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Introduction: The purpose of this study was to compare 2-field (2F) and 5-field (5F) mydriatic handheld retinal imaging for the assessment of diabetic retinopathy (DR) severity in a community-based DR screening program (DRSP). Methods: This was a prospective, cross-sectional diagnostic study, evaluating images of 805 eyes from 407 consecutive patients with diabetes acquired from a community-based DRSP. Mydriatic standardized 5F imaging (macula, disc, superior, inferior, temporal) with handheld retinal camera was performed. 2F (disc, macula), and 5F images were independently assessed using the International DR classification at a centralized reading center. Simple (K) and weighted (Kw) kappa statistics were calculated for DR. Sensitivity and specificity for referable DR ([refDR] moderate nonproliferative DR [NPDR] or worse) and vision-threatening DR ([vtDR] severe NPDR or worse) for 2F compared to 5F imaging were calculated. Results: Distribution of DR severity by 2F/5F images (%): no DR 66.0/61.7, mild NPDR 10.7/14.4, moderate NPDR 7.9/8.1, severe NPDR 3.3/5.6, proliferative DR 5.6/4.6, ungradable 6.5/5.6. Exact agreement of DR grading between 2F and 5F was 81.7%, within 1-step 97.1% (K = 0.64, Kw = 0.78). Sensitivity/specificity for 2F compared 5F was refDR 0.80/0.97, vtDR 0.73/0.98. The ungradable images rate with 2F was 16.1% higher than with 5F (6.5 vs. 5.6%, p < 0.001). Conclusions: Mydriatic 2F and 5F handheld imaging have substantial agreement in assessing severity of DR. However, the use of mydriatic 2F handheld imaging only meets the minimum standards for sensitivity and specificity for refDR but not for vtDR. When using handheld cameras, the addition of peripheral fields in 5F imaging further refines the referral approach by decreasing ungradable rate and increasing sensitivity for vtDR. [ABSTRACT FROM AUTHOR]

The important role of ascorbic acid (AA) as an anti-oxidant is particularly relevant in diabetes mellitus where plasma concentrations of AA are reduced. This study was conducted to evaluate the effects of treatment with AA or an aldose reductase inhibitor, tolrestat, on AA metabolism and urinary albumin excretion in diabetes. Blood and urine samples were collected at 0, 3, 6, 9, and 12 months from 20 diabetic subjects who were randomized into two groups to receive either oral AA 500 mg twice daily or placebo. Systolic and diastolic blood pressures, HbA[sub 1c] , plasma lipids, urinary albumin, and total glycosaminoglycan excretion were measured at all time points, and heparan sulphate (glycosaminoglycan) was measured at 0 and 12 months. The same parameters, as well as urinary AA excretion, were determined at 0 and 3 months for 16 diabetes subjects receiving 200 mg tolrestat/day. AA treatment increased plasma AA (ANOVA, F ratio = 12.1, p = 0.004) and reduced albumin excretion rate (AER) after 9 months (ANOVA, F ratio = 3.2, p = 0.03), but did not change the other parameters measured. Tolrestat lowered plasma AA (Wilcoxon’s signed-rank test, p < 0.05), but did not change AER or the other parameters measured. The ability of AA treatment to decrease AER may be related to changes in extracellular matrix or improvement in oxidative defence mechanism. Unlike the rat model of diabetes, inhibition of aldose reductase did not normalize plasma AA or AER in humans. In fact, tolrestat reduced the plasma AA concentration, a phenomenon which may be due to increased utilization of AA. Dietary supplementation of AA in diabetic subjects may have long-term benefits in attenuating the progression of diabetic complications. [ABSTRACT FROM AUTHOR]

Introduction: Handheld retinal imaging cameras are relatively inexpensive and highly portable devices that have the potential to significantly expand diabetic retinopathy (DR) screening, allowing a much broader population to be evaluated. However, it is essential to evaluate if these devices can accurately identify vision-threatening macular diseases if DR screening programs will rely on these instruments. Thus, the purpose of this study was to evaluate the detection of diabetic macular pathology using monoscopic macula-centered images using mydriatic handheld retinal imaging compared with spectral domain optical coherence tomography (SDOCT). Methods: Mydriatic 40°–60° macula-centered images taken with 3 handheld retinal imaging devices (Aurora [AU], SmartScope [SS], RetinaVue 700 [RV]) were compared with the Cirrus 6000 SDOCT taken during the same visit. Images were evaluated for the presence of diabetic macular edema (DME) on monoscopic fundus photographs adapted from Early Treatment Diabetic Retinopathy Study (ETDRS) definitions (no DME, noncenter-involved DME [non-ciDME], and center-involved DME [ciDME]). Sensitivity, specificity, positive predictive value, and negative predictive value were calculated for each device with SDOCT as gold standard. Results: Severity by ETDRS photos: no DR 33.3%, mild NPDR 20.4%, moderate 14.2%, severe 11.6%, proliferative 20.4%, and ungradable for DR 0%; no DME 83.1%, non-ciDME 4.9%, ciDME 12.0%, and ungradable for DME 0%. Gradable images by SDOCT (N = 217, 96.4%) showed no DME in 75.6%, non-ciDME in 9.8%, and ciDME in 11.1%. The ungradable rate for images (poor visualization in >50% of the macula) was AU: 0.9%, SS: 4.4%, and RV: 6.2%. For DME, sensitivity and specificity were similar across devices (0.5–0.64, 0.93–0.97). For nondiabetic macular pathology (ERM, pigment epithelial detachment, traction retinal detachment) across all devices, sensitivity was low to moderate (0.2–0.5) but highly specific (0.93–1.00). Conclusions: Compared to SDOCT, handheld macular imaging attained high specificity but low sensitivity in identifying macular pathology. This suggests the importance of SDOCT evaluation for patients suspected to have DME on fundus photography, leading to more appropriate referral refinement. [ABSTRACT FROM AUTHOR]