Abstract
Purpose :
The transient or persistent disturbance of blood flow is one of several clinical findings of vascular lesions and exacerbate neuronal impairment in diabetic retinopathy (DR). Optical coherence tomography angiography (OCTA) allows us to quantify vascular density or vascular density length, which are modestly associated with DR severity. In this study, we characterized the intercapillary spaces on OCTA images and investigated their clinical significance in DR.
Methods :
In this retrospective study, we reviewed 88 eyes of 76 patients with treatment-naïve DR, for whom 3x3 mm OCTA images centered on the macula were acquired using PLEX Elite 9000 (Carl Zeiss Meditec). The superficial slab images with a 2-mm diameter were prepared and processed by binarization. The intercapillary spaces were automatically detected and quantified using ‘Analyze Particles’ function in ImageJ (NIH, Bethesda, MD). The number of intercapillary spaces was applied to receiver operating characteristics (ROC) curve analyses to discriminate DR from nondiabetic subjects.
Results :
The intercapillary spaces were detected in the superficial capillary layer, although they were rarely found in the deep layer. The numbers of intercapillary spaces were 540±117, 421±162, 365±145, 256±162, 283±109, and 236±154 in nondiabetic subjects, no apparent retinopathy (of diabetic patients), mild nonproliferative diabetic retinopathy (NPDR), moderate NPDR, severe NPDR, and prliferative diabetic retinopathy (PDR). The numbers of intercapillary spaces were greater in nondiabetic subjects than those in diabetic eyes (P<0.001). Eyes with DR had more spaces than those with no apparent retinopathy (P=0.001). The area under ROC curve (AROC) was better for discriminating diabetic eyes from nondiabetic subjects (AROC = 0.895) than that for discriminating no apparent retinopathy from DR (AROC = 0.771).
Conclusions :
The numbers of intercapillary spaces decreased according to the DR severity. The ROC analyses suggested that the number of intercapillary spaces in the macula has a diagnostic significance in diabetic eyes.
This is a 2021 ARVO Annual Meeting abstract.