Microperimetric changes in neovascular age-related macular degeneration treated with ranibizumab

Abstract

To assess the value of microperimetry in eyes with neovascular age-related macular degeneration previously treated with ranibizumab and now in the maintenance phase of therapy. A total of 21 eyes (14 patients) were included. Microperimetry was performed using the Macular Integrity Assessment Device on at least three occasions for each eye. Intravitreal ranibizumab was administered if visual acuity (VA) or optical coherence tomography (OCT) showed signs of active disease. Five eyes showed no change in VA or OCT findings, and required no intravitreal injections. In these eyes, mean threshold sensitivity (TS) decreased by 13% (paired t-test, P=0.05) during the study period, but fixation stability (FS) was unchanged. In all, 16 eyes showed signs of disease activity, and therefore required ranibizumab injections during the study. In these eyes, VA, central retinal thickness (CRT), FS, and TS remained unchanged during follow-up. Peak TS was noted when CRT was 210 μm; above or below 210 μm, there was a gradual reduction in TS. This study has provided novel information on the relationship between macular sensitivity, CRT, and VA in the maintenance phase of ranibizumab therapy. Patients with stable VA and CRT may still have deteriorating retinal sensitivity. This is usually a late manifestation and may indicate subclinical CNV activity.