Vascular macular capillary plexus in patient with Type 1 diabetes with no retinopathy are correlated with OCT volume changes

Abstract

PurposeDiabetic retina undergoes neurodegenerative changes at the neuronal level in addition to vascular changes. Neuronal changes can be study indirectly using spectral domain OCT thickness and volumen. OCT angiography (OCTA) allows studying the macular vascular plexus in a non‐invasive way. The purpose of our study was to evaluate changes in the macular vascular density changes using OCTA, and to examine its correlation with OCT macular thickness diminution over 8 year follow‐up in patients with type 1 diabetes and no signs of diabetic retinopathy. To quantify foveal avascular zona (FAZ) area and to correlate with vascular modifications.Methods18 eyes of 9 diabetic patients with no retinopathy were studied by SD‐OCT at 2009. The patients were reexamined by SD‐OCT looking for changes in macular thickness and volumen; all eyes underwent angio OCT. FAZ was manually measured. Macular thickness and volume changes over these 8 years were correlated with finding at the OCTA and FAZ area.ResultsMean age of the patients was 35.32±14.23 years (range 23‐54). Mean time of diabetes evolution was 15.96±11.46 years. Best corrected visual acuity (BCVA) was between 0 and ‐0.3 logMAR. 16 eyes showed no signs of diabetic retinopathy. One patient had mild‐moderate diabetic retinopathy with macular edema in his LE. Eyes with OCTA changes showed modification in both superficial and deep plexus. Vascular changes included reduced capillary density, regions of capillary dropout and foveal avascular enlargement. Patients with OCTA changes displayed a diminished macular volume over the 8 years of follow up (excluding the one with diabetic retinopathy).ConclusionsDespite we are not able to find signs of diabetic retinopathy, type 1 diabetic patients develop changes at the vascular level that are related to a diminution of the OCT macular volume.