Bevacizumab and Ranibizumab Tachyphylaxis in the Treatment of Choroidal Neovascularization

Abstract

Purpose: : To evaluate patients with choroidal neovascularization(CNV) with poor initial morphologic response to ranibizumab or bevicizumab therapy, to determine if these patients respond after changing the treatment regimen to a different anti-vascular endothelial growth factor (VEGF) drug, bevacizumab or ranibizumab.

Methods: : Retrospective chart review of patients treated for CNV at the Doheny Eye Institute from September 2006 through November 2007 with both ranibizumab and bevacizumab. OCT features of exudation [subretinal fluid (SRF), pigment epithelial detachment (PED), and/or cystoid macular edema (CME)] were evaluated during the course of therapy. Lack of reduction or an increase in exudation was considered evidence of poor response.

Results: : 22 eyes of 23 patients were treated with both bevacizumab and ranibizumab for CNV. 6 of the 22 eyes were initially treated with bevacizumab. These eyes received on average 5 injections of bevacizumab prior to changing the treatment regimen to ranibizumab for non-responding SRF, PED, and/or CME. 2 of the 6 eyes were initially treated with bevacizumab for classic CNV and 4 eyes for an occult CNV with pigment epithelial detachment (PED). Of the 2 eyes with classic CNV, in one eye, SRF completely resolved after 4 ranibizumab injections, while the other eye is still undergoing treatment for improving but persistent SRF. All 4 eyes with occult CNV started to respond after 1 ranibizumab injection.17 of the 22 eyes were initially treated with ranibizumab. These eyes received on average 5 injections of ranibizumab prior to changing the treatment regimen to bevacizumab for poor response. On average, 3 injections of bevacizumab were administered. Of the 17 eyes initially treated with ranibizumab, 1 eye was treated for classic CNV and 16 eyes for occult CNV (14/16 eyes had PED). 3 eyes did not respond to the change to bevacizumab, while 9 eyes showed a response (reduction or resolution) after only 1 injection and 5 eyes after 2 injections.

Conclusions: : Patients with CNV that show a poor initial response to ranibizumab or bevacizumab therapy may yield a better response after switching to another anti-VEGF drug. Some patients require multiple injections to demonstrate a treatment response.

Keywords: age-related macular degeneration • vascular endothelial growth factor • retinal neovascularization