Subfoveal choroidal thickness as a potential predictor of visual outcome and treatment response after intravitreal ranibizumab injections for typical exudative age-related macular degeneration

Abstract

Purpose: To investigate the prognostic implication of subfoveal choroidal thickness on treatment outcome after intravitreal ranibizumab injections for typical exudative age-related macular degeneration (AMD).

Design: Retrospective study.

Methods: A total of 40 eyes of 37 patients who completed 6-month follow-up were analyzed. Patients' data were retrieved from medical records including best-corrected visual acuity (BCVA). Subfoveal choroidal thickness at baseline, 3 months, and 6 months was measured by enhanced depth imaging optical coherence tomography and adjusted for age and sex before statistical analysis. Treatment response was after 3 monthly intravitreal ranibizumab injections. Responders (responder group) were defined as a 100 μm or more decrease or complete resolution of subretinal fluid, whereas nonresponders (nonresponder group) were defined as changes less than 100 μm or more than 100 μm increase of subretinal fluid by optical coherence tomography.

Results: Mean age at diagnosis was 72.1 ± 8.1 years, and 22 eyes (55.0%) were responders. The responder group had thicker subfoveal choroid (257.2 ± 108.3 μm) and smaller lesions (1.3 ± 0.8 μm) at baseline than the nonresponder group (167.1 ± 62.4 μm, P = .003; and 2.0 ± 1.0 μm, P = .008). The responder group showed significantly better BCVA and thicker subfoveal choroid than the nonresponder group at 3 months (P = .002 and P = .023) and 6 months (P = .004 and P = .031). Stepwise and binary regression analysis demonstrated that subfoveal choroidal thickness was significantly correlated with visual outcome (B = -0.002, P = .003) and treatment response (B = 8.136, P = .018).

Conclusion: Subfoveal choroidal thickness may be a predictive factor for visual outcome and treatment response in typical exudative AMD after intravitreal ranibizumab injections.