Initial non-responders to ranibizumab in the treatment of age-related macular degeneration (AMD)

BACKGROUND: Patients with exudative age-related macular degeneration (AMD) who did not respond to ranibizumab at the induction phase were assessed and referred to as initial non-responders. METHODS: We retrospectively reviewed the medical records of 215 patients (218 eyes) with exudative AMD. For the initial treatments, patients received three intravitreal injections of ranibizumab (IVR) every 4 weeks. Minimum follow-up period was 12 months. We defined patients with no improvement of best corrected logMAR visual acuity (BCVA), and with no decrease of central retinal thickness (CRT) at the end of the initial treatment, as initial non-responders. Patients who had previous treatment history prior to this investigation were included, but patients who had photodynamic therapy (PDT) with IVR were excluded. RESULTS: Twenty-two eyes (10.1%) were identified as initial non-responders. The mean BCVA of initial non-responders before IVR and after induction phase were 0.39 and 0.36, respectively. There was no significant difference between these values, however the mean BCVA decreased significantly to 0.55 at 12 months after the beginning of the induction phase (P = 0.021). The mean greatest linear dimension (GLD) of the lesion before IVR of initial non-responders was 4,121 μm. We found 16 eyes with typical AMD, and six eyes with polypoidal choroidal vasculopathy. One eye had predominantly classic choroidal neovascularization (CNV), and others had occult CNV of typical AMD. As additional treatments, twelve eyes received PDT, and in three of the eyes exudation remained after PDT. CONCLUSION: Initial non-responders were more prevalent in patients with occult CNV than in patients with other CNV types. Some of the initial non-responders did not respond to PDT. This study suggested possible involvement of other factors, in addition to vascular endothelial growth factor, in the occurrence of CNV in initial non-responder patients.