Factors Associated with the Response of Age-related Macular Degeneration to Intravitreal Ranibizumab Treatment

Abstract

Purpose: : To investigate factors which can affect the response to intravitreal Ranibizumab treatment for age-related macular degeneration (AMD).

Methods: : We retrospectively reviewed the medical records of 50 eyes of 50 consecutive patients (39 male, 11 female, median 75.0 years old) with AMD who were treated with three loading intravitreal injections of 0.5mg Ranibizumab at a month interval. At the initial visit, all patients were examined with fluorescein angiography, indocyanine green angiography, and optical coherence tomography (OCT). The diagnosis of polypoidal choroidal vasculopathy(PCV) was based on indocyanine green angiography, which showed a branching vascular network terminating in polypoidal swellings. We investigated the association of three major AMD-susceptibility single nucleotide polymorphisms (SNPs) of CFH Y402H, I62V, and ARMS2 A69S and the response to Ranibizumab treatment. Furthermore, we examined preoperative feature of OCT in association to the treatment response. The response to treatment was evaluated with best-corrected visual acuity (BCVA) at three month and one year after the first injection and morphologic change in OCT at three month.

Results: : Of the 50 eyes evaluated, 20 eyes was typical AMD (tAMD) and 30 eyes was PCV. Exudative features shown with OCT disappeared at three month in 19 eyes (63%) of PCV and in 12 eys (60%) of tAMD. However, BCVA improved only in PCV from 0.43 to 0.33 in logMAR at three months (P < 0.01), whereas BCVA in tAMD had no significant change (from 0.55 to 0.51 P=0.36). BCVA at twelve month were maintained in both subtypes. There was no significant association between three SNPs examined and BCVA at three month. Furthermore, three SNPs were not significantly associated with the anatomical findings in OCT at three month. The baseline OCT findings (existence of serous retinal detachment, macula edema, or cyctoid macula edema) did not have any association to the response to three loading Ranibizumab injections.

Conclusions: : Ranibizumab was equivalently effective for both tAMD and PCV. Although visual acuity improved only in PCV at three month, there was no significant difference in visual acuity at 12 month between tAMD and PCV. Both three SNPs evaluated and baseline feature of OCT could not estimate the response of AMD/PCV to Ranibizumab treatment.

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