Visual functions affecting stereopsis in patients with branch retinal vein occlusion

Abstract

Purpose: To quantify stereopsis and other visual functions in patients with unilateral branch retinal vein occlusion (BRVO) and to investigate vision-related parameters that affect stereopsis. Design: Prospective observational study. Subjects: Forty-five patients undergoing intravitreal ranibizumab (IVR) treatment for unilateral BRVO. Methods: We examined stereopsis using the Titmus stereo test (TST) and TNO stereotest (TNO), best corrected visual acuity (BCVA), letter contrast sensitivity, severity of metamorphopsia and degree of aniseikonia before and 6 months after IVR. Main outcome measures: Visual functions that affect stereopsis. Results: Baseline stereopsis in patients with BRVO was 2.7 ± 0.6 (range, 1.6–3.5) in the TST and 2.8 ± 0.5 (range, 1.8–3.3) in TNO. TST and TNO scores were significantly correlated with BCVA and letter contrast sensitivity at baseline (P < 0.001) but not with other visual functions. IVR treatment significantly improved stereopsis, BCVA, and letter contrast sensitivity. After treatment, TST scores were significantly correlated with BCVA (P < 0.001), letter contrast sensitivity (P < 0.001), and aniseikonia (P < 0.01). TNO scores were significantly correlated with BCVA (P < 0.01) and letter contrast sensitivity (P < 0.01). TST and TNO scores after treatment were significantly correlated with BCVA at baseline (P < 0.01 for both). Conclusions: Deterioration of stereopsis in patients with BRVO was associated with changes in visual acuity and contrast sensitivity after treatment. Initial visual acuity is a prognostic factor for posttreatment stereopsis.