Race/ethnicity and socioeconomic-based analysis of vascular alterations on optical coherence tomography angiography (OCTA) in patients with diabetes

Abu T Taha, Yi Stephanie Zhang, Isabel Thompson, Jeremy D Keenan, Aunoy Poddar, John Dickson, Ricardo Lamy, Jay M Stewart

 

Purpose

Racial and ethnic minorities have a higher prevalence of diabetic retinopathy (DR) and present at advanced stages.^1–3 Two studies have measured DR in racial/ethnic groups using OCTA. However, neither included adjustments for socioeconomic (SES) factors.^4,5 We performed a retrospective observational study using optical coherence tomography angiography (OCTA) to investigate microvascular differences between racial/ethnic groups and their respective SES scores from the area deprivation index (ADI). Patients with diabetes were grouped into: no DR, mild to severe non-proliferative diabetic retinopathy (NPDR), and proliferative diabetic retinopathy (PDR).

 

Methods:

We obtained 3x3mm macular OCTA scans from patients without other ocular comorbidities or prior DR treatments. One eye per patient was included in the analysis. Parameters analyzed included foveal avascular zone (FAZ), superficial capillary plexus (SCP) and deep capillary plexus (DCP) for parafoveal vessel density (VD), vessel length density (VLD), and flow index (FI). SES was measured using patients’ addresses and ADI. Multivariable linear regression was used to adjust estimates for potential confounders of age, SS, hypertension, gender, duration of disease, and HbgA1C.

Results:

227 controls and 1993 diabetics were included in the study. Racial breakdown was 43% Hispanic, 24.4% NH Asian, 6.8% NH Black, 9.6% NH Caucasians, and 16.3% Other. In all comparisons, Hispanic group was used as the referent. Among controls, Caucasian patients had smaller FAZ area (ß = -0.089, P < 0.001) and FAZ perimeter (ß = -0.325, P < 0.001). Among all diabetics combined, Caucasians had smaller FAZ area (ß = -0.100, P < 0.001) and FAZ perimeter (ß = -0.406, P < 0.001), but higher deep VD (ß = 1.227, P < 0.001) and deep VLD (ß = 0.362, P < 0.001). Asian participants also had higher deep VD (ß = 0.566, P < 0.001).

Additionally, “Other” had smaller FAZ area (ß = -0.028, P < 0.001) and FAZ perimeter (ß = - 0.135, P < 0.001). Lastly, the addition of SES scores both at a national and state level, did not modify any of the racial regression models significantly.

 

Conclusions/Discussion

Our findings from a large county population suggest that at baseline, there are differences in the microvascular alterations between racial/ethnic groups that cannot be explained by their SES. Albeit statistically significant, further investigation is needed to determine whether these differences are meaningful enough to change clinical DR practices.