Diabetic Retinopathy Lesion Distribution Varies Among Ethnicities

The distribution of diabetic retinopathy lesions varies among different ethnicities, especially in the case of patients with East Asian ethnicity, who tend to develop disease more peripherally than other groups, according to research published in the American Journal of Ophthalmology.

Researchers conducted a multicenter, retrospective cohort study to evaluate whether the distribution of diabetic retinopathy lesions differs among various ethnicities.

The team used records of diabetic patients presenting to the Doheny-UCLA retina clinics (USA), the Harbor-UCLA clinic (USA), the Narayana Nethralaya Eye Institute (India), and Second Hospital of Tianjin Medical University (China) to accrue a cohort comprising patients of multiple ethnicities who had undergone ultra-widefield pseudocolor imaging. They manually annotated the images for diabetic retinopathy lesions and classified the eyes as having predominantly peripheral (PPL) or predominantly central lesions (PCL), then compared the percent distribution of PPL to PCL among the different ethnicities.

The cohort included 226 eyes with diabetic retinopathy of 145 patients: 51 East Asian eyes, 102 South Asian eyes, 30 White eyes, and 43 Latino eyes. Overall, 158 eyes were treatment naïve (48 East Asian eyes, 54 South Asian eyes, 20 White eyes, and 36 Latino eyes).

Using a single-field lesion frequency-based method, the researchers found East Asian eyes more frequently demonstrated a PPL distribution (86.3%) and South Asian eyes more frequently demonstrated a PCL distribution (64.7%). 

They observed similar findings when considering only the subset of treatment-naïve eyes. In treatment naïve eyes without proliferative diabetic retinopathy, they found the percent distribution of PPL to PCL in East Asian eyes was significantly different from those of the other ethnicities (85.4% vs 35.2% in South Asian eyes; P <.0001; 85.4% vs 51.7% in White eyes; P =.035; 85.4% vs 46.2% in Latino eyes; P =.0003). 

“Given that a PPL distribution is connected to a higher risk of progression, this is [a] potentially important finding,” the researchers explain. “The reason for the disparity in lesion distribution between ethnic groups remains uncertain. A recent study reported that patients with PPL were more likely to have type 1 diabetes and a longer duration of diabetes than those without PPL. Another study showed that higher fasting plasma glucose was an independent risk factor for mild [nonproliferative diabetic retinopathy] eyes with predominantly posterior lesions. However, the findings from these groups remain to be replicated by other studies to establish the contribution of these different factors towards PPL distribution.”

Limitations of the study included the retrospective, cross-sectional design, potential ascertainment bias, inclusion of only patients who had undergone ultra-widefield imaging, a relatively small sample size, inability to include patients of African origin in the study, and inability to control for other potential confounders or differences between groups including various systemic and demographic factors.

Disclosure: One study author declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.