Factors Contributing to Persistent Macular Edema in Retinal Vein Occlusion

Abstract

Purpose : We performed a post-hoc analysis of a randomized controlled trial (RELATE Study) to identify factors that contribute to persistent macular edema (ME) in retinal vein occlusion (RVO)

Methods : Forty-two BRVO and 39 CRVO subjects were included. Subjects not able to achieve a 3-month edema free period as determined by spectral domain optical coherence tomography (SD-OCT) throughout the 36 month trial were categorized as Persistent ME (group 1) whereas those with at least one 3-month edema-free period were Intermittent ME (group 2). Factors that could contribute to persistent ME, such as microvascular changes (microaneurysms; MAs), age and disease duration, as well as visual and anatomic outcomes and treatment burden were compared between the 2 groups.

Results : Forty-six percent of BRVO and 38% of CRVO subjects had persistent ME. For BRVO, age, disease duration, central subfield thickness (CST, µm) and best-corrected visual acuity (BCVA, ETDRS letters) were balanced at baseline (BL), but there were more patients with MAs in group 1 (60% vs 27.3%, p=0.03). At month (M) 6, BCVA was significantly lower in group 1 vs group 2 (58.9+2.5 vs 69.4+3.2, p=0.01), but was comparable at all other time points. CST (all time points) and number of anti-VEGF injections were comparable. The greater number of group 1 patients with MAs persisted at M6 (73.3% vs 23.8%, p=0.003) and M12 (81.3% vs 26.3%, p=0.001), but not at later time points.
For CRVO, age, disease duration, CST, and patients with MAs were balanced between the 2 groups, but group 1 patients had significantly lower BCVA (38.6+3.0 vs 53.9+2.7, p=0.001) at BL, which was maintained at M6 (51.8+3.7 vs 70.3+2.95, p<0.001), M12 (50.3+4.9 vs 69.8+3.4, p=0.003) and M24 (53.5+4.9 vs 69.2+3.52, p=0.02). Group 1 patients had a significantly greater CST at M6 (363.4+37.1 vs 281.6+17.4, p=0.04), M12 (458.1+50.3 vs 317.6+22.0, p=0.02) and M24 (369.3+36.6 vs 285.8+20.8, p=0.04), but not M36. The number of patients with MAs was comparable in the 2 groups at BL and early time points, but was significantly greater in group 1 at M36 (83.3% vs 41.7%, p=0.05). Patients in group 1 received significantly more anti-VEGF injections (22.2+2.3 vs 16.0+1.3, p=0.02).

Conclusions : MAs are associated with persistent ME in patients with BRVO and CRVO, which may increase treatment burden. Poor vision at BL in patients with CRVO may predict persistent ME which is associated with poor visual and anatomic outcomes

This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.