Long-term changes in retinal layers in patients undergoing intravitreal ranibizumab for neovascular age-related macular degeneration : Retinal layers after anti-VEGF therapy.

Abstract

To 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). The 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 0.5mm) and the inner ring (R2) (r 0.5-1.5mm) 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. The mean age was 72 ± 7.4years. The mean number of injections was 9.08 (range 6-11). Mean BCVA improved from 49.7 ± 22.1 to 60.1 ± 19.8 letters. Central macular thickness decreased from 390.25 ± 149.6 to 312.74 ± 118.4μm. Thicknesses of GCL (from 23.93 ± 13.73 to 19.50 ± 9.50μm in R1; p 0.001, and from 44.5 ± 12.6 to 39.6 ± 10.6μm in R2; p 0.005), IPL (from 28.90 ± 14.36 to 22.35 ± 6.23μm in R1; p 0.001, and from 39.34 ± 8.53 to 35.58 ± 7.93μm in R2; p 0.004), and total inner RL (ILM to ELM) (from 222.93 ± 93.09 to 180 ± 53μm in R1; p 0.001, and from 255.06 ± 42.74 to 240.25 ± 40.37μm 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 ± 15.33 to 27.60 ± 12.59μm in R1; p 0.001), while decreases in total outer RLs (ELM to RPE) (from 128.32 ± 26.92 to 115.54 ± 43.98μm in R1; p 0.001, and 103.81 ± 16.73 to 96.38 ± 16.22μm in R2; p 0.014) and RPE (from 39.12 ± 22.33 to 29.70 ± 22.05μm in R1; p 0.001, and from 31.27 ± 13.11 to 24.40 ± 9.99μm in R2; p 0.001) were limited to month-3. Significant 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.