OCT angiography (OCTA) has provided a wealth of new information about the characteristics and course of retinal vascular diseases. It provides information about individual retinal vascular layers and the choriocapillaris that was previously undetectable or obtainable only by using invasive and time-consuming fluorescein angiography. The novel findings are the foundation for earlier disease detection, an improved ability to predict disease progression, and more precise patient monitoring. A study my colleagues and I recently conducted produced interesting findings about the apparently healthy eye in patients whose other eye had retinal vein occlusion (RVO).
Our study involved 48 patients with unilateral RVO and a control group of 17 individuals with no history of ocular disease or ocular surgery. Using OCTA, we compared the eyes affected by RVO with the contralateral unaffected eyes, and we compared the contralateral unaffected eyes to the control group eyes.1 In the RVO eyes, OCTA showed retinal vascular obstruction, decreased blood flow, angiogenesis, and other pathological changes. It also showed changes in the vasculature of the contralateral eyes. In all regions of the retina except the foveal region, eyes with RVO exhibited lower vessel density in the superficial and deep retinal layers than the contralateral eyes. A less-expected finding was that the unaffected eyes of patients with unilateral RVO exhibited lower vessel density than the control group eyes in those same areas.
Our results indicate that the contralateral eyes of patients with unilateral RVO may, in fact, not be healthy and, therefore, may require more frequent monitoring. Furthermore, the results suggest that RVO is a systemic disease for which OCTA can provide biomarkers useful for improving care.
Figures 1-2. OCT angiography shows different degrees of capillary loss in the superficial and deep retinal vascular network of different RVO patients.
1. Wang Q, Chan SY, Yan Y, et al. Optical coherence tomography angiography in retinal vein occlusions. Graefes Arch Clin Exp Ophthalmol. 2018;256(9):1615-1622.
Wei Wenbin is a professor and the director of the Department of Ophthalmology at Beijing Tongren Hospital, Capital Medical University, Beijing, China.