Intravitreal Bevacizumab For Choroidal Neovascularization Previously Treated With Photodynamic Therapy

Abstract

Purpose: : To compare the outcomes of intravitreal bevacizumab (IVB) in predominantly classic choroidal neovascular membranes (CNV) secondary to age-related macular degeneration (AMD) that have been treated previously with photodynamic therapy (PDT) and treatment naïve cases.

Methods: : The outcomes of all patients with predominantly classic CNV secondary to AMD who underwent PDT followed by IVB was compared to those that had IVB as a primary treatment. In the first group patients that did not respond to PDT (loss of more than 15 letters ETDRS) were initiated on 6 weekly IVB while the second group was treated with IVB from baseline. Visual acuity and central macular thickness (CMT) on optical coherence tomography (OCT) were assessed at each visit. Fluorescein angiogram was done if there was evidence of intra-retinal or sub-retinal fluid on fundus examination and/or OCT appearance.

Results: : Six eyes of 6 patients received PDT initially followed by IVB. One patient had received 3 PDT treatments and the remaining five had 1 each. The mean pre-PDT visual acuity was 64 letters and at 3 months post-PDT 54 letters (p=0.1661). The mean duration of follow-up (after IVB) was 30 weeks with a range of 18 to 42 weeks. The mean number of injections per eye was 2.3, range 1 to 4. Initial mean central macular thickness was 373µ, which reduced to 259µ at the 18-week follow-up (p=0.0063). Initial mean visual acuity was 64 letters and 38 letters at 18 weeks (p=0.0034). There was no difference in mean CMT (p=0.88) between previously treated and treatment naïve patients but the mean visual acuity was better in the treatment naïve group (p=0.05). No systemic or ocular adverse events were recorded in either group.

Conclusions: : Although there is no significant difference in change in CMT between the PDT pre-treated group and treatment naïve group, the visual outcome was significantly better in the treatment naïve group. A longer follow up is suggested to analyze the long-term effects of the treatment and to ascertain if the beneficial effects are sustained.

Keywords: age-related macular degeneration • photodynamic therapy • vascular endothelial growth factor