Abstract
Purpose :
The retinal microvasculature is remodeled in hypertension and in diabetes but little is known about the actual remodeling that occurs in human in vivo small arterioles (<50 μm) due to limitations in imaging techniques. High-resolution retinal imaging allows us to visualize and measure the fine structure of small retinal arterioles non-invasively. We used adaptive optics scanning laser ophthalmoscopy (AOSLO) to investigate the differences in arteriolar remodeling in retinal arterioles with diameters under 50 μm in diabetes and hypertension.
Methods :
The posterior pole of 52 participants was imaged with the Indiana AOSLO sampled at 1 μm/pixel or less with a video rate of 28 frames/s. After the imaging session, MATLAB (Mathworks Inc., Natick, Ma) was used to correct for eye movements to create averaged images. Custom MATLAB software was used to measure the vessel wall structure of arteriole segments less than 50 μm in diameter from the imaging sessions. 72 arteriole segments from control participants, 156 arteriole segments from participants with diabetes, and 41 arteriole segments from participants with hypertension were measured. The differences the wall thicknesses, wall-to-lumen ratios (WLR), wall-cross sectional area (WCSA), and the retinal arteriole index (a ratio of the actual to predicted lumen diameter based on the outer diameter to actual inner diameter from control data) were analyzed in SPSS (IBM SPSS Statistics for Windows, Chicago, IL) using Welch’s ANOVA and the Games-Howell post hoc test.
Results :
A statistically significant difference was present for the arteriole index, wall-to-lumen ratio, and wall thickness between the control group and the group with diabetes (p<.001) and between the control group and hypertension group (p<.001). There was no difference between any groups for the wall cross-sectional area. For all parameters there was no difference between the groups with hypertension and diabetes
Conclusions :
Our results suggest that despite the loss of myogenic control in diabetes, there is similar vascular remodeling occurring in the two diseases in small retinal arterioles. Most of our sample of participants with diabetes were also hypertensive suggesting that hypertension is driving the remodeling observed. In addition, the similarity of WCSA between all three groups suggest that the remodeling occurring in the vessels maintains wall volume, which is consistent with eutrophic remodeling.
This is a 2021 ARVO Annual Meeting abstract.