Long-term changes in retinal layers in patients undergoing intravitreal ranibizumab for neovascular age-related macular degeneration

Abstract

PurposeTo analyze long-term changes in individual retinal layers (RLs) after intravitreal injections of ranibizumab (IVRs) in patients with neovascular age-related macular degeneration (n-AMD).MethodsThe patients were treated with 0.5-mg IVRs based on an as-needed protocol after the first three monthly doses over a 12-month follow-up period. Patients underwent optical coherence tomography and best-corrected visual acuity (BCVA) evaluation at each visit. The ETDRS grid with central subfield (R1) (r 0.5\xa0mm) and the inner ring (R2) (r 0.5–1.5\xa0mm) was used for calculation of the mean thickness of each RL. Changes in the thickness of segmented RLs within the R1 and R2 of ETDRS circles at months-3, -6, and -12 were compared to baseline.ResultsThe mean age was 72\u2009±\u20097.4\xa0years. The mean number of injections was 9.08 (range 6–11). Mean BCVA improved from 49.7\u2009±\u200922.1 to 60.1\u2009±\u200919.8 letters. Central macular thickness decreased from 390.25\u2009±\u2009149.6 to 312.74\u2009±\u2009118.4\xa0μm. Thicknesses of GCL (from 23.93\u2009±\u200913.73 to 19.50\u2009±\u20099.50\xa0μm in R1; p 0.001, and from 44.5\u2009±\u200912.6 to 39.6\u2009±\u200910.6\xa0μm in R2; p 0.005), IPL (from 28.90\u2009±\u200914.36 to 22.35\u2009±\u20096.23\xa0μm in R1; p 0.001, and from 39.34\u2009±\u20098.53 to 35.58\u2009±\u20097.93\xa0μm in R2; p 0.004), and total inner RL (ILM to ELM) (from 222.93\u2009±\u200993.09 to 180\u2009±\u200953\xa0μm in R1; p 0.001, and from 255.06\u2009±\u200942.74 to 240.25\u2009±\u200940.37\xa0μm in R2; p 0.003) in the central and parafoveal rings decreased statistically at month-12. Decrease in INL was limited to month-6 (from 34.80\u2009±\u200915.33 to 27.60\u2009±\u200912.59\xa0μm in R1; p 0.001), while decreases in total outer RLs (ELM to RPE) (from 128.32\u2009±\u200926.92 to 115.54\u2009±\u200943.98\xa0μm in R1; p 0.001, and 103.81\u2009±\u200916.73 to 96.38\u2009±\u200916.22\xa0μm in R2; p 0.014) and RPE (from 39.12\u2009±\u200922.33 to 29.70\u2009±\u200922.05\xa0μm in R1; p 0.001, and from 31.27\u2009±\u200913.11 to 24.40\u2009±\u20099.99\xa0μm in R2; p 0.001) were limited to month-3.ConclusionsSignificant changes were observed in the thickness of the inner RLs after 1-year treatment with IVRs for n-AMD. A significant decrease in RPE thickness confined to the first months disappeared at month-12.