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OBJECTIVE -Alterations in retinal vascular caliber may reflect early subclinical microvascular dysfunction. In this study, we examined the association of retinal vascular caliber to incident retinopathy in young patients with type 1 diabetes.RESEARCH DESIGN AND METHODS -This was a prospective cohort study of 645 initially retinopathy-free type 1 diabetic patients, aged 12-20 years. Participants had seven-field stereoscopic retinal photographs taken of both eyes at baseline and follow-up. Retinal vascular caliber was measured from baseline photographs using a computer-based program following a standardized protocol. Incident retinopathy was graded according to the modified Airlie House classification from follow-up photographs.RESULTS -Over a median follow-up of 2.5 years, 274 participants developed retinopathy (14.8 per 100 person-years). After adjustments for age, sex, diabetes duration, glycemia, mean arterial blood pressure, BMI, and cholesterol levels, larger retinal arteriolar caliber (fourth versus first quartile) was associated with a more than threefold higher risk of retinopathy (hazard rate ratio 3.44 [95% CI 2.08 -5.66]). Each SD increase in retinal arteriolar caliber was associated with a 46% increase in retinopathy risk (1.46 [1.22-1.74]). This association was stronger in female than in male participants. After similar adjustments, retinal venular caliber was not consistently associated with incident retinopathy.CONCLUSIONS -Retinal arteriolar dilatation predicts retinopathy development in young patients with type 1 diabetes. Our data suggest that arteriolar dysfunction may play a critical role in the pathogenesis of early diabetic retinopathy and that computer-based retinal vascular caliber measurements may provide additional prognostic information regarding risk of diabetes microvascular complications.

Changes in retinal vascular caliber may reflect subclinical microvascular disease and provide prognostic information regarding risk of retinopathy. In this study, we examined the prospective association of retinal vascular caliber with retinopathy risk in an Australian population-based cohort. A total of 906 participants without retinopathy at baseline had retinal vascular caliber measured from photographs and were followed-up for 5 years for incident retinopathy. After adjusting for age, sex, systolic blood pressure, A1C, and other risk factors, individuals with wider retinal arteriolar caliber (widest 25% vs. the remaining three-quarters of the population) were more likely to develop incident retinopathy (odds ratio 4.79 [95% CI 1.57-14.58]). This association was not significant in individuals without diabetes. Venular caliber did not predict incident retinopathy. Our findings suggest that retinal arteriolar dilatation is a specific sign of diabetic microvascular dysfunction and may be a preclinical marker of diabetic retinopathy.

Objective To determine whether vitamin E supplementation influences the incidence or rate of progression of age related maculopathy (AMD). Design Prospective randomised placebo controlled clinical trial. Setting An urban study centre in a residential area supervised by university research staff. Participants 1193 healthy volunteers aged between 55 and 80 years; 73% completed the trial on full protocol.Interventions Vitamin E 500 IU or placebo daily for four years. Main outcome measures Primary outcome: development of early age related macular degeneration in retinal photographs. Other measures included alternative definitions of age related macular degeneration, progression, changes in component features, visual acuity, and visual function Results The incidence of early age related macular degeneration (early AMD 3) was 8.6% in those receiving vitamin E versus 8.1% in those on placebo (relative risk 1.05, 95% confidence interval 0.69 to 1.61). For late disease the incidence was 0.8% versus 0.6% (1.36, 0.67 to 2.77). Further analysis showed no consistent differences in secondary outcomes. Conclusion Daily supplement with vitamin E supplement does not prevent the development or progression of early or later stages of age related macular degeneration.