Macular Sensitivity after Intravitreal Ranibizumab Injection for Macular Edema in Central Retinal Vein Occlusion: One Versus Three Initial Monthly Injections

Background: We aimed to compare the macular sensitivity after one initial intravitreal injection of an anti-vascular endothelial growth factor (VEGF) agent followed by pro re nata (PRN) dosing with that after three initial monthly injections followed by PRN dosing in patients with central retinal vein occlusion (CRVO) and macular edema. Methods: We included 20 eyes of 20 patients with treatment-naïve macular edema in CRVO and followed them for 12 months after intravitreal ranibizumab injection (IRI). Before and 1, 3, 6, and 12 months after IRI, macular sensitivity within the central 1 mm, 3 mm, and 6 mm fields was measured with an MP3 microperimeter and best-corrected visual acuity (BCVA) was assessed. Eleven eyes received one initial IRI (1 + PRN group), and nine received three initial monthly IRIs (3 + PRN group). PRN injections were performed when fovea exudative changes were evident. Results: Mean macular sensitivity within the central 1 mm, 3 mm, and 6 mm fields significantly improved from baseline to month 12 in all treated eyes. We found no significant differences in macular sensitivity in the central 1 mm, 3 mm, or 6 mm fields between the two groups at month 1, 3, 6, or 12. The choice of treatment regimen (1 + PRN or 3 + PRN) showed no association with either macular sensitivity in the central 1 mm, 3 mm, and 6 mm fields or BCVA at month 12. Conclusions: These findings suggest that a 1 + PRN regimen improves macular sensitivity to a similar extent as a 3 + PRN regimen.