Abstract
Purpose :
To describe in detail the retinal vascular blood flow of patients with central or branch retinal vein occlusions.
Methods :
Subjects who have received a diagnosis of central or branch retinal vein occlusion from BIDMC’s Retina Service and had no retinal conditions in their fellow eye and were at least 3 months removed from their last treatment were imaged using the Laser Speckle Flowgraphy. Each subject (14 CRVO, 11 BRVO) was recorded three times per session, with each image automatically broken down into several “frames” over the course of a patient’s heartbeat (mean: 12.1 frames, standard deviation 7.6). In order to ensure stability over time, subjects were asked to return for another imaging session no more than 1 month (mean 1.5 sessions, standard deviation 0.75). Data were then analyzed with a mixed-effects model, with individual subjects represented by a random effect and subject eye, recording number (same date, different recording) and session number (different date) represented by fixed-effects.
As a comparison, healthy subjects (n = 7) were imaged following similar protocols to determine if patients’ healthy other eye could serve as controls.
Results :
Central Retinal Vein Occlusions typically restricted retinal vascular blood flow by 22.8% (SE: 7.5%, P < .001, n = 14), while Branch Retinal Vein Occlusions typically resulted in a 13.5% (SE: 1.0%, P < .001, n = 11) decrease. There was no significance difference in fixed-effect coefficients for recordings (P = .12) and sessions (P = .032) or between eyes of healthy subjects (P = .67).
Conclusions :
Branch and central retinal vein occlusions result in a partial blockage of retinal vascular blood flow. This blockage is measurable and consistent over short time frames within a single subject. Moreover in monocular diseases, subjects’ healthy fellow eye can serve as a reasonable control. Any discrepancy between eyes can therefore be attributed to their retinal condition.
This is a 2020 ARVO Annual Meeting abstract.