Sears CM, Hirano T, Nittala MG, Mehta NS, Sinha S, Jayadev C, Singh G, Verhoek M, Fleming A, van Hmert J, Tsui I, Prasad P, Sadda SR. Ethnic variation in diabetic retinopathy lesion distribution. Poster presented at the 2018 ARVO Annual Meeting; April 29, 2018. Honolulu, HI. [abstract] Invest Ophth Vis Sci. 2018 Jul 1; 59(9):4681.

PURPOSE: Peripheral lesions in eyes with diabetic retinopathy (DR) have recently been suggested to be of prognostic importance. In this study, we sought to examine differences in lesion distribution in eyes with diabetic retinopathy (DR) of patients of different ethnic backgrounds.

METHODS: A total of 220 eyes with DR were randomly selected for this IRB-approved retrospective study. 104 eyes were Indian, 34 Caucasian, 52 Latino, 10 African American, 12 Asian, and 8 other. The average age was 64-years-old. Ultrawidefield (UWF) pseudocolor images (fovea-centered) were obtained from a cohort of patients recruited for DR screening at the Narayana Nethralaya Eye Institute and at the Doheny-UCLA retina clinics. All DR lesions (microaneurysms, hemorrhages, cotton wool spots, exudates, intra-retinal microvascular abnormalities, neovascularization) were manually segmented by certified graders at the Doheny Image Reading Center. Eyes were classified as having predominantly central lesions (PCL) or predominantly peripheral lesions (PPL) based on lesion frequencies within and outside the 7-ETDRS fields, respectively (i.e. >50% of lesions outside EDTRS fields = PPL).

RESULTS: A PCL distribution was observed in 94% of Indian eyes, 76% of Caucasian eyes, 92% of Latino eyes, 60% of African American eyes, and 42% of Asian eyes (p < 0.001). A PPL distribution was observed in 6% of Indian eyes, 24% of Caucasian eyes, 6% of Latino eyes, 40% of African American eyes, and 58% of Asian eyes (p = 0.55). DR lesions in African American eyes exhibited the shortest mean distance to the fovea at 7.9mm, while Asian eyes demonstrated the longest mean distance to the fovea at 9.9mm. The difference in mean distance from the foveal center to the DR lesions among the ethnic groups was not statistically significant (p = 0.18). There were, however, significant differences in lesion frequency within the 7-ETDRS fields when comparing the various ethnicities (p = 0.016), with Indian eyes containing the highest number (mean of 73) and percentage of lesions centrally.

CONCLUSIONS: DR lesions tend to be distributed more peripherally in Caucasian eyes compared to Indian eyes. These findings suggest that there may be ethnic differences in manifestation of DR which could have implications for disease staging and risk of progression.