Abstract
Purpose:
To identify structural and physiologic features of microaneurysms (MAs) in diabetic eyes using adaptive optics scanning laser ophthalmoscopy (AOSLO) that are correlated with fluorescein leakage and surrounding neural pathology.
Methods:
AOSLO confocal and pinhole aperture offset techniques were used to image MAs in diabetic eyes. After image dewarping, averaging and automatic registration/alignment, videos (50 frame blocks, 30 frames/sec) were graded for MA dimension, presence of wall deformability (WD: deformation of the vascular wall due to blood cell flow), wall hyperreflectivity (WH) and perfusion pattern. All eyes underwent Spectralis spectral domain optical coherence tomography (SDOCT). Substacks of 5 B-scans were graded within a 500µm box centered on each MA for neural pathology including inner layer disorganization, outer layer disruption, hyperreflective foci, cysts and subretinal fluid. Vascular permeability was evaluated by fluorescein angiography (FA) in a small subset of eyes.
Results:
109 MAs (mean±SD: longest dimension 69±35µm, 31% with WH, 47% partially vs totally perfused, 70% visible on 30° photos) were evaluated from 30 eyes of 29 subjects (age 46±13yrs, 62% male, DM duration 26±10yrs, 76% type 1 DM). MAs with vs without WH were larger (longest dimension 102±33 vs 54±25µm, p<0.0001), more visible on 30° photos (93% vs 60%, p=0.0007), more likely to have central lumen clots (68% vs 17%, p<0.0001) and were partially versus completely perfused (76% vs 33%, p<0.0001). WH was associated with increased local inner layer disorganization (15% vs 3%, p=0.02) but was not related to AOSLO WD, SDOCT ring sign or SDOCT MA hyper/hyporeflectivity. MAs with WD were more likely to be visible on photos (100% vs 61%, p<0.05) and associated with retinal inner layer disorganization (14% vs 0%, p=0.03). FA leakage was present for 17 of 38 MAs (4 eyes). Leakage was more evident in MAs with WD than those without (41% vs 0%, p = 0.001), but was not associated with size, perfusion pattern or WH.
Conclusions:
AOSLO features of the MA wall such as deformability and hyperreflectivity are associated with diabetic vascular permeability and surrounding neural pathology. These data suggest that AOSLO may provide a tool to define MA-related biomarkers of developing diabetic retinal disease.
Keywords: 499 diabetic retinopathy •
498 diabetes •
550 imaging/image analysis: clinical