Time course of changes in contrast sensitivity following intravitreal ranibizumab injection for branch retinal vein...

To evaluate contrast sensitivity (CS) in patients with branch retinal vein occlusion (BRVO) following intravitreal ranibizumab injection (IVR), and to investigate the relationship between CS and retinal microstructure.

A retrospective, observational case series.

We included 23 eyes with treatment naïve BRVO followed up for 6 months after treatment. Best-corrected visual acuity (BCVA), letter contrast sensitivity (LC), and 10% low contrast visual acuity (LCVA) were measured. All tests were performed before and 1, 2, 3, 4, 5, and 6 months after treatment. Based on optical coherence tomography (OCT) images, we assessed central retinal thickness (CRT), presence of serous retinal detachment (SRD), and status of the external limiting membrane (ELM) and ellipsoid zone (EZ).

IVR treatment significantly improved CS (LC: P < 0.0001, LCVA: P = 0.004) as well as BCVA (P = 0.015) and CRT (P < 0.0001). LC and LCVA at 6 months after treatment were significantly correlated with presence of SRD before treatment. At 6 months after treatment, LCVA was significantly correlated with pre-treatment CRT (P = 0.042). In patients with good baseline BCVA, LCVA showed significant improvements (P = 0.022) although their BCVA did not change. In patients with poor improvement in BCVA, LC and LCVA also showed significant improvements (P = 0.008, P = 0.005).

IVR treatment for BRVO improves both BCVA and CS. Even in patients without any improvement in visual acuity, CS does improve.