Comparison of two intravitreal ranibizumab treatment schedules for neovascular age-related macular degeneration

Introduction Ranibizumab (Lucentis), a humanised antibody fragment that inhibits vascular endothelial growth factor (VEGF)-A, is widely used for the treatment of neovascular age-related macular degeneration (NV-AMD). The objective of this study was to compare the outcomes of two different treatment protocols: loading dose (LD) and pro re nata (PRN (as needed)) dosing schedule from baseline. Methods This retrospective chart review was conducted at King's College Hospital, London, UK. Consecutive patients were identified using the 'Ranibizumab in NV-AMD' database. These patients had treatment-naive choroidal neovascularisation (CNV) secondary to AMD, received ranibizumab therapy and had completed 12 months of follow-up. Baseline examination included visual acuity (Early Treatment Diabetic Retinopathy Study (ETDRS) letters), slit-lamp biomicroscopy, fluorescein angiography, and qualitative and quantitative assessment of central macular characteristics on optical coherent tomography (OCT). Intravitreal ranibizumab (0.5 mg/0.05 ml) was given to all patients at baseline. Patients on LD regimen received two further consecutive monthly intravitreal ranibizumab injections independent of clinical findings. Further injections were determined by the same re-treatment criteria as patients on PRN schedule from baseline. The main outcome variables in the two treatment groups were visual acuity and central macular thickness at different time points. Results The LD group contained 47 patients and the PRN group contained 31 patients. There were no significant differences between groups in the mean changes in visual acuity or central macular thickness. Visual acuity was similar in both groups at 6 months. However, twice as many patients improved visual acuity by 15 or more letters in the LD group (29.8% in the LD group compared with 12.9% in the PRN group (p=0.01)). Conclusion This study showed that standard protocols used for OCT-guided retreatment achieved smaller mean gains in vision than those obtained with monthly ranibizumab administration. Further, loading doses of ranibizumab resulted in more visual gains than the PRN protocol.