Search

Location of the gene for macular corneal dystrophy (MCD) type 1 has been narrowed to a region of less than 1 cM between markers D16S3115 and D16S3083 through a haplotype analysis of 10 Icelandic families. Evidence also suggests that the different immunophenotypes of MCD may be allelic. MCD type I in Iceland may have been caused by multiple mutations or else a very old mutation with multiple recombinants.

Objective To investigate the association between the methylenetetrahydrofolate reductase gene C677T ( MTHFR C677T) polymorphism and diabetic retinopathy (DR). Methods A total of 6971 subjects including 2707 DR patients and 4264 controls from 23 studies were enrolled in the study. A random-effects model was applied to estimate the overall effects and the stratified effects of the MTHFR C677T polymorphism on the risk of DR, and study quality was also assessed. Results Strong associations were observed between the MTHFR C677T polymorphism and DR. The carries of MTHFR C677T were more likely to be found in the DR group in relative to the healthy control group with odds ratio 1.68, 2.55, and 2.31 respectively in allele contrast model (T vs. C, 95% CI : 1.29-2.18, P <0.001, I 2 =78.4%), homozygous model (TT vs. CC, 95% CI : 1.70-3.83, P =0.008, I 2 =54.4%) and dominant model (TT+CT vs . CC, 95% CI : 1.62-3.29, P <0.001, I 2 =74.7%). This association can also be found in contrast to the Ncd (non-complicated diabetic mellitus) group (allele contrast, OR =1.50, 95% CI : 1.07-2.11, P =0.032, I 2 =62.1%; homozygous, OR =2.39, 95% CI : 1.06-5.38, P =0.017, I 2 =66.7%; dominant, OR =1.59, 95% CI : 0.97-2.62, P =0.056, I 2 =56.5%). For the heterozygous model (CT vs. CC), the association was significant in contrast to the healthy control group ( OR =1.46, 95% CI : 1.64-3.69, P =0, I 2 =77.3%), while in contrast to the Ncd control group the association was not statistically meaningful ( OR =1.38, 95% CI : 0.87-2.18, P =0.131, I 2 =43.7%). For the recessive model, 1.92-fold increased risk was found only in contrast to the Ncd control group (95% CI : 1.07-3.43, P =0.064, I 2 =55.0%). There was no significant association found in the models in contrast to the DM control group. Conclusion In this meta-analysis, we found an association between the MTHFR C677T polymorphism and DR, especially in contrast to the Ncd control group. Further studies are required to establish more definite relationship.

Aim: To investigate the association between a set of six candidate genes and the risk of diabetic retinopathy (DR) in an urban community cohort of Chinese patients with type 2 diabetes mellitus (T2DM)., Methods: A population-based cross-sectional study. The diabetic subjects were recruited from an urban community in Beijing and categorized into groups of proliferative diabetic retinopathy (PDR), non-proliferative diabetic retinopathy (NPDR), or diabetic without any retinopathy (DWR) based on the fundus photography and duration of diabetes. Six candidate genes, including advanced glycation end product specific receptor ( AGER ), aldose reductase ( AKR1B1 ), inducible nitric oxide synthase ( iNOS ), pigment epithelium derived factor ( PEDF ), tumor necrosis factor-alpha ( TNF-α ), and paraoxonase 1 ( PON1 ), were chosen based on Meta-analysis of genetic association studies for DR and biochemical pathways implicated in DR progression. The allele and genotype distribution of 21 functional single-nucleotide polymorphisms (SNPs) in those 6 candidate genes were investigated using MassARRAY genotyping system., Results: Among 1461 diabetic patients recruited from community, 569 were selected in following genotyping analysis, including 97 patients with PDR, 217 with NPDR, and 255 with DWR. For the promoter variant rs1051993 in AGER gene, the distribution of allele and genotype in PDR group differed from that in DWR group (allele: P =0.011; genotype: P =0.01). Compared with DWR, patients with PDR had lower frequencies of heterozygous genotype GT (9.8% for DWR, 1% for PDR, OR: 0.10, 95%CI: 0.01-0.72) and minor allele T (4.9% for DWR, 0.5% for PDR, OR: 0.10, 95%CI: 0.01-0.75). In multivariate model, the distribution of genotype for rs1051993 in PDR group was significantly different from that in DWR group (GT vs GG: OR: 0.07, 95%CI: 0.01-0.61, P <0.001). No association with DR was observed in other genotyped SNPs., Conclusion: The data suggest a significant association of the promoter variant rs1051993 in AGER gene with PDR in Chinese cohort with T2DM., (International Journal of Ophthalmology Press.)

Aim: To investigate the relationship between insulin resistance (IR)/β-cell dysfunction and diabetic retinopathy (DR) in Chinese patients with type 2 diabetes mellitus (T2DM), and to explore further whether there were differences in the relationship among diabetic patients with higher and lower body mass index (BMI)., Methods: Cross-sectional study. A total of 1466 subjects with T2DM were recruited in a local Desheng Community of urban Beijing from November 2009 to June 2012 for the cohort of Beijing Desheng Diabetic Eye Study. Standardized evaluation was carried out for each participant, including questionnaire, ocular and anthropometric examinations, and laboratory tests. Seven fields 30° color fundus photographs were used for DR grading according to the Early Treatment Diabetic Retinopathy Study protocols. Homeostatis Model Assessment (HOMA) method was employed for IR and β-cell function assessment., Results: After excluding those participants who were treated with insulin ( n =352) or had missing data of fasting insulin ( n =96), and further excluding those with poor quality of retinal photographs ( n =10), a total of 1008 subjects were included for the final analysis, 406 (40.3%) were men and 602 (59.7%) were women, age ranging from 34 to 86 (64.87±8.28)y. Any DR (levels 14 and above) was present in 278 (27.6%) subjects. After adjusting for possible covariates, the presence of any DR did not correlate with HOMA IR [odds ratio (OR) 1.51, 95% confidence interval (CI) 0.87-2.61, P =0.14] or HOMA β-cell (OR 0.71, 95%CI 0.40-1.26, P =0.25). After stratification by BMI, the presence of any DR was associated positively with HOMA IR (OR 2.46, 95%CI: 1.18-5.12, P =0.016), and negatively with HOMA β-cell (OR 0.40, 95%CI: 0.19-0.87, P =0.021) in the group of patients with higher BMI (≥25 kg/m 2 ). In the group of patients with lower BMI (<25 kg/m 2 ), the presence of any DR was not associated with HOMA IR (OR 1.00, 95%CI: 0.43-2.33, P =1.00) or HOMA β-cell (OR 1.41, 95%CI: 0.60-3.32, P =0.43)., Conclusion: The data suggest that higher IR and lower β-cell function are associated with the presence of DR in the subgroup of diabetic patients with higher BMI. However, this association is not statistically significant in diabetic patients with lower BMI.

Aim: To present the rationale, design, methodology, and the baseline data of the Beijing Desheng Diabetic Eye Study (BDDES), and to determine the prevalence of diabetic retinopathy (DR) and possible risk factors in patients with type 2 diabetes mellitus (T2DM) in an urban community of Beijing, China., Methods: Community-based prospective cohort study of persons diagnosed with T2DM aged 30y or older. The main variables of interest are the presence and progression of DR as determined by the standardized ETDRS grading of seven fields fundus photographs. The presence and severity of DR were analyzed for possible correlations to non-genetic and genetic dispositions., Results: A total of 1438 participants with data available for analysis, the prevalence of any DR was 35.4%. The prevalence of mild non-proliferative diabetic retinopathy (NPDR), moderate NPDR, severe NPDR, and proliferative diabetic retinopathy was 27.7%, 2.6%, 0.5% and 4.5%, respectively. By multiple logistic regression analysis, risk factors for the presence of any DR included male ( P =0.031), lower income level ( P =0.011), lower education background ( P =0.022), longer duration of diabetes ( P =0.001), younger age at diabetic onset ( P =0.001), higher systolic blood pressure ( P =0.007), higher glycosylated hemoglobin A1c levels ( P =0.001), high albuminuria ( P =0.03), and use of insulin ( P <0.001). For vision-threatening DR, four factors were significant: younger age at diabetic onset ( P <0.001), higher systolic blood pressure ( P =0.042), high albuminuria ( P <0.001), and use of insulin ( P <0.001)., Conclusion: The BDDES is the first large-scale ongoing cohort study of a Chinese urban population of persons with type 2 diabetes. Using standardized grading system comparable to large cohort studies from western populations, our baseline data shows that the prevalence of DR and major risk factors in this Chinese ethnic population are comparable to that found in the western population studies.

Aim: To evaluate the surgical outcomes in eyes with persistent fetal vasculatures (PFV) managed by small gauge pars plicata vitrectomy., Methods: Consecutive patients with PFV treated by small gauge pars plicata vitrectomy at Beijing Tongren Eye Center between January 2010 and January 2013 were retrospectively reviewed., Results: A total of 118 eyes of 105 patients with PFV were included and undergone small gauge pars plicata vitrectomy, of which 84 (71.2%) eyes had lensectomy and 16 (13.6%) eyes had lens aspiration and immediate intraocular lens implantation. The percentage of sutured scleral incision of 23 gauge vitrectomy (71.7%, 33/46) was higher than that of the 25 gauge vitrectomy (18.1%, 13/72). At last follow-up, visual acuity remained stable in 34 eyes (28.8%) and improved in 84 eyes (71.2%). Age at surgery (less than 2y), anterior type of PFV, and immediate IOL implantation were associated with postoperative improved visual acuity. Sixty five (55.1%) eyes had retinal detachment preoperatively, among which 33 (50.8%, 33/65) eyes had retinal reattachment or partial retinal reattachment., Conclusion: The results suggest that cases with PFV have a potential for developing good visual acuity after small gauge pars plicata vitrectomy with favorable anatomic outcomes and acceptable rate of serious surgical complications.

Aim: To assess the correlation between choroidal thickness (CT) and the early stages of diabetic retinopathy (DR) in type 2 diabetic patients., Methods: We divided 83 diabetic patients (51-80 years of age; 50 females) into non diabetic retinopathy group (NDR) and mild/moderate nonproliferative diabetic retinopathy (NPDR) group, and compared them with 26 non-diabetic control subjects (51-78 years of age; 16 females). Subfoveal choroidal thickness (SFCT) and parafoveal choroidal thickness (PFCT) were measured using enhanced depth imaging spectral-domain optical coherence tomography (EDI-OCT). Ocular health status, disease duration, body mass index, and hemoglobin A1c (HbA1c) were recorded., Results: The mean ages of the NDR, NPDR, and control groups were 68.0±6.9y, 67.8±6.4y, and 65.1±6.3y, respectively ( P =0.17). Pearson correlation of the right and left eyes for the control subjects was 0.95 and for the NDR subjects was 0.93. SFCT for the right eyes of the controls was 252.77± 41.10 µm, which was significantly thicker than that of the right eyes in NDR group (221.51±46.56 µm) and the worse eyes of the NPDR group (207.18±61.87 µm; ANOVA, P <0.01). In the diabetic patients pooled together, age was the only variable significantly associated with SFCT (multiple linear regression analysis, P =0.01)., Conclusion: CT decreased significantly in the NDR and mild/moderate NPDR eyes compared with the control eyes. Age is significantly associated with SFCT in the diabetic patients. Diabetic choroidopathy may be present before clinical retinopathy.

Aim: To report a cohort of patients with polypoidal choroidal vasculopathy (PCV) treated with photodynamic therapy (PDT) followed by intravitreal ranibizumab injection 24-48h later, and to compare the results between eyes with PCV treated by PDT followed by intravitreal anti-vascular endothelial growth factor (VEGF) injection and intravitreal anti-VEGF injection followed by PDT by Meta-analysis., Methods: Retrospective study and systematic literature review. Medical records of patients with PCV who were initially treated using PDT followed by intravitreal ranibizumab injection 24-48h after PDT and had completed at least 2y follow-up were reviewed and analyzed. Clinical data, including age, sex, best-corrected visual acuity (BCVA), fundus photograph, fluorescein angiography, indocyanine green angiography and optical coherence tomography were investigated. A systematic literature review was also conducted, and a visual outcome of studies over 1y was compared using Meta-analysis., Results: A total of 52 patients were included in the study. Mean BCVA at baseline and follow-up at 1 or 2y were 0.71±0.61, 0.51±0.36 and 0.68±0.51 logMAR, respectively. The cumulative hazard rate for recurrence at 1 and 2y follow-up was 15.4% and 30.3% respectively. The percentage of eyes with polyps regression at 3, 12 and 24mo follow-up was 88.5%, 84.6% and 67.3% respectively. A Meta-analysis based on 22 independent studies showed the overall vision improvements at 1, 2 and 3y follow-up were 0.13±0.04 ( P <0.001), 0.12±0.03 ( P <0.001), 0.16±0.06 ( P <0.001), respectively. The proportion of polyps regression at 1y follow-up was 64.6% (95%CI: 51.5%, 77.7%, P <0.001) in 434 eyes treated by intravitreal anti-VEGF agents before PDT and 76.0% (95%CI: 64.8%, 87.3%, P =0.001) in 199 eyes treated by intravitreal anti-VEGF agents after PDT., Conclusion: Intravitreal ranibizumab injection 24-48h following PDT effectively stabilizes visual acuity in the eye with PCV. PDT followed by intravitreal anti-VEGF agents may contribute to a relatively higher proportion of polyps' regression as compared to that of intravitreal anti-VEGF before PDT.

Aim: To detect the association between macular pigment optical density (MPOD), which reflects the antioxidant ability of retina, and diabetic retinopathy (DR) and to investigate the correlated factors of MPOD., Methods: Totally 435 subjects of urban Chinese were recruited to the study and divided into 3 groups: non-diabetes mellitus controls (NDM), diabetic patients without retinopathy (DWR), and patients with early stage of non-proliferative diabetic retinopathy (DR). Demographic and lifestyle characteristics were ascertained by questionnaire. A food-frequency questionnaire, general physical and ophthalmic examinations were completed for all participants. MPOD was measured by heterochromatic flicker photometry. Foveal thickness was measured by optical coherence tomography. The difference of MPOD among 3 groups was analyzed by analysis of covariance. The correlation analyses of MPOD with the candidate influence factors were assessed using the generalized estimating equations (GEE) model., Results: Of the 435 participants, 34 could not perform the MPOD measurements. Final analysis included 401 subjects, including 48 were in DR group, 134 in DWR group, and 219 in NDM group. MPOD was not significantly different among DR (0.49±0.21), DWR (0.45±0.21), and NDM (0.49±0.17) groups ( P =0.24) after adjustment for fasting plasma glycemia, central foveal thickness, green vegetables, Chinese wolfberry, carotene and vitamin E. For all the 401 participants included, MPOD was positively associated with central foveal thickness (E=0.0007, P =0.001), Chinese wolfberry (E=0.0345, P =0.01), and green vegetables (E=0.0596, P <0.001) intake., Conclusion: The data suggest that MPOD level is not statistically significantly influenced by the onset of diabetes or early stage of DR in the studied population. MPOD level is positively associated with thicker central foveal thickness and higher intake of foods containing carotenoids.

Aim: To evaluate the effect of strabismus surgery on retinal vessels calibers with digital color fundus photographs., Methods: Two hundred consecutive strabismus patients underwent surgery, and 118 patients (female/male, 55/63) who finished 6-month follow-up were finally included in this study. Optic disc-centered digital color fundus photographs of both eyes of all patients were taken prior to surgery and 6mo post surgery. The retinal vascular caliber of 116 operated eyes were measured using the computer program IVAN. The operated eyes were divided into 3 groups according to the surgical methods, recession of one muscle, one muscle recession and one muscle folding, one muscle resection and one muscle recession. The effect of number of altered muscles on retinal vessels was analyzed using statistic software SPSS 16.0., Results: The mean age was 12.4±8.6y. Averaged central retinal artery equivalent (CRAE) of all patients was 120.31±23.02 µm preoperatively, and 122.87±15.93 µm six months after surgery. Averaged central retinal vein equivalent (CRVE) was 171.11±31.73 µm preoperatively and 175.02±21.00 µm postoperatively. There was no significant difference of averaged CRAE (P=0.22) or CRVE (P=0.19) before and after operation. Averaged arteriole to venule ratio (AVR) was 0.71±0.07 before surgery and 0.70±0.07 after surgery. Comparison of preoperative and postoperative retinal vessels calibers among different surgical groups did not show significant differences. Also, there was no advantage of rectus muscle folding to muscle resection., Conclusion: Up to 6mo after strabismus surgery, the retinal vascular calibers were not altered. No more than two muscles in one surgery are safe for retinal perfusion.

Aim: To investigate the pattern of diurnal variations of choroidal thickness of macular region of healthyindividuals., Methods: A prospective study of 32 healthy female subjects was conducted. Each subject underwent 1) a questionnaire on daily schedule, 2) the Pittsburgh Sleep Quality Index questionnaire (PSQI), and 3) ocular examinations including an eye dominance test, fundus photography, and sequential optical coherence tomography (OCT) imaging, on two separate days at five fixed 3h time intervals. Choroidal thickness was measured by two masked graders., Results: A significant diurnal variation of choriodal thickness at fovea (P<0.001), at 500 µm nasal (P<0.001), temporal to fovea (P=0.01) or 1500 µm nasal to fovea (P=0.001) was observed. The median choroidal thickness peaked at 11:00 at fovea (P=0.01), at 500 µm nasal (P=0.009) and temporal (P=0.03) to fovea. The median amplitude of foveal choroidal thickness was 20.5 µm (13, 31) and 20.0 µm (12.5, 28.2) for the first and second series of measurements, respectively. The greater amplitude of foveal choroidal thickness was associated with thickner initial foveal choroidal thickness [0.05 (0.03, 0.08), P=0.01], dominant eye [10.51 (4.02, 14.60), P=0.04] in the multivariate linear regression., Conclusion: Our data show a significant diurnal variation of the choroidal thickness at fovea, at 500 µm nasal and temporal to fovea and 1500 µm nasal to fovea. Thicker initial foveal choroidal thickness and being dominant eye may influence the amplitude of foveal choroidal thickness.

Aim: To investigate the relationship between C-reactive protein (CRP) and diabetic retinopathy (DR) in a cohort of Chinese patients with type 2 diabetes mellitus (T2DM)., Methods: Community-based observational cohort study. There were 1131 participants recruited from November 2009 to September 2011 in Desheng community in urban Beijing. Patients diagnosed T2DM were recruited and underwent a standardized evaluation consisting of a questionnaire, ocular and anthropometric examinations and laboratory investigation. The presence and severity of DR were assessed by seven fields 30° color fundus photographs. Subjects were then classified into groups with no DR, any DR, or vision-threatening DR. CRP was analyzed from serum of study subjects., Results: A total of 1007 patients with T2DM were included for analysis, including 408 (40.5%) men and 599 (59.5%) women. The median CRP level was 1.5 mg/L for women and 1.1 mg/L for men (P=0.004, OR 0.37, 95% CI 0.18-0.74). After adjusting for possible covariates, higher levels of CRP were associated with lower prevalence of any DR (P=0.02, OR 0.55, 95% CI 0.35-0.89), but not associated with vision-threatening DR (P=0.62, OR 0.78, 95% CI 0.28-2.14). After stratification by sex, the inverse association between CRP and DR was found to be statistically significant in men (P=0.006, OR 0.35, 95% CI 0.16-0.73), but not in women (P=0.58, OR 0.88, 95% CI 0.29-1.16)., Conclusion: The data drawn from a Chinese population with T2DM suggest that increasing CRP levels may be inversely associated with development of DR.

Aim: To measure the macular pigment optical density (MPOD) in healthy Chinese people and patients with early age-related macular degeneration (AMD)., Methods: Cross-sectional population based study. Demographic and lifestyle characteristics were ascertained by questionnaire. A food frequency questionnaire was completed for all participants. Participants underwent general physical and ophthalmic examinations and MPOD was measured by heterochromatic flicker photometry. Foveal architecture was measured by optical coherence tomography., Results: MPOD of 225 participants (122 healthy and 103 early AMD) was 0.48±0.18. Patients with early AMD (0.52±0.19) tended to have higher MPOD levels than healthy people (0.47±0.17), but the difference was not statistically significant (P=0.06). Participants with carrot or corn oil intake every week tended to have higher levels of MPOD (P=0.002 and 0.008 respectively) while those with corn intake had relatively lower level of MPOD (P=0.01). MPOD increased with the center foveal thickness (P=0.01)., Conclusion: Our findings show that there is no statistically significant association between MPOD and early AMD in the studied population. MPOD is related to center foveal thickness and diets would influence MPOD levels.

Aim: To collectively evaluate the association of intercellular adhesion molecule-1 (ICAM-1) gene K469E polymorphism (rs5498) with diabetic retinopathy (DR) in patients with type 2 diabetic mellitus (T2DM)., Methods: Overall review of available literatures relating K469E polymorphism to the risk of DR was conducted on 4 electronic databases. Meta-analysis was performed by Stata 12.0 to calculate pooled odds ratios (ORs). Potential sources of heterogeneity and bias were explored., Results: Seven studies with genotype frequency data including 1120 cases with DR and 956 diabetic controls free of DR were included. Meta-analysis did not show significant association of K469E polymorphism with DR (P>0.05). A statistically significant association was detected between the K469E polymorphism and proliferative diabetic retinopathy (PDR) in Asians only in dominant model (GG+AG vs AA) with pooled OR of 0.729 (95%CI: 0.564-0.942, P=0.016, P heterogeneity=0.143), however, this association was not detected in recessive model (GA+AA vs GG; OR=1.178, 95%CI: 0.898-1.545, P=0.236, P heterogeneity=0.248) or allelic model (G vs A; OR=0.769, 95% CI: 0.576-1.026, P=0.074, P heterogeneity=0.094). No publication bias was found by Funnel plot, Begg's and Egger's test., Conclusion: This research found no statistically significant association between ICAM-1 gene K469E polymorphism and DR in patients with T2DM, but showed significant association of the K469E polymorphism with PDR in Asian diabetic patients only in dominant model. Further investigation would be required to consolidate the conclusion.

Objective: To investigate the association of diabetic self-management with the risk of diabetic retinopathy (DR) in patients with type 2 diabetes mellitus., Methods: Cross-sectional study. Recruited patients with type 2 diabetes mellitus in the Desheng community of urban Beijing between November 2009 and May 2011. All patients were surveyed using a standardized questionnaire and underwent detailed ophthalmic examination. Patients were classified into DR group or diabetic without retinopathy (DWR) group according to the grading of fundus color photographs using the Early Treatment of Diabetic Retinopathy Study (ETDRS) standard grading protocol. In the DR group, proliferative diabetic retinopathy (PDR) was further defined. The overall levels of diabetes self-management in the study population were assessed and compared for the differences between DR and DWR, PDR and NPDR groups., Results: One thousand one hundred patients with type 2 diabetes mellitus were recruited. The prevalence of DR was 32.1% (353/1100) in the study population. Sixty-three percent (652/1035) of patients had glycated hemoglobin (HbA1c) level less than 7.0%. The majority of patients (85.4%, 916/1072) conducted a diet control, 77.3% (827/1070) exercised, 56.0% (609/1088) monitored blood glucose regularly, 56.8% (416/733) detected HbA1c more than once every six months, 71.7% (762/1062) had ophthalmologic examination after the diagnosis of diabetes mellitus, and 47.9% (525/1097) had mydriatic check-up. Increased risk of DR was associated with longer duration of diabetes (more than 10 years) (OR = 3.90, 95% CI:2.97-5.51, P < 0.05), higher HbA1c level of ≥ 7.0% (OR = 3.23, 95% CI:2.44-4.28, P < 0.05), insulin therapy (OR = 4.82, 95% CI:3.55-6.57, P < 0.05), male gender (OR = 1.41, 95% CI:1.08-1.84, P < 0.05), lower level of education (OR = 1.90, 95% CI:1.39-2.62, P < 0.05), lower monthly income (OR = 1.46, 95% CI:1.12-1.91, P < 0.05), lower obedience to diet control (OR = 1.72, 95% CI:1.22-2.43, P < 0.05), no exercise (OR = 1.42, 95% CI:1.04-1.94, P < 0.05), change of therapeutic protocol during the last five years (OR = 1.78, 95% CI:1.32-2.41, P < 0.05), and family history of diabetes (OR = 1.35, 95% CI:1.01-1.78, P < 0.05). Increased risk of PDR was associated with the diagnosis age of diabetes (OR = 0.92, 95% CI:0.89-0.95, P < 0.05), longer duration of diabetes (more than 10 years) (OR = 4.54, 95% CI:1.95-12.32, P < 0.05), and insulin therapy (OR = 4.85, 95% CI:2.34-10.90, P < 0.05). In the multifactor logistic regression model, male gender (OR = 2.21, 95% CI:1.57-3.11, P < 0.05), lower level of education (OR = 1.98, 95% CI:1.33-2.94, P < 0.05), lower monthly income (OR = 1.66, 95% CI:1.15-2.39, P < 0.05) ,longer duration of diabetes (more than 10 years) (OR = 2.46, 95% CI:1.77-3.41, P < 0.05) ,HbA1c ≥ 7.0% (OR = 2.24, 95% CI:1.64-3.07, P < 0.05) and insulin therapy (OR = 3.38, 95% CI:2.38-4.8, P < 0.05) were associated with higher risk of DR. The diagnosis age of diabetes (OR = 0.94, 95% CI:0.91-0.98, P < 0.05) and insulin therapy (OR = 3.49, 95% CI:1.47-8.27, P < 0.05) were associated with PDR., Conclusion: Higher risk of DR is associated with longer duration of diabetes,insulin therapy, higher HbA1c level, male gender, and lower level of education, whereas higher risk of DR is also associated with lower obedience to diet control and less exercise, which suggest that lower level of diabetic self-management increased the risk of DR.

Objective: To investigate the association of three single nucleotide polymorphism (SNP) in the upstream of the complement factor I (CFI) gene with age-related macular degeneration (AMD) in a Chinese population., Methods: Case-control study. Patients with early or late stages of AMD and healthy control subjects were recruited. Genomic DNA was extracted from the peripheral venous blood. Genotyping for SNP rs10033900: T > C, rs13117504: C > G and rs2285714: C > T in the upstream of the CFI gene was determined by using a method of polymerase chain reaction (PCR) followed by restriction enzyme digestion and direct sequencing. Statistical analysis was performed using the R statistical analysis package., Results: A total of three hundreds and seventy nine participants were enrolled in the study, including 119 patients with exudative AMD, 120 patients with early AMD and 140 control individuals without AMD. Frequency of the minor allele C of rs10033900 in exudative AMD, early AMD and control groups were 17.4% (40/230), 22.5% (54/240) and 29.3% (82/280), respectively. Significant association of rs10033900 was detected with exudative AMD (χ(2) = 9.82, P = 0.002, OR = 0.57, 95%CI: 0.36 - 0.88), but not with early AMD (χ(2) = 3.08, P = 0.079). Frequency of the minor allele G of rs13117504 in exudative AMD, early AMD and control groups were 38.6% (91/236), 54.2% (130/240) and 51.8% (145/280), respectively. Significant association of rs13117504 was detected with exudative AMD (χ(2) = 9.03, P = 0.003, OR = 0.56, 95%CI: 0.39 - 0.82), but not with early AMD (χ(2) = 0.29, P = 0.59). No association was detected between rs2285714 and exudative AMD (χ(2) = 0.72, P = 0.31) or between rs2285714 and early AMD (χ(2) = 2.30, P = 0.13)., Conclusion: The minor allele of rs10033900 and rs13117504 in the CFI gene may have a protective role against the risk of exudative AMD.

Objective: To investigate the association between angiotensin converting enzyme (ACE) gene locus rs1799752 insertion/deletion (I/D) polymorphism and diabetic retinopathy (DR) in type 2 diabetes mellitus., Methods: Case-control study. Type 2 diabetes patients were recruited and assigned into DR group, which included proliferative diabetic retinopathy (PDR) group or diabetes without retinopathy (DWR) group. Volunteers without diabetes from the same community were recruited as the control group. PCR and agarose gel electrophoresis methods were adopted to determine the rs1799752 I/D polymorphism genotypes of the ACE gene. The frequency of genotypes and alleles was compared among the various groups., Results: Four hundred and twelve diabetes patients: (207 subjects of DR, including 53 subjects of PDR and 205 subjects of DWR) and 97 non-diabetic control subjects were included in the study. The frequencies of the I and D alleles of ACE rs1799752 polymorphism were 54.1% and 45.9%, respectively, in the DR group, 52.8% and 47.2% in the PDR group, and 48.0% and 52.0% in the DWR group. There were no statistical differences between DR and DWR groups (χ(2) = 3.02, P > 0.05) or between PDR and DWR groups (χ(2) = 0.77, P > 0.05). Moreover, there were no statistical differences in the distribution of the ACE genotypes between DR group (II 25.1%, ID 58.0%, DD 16.9%) and DWR group (II 22.0%, ID 52.2%, DD 25.9%) (χ(2) = 4.92, P > 0.05) or between PDR group (II 20.7%, ID 64.2%, DD 15.1%) and DWR group (χ(2) = 3.19, P > 0.05). No statistical differences were found in the frequencies of the I and D alleles, and the distributions of I/D genotypes between diabetic group and the control group (χ(2) = 0.25, 4.98; P > 0.05). In the multiple regressions model including clinical factors such as the age of onset of diabetes, urinary albumin, insulin usage, creatinine, glycated hemoglobin, fast glucose, and the use of ACE inhibitor, no association was found between ACE gene polymorphism and DR (OR = 0.80, 95%CI: 0.59 - 1.09) or PDR (OR = 1.23, 95%CI: 0.78 - 1.93)., Conclusion: There is no association between ACE rs1799752 gene insertion/deletion (I/D) polymorphism and DR in patients with type 2 diabetes mellitus.

Objective: To determine the interaction of susceptibility genes in patients with exudative age-related macular degeneration (AMD) in a Chinese case-control cohort., Methods: It was a case-control study. Six single nucleotide polymorphisms (SNPs) previously genotyped in cases with exudative AMD and control individuals, including complement factor H (CFH) non-coding variant rs1410996, CFH rs1061170 (Y402H), LOC387715 rs10490924, C3 rs2230199 (R102G), C3 rs1047286 (P314L), and HTRA1 rs11200638, were selected for analyzing the interactions among susceptibility genes. The numerical data were examined by Student t test. The genotype distributions between cases and controls were compared using the Chi2 test. Genetic interactions were examined using logistic regression model and synergy index (SI) value based on crossover analysis table., Results: A total of 150 cases with exudative AMD (88 male, 62 female) and 161 control individuals (84 male, 77 female) were included in this study. There was no significant difference in age (t = 0.91, P = 0.37) or gender (Chi2 = 1.32, P = 0.25) between the AMD cases and the controls. SNPs associated with the risk of exudative AMD included CFH non-coding variant rs1410996 (Chi2 = 17.83, P < 0.05), LOC387715 rs10490924 (Chi2 = 17.71, P < 0.05) and HTRA1 rs11200138 (Chi2 = 2.77, P < 0.05). No interaction was observed between CFH rs1410996 and LOC387715 rs10490924 (logistic regression, P = 0.41; SI = 1.04, P = 0.45) or between CFH rs1410996 and HTRA1 rs 11200138 (logistic regression, P = 0.91; SI = 1.42, P = 0.17)., Conclusion: The data suggest that LOC387715 rs10490924 / HTRA1 rs11200138 and CFH rs1410996 are independently associated with the risk of exudative AMD in Chinese.

Objective: The collection of buccal cells with swabs provides a noninvasive method for obtaining genomic DNA for genetic screening. We aimed to study the feasibility of using buccal swabs for genetic screening in patients with exudative age-related macular degeneration (AMD)., Methods: Blood and buccal swabs were collected for genetic analysis from 65 patients with exudative AMD. Genomic DNA was isolated from either blood or buccal swabs. The yield of genomic DNA from both sources was determined by spectrophotometer. Genotyping for CFH, LOC387715, and HTRA1 Polymorphisms was performed using a method of polymerase chain reaction (PCR) followed by restriction enzyme digestion. Results using genomic DNA from blood or buccal swabs were compared., Results: Three swabs were obtained from each patient, 2 from each side of buccal mucosa, and 1 from both upper and inferior gingival mucosa. From swabs with genomic DNA extracted within a week after sample collection, an average of (3.17 ± 1.46) µg genomic DNA was obtained from swab collected from the left or right side buccal mucosa, and (3.94 ± 1.04) µg from swab collected from the upper and inferior gingival mucosa, with relatively higher yield of genomic DNA from the upper and inferior gingival mucosa (t = 6.79, P < 0.05). From swabs of the left or right side buccal mucosa after being stored at -20°C for 12 months, an average of (3.10 ± 1.17) µg genomic DNA was obtained, which showed no statistically significant difference as compared to the yield of genomic DNA extracted from newly collected swabs (t = 0.59, P > 0.05). In all 65 patients, genomic DNA isolated from either buccal swabs or blood samples showed exactly the same results regarding the genotypes of CFH, LOC387715, and HTRA1 Polymorphisms., Conclusions: Buccal swab is a simple, noninvasive, and reliable source for obtaining genomic DNA. Swabs stored for 12 months at -20°C provide similar amount of genomic DNA as the freshly collected swabs.

Age related macular degeneration (AMD) is the most common cause of irreversible blindness in the aged population in the western world. AMD is considered to be a multifactorial disease with involvement of both genetic and environmental factors. With the development of molecular biology and molecular genetics, numerous susceptibility genes have been identified. Here we review the recent advances in the genetic studies regarding the AMD susceptibility genes.

Objective: To identify the disease-causing mutation in a family of Leber hereditary optic neuropathy (LHON)., Methods: Clinical data and family information were collected. Peripheral venous blood was drawn from patients and family members who agreed to donate the blood samples. Genomic DNA was extracted from blood leukocytes. Three primary mitochondrial DNA (mtDNA) mutations, G3460A, G11778A, and T14484C were screened using a method of polymerase chain reaction (PCR) followed by direct sequencing., Results: This 3-generation family had 14 members. Seven family members were affected, including 5 female patients and 2 male patients. Pedigree analysis showed maternal inheritance. Mutation analysis in 4 affected and 3 unaffected family members showed G11778A mutation in all 4 affected and 2 of the 3 unaffected individuals., Conclusions: G11778A mutation in mtDNA is the disease-causing mutation in this family of LHON. For the mutation carriers, early intervention may prevent or delay the onset of the disease.

Objective: To investigate the association of M299V variant in the elongation of very long chain fatty acids-like 4 (ELOVL4) gene with exudative age-related macular degeneration (AMD) in a Chinese population., Methods: A total of 262 participants enrolled this study, including 145 patients with exudative AMD and 117 control individuals without AMD. Genomic DNA was extracted from peripheral blood. Genotyping for single nucleotide polymorphism (SNP) rs3812153: A > G (M299V) in ELOVL4 gene was performed using a method of polymerase chain reaction (PCR) followed by restriction enzyme digestion and direct sequencing. Numerical data were examined by Student t test. Genotypes and allele frequencies between AMD cases and the controls were compared by using the chi(2) test. Odd ratios (OR) and 95% confidence intervals (CI) were calculated according to the Woolf's equation. Compliance to Hardy-Weinberg equilibrium for distribution of genotypes was examined using Haploview version 4.0., Results: There was no significant difference in age or gender between AMD cases and the controls. Genotype distributions for M299V in AMD cases or the control subjects were in Hardy-Weinberg equilibrium. The M299V variant in ELOVL4 gene was not associated with exudative AMD in the population sample studied (chi(2) = 0.960, P = 0.619). Frequency of the rare allele G was 17.2% in cases with exudative AMD and 19.7% in the control individuals (chi(2) = 0.505, P = 0.477). Compared to the wild-type AA genotype, OR for risk of AMD was 0.99 (95%CI: 0.78 - 1.26) in heterozygous AG genotype and 0.56 (95%CI: 0.17 - 1.82) in homozygous GG genotype., Conclusion: Our data suggested that there was no association between the M299V variant in ELOVL4 gene and exudative AMD in the Chinese population.

Age-related macular degeneration (AMD) is the leading cause of blindness in the elderly population and threatens the ability of patients to live independently. Ethnic differences are evident in the prevalence of AMD, its clinical features, as well as treatment responses to photodynamic therapy (PDT), most likely due to the differences in genetic backgrounds, disease susceptibility, living environments and habits. This article reviewed ethnic/racial differences in AMD, paying particular attention to the Chinese population, and highlighted the key findings. Compared to Caucasians, the prevalence of early and late stages of AMD is relatively lower and the polypoidal choroidal vasculopathy (PCV) is more commonly seen in the Chinese population. Regarding genetic susceptibility, the complement factor H (CFH) Y402H variant is not associated with exudative AMD in Chinese although it is strongly associated with AMD in Caucasians. In addition, visual outcome in Chinese patients with AMD seems to be better than that in Caucasian patients after PDT at 1 year follow-up.

Objective: To assess the risk factors and prognosis of peripheral retinal breaks complicating pars plana vitrectomy., Methods: Retrospective observational case series. Four hundred and four consecutive vitrectomies performed on eyes without preexisting retinal breaks or retinal detachments were retrospectively reviewed. Cases with peripheral retinal breaks found during or after the vitrectomy were recorded and analyzed., Results: Of the 404 vitrectomies, 32 eyes had 55 iatrogenic peripheral retinal breaks with an average incidence of 7.9%. Peripheral retinal breaks were most common in cases with branch retinal vein occlusion (BRVO) (13.3%) and less common in proliferative diabetic retinopathy (PDR) (3.7%) (chi2 =9.18, P<0.01). Of the 55 breaks, 51 (92.7%) occurred around the sclerotomy sites, and 29 (52.7%) in the quadrant corresponding to the predominant hand of the surgeon. Cases with breaks detected during surgery had a better outcome of retinal reattachment as compared with cases identified postoperatively., Conclusions: Peripheral retinal breaks complicating pars plana vitrectomy is mainly sclerotomy-related and is more common in cases with BRVO than in cases with PDR. Early detection during surgery tends to have a better outcome.

Purpose: To identify CHST6 mutations in five additional Icelandic cases of macular corneal dystrophy (MCD) type I and in four families with MCD type II from Iceland., Methods: Genomic DNA was extracted from blood leukocytes of patients with MCD, their healthy family members, and from control individuals. CHST6 mutations were determined by PCR-sequencing. Immunophenotypes of MCD were determined by measuring antigenic keratan sulfate (AgKS) levels in serum and by an immunohistochemical study on corneal tissue., Results: Five additional cases of MCD type I and four families with MCD type II from Iceland were studied. A homozygous p.A128V mutation in the coding region of the CHST6 gene was identified in four of the five MCD type I cases. The other person with MCD type I was a compound heterozygote for p.A128V and a frameshift p.V6fs resulting from a 10-base pair insertion (c.15&#95;16insATGCTGTGCG). Four of five individuals with MCD type II were compound heterozygotes for p.A128V and p.V329L, thus sharing the same p.A128V mutation as MCD type I. One patient with MCD type II was homozygous for p.V329L. The p.V329L mutation was only found in MCD type II patients. An analysis of the upstream region of CHST6 disclosed no upstream deletion or replacements in Icelandic patients with MCD type II., Conclusions: The findings fit the haplotype analysis that we reported previously in Icelandic MCD families and indicate that different mutations in CHST6 cause MCD type I and type II in Iceland.

Based on the manuscripts received by several ophthalmologic journals, major issues regarding current ophthalmic research aspects in China were analyzed and discussed, including the selection of project, the design of research, the choice of statistical treatments and the techniques of writing research manuscripts. This article provides suggestions for Chinese ophthalmologists to improve the quality of their research work.

Objective: To study whether Chinese patients with various corneal dystrophy carry mutations in BIGH3 gene., Methods: Genomic DNA was extracted from Chinese patients with Avellino corneal dystrophy (ACD, 10 cases), Reis-Bücklers corneal dystrophy (CDRB, 2 cases), granular corneal dystrophy (GCD, 3 cases) and 5 control subjects. The exons 4 and 12 of BIGH3 gene were amplified by PCR and the product was sequenced directly., Results: All 15 patients carried mutations in BIGH3 gene, R124H in 10 cases with ACD, R124L in 2 cases with CDRB and R555W in 3 cases with GCD., Conclusions: Corneal lesions in all 15 Chinese patients clinically diagnosed with corneal dystrophies are caused by mutations in BIGH3 gene. Dose-effect analysis shows that corneal lesions are more severe in homozygous patients than those in heterozygous cases and that clinical manifestation of patients with R124L mutation is more severe than that of patients with R124H mutation.