Abstract
Purpose: :
Pathohistological publications documented various changes in microaneurysms (MAs) in diabetic retinopathy (DR); thick or thin basement membrane, loss of pericytes, and endothelial hypercellularity or acellularity. We characterized MAs in DR depicted by spectral-domain optical coherence tomography (SD-OCT) and evaluated their association with cystoid spaces in the neighborhood.
Methods: :
Consecutive series of 160 eyes from 109 patients suffering from DR that had SD-OCT (Spectralis HRA+OCT; Heidelberg engineering, Heidelberg, Germany) and color fundus photograph data obtained on the same day were participated. MAs in OCT images appeared well demarcated, oval lesions in the sensory retinas corresponding to white or red or mixed dots in color fundus photograph. Their characteristics in vascular walls, contents, and location were documented, and the association between these characteristics and cystoid spaces in the neighborhood was evaluated.
Results: :
According to the appearance of capsular structure, we classified 466 MAs depicted by Spectralis OCT; 95 with complete capsular structure (ring sign), 162 with incomplete, or 209 with absent. MAs with absent ring sign presented hyperreflective spots in their lumen and were accompanied with cystoid spaces in the neighborhood more frequently than other types (p<0.001 and p=0.012). Intriguingly, 45 of 202 MAs with cystoid spaces in the neighborhood were protruded into cystoid spaces, and 37 MAs (82.2%) presented absent ring sign. The location of MAs was also investigated; 8 (1.7%) in nerve fiber layer, 73(15.7%) in ganglion cell layer or inner plexiform layer, 355 (76.2%) in inner nuclear layer, 30 (6.4%) in outer plexiform layer/outer nuclear layer, although we could not find the significant correlation between the location and cystoid spaces in the neighborhood.
Conclusions: :
These data would shed light on the investigation of diabetic macular edema pathogenesis and the improvement in a conventional treatment, focal photocoagulation.
Keywords: diabetic retinopathy • imaging/image analysis: clinical • retina