Comparative study of the vascular structures of the retina and choroid in Chinese Han and Uygur populations with proliferative diabetic retinopathy: An OCTA study

To compare the vascular structures of the retina and choroid in Chinese Han and Uygur populations with proliferative diabetic retinopathy (PDR) using swept-source OCTA (SS-OCTA). Fifty-three eyes of 53 healthy volunteers (25 from Hans and 28 from Uygurs) and 40 eyes of 40 PDR patients (20 from Hans and 20 from Uygurs) were included. Retinal and choroidal parameters, including thickness, vessel flow density (VFD), foveal avascular zone (FAZ) area, choroidal vascularity volume and index (CVV and CVI) were evaluated. Compared with the respective controls, superficial capillary plexus (SCP)-VFD and deep capillary plexus (DCP)-VFD, the areas of FAZ in SCP and DCP were significantly decreased in both Han and Uygur PDR patients. choroidal parameters analysis found that Uygur controls had substantially higher choroidal thickness (CT) than Han controls ( p = 0.020) and PDR eyes showed significantly decreased CT. Both races with PDR exhibited significantly reduced choriocapillaris layer-VFD, large and medium choroidal vessel (LMCV) layer-VFD, CVV and CVI, however, Uygur PDR patients had significant lower LMCV layer-VFD, CVV and CVI compared to Han PDR patients. Diabetes duration was the most significant factor affecting CVV and CVI. Both Han and Uygur PDR patients had significantly lower CT and decreased vessel densities compared to controls, but the Uygur PDR patients had more severe choroidal damage than Han PDR patients, which is most likely related to worse visual prognosis. These findings indicate that more frequent screenings and prompt therapy are urgent for Uygur PDR patients.