Retinal and choroidal blood flow changes in dialysis patients assessed by wide-field swept-source optical coherence tomography angiography (SS-OCTA)

Li Wan¹Zhou Qing²Ni jiu lin¹Li Min¹Fei Hua¹Pan Xun¹Tang Huan^2*LI Shu ting^1*

• ¹First People's Hospital of Changzhou, Changzhou, China
• ²Changzhou Traditional Chinese Medicine Hospital, Changzhou, Jiangsu Province, China

The study utilized wide-field swept-source optical coherence tomography angiography (SS-OCTA) to examine the alterations in retinal and choroidal blood flow in patients with end-stage renal disease (ESRD)before and after hemodialysis.Forty-two eyes of twenty-four participants with end-stage renal disease were enrolled in this prospective and cross-sectional study. A full ophthalmic examination was conducted on each participant one hour before and after hemodialysis, which included wide-field SS-OCTA imaging on OCTA scans measuring 9 mm x 9 mm. The mean perfusion area (PA), superficial vessel density (SVD), retinal inner VD (RIVD), and choroidal vascularity index (CVI) were evaluated independently before and after hemodialysis in both macular and optic disc areas across all 16 sectors defined by the Early Treatment Diabetic Retinopathy Study (ETDRS).The study subjects consisted of 18 men and 6 women, comprising 9 patients with diabetic renal failure and 23 patients with hypertension. The mean age of the patients with end-stage renal disease was 57.3 ± 12.7 years. In the central ring, retinal inner VD were signifcantly decreased after HD(P<0.05), but there were no signifcant differences in the average PA ,SVD, and CVI between before and after single HD session. In the 3 mm radius, inferior quadrant of macular retinal inner VD , PA of the macular and optic disc were signifcantly decreased after HD(P<0.05). In the 6 mm radius, the temporal section of the retinal inner VD , nasal and inferior of PA were noticeably reduced in the HD group. In the wide-feld scans (9 mm radius), there was exhibited a more pronounced reduction in inferior PA , SVD and retinal inner VD of optic disc area in inferior sectors after HD. Fairly consistent CVI values were noted in the macular zone, except for a statistically significant decrease in the temporal quadrant at 3mm and 6mm within the optic disc area (p=0.040 and 0.048, respectively).Results revealed a more significant decrease in indicators of the choroid and optic disc area compared to the inner retina and macular zone.Wide-field SS-OCTA displays potential as an imaging technique for early detection of microcirculation changes in hemodialysis patients.