, those who consumed alcohol had nearly two-thirds reduced odds of incident DR (OR (95% CI): 0.36 (0.13 to 0.98)) compared with those who did not. Participants with infrequent consumption of alcohol also had a reduction in odds of incident DR (0.17 (0.04 to 0.69)), compared with non-drinkers. No association was found between alcohol consumption and DR progression., Conclusions and Relevance: In our longitudinal population of Singapore Indians, baseline alcohol intake, particularly infrequent consumption, was associated with lower risk of developing DR, compared with non-drinkers, in line with previous cross-sectional findings., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2021. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: To estimate the 10-year incidence of referable diabetic retinopathy (DR) in a French population with type 1 and 2 diabetes mellitus (DM). A secondary objective was the assessment of safe screening intervals in patients with diabetes without retinopathy., Methods: Observational, prospective and multicentric study between June 2004 and September 2017 based on a regional screening programme for DR in the Paris region. The incidence of referable DR in patients without retinopathy at baseline was calculated by the Turnbull survival estimator. A safe screening interval was defined as a 95% probability of remaining without referable DR., Results: Among the 25 745 participants with type 1 (n=6086) or type 2 (n=19 659) DM, the 10-year cumulative incidence of referable DR was 19.10% (95% CI 17.21% to 21.14%) and 17.03% (15.78% to 18.35%), median (IQR) follow-up=3.33 (4.24) years. The safe screening interval for patients without DR at the first examination for type 1 and 2 DM was 2.2 (95% CI 2.0 to 2.4) and 3.0 (2.9 to 3.1) years, respectively. In a subgroup of low-risk patients with type 2 DM, the safe screening interval was 4.2 (3.8 to 4.6) years., Conclusions: These data suggest that in Paris area, a 2-year, 3-year and 4-year screening interval was considered safe for type 1 DM, type 2 DM and for low-risk patients with type 2 DM, respectively, without DR at the first examination. While these data might be used to support the consideration of extending screening intervals, a randomised clinical trial would be suitable to confirm the safety for patients with DM., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2021. No commercial re-use. See rights and permissions. Published by BMJ.)

Purpose: Chronic kidney disease (CKD) patients often develop cardiovascular disease (CVD) and retinopathy. The purpose of this study was to assess the association between progression of retinopathy and concurrent incidence of CVD events in participants with CKD., Design: We assessed 1051 out of 1936 participants in the Chronic Renal Insufficiency Cohort Study that were invited to have fundus photographs obtained at two timepoints separated by 3.5 years, on average., Methods: Using standard protocols, presence and severity of retinopathy (diabetic, hypertensive or other) and vessel diameter calibre were assessed at a retinal image reading centre by trained graders masked to study participants' information. Participants with a self-reported history of CVD were excluded. Incident CVD events were physician adjudicated using medical records and standardised criteria. Kidney function and proteinuria measurements along with CVD risk factors were obtained at study visits., Results: Worsening of retinopathy by two or more steps in the EDTRS retinopathy grading scale was observed in 9.8% of participants, and was associated with increased risk of incidence of any CVD in analysis adjusting for other CVD and CKD risk factors (OR 2.56, 95% CI 1.25 to 5.22, p<0.01). After imputation of missing data, these values were OR=1.66 (0.87 to 3.16), p=0.12., Conclusion: Progression of retinopathy is associated with higher incidence of CVD events, and retinal-vascular pathology may be indicative of macrovascular disease even after adjustment for kidney diseases and CVD risk factors. Assessment of retinal morphology may provide important information when assessing CVD in patients with CKD., Competing Interests: Competing interests: RRT is a consultant for Medtronic, ROX Medical, and receives royalties from UpToDate. ASG has received research funding from Novartis, GlaxoSmithKline and Sanofi. All other coauthors have no financial conflict of interest regarding the contents of this manuscript., (© Author(s) (or their employer(s)) 2021. No commercial re-use. See rights and permissions. Published by BMJ.)

Aim: To estimate the prevalence, causes and risk factors for presenting distance and near vision impairment (VI) in Trinidad and Tobago., Methods: This is a national, population-based survey using multistage, cluster random sampling in 120 clusters with probability-proportionate-to-size methods. Stage 1 included standardised, community-based measurement of visual acuity. Stage 2 invited all 4263 people aged ≥40 years for comprehensive clinic-based assessment. The Moorfields Eye Hospital Reading Centre graded fundus photographs and optical coherence tomography images independently., Results: The response rates were 84.2% (n=3589) (stage 1) and 65.4% (n=2790) (stage 2), including 97.1% with VI. The mean age was 57.2 (SD 11.9) years, 54.5% were female, 42.6% were of African descent and 39.0% were of South Asian descent. 11.88% (95% CI 10.88 to 12.97, n=468) had distance VI (logarithm of the minimum angle of resolution [logMAR] >0.30), including blindness (logMAR >1.30) in 0.73% (95% CI 0.48 to 0.97, n=31), after adjustment for study design, non-response, age, sex and municipality. The leading causes of blindness included glaucoma (31.7%, 95% CI 18.7 to 44.8), cataract (28.8%, 95% CI 12.6 to 45.1) and diabetic retinopathy (19.1%, 95% CI 4.2 to 34.0). The leading cause of distance VI was uncorrected refractive error (47.4%, 95% CI 43.4 to 51.3). Potentially avoidable VI accounted for 86.1% (95% CI 82.88 to 88.81), an estimated 176 323 cases in the national population aged ≥40 years. 22.3% (95% CI 20.7 to 23.8, n=695) had uncorrected near VI (logMAR >0.30 at 40 cm with distance acuity <0.30). Significant independent associations with distance VI included increasing age, diagnosed diabetes and unemployment. Significant independent associations with near VI included male sex, no health insurance and unemployment., Conclusions: Trinidad and Tobago's burden of avoidable VI exceeds that of other high-income countries. Population and health system priorities are identified to help close the gap., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2020. No commercial re-use. See rights and permissions. Published by BMJ.)

Aim: To evaluate clinical comorbidities and steroid use as risk factors for central serous retinopathy (CSR)., Methods: Using national insurance databases, we conducted a case-control study of beneficiaries with an incident diagnosis of CSR between 2007 and 2015 (n=35 492) and randomly selected controls matched on age-based and sex-based propensity scores (n=1 77 460)., Results: The mean age (SD) of cases was 49.1 (12.2) years, and the majority (69.2%) were male. Cases were more likely to have received steroids in the past year (OR 1.14, 95% CI 1.09 to 1.19, p<0.001) and to have comorbid Cushing's syndrome (OR 2.19, 95% CI 1.33 to 3.59, p=0.002), age-related macular degeneration (OR 5.24, 95% CI 5.00 to 5.49, p<0.001), diabetic macular oedema (OR 2.05, 95% CI 1.71 to 2.47, p<0.001) and diabetes mellitus (OR 1.44, 95% CI 1.33 to 1.56, p<0.001). Glaucoma was associated with lower odds of CSR (OR 0.54, 95% CI 0.51 to 0.56, p<0.001). Patients with other previously hypothesised risk factors (including essential hypertension, pregnancy, other autoimmune disease, sleep disorders, Helicobacter pylori infection and gastro-oesophageal reflux disease) had lower odds of CSR., Conclusions: Male middle-aged patients with recent steroid exposure were significantly more likely to develop CSR. Other risk factors include diabetes mellitus, diabetic macular oedema and age-related macular degeneration. Other previously hypothesised risk factors did not appear to confer increased risk. More research is needed to confirm and examine underlying pathophysiology., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2019. No commercial re-use. See rights and permissions. Published by BMJ.)

Background/aim: The relationship between diabetic retinopathy (DR) and cognitive impairment (CI) is unclear due to equivocal findings from cross-sectional studies and a lack of long-term data. In this population-based cohort study, we investigated the longitudinal association between the severity of DR and the incidence of CI., Methods: 682 participants with diabetes, gradable retinal photographs and no CI at baseline 2004-2011) and complete relevant data at follow-up 2010-2016 from the Singapore Epidemiology of Eye Disease Study were included. CI was assessed using the validated Abbreviated Mental Test (AMT), defined as scores of ≤6 and ≤8 for those with 0-6 and >6 years of formal education, respectively. Six-year incident CI was defined as having no CI at baseline but present at the follow-up visit., Results: Of the 682 included participants, 483 (70.8%) had no DR and 199 (29.2%) had any DR. Of those with DR, 142 (20.8%) had minimal/mild DR and 57 (8.4%) had moderate or worse DR at baseline. At the follow-up visit, 40 (5.9%) participants had incident CI based on AMT. In multivariate analysis compared with participants without DR, those with any DR had more than twofold increased odds of incident CI (OR (95% CI): 2.32 (1.07 to 5.03)). Participants with moderate or worse DR had threefold increased odds of developing CI (3.41 (1.06 to 11.00)), compared with those with no DR., Conclusions: DR, particularly at the more severe stages, is associated with increased risk of developing CI, independent of vision and other risk factors., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2019. No commercial re-use. See rights and permissions. Published by BMJ.)

Aim: To assess the impact of deprivation on diabetic retinopathy presentation and related treatment interventions, as observed within the UK hospital eye service., Methods: This is a multicentre, national diabetic retinopathy database study with anonymised data extraction across 22 centres from an electronic medical record system. The following were the inclusion criteria: all patients with diabetes and a recorded, structured diabetic retinopathy grade. The minimum data set included, for baseline, age and Index of Multiple Deprivation, based on residential postcode; and for all time points, visual acuity, ETDRS grading of retinopathy and maculopathy, and interventions (laser, intravitreal therapies and surgery). The main  outcome measures were (1) visual acuity and binocular visual state, and (2) presence of sight-threatening complications and need for early treatment., Results: 79 775 patients met the inclusion criteria. Deprivation was associated with later presentation in patients with diabetic eye disease: the OR of being sight-impaired at entry into the hospital eye service (defined as 6/18 to better than 3/60 in the better seeing eye) was 1.29 (95% CI 1.20 to 1.39) for the most deprived decile vs 0.77 (95% CI 0.70 to 0.86) for the least deprived decile; the OR for being severely sight-impaired (3/60 or worse in the better seeing eye) was 1.17 (95% CI 0.90 to 1.55) for the most deprived decile vs 0.88 (95% CI 0.61 to 1.27) for the least deprived decile (reference=fifth decile in all cases). There is also variation in sight-threatening complications at presentation and treatment undertaken: the least deprived deciles had lower chance of having a tractional retinal detachment (OR=0.48 and 0.58 for deciles 9 and 10, 95% CI 0.24 to 0.90 and 0.29 to 1.09, respectively); in terms of accessing treatment, the rate of having a vitrectomy was lowest in the most deprived cohort (OR=0.34, 95% CI 0.19 to 0.58)., Conclusions: This large real-world study suggests that first presentation at a hospital eye clinic with visual loss or sight-threatening diabetic eye disease is associated with deprivation. These initial hospital visits represent the first opportunities to receive treatment and to formally engage with support services. Such patients are more likely to be sight-impaired or severely sight-impaired at presentation, and may need additional resources to engage with the hospital eye services over complex treatment schedules., Competing Interests: Competing interests: CAE has received consultancy fees from Medisoft. LD has undertaken advisory board work previously for Novartis, Bayer, Allergan, Alimera, Alcon, Oraya and Thrombogenics; and received speaker fees from Bayer, Novartis and Alimera, and travel grants from Novartis, Bayer and Allergan. HE has undertaken advisory board work for Novartis and Bayer; received speaker fees from Novartis, and travel grants from Novartis, Bayer and Allergan. RM has undertaken advisory board work for Alimera; received speaker fees from Bayer and Alcon; and obtained travel and educational grants from Novartis and Bayer. UC has undertaken advisory board work for Allergan, Bayer, Novartis and Roche; and received speaker fees from Heidelberg and Zeiss. SP has undertaken advisory board work and received travel grants from Bayer, Alimera, Allergan and Novartis. DPC has received speaker fees from Allergan and Santen. DAS has received consultancy fees from Big Picture Medical; speaker fees from Bayer, Novartis, Allergan and Haag-Streit; and travel grants from Bayer and Allergan. AnL has received travel grants from Bayer and Allergan. CB has undertaken advisory board work for Alimera, Bayer and Novartis, and received travel support/speaker fees from Alimera, Bayer and Novartis. FG has undertaken advisory board work for Novartis, Bayer, Allergan, Alimera, Alcon and Roche; received speaker fees from Bayer, Novartis, Alimera and Allergan, and travel grants from Bayer and Allergan. RK has undertaken advisory board work for Alimera; received speaker fees from Novartis, and travel grants from Novartis, Bayer, Alimera and Allergan. TA has undertaken advisory board work for Bayer; received speaker fees from Novartis, and travel grants from Novartis and Bayer. HP has received travel grants from Bayer and Alimera. RA has received travel grants from Novartis, Bayer and Allergan. VK has undertaken advisory board work for Polyphotonix and received speaker fees from Heidelberg. ND has undertaken advisory board work for Novartis and Allergan; received speaker fees for Novartis and Bayer; and received travel grants from Novartis, Allergan and Bayer., (© Author(s) (or their employer(s)) 2019. Re-use permitted under CC BY. Published by BMJ.)

Background/aims: To conduct an assessment of avoidable blindness, diabetes mellitus and diabetic retinopathy (DR) in adults aged 50 years and older in the National Capital District (NCD) region of Papua New Guinea (PNG)., Methods: A cross-sectional population-based survey was performed for which 25 clusters of 50 people aged ≥50 years were randomly selected from the NCD region. The standardised rapid assessment of avoidable blindness (RAAB) with diabetic retinopathy (+DR) methodology was used. Blindness was defined as presenting visual acuity <3/60 in the better eye. Participants were classified as having diabetes if they were known to have diabetes or if their random blood glucose level was ≥200 mg/dL. Dilated fundus examination and Scottish DR grading were performed., Results: In total, 1192 out of 1250 eligible participants (95.4%) were examined. Of these, 7.8% had known or newly diagnosed diabetes. Seventy-one per cent of participants with known diabetes had a blood glucose level ≥200 mg/dL, and 82.9% had never had an ophthalmological examination for DR. Prevalence of DR and/or maculopathy was 46.4%. The age-adjusted and sex-adjusted prevalence of diabetes was estimated at 8.1% (95% CI 5.7% to 10.4%) in the population aged 50 years or older in the NCD region of PNG., Conclusions: Prevalence of diabetes in adults aged 50 years and older was lower than reported elsewhere in the region, and lower than other RAAB+DR surveys. Despite this, the prevalence of DR is high compared with other RAAB+DR surveys and demonstrates the need for increased awareness and accessibility to eye services for people with diabetes., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2019. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: To evaluate retinal thickness profiles in eyes with and without diabetic retinopathy (DR) using spectral-domain optical coherence tomography (SD-OCT) among individuals with diabetes., Methods: Participants were recruited from the Singapore Epidemiology of Eye Diseases Study, a population-based study among Chinese, Malays and Indians aged 40 years or older residing in Singapore. All participants underwent standardised systemic and ophthalmic examinations. Average thickness of the macula, ganglion cell-inner plexiform layer and outer retina layer (from the outer plexiform layer to the retinal pigment epithelium layer) were measured using SD-OCT. DR status and severity were graded based on fundus photographs using the modified Airlie House classification system. Participants with macular oedema were excluded., Results: 2240 eyes from 1280 participants were included. Of these, 1764 (78.7%) eyes had no DR, 351 (15.7%) eyes had minimal or mild DR and 125 (5.6%) eyes had moderate or worse DR. After adjusting for age, gender, ethnicity, axial length, hypertension, glycated haemoglobin, body mass index, total cholesterol and diabetes duration, eyes with DR had thicker macula (245.44 µm vs 243.04 µm, P=0.03) and outer retina (124.26 µm vs 123.08 µm, P=0.01) than eyes without DR. When stratified by DR severity, thicker macula (250.24 µm vs 242.88 µm, P=0.011) and outer retina (126.4 µm vs 123.0 μm, P=0.006) were observed in eyes with moderate or worse, but not minimal or mild DR, compared with eyes without DR., Conclusions: Even in the absence of macular oedema, eyes with DR, particularly those with more severe DR, had thicker macular and outer retinal layers than eyes without DR., Competing Interests: Competing interests: None declared., (© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

Purpose: To determine the prevalence and risk factors for diabetic retinopathy (DR) and sight-threatening diabetic retinopathy (STDR) in a multi-hospital-based DR screening programme among patients with diabetes in China, the Lifeline Express Diabetic Retinopathy Screening Program., Methods: Patients with diabetes in eight hospitals across mainland China (both southern and northern) from January 2014 to July 2016 were recruited in this programme. All participants underwent a standardised interview and examinations and received digital fundus photography. DR severity was graded from retinal fundus photographs by retina specialists in the reading centre of Joint Shantou International Eye Center, according to the grading standards of the English National Screening Programme. STDR was defined as the presence of preproliferative DR (R2), proliferative DR (R3) and/or maculopathy (M1)., Results: 16 305 patients with diabetes were screened for DR in total. Fundus photographs were gradable for 15 078 patients (92.5%). The age-gender-standardised prevalence of any DR and STDR was 27.9% (95% CI, 27.2% to 28.6%) and 12.6% (95% CI, 12.1% to 13.1%), respectively. In the multiple logistic regression analysis, younger age (OR, 0.967), longer duration of diabetes (OR, 1.093), higher haemoglobin A1c (OR, 1.115), higher fasting plasma glucose (OR, 1.074), higher systolic blood pressure (OR, 1.014), faster heart rate (OR, 1.010), higher low-density lipoprotein (OR, 1.149), lower triglycerides (OR, 0.975), higher blood urea nitrogen (BUN) (OR, 1.012) and elevated serum creatinine level (OR, 1.003) were associated with the presence of DR. Similar risk factors, except for BUN and triglycerides, were found for STDR., Conclusions: The prevalence of DR and STDR in diabetes was 27.9% and 12.6%, respectively in this multi-hospital-based population across China. Compared with Western population with diabetes, similar risk factors for DR and STDR were found in Chinese patients with diabetes., Competing Interests: Competing interests: None declared., (© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

Background: Diabetic retinopathy (DR) is a blinding yet treatable complication of diabetes. DR screening is highly cost-effective at reducing blindness. Amidst the rapidly growing diabetic population in Asia, the prevalence of DR in the region is relatively less well known., Aims: To review existing national DR screening guidelines of 50 countries in Asia, compare them against the International Council of Ophthalmology (ICO) guideline, and summarise the prevalence rates of DR and sight-threatening DR (STDR) in these countries., Methods: We systematically searched for published guidelines from the National Guideline Clearinghouse and other databases, and contacted local diabetic and ophthalmological associations of all 50 Asian countries., Results: Eleven Asian countries have published relevant guidelines, nine of which pertain to general diabetes care and two are DR-specific, covering less than half of Asia's population. The median DR prevalence among patients with diabetes is 30.5% (IQR: 23.2%-36.8%), similar to the USA and the UK. However, rates of STDR are consistently higher. All guidelines from the 11 Asian countries fulfil the ICO standard on when to start and repeat screening, except for screening interval for pregnant patients. However, only 2 of the 11 guidelines fulfil the ICO referral criteria and 6 partially fulfil. A third of the recommendations on screening process, equipment and personnel is either unavailable or incomplete., Conclusions: Countries in Asia need to establish more comprehensive and evidence-based DR screening guidelines to facilitate the execution of robust screening programmes that could help reduce DR-related blindness, improve patient outcomes and reduce healthcare costs., Competing Interests: Competing interests: None declared., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.)

Background/aims: To determine the incidence of any diabetic retinopathy (any-DR), sight-threatening diabetic retinopathy (STDR) and diabetic macular oedema (DMO) and their risk factors in type 1 diabetes mellitus (T1DM) over a screening programme., Methods: Nine-year follow-up, prospective population-based study of 366 patients with T1DM and 15 030 with T2DM. Epidemiological risk factors were as follows: current age, age at DM diagnosis, sex, type of DM, duration of DM, arterial hypertension, levels of glycosylated haemoglobin (HbA 1c ), triglycerides, cholesterol fractions, serum creatinine, estimated glomerular filtration rate (eGFR) and urine albumin to creatinine ratio (UACR)., Results: Sum incidence of any-DR was 47.26% with annual incidence 15.16±2.19% in T1DM, and 26.49% with annual incidence 8.13% in T2DM. Sum incidence of STDR was 18.03% with annual incidence 5.77±1.21% in T1DM, and 7.59% with annual incidence 2.64±0.15% in T2DM. Sum incidence of DMO was 8.46% with annual incidence 2.68±038% in patients with T1DM and 6.36% with annual incidence 2.19±0.18% in T2DM. Cox's survival analysis showed that current age and age at diagnosis were risk factors at p<0.001, as high HbA1c levels at p<0.001, LDL cholesterol was significant at p<0.001, eGFR was significant at p<0.001 and UACR at p=0.017., Conclusions: The incidence of any-DR and STDR was higher in patients with T1DM than those with T2DM. Also, the 47.26% sum incidence of any-DR in patients with T1DM was higher than in a previous study (35.9%), which can be linked to poor metabolic control of DM. Our results suggest that physicians should be encouraged to pay greater attention to treatment protocols for T1DM in patients., Competing Interests: Competing interests: None declared., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.)

Background/aims: The purpose of this study was to estimate the prevalence of diabetes mellitus (DM) and diabetic retinopathy (DR) in the population aged 50 years and older in Hungary, and to assess the coverage of diabetic eye care services., Methods: In total, 105 clusters of 35 people aged 50 years or older were randomly selected. The standardised rapid assessment of avoidable blindness (RAAB) with the diabetic retinopathy module (DRM) was used. Participants were classified as having DM if they were known to have DM or if their random blood glucose level was ≥200 mg/dL. Dilated fundus examination and Scottish DR grading were performed., Results: In total, 3523 (95.9%) out of 3675 eligible subjects were examined. And 705 (20.0%) out of 3523 had known (661) or newly diagnosed DM (44). Twenty per cent of participants with known DM had a blood glucose level ≥200 mg/dL, and 27.4% had never had an ophthalmological examination for DR. Prevalence of DR and/or maculopathy was 20.7% and prevalence of sight-threatening DR (STDR) was 4.3% in one or both eyes among participants with DM., Conclusions: Prevalence of DM was in line with findings of other RAAB+DRM surveys and slightly lower than the unpublished earlier age-matched Hungarian estimate. Prevalence of DR was slightly lower than expected. The prevalence of STDR was low in people aged 50 years and older in Hungary compared with the results of other RAAB with DRM surveys. DR screening coverage was low. To prevent severe complications of DM and possible concomitant visual loss, the coverage of ophthalmic examinations in patients with DM should be increased., Competing Interests: Competing interests: JN reported grants from LCIF SightFirst research grant. HL reported personal fees from Semmelweis University, Budapest, during the training for the study., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.)

Background/aims: To determine the changes in the incidence of diabetic retinopathy (DR), diabetic macular oedema (DMO) and their risk factors in a population-based study of patients with diabetes mellitus (DM) referred to our 16 Primary Health Care Areas (HCAs)., Methods: Prospective population-based study of a total of 15 396 Caucasian patients with DM, who represent 86.53% of the total patients with DM in our HCAs, were studied over an 8-year follow-up period. All patients were screened with a mean follow-up of 3.18±1.11 times for each patient over the 8 years., Results: The yearly mean value of any DR was 8.37±2.19% (8.09%-8.99%); of advanced DR yearly mean value of 0.46±0.22% (0.03-0.78); and of DMO a yearly mean value of 2.19±0.18% (2%-2.49%). A clear increase was observed in the last 3 years, any DR increased from 8.09% in 2007 to 8.99% in 2014, and DMO from 2% in 2007 to 2.49% in 2014. These increases were more evident in some age groups. For patients with any DR aged 41-50 and 51-60 and for patients with advanced DR aged 41-50, 51-60 and 61-70, the increase was more marked, related to an increase in HbA1c values or to patients treated with insulin., Conclusions: An increase in the incidence of DR and DMO was observed, especially in the younger patients aged between 31 and 70 years. This is linked to bad metabolic control of DM. Our results suggest a greater number of ocular complications in the near future, such as neovascular glaucoma, if these current findings are not addressed., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/)

Aims: To describe the relationship of retinal arteriolar and venular calibre with diabetic retinopathy (DR) and related risk factors, including glucose levels and other biomarkers in a Chinese population with type 2 diabetes mellitus (T2DM)., Methods: A cross-sectional study. Patients with T2DM were recruited from a local community in urban Beijing. Seven fields 30° colour fundus photographs were taken and examined for the presence and severity of DR using a standardised grading system. Retinal vascular calibres were measured and expressed as average central retinal arteriolar and venular equivalent using a computer-based program., Results: A total of 1340 patients with T2DM were included for analysis. Of these, 472 (35.22%) had DR. Wider retinal venular calibre, but not arteriolar calibre, was associated with increasing glucose and glycosylated haemoglobin A1c levels (p<0.006) and dyslipidaemia (p for trend <0.05). After adjusting for possible covariates, the higher quartile of retinal venular calibre was associated with higher prevalence of any DR (OR 2, 95% CI 1.36 to 2.95). Venular calibre increased from 224.33 μm in those without retinopathy to 231.21 μm in those with mild, 241.01 μm in those with moderate and 235.65 μm in those with severe retinopathy (p for trend <0.001). Arteriolar calibre was not associated with DR., Conclusions: In the current study, wider venular calibre, but not arteriolar calibre, was shown to be associated with development and increased severity of DR independently from other risk factors in a Chinese diabetic population., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/)

Background/aims: Population-based surveys on diabetes and diabetic retinopathy (DR) are necessary to increase awareness and develop screening and therapeutic programmes. The aim was to estimate the prevalence of DR in older adults of different ethnic backgrounds in Suriname., Methods: Fifty clusters of 60 people aged ≥50 years were randomly selected with a probability proportional to the size of the population unit. Eligible people were randomly selected through compact segment sampling and examined using the Rapid Assessment of Avoidable Blindness plus Diabetic Retinopathy (RAAB + DR) protocol. Participants were classified as having diabetes if they: were previously diagnosed with diabetes; were receiving treatment for glucose control; had a random blood glucose level >200 mg/dL. These participants were dilated for funduscopy, assessed for DR following the Scottish DR grading protocol and evaluated for ethnicity and DR ophthalmic screening frequencies., Results: A total of 2806 individuals was examined (response 93.6%). The prevalence of diabetes was 24.6%. In these patients any type of DR and/or maculopathy occurred in 21.6% and sight-threatening DR in 8.0%. Of the known diabetics, 34.2% never had an eye examination for DR and in 13.0% the last examination was >24 months ago. The prevalence of diabetes was significantly higher in Hindustani people compared with other major ethnic groups., Conclusions: The prevalence of diabetes and diabetics without regular DR control in people aged ≥50 years in Suriname was higher than expected. The uptake for special services for DR has to be expanded to decrease patient delay and DR-induced blindness., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/)

Aim: To evaluate retinal sensitivity (RS) in subjects with diabetes in a population-based study and to elucidate associated risk factors for abnormal RS., Methods: A subset of 357 subjects from Sankara Nethralaya Diabetic Retinopathy Epidemiology and Molecular Genetics Study-II was included in this study. All subjects underwent detailed ophthalmic evaluation including microperimetry and spectral domain optical coherence tomography., Results: The prevalence of abnormal mean retinal sensitivity (MRS) was 89.1%. MRS was significantly reduced in subjects with diabetes but no retinopathy when compared with non-diabetic subjects. MRS was reduced in moderate non-proliferative diabetic retinopathy (DR) and macular oedema (ME) at 8° (p=0.04, p=0.01, respectively) and in ME at 10° (p=0.009) and 12° (p=0.036) compared with no DR. Significant negative correlation was found between MRS and best corrected visual acuity, duration of diabetes, glycosylated haemoglobin and central foveal thickness. Increased retinal thickness remained a significant risk factor (OR, 1.02; p=0.044) for abnormal MRS. Altered inner retinal layers and foveal contour were associated with reduced MRS among subjects with DR and presence of epiretinal membrane, altered foveal contour and altered retinal pigment epithelium were associated with reduced MRS., Conclusions: Reduced RS in those subjects with diabetes but no retinopathy suggests the early neuronal damage in type 2 diabetes mellitus., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/)

Background/aims: Retinal photography with a non-mydriatic camera is the method currently employed for diabetic retinography (DR) screening. We designed this study in order to evaluate the prevalence and severity of DR, and associated risk factors, in patients with type 2 diabetes (T2DM) screened in Catalan Primary Health Care., Methods: Retrospective, cross-sectional, population based study performed in Catalonia (Spain) with patients with T2DM, aged between 30 years and 90 years (on 31 December 2012) screened with retinal photography and whose DR category was recorded in their medical records. DR was classified as: no apparent retinopathy (no DR), mild non-proliferative DR (mild NPDR), moderate NPDR, severe NPDR, proliferative DR (PDR) and diabetic macular oedema (DMO). Non-vision threatening DR (non-VTDR) included mild and moderate NPDR; VTDR included severe NPDR, PDR and DMO. Clinical data were obtained retrospectively from the SIDIAP database (System for Research and Development in Primary Care)., Results: 108 723 patients with T2DM had been screened with retinal photography. The prevalence of any kind of DR was 12.3% (95% CI 12.1% to 12.5%). Non-VTDR and VTDR were present in 10.8% (mild 7.5% and moderate NPDR 3.3%) and 1.4% (severe NPDR 0.86%, PDR 0.36% and DMO 0.18%) of the study patients, respectively., Conclusions: The prevalence of any type of DR in patients with T2DM screened with retinal photography was lower when compared with earlier studies., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/)

Background/aims: In Portugal, so far, there is no study or even accurate data on the prevalence of diabetic retinopathy (DR), based on a large representative sample and on a long-term follow-up. The objective of our study was to determine the prevalence of DR based on a national screening community-based programme., Methods: A 5-year retrospective analysis of the RETINODIAB screening programme results was implemented in Lisbon and Tagus Valley area between July 2009 and October 2014. We estimated the prevalence of retinopathy for all patients with type 2 diabetes and studied the association between known risk factors and retinopathy emergence at their first screening., Results: Throughout this period, from a total of 103 102 DR readable screening examinations, 52 739 corresponded to patients who attended RETINODIAB screening at entry. Globally, DR was detected in 8584 patients (16.3%). Of these, 5484 patients (10.4%) had mild non-proliferative (NP) DR, 1457 patients (2.8%) had moderate NPDR and 672 (1.3%) had severe NPDR. Finally, 971 patients (1.8%) had proliferative DR requiring urgent referral to an ophthalmologist. The presence of any DR, non-referable DR or referable DR was strongly associated with increasing duration of diabetes and earlier age at diagnosis., Conclusions: The prevalence rate of DR in our study (16.3%) was slightly lower than other published international data. The RETINODIAB network proved to be an effective screening programme as it improved DR screening in Lisbon and Tagus Valley surrounding area., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.)

Objective: To evaluate the prevalence and causes of blindness and visual impairment, the prevalence of diabetes mellitus and diabetic retinopathy among people aged ≥50 years in the Republic of Moldova using Rapid Assessment of Avoidable Blindness plus Diabetic Retinopathy ('RAAB+DR') techniques., Materials and Methods: 111 communities of people aged ≥50 years were randomly selected. In addition to standard RAAB procedures in all people with diabetes (previous history of the disease or with a random blood glucose level >11.1 mm/L (200 mg/dL)), a dilated fundus examination was performed to assess the presence and the degree of diabetic retinopathy using the Scottish DR grading system., Results: 3877 (98%) people out of the 3885 eligible people were examined. The prevalence of blindness was 1.4% (95% CI 1.0% to 1.8%). The major causes of blindness and severe visual impairment were untreated cataract (58.2%), glaucoma (10.9%), and other posterior segment causes (10.9%). The estimated prevalence of diabetes was 11.4%. Among all people with diabetes, 55.9% had some form of retinopathy, and sight threatening diabetic retinopathy affected 14.6%., Conclusions: The RAAB+DR survey in the Republic of Moldova established that untreated cataract is the major cause of avoidable blindness in rural areas. This needs to be tackled by expanding the geographical coverage of cataract surgical services., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.)

Aims: Determine the prevalence and severity of diabetic retinopathy (DR) and risk factors in a large community based screening programme, in order to accurately estimate the future burden of this specific and debilitating complication of diabetes., Methods: A cross-sectional analysis of 91,393 persons with diabetes, 5003 type 1 diabetes and 86,390 type 2 diabetes, at their first screening by the community based National Diabetic Retinopathy Screening Service for Wales from 2005 to 2009. Image capture used 2×45° digital images per eye following mydriasis, classified by qualified retinal graders with final grading based on the worst eye., Results: The prevalence of any DR and sight-threatening DR in those with type 1 diabetes was 56.0% and 11.2%, respectively, and in type 2 diabetes was 30.3% and 2.9%, respectively. The presence of DR, non-sight-threatening and sight-threatening, was strongly associated with increasing duration of diabetes for either type 1 or type 2 diabetes and also associated with insulin therapy in those with type 2 diabetes., Conclusions: Prevalence of DR within the largest reported community-based, quality assured, DR screening programme, was higher in persons with type 1 diabetes; however, the major burden is represented by type 2 diabetes which is 94% of the screened population., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.)

Aims: Diabetic retinopathy screening aims to detect people at risk of visual loss due to proliferative diabetic retinopathy, but also refers cases of suspected macular oedema (maculopathy). At the introduction of screening, ophthalmology was concerned that referral rates would be unmanageable. We report yield of referable disease by referral reason for the first 5 years of the programme., Methods: We extracted screening results from a nationwide clinical diabetes database to calculate annual referral rates to ophthalmic clinics. We used logistic regression to examine associations between clinical measures and referable disease., Results: 182 397 people underwent ≥ 1successful retinal screening between 2006 and 2010. The yield of referable eye disease was highest in the first 2 years of screening (7.0% and 6.0%) before stabilising at ∼4.3%. The majority of referrals are due to maculopathy with 73% of referrals in 2010 based on a finding of maculopathy., Conclusions: The commonest cause for referral is for suspected macular oedema (maculopathy). Referral rates for retinopathy have stabilised, as predicted, at relatively low rates. However, ophthalmology workload continues to rise as new treatment options (ie, monthly intraocular injections) have unexpectedly increased the impact on ophthalmology. A review of the screening referral path for maculopathy may be timely., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.)

Background/aims: To assess the relationship between ocular blood flow parameters and diabetic retinopathy and coronary artery disease in diabetic patients., Methods: 56 patients participated in the study. Colour Doppler imaging was used to assess the peak systolic and end-diastolic blood velocities as well as resistivity index in the ophthalmic, central retinal and posterior ciliary arteries. The diagnosis of coronary artery disease was based on the coronary angiogram., Results: As compared to controls, the peak systolic and end-diastolic blood velocities in all three evaluated vessels were significantly lower in the case of diabetic patients with coronary artery disease. Diabetic patients without coronary artery disease showed only decreased end-diastolic velocity values in the ophthalmic artery compared with the controls. Among diabetic patients, coronary artery disease was related to lower peak systolic and end-diastolic velocities in the central retinal artery and peak systolic velocities in the short posterior ciliary arteries. Diabetic retinopathy was significantly associated with a further decrease in end-diastolic blood velocity and an increase in resistivity index in the central retinal artery., Conclusions: (1) Flow disturbances within the ocular blood vessels of patients with type 2 diabetes were associated with atherogenic changes of coronary arteries. (2) In patients with type 2 diabetes and concomitant coronary artery disease, impaired blood flow within the ophthalmic and short posterior ciliary arteries was not related to diabetic retinopathy, but diabetic retinopathy was related to additional blood flow impairment within the central retinal artery.

Background/aims: To estimate the prevalence of blindness, diabetes and diabetic retinopathy (DR) in Taif, Saudi Arabia using the Rapid Assessment of Avoidable Blindness (RAAB) framework., Methods: 66 clusters of 50 people aged ≥50 years were randomly selected. Participants underwent visual acuity measurement and examination by an ophthalmologist. DR among diabetic participants (previous diagnosis and/or random blood glucose >200 mg/dl) was assessed through dilated fundus examination by an ophthalmologist using a direct and indirect ophthalmoscope ('clinical examination') and dilated digital fundus photographs graded by a retinal specialist following the Scottish DR grading system ('reference standard')., Results: 3052 (93%) out of 3300 eligible people were examined. The prevalence of blindness was 2.6% (95% CI 2.0% to 3.2%). Posterior segment diseases (44%) and cataract (41%) were the leading causes of blindness. The estimated prevalence of diabetes was 29.7% (28.1% to 31.4%), among whom the prevalence of DR was 36.8% (33.3% to 40.2%) and sight-threatening DR (STDR) was 17.5% (CI 15.1% to 20.0%). Agreement was good (κ>0.6) between the clinical examination and reference standard for any DR and STDR., Conclusions: There was a high prevalence of diabetes, DR and STDR. It was possible to assess diabetes and DR within RAAB but it increased the survey duration, cost and complexity.

Aims: To address the absence from the public health ophthalmology literature of age- and sex-specific prevalence and related resource use for diabetic macular oedema (DMO) in England, UK., Methods: Calculation of age- and sex-specific rates from primary source clinical data, and application to the demographic structure of England to estimate the number of cases affected by DMO. A public health commissioner and provider of social care perspective was adopted in a standard cost of illness study., Results: The number of people with diabetes in England in 2010 was estimated at 2,342,951 of which 2,334,550 were aged ≥ 12 years. An estimated 166,325 (7.12%) had DMO in one or both eyes, and of these, 64,725 individuals had clinically significant DMO reducing the visual acuity to poorer than 6/6 in at least one eye. The overall health and social care costs in 2010, on the pathway from screening to rehabilitation and care in the home, are estimated at £116,296,038., Conclusions: The outcomes of this study should alert public health commissioners and clinical providers to the burden of DMO. The methods employed should also encourage the use of clinical ophthalmic data at the interface between local population and hospital-based recording systems.

Diabetic retinopathy (DR), a common complication of both type 1 and type 2 diabetes, is rarely expressed at a level greater than background retinopathy during childhood and adolescence. Epidemiological studies in paediatric diabetic patients together with data from the Diabetes Control and Complications Trial have demonstrated the importance of glycaemic control in delaying or preventing the development of DR; thus, the incidence of DR has declined somewhat over the past two decades. Both prepubertal and postpubertal years with diabetes contribute to the overall probability of DR development. In addition to duration of disease and degree of glycaemic control, other risk factors for DR development include elevated blood pressure, lipid profiles, serum levels of advanced glycation endproducts, evidence for early stage atherosclerosis, increased calibre of retinal blood vessels and several genetic factors, such as enzymes involved in glucose and lipid metabolism. Annual screening is recommended, with mydriatic stereoscopic fundus photography being the most sensitive detection method. Both pathophysiology and treatment in paediatric populations are essentially the same as described for adult populations, with treatment usually not required until adulthood is reached.

Objective: To evaluate the prevalence of and risk factors for diabetic retinopathy (DR) in Koreans with type II diabetes., Methods: Subjects (400 male, 296 female) aged 30-65 years (mean 55.3 years) with hyperglycaemia (fasting plasma glucose ≥7.0 mmol/ml) or known diabetes (mean±SD duration 6.36±5.73 years) were enrolled in the Seoul Metro-City Diabetes Prevention Program (SMC-DPP) from September 2008 to September 2009. The severity of DR was diagnosed by grading fundus photographs taken from five standard fields per eye and categorised following the Early Treatment of Diabetic Retinopathy Study grading protocol. All participants underwent routine clinical and laboratory examinations to evaluate risk factors for DR., Results: The overall prevalence of any type of DR was 18.7%. Logistic regression analyses showed that the following factors were significantly associated with DR after adjustment for age and gender, duration of diabetes, serum glycated haemoglobin A1c (HbA1c), mean arterial pressure, serum total cholesterol and serum triglycerides: duration of diabetes (OR 1.14, 95% CI 1.10 to 1.18, for 1 year increase), HbA1c (OR 1.49, 95% CI 1.20 to 1.85, for 1% increase), serum concentration of insulin (OR 0.87, 95% CI 0.81 to 0.94, for 1 μIU/ml increase), homoeostasis model assessment of insulin resistance (OR 0.06, 95% CI 0.01 to 0.29, for 10 unit increase), and presence of macroalbuminuria (OR 5.14, 95% CI 1.45 to 18.20, albumin to creatinine ratio >300 mg/g)., Conclusions: In addition to traditional risk factors, insulin resistance was associated with an increased risk of DR in Koreans with type 2 diabetes.

Background/aims: There are few published data on the prevalence of diabetic retinopathy in sub-Saharan Africa. We report the prevalence of all grades of retinopathy and associations with systemic parameters in patients attending a secondary care diabetes clinic in Blantyre, Malawi., Methods: Cross-sectional study of all patients attending for diabetes care in a hospital setting. Clinical examination and biochemical testing was performed to assess visual acuity (VA), grade of retinopathy (slit lamp biomicroscopy), microvascular complications, glycaemic control, hypertension and HIV status. Sight-threatening diabetic retinopathy (STDR) was defined as moderate preproliferative retinopathy or worse, circinate maculopathy or exudates within one disc diameter of the foveal centre or clinically significant macular oedema., Results: In patients with type 2 diabetes (n=249) the prevalence (95% CI) of any retinopathy, STDR and proliferative diabetic retinopathy (PDR) was 32.5% (26.7 to 38.3%), 19.7% (14.7 to 24.6%) and 4.8% (2.2 to 7.5%), respectively. The presence of STDR was associated with albuminuria (OR 2.6; p=0.02), the presence of neuropathy (OR 3.4; p=0.005) and insulin use (OR 5.3; p=0.0004), but not with HIV status. In patients with type 1 diabetes (n= 32), the prevalence of any retinopathy, STDR and PDR was 28.1% (12.5 to 43.7%), 18.8% (5.2 to 32.2%) and 12.5% (1.0 to 24.0%), respectively. 12.1% of study subjects had VA worse than 6/18 (20/60)., Conclusion: This study provides baseline information on prevalence of all grades of retinopathy and STDR in consecutive cases attending an urban/semi-urban diabetes clinic in sub-Saharan Africa. Prevalence of STDR was high and in type 2 diabetes was associated with albuminuria, neuropathy and insulin use.

Aims: To extrapolate, from the proportion of subjects with observable retinopathy at diagnosis of type 2 diabetes mellitus in routine clinical practice, the mean duration of undiagnosed diabetes., Methods: On 1 October 1999, there were 4313 patients with type 2 diabetes in the 41 participating practices in the Tayside region (registered with one of 166 GPs). 501 (12%; 95% CI 11 to 13%) patients were selected using a pseudo-random number allocation algorithm, and practice lists checked for recently deceased, non-residents (45 exclusions). Retinopathy was graded by validated slit lamp biomicroscopy and four-field stereo photography. Date of first diagnosis of diabetes was ascertained from the regional diabetes register created using multiple source data capture., Results: Of living Tayside resident patients, 295 from 456 invited type 2 patients (65%) were examined. 14.68% (95% CI 12.48 to 16.88%) were found to have retinopathy at diagnosis. Assuming a linear model, these data suggest that the onset of detectable retinopathy occurs 5.77 years (95% CI 4.6 to 7 years) before diagnosis. Comparison using the log rank test with survival to onset of sight threatening retinopathy/maculopathy in 291 patients with type 1 diabetes mellitus also examined from the same population cohort showed the 95% CIs of length of preclinical diabetes to be between 3.0 and 9.4 years., Conclusion: There is accumulating evidence to question the assumption of linearity as a model of choice. The authors' understanding of a distinct glycaemic threshold for retinal change is also overly simplistic and consequently the bounds of uncertainty concerning the preclinical duration of disease are considerable.

Background/aims: Automated grading software has the potential to reduce the manual grading workload within diabetic retinopathy screening programmes. This audit was undertaken at the request of Scotland's National Diabetic Retinopathy Screening Collaborative to assess whether the introduction of automated grading software into the national screening programme would be safe, robust and effective., Methods: Automated grading, performed by software for image quality assessment and for microaneurysm/dot haemorrhage detection, was carried out on 78,601 images, obtained from 33,535 consecutive patients, which had been manually graded at one of two regional diabetic retinopathy screening programmes. Cases where the automated grading software assessment indicated gradable images with no disease but the screening programme indicated ungradable images or disease more severe than mild retinopathy were arbitrated by seven senior ophthalmologists., Results: 100% (180/180) of patients with proliferative retinopathy, 100% (324/324) with referable background retinopathy, 100% (193/193) with observable background retinopathy, 97.3% (1099/1130) with referable maculopathy, 99.2% (384/387) with observable maculopathy and 99.8% (1824/1827) with ungradable images were detected by the software., Conclusion: The automated grading software operated to previously published results when applied to a large, unselected population attending two regional screening programmes. Manual grading workload reduction would be 36.3%.

Objective: To examine the association between self-reported diabetes history and early or late age-related macular degeneration (AMD) in the European population., Methods: Participants aged 65 years and over in the cross-sectional population-based EUREYE study underwent an eye examination including digital retinal photography. The images were graded at a single centre. A structured questionnaire was administered by trained field workers for putative risk factors for AMD including history of diabetes mellitus. Logistic regression models were used to examine the association between diabetes and stages of AMD, taking account of potential demographic, behavioural, dietary and medical (history of cardiovascular disease) confounders., Main Outcome Measures: Photographic images were graded according to the modified International Classification System for AMD and stratified into five exclusive stages from no signs of AMD (AMD stage 0), early AMD (Stages 1-3) and late AMD (Stage 4). Late AMD was subdivided in neovascular AMD (NV-AMD) or geographic atrophy (GA)., Results: Data on diabetes history and potential confounders were available in 2117 control subjects without AMD, 2182 with early AMD, 49 with GA and 101 with NV-AMD. Of all participants, 13.1% reported a history of diabetes. After adjusting for potential confounders, subjects with neovascular AMD compared with controls had increased odds for diabetes (odds ratio 1.81; 95% confidence interval, 1.10 to 2.98, p = 0.02). Subjects with AMD grades 1 to 3 or GA had no increased odds for diabetes compared with those without AMD., Conclusions: In the EUREYE study, after multiple adjustments, positive association of diabetes mellitus with neovascular AMD was found. The hypothesis that diabetes is associated with neovascular AMD but not with geographic atrophy may suggest a different pathogenesis of the two advanced forms of the disease and needs to be further evaluated.

Aim: The aim of the study was to investigate trends in the incidence of blindness and the association with laser photocoagulation in patients with type 1 diabetes in Japan., Methods: Patients diagnosed between 1965 and 1979 aged under 18 years old were studied. The status of blindness and laser photocoagulation was identified as of 1 January 1995. To examine the time trend, we divided the cohort into two groups: 285 patients diagnosed between 1965 and 1969 (65-69 cohort) and 769 patients diagnosed between 1975 and 1979 (75-79 cohort). Survival analysis was performed using the Kaplan-Meier method. Cox proportional hazard models were used to assess the demographic characteristics., Results: Blindness developed in 60 subjects in the 65-69 cohort and 15 subjects in the 75-79 cohort. The incidence of blindness in the 75-79 cohort was significantly lower than that in the 65-69 cohort (p<0.0001). In spite of no change in the use of laser photocoagulation in the 75-79 cohort compared with the 65-69 cohort, the hazard ratio for the blindness in those who received laser photocoagulation in the 75-79 cohort decreased significantly to 0.55 (p<0.01) compared with those in the 65-69 cohort when adjusted for the age of onset, sex, and time of diagnosis., Conclusion: The incidence of blindness decreased significantly for the subjects diagnosed more recently. The change in quality and the earlier introduction of laser photocoagulation might have contributed to the decreased incidence of blindness observed over time.

This study is aimed at reporting experiences with telemedicine between Nepal and the USA and at reporting the prevalence of age-related macular degeneration (AMD) and diabetic retinopathy (DR) in rural Nepal. AMD and DR are becoming more significant factors for non-reversible vision loss in rural Nepal due to increasing life expectancy and urbanisation. The prevalence of DM is low compared with the developed world, but the percentage of diabetics with DR is high, presumably due to limited access to healthcare. The higher prevalence of DM in Hetauda is explained as being due to a more urban lifestyle, dietary habits (more deep-fried food) and more advanced age.