Retinal vein occlusions: an OCT- Angiography analysis

To analyze microcirculatory abnormalities, central avascular area and capillary density in OCT-angiography in retinal venous occlusions (RVO).

This is a descriptive study of 35 patients (35 eyes) with RVO who consulted at the  ophthalmology department of Farhat Hached Hospital in Sousse between January 2014 and July 2018. The diagnosis of retinal venous occlusion was established on clinical examination, fundus photography and fluorescein angiography. All patients underwent OCT-angiography and OCT B-scan.

Our study includes a total of 35 patients (35 eyes). Of these patients, 20 (57.1%) had branch retinal vein occlusion and 15 (42.8%) had central retinal vein occlusion. The loss or rarefaction of the capillary plexus concerned the deep capillary plexus (DCP) more than the superficial one (SCP). This rarefaction was observed in 25 eyes (71.42%) in both DCP and SCP. The widening of the central avascular zone and the rupture of the peri-foveolar anastomotic mesh were better or as visible as fluorescein angiography. Vascular tortuosity was easy to analyze and was more evident in the SCP than the DCP. Twenty-six (74.28%) patients had vascular tortuosity in DCP and 30 patients (85.71%) had this vascular tortuosity in SCP. Capillary dilatation and microaneurysms were better visible in the DCP than the SCP. These vascular abnormalities were found in 26 cases (74.28%) in the DCP and in 17 cases (48.57%) in the SCP.

OCT-A is a non-invasive examination that allows very precise analysis and follow-up of both macular edema and superficial and deep capillary plexus architecture during retinal vein occlusions.