COMPARISON OF ANTERIOR SEGMENT OPTICAL COHERENCE TOMOGRAPHY PARAMETERS BETWEEN CENTRAL RETINAL VEIN OCCLUSION AND NORMAL EYES: Is Primary Angle Closure a Risk Factor for Central Retinal Vein Occlusion?

Abstract

To compare anterior segment parameters in patients with central retinal vein occlusion (CRVO) with normal control subjects by anterior segment optical coherence tomography (AS-OCT). In this coss-sectional case-control study, 42 eyes from 21 patients with unilateral CRVO and 21 eyes from 21 age- and sex-matched healthy control subjects were recruited. Study eyes were divided into three groups: involved eyes of CRVO patients (CRVO eyes), fellow eyes of CRVO patients (fellow eyes), and control eyes. Complete ocular examination and AS-OCT were performed for each eye. The AS-OCT parameters (anterior chamber depth, scleral spur angle, angle opening distance [AOD] at 500 and 750 μm from scleral spur [AOD500 and 750] and trabecular-iris space area [TISA] at 500 and 750 μm from scleral spur [TISA500 and 750]) and the rate of narrow angles (based on gonioscopy) in CRVO and fellow eyes were compared with control eyes. The mean (SD) age of the patients and the control group were 60.09 (9.43) and 59.52 (6.66), respectively. The mean intraocular pressure in both eyes of the patients was significantly higher than the control eyes (P < 0.05). All AS-OCT parameters were significantly different among the three groups (P < 0.05). Comparing with the control eyes, CRVO eyes had shallower anterior chamber depth (2.53 vs. 2.85 mm; P = 0.002) and narrower AS-OCT angle parameters (scleral spur angle, AOD500 and 750, TISA500 and 750). Fellow eyes had also shallower anterior chamber depth (2.56 vs. 2.85 mm; P = 0.005) than control eyes and smaller scleral spur angle, AOD500 and AOD750. Five CRVO patients (23.8%) were diagnosed with narrow angles in both eyes based on gonioscopy, whereas no eye in the control group had narrow angles (P = 0.05). Imaging with AS-OCT showed that CRVO patients had shallower anterior chamber depth and narrower angle parameters in both eyes in comparison with control eyes. Furthermore, CRVO patients had higher rates of narrow angles on gonioscopic examination.