Abstract
Purpose: :
To determine predictive clinical factors for central retinal thickness response to Ranibizumab in wet age-related macular degeneration (AMD).
Methods: :
210 eyes of 182 patients treated with Ranibizumab 0.5mg (Lucentis®) for wet AMD in a PRN modus were analysed retrospectively over the course of 3.5 years. Mean follow-up was 1.34 years (SD ± 0.77). In total 1141 injections were assessed, mean number of injections was 6 (SD ± 2.7). As reference central retinal thickness (RCRT), we used the mean of central retinal thicknesses (CRTs) of all examinations in which no intraretinal (IRF) or subretinal fluid (SRF) or pigment epithelium detachment (PED) could be observed. To identify predictors for relative mean central retinal thickness change to RCRT, a linear mixed effects model was performed. The analysed factors were gender, age, initial BCVA (tested by EDTRS-Charts), prior photodynamic therapy, lesion type (classic/predominantly classic versus occult/minimally classic), type of macular edema (cystoid type IRF = cystdiameter >150µm, spongoid type IRF = cystdiameter <150µm, SRF, PED) and total number of injections.
Results: :
Central retinal thickness reduction in women was significantly inferior to that in men (Δ-6.47%, 95%CI ± 6.56, p=0.05). Patients with cystoid macular edema (Δ to RCRT 44.26%, 95%CI ± 10.76) had a significantly greater reduction of macular thickness compared to patients with spongoid type macular edema (Δ to RCRT 27.17%, 95%CI ± 10.86, p=0.001), subretinal fluid (Δ to RCRT 28.97%, 95%CI ± 9.34, p=0.001) or pigment epithelium detachment (Δ to RCRT 27.61%, 95%CI ± 10.61, p=<0.001). After total number of 6 injections, further injections did not lead to significant additional decrease of macular thickness compared to RCRT (Δ to RCRT <12%). Age, initial BCVA, prior photodynamic therapy and lesion type had no effect on macular thickness response.
Conclusions: :
Predictive clinical factors for a poor CRT response to Ranibizumab include female gender, spongoid type IRF, SRF and PED. After six injections, no additional significant macular thickness response could be observed. These factors should be taken in account when treating patients with Ranibizumab for wet AMD in order to evaluate the prognosis and finally to improve the efficacy of the treatment.
Keywords: age-related macular degeneration • clinical (human) or epidemiologic studies: risk factor assessment • drug toxicity/drug effects