Features of structural and microvascular changes of the choroid in angioretinopathy of various etiologies

Abstract

To study structural and microvascular changes in the choroid in patients with chronic kidney disease (CKD), diabetic retinopathy (DR) and arterial hypertension (AH), and their relationship with the level of renal function, carbohydrate metabolism and blood pressure. The study involved 172 patients (325 eyes): 56 patients with CKD (109 eyes); 66 patients with DR (121 eyes); 50 patients with AH (95 eyes). All patients underwent comprehensive ophthalmological examination including visometry, biomicroscopy, ophthalmoscopy, optical coherence tomography (OCT) and OCT angiography. In patients with DR and CKD, a decrease in the thickness of the ganglion cell complex and the inner plexiform layer (GCL+IPL) was noted: in proliferative DR (PDR) - 62.45±4.25 µm, in stage 4-5 CKD - 75.23±6.43 µm; a decrease in choroidal thickness (CT) of minimal values in stage 4-5 CKD (179.9±37.72 µm) and PDR (211.0±40.7 µm). The decrease in choroidal vascularity index (CVI) depended on the stage of CKD and PDR (in PDR - 63.47±1.37, in stage 4-5 CKD - 65.93±2.01). Maximum decrease in perfusion density and vascular density was found in patients with DR (37.22±9.00% and 15.11±3.39 mm, respectively). An increase in the area, perimeter of the foveolar avascular zone (FAZ), and a decrease in the circularity index were noted in all groups, with most pronounced changes in PDR and stage 4-5 CKD. Patients with CKD were found to have strong correlations of CT and CVI with creatinine, urea, proteinuria and glomerular filtration rate (GFR). Patients with diabetes mellitus and PDR were revealed to have strong relations of CT, CVI, GCL+IPL, the area and perimeter of FAZ with creatinine levels and the duration of diabetes mellitus. Choroidal thickness and choroidal vascularity index are important diagnostic markers of disorders of chorioretinal microcirculation that allow stratifying individual assessment of risk factors for progression of both chronic kidney disease and diabetic retinopathy.