Initial Factors Associated with Resistance to Intravitreal Aflibercept Injection in Polypoidal Choroidal Vasculopathy

Abstract

Purpose: To identify initial factors contributing to the resistance against intravitreal aflibercept treatment in polypoidal choroidal vasculopathy (PCV) patients.Methods: This study included PCV patients initially treated with aflibercept. Resistance was defined when treatment did not reduce subretinal fluid (SRF) or intraretinal fluid (IRF) by 100 μm or more after three consecutive 4-week intervals, and the treatment interval could not be extended beyond 8 weeks. To identify initial factors associated with resistance to aflibercept treatment, we examined visual acuity and central choroidal thickness before initial treatment and after three treatments. Choroidal thickness was divided into the thickness of the large choroidal vessel layer and the layer that includes choriocapillaris and medium choroidal vessel thickness (termed medium choroidal vessel/choriocapillaris layer thickness, MCCT). Additionally, the volume of SRF, IRF, subretinal hyperreflective material, and pigment epithelial detachment in optical coherence tomography (OCT) images was investigated. The statistical significance of each factor was assessed through logistic regression analysis.Results: The study included 39 eyes showing no resistance to aflibercept and 37 eyes that exhibited resistance. Multiple logistic regression analysis, adjusted for age and sex, indicated that a lower initial ratio of MCCT to choroidal thickness at the fovea was associated with resistance to aflibercept.Conclusions: In patients with PCV treated with aflibercept, early OCT anatomical structures, such as the initial MCCT-choroidal thickness ratio at the fovea, may predict response to treatment injections.