The prognostic value of total macular external limiting membrane and ellipsoid zone damage for clinical outcome in treatment-resistant neovascular age-related macular degeneration

Purpose To examine the prognostic value of the extent of damage to the ellipsoid zone (EZ) and external limiting membrane (ELM) in response to the treatment of age-related macular degeneration (AMD) eyes switched from ranibizumab to aflibercept. Methods This is a retrospective study of patients with neovascular AMD resistant to ranibizumab defined as having persistent intra- or subretinal fluid on OCT scans despite at least 6-month treatment and switched to aflibercept. Clinical data was collected and quantitative measurements of the area of EZ and ELM damage were obtained, on en-face optical coherence tomography images, at the time of switch to aflibercept (baseline) and up to 6 months of follow-up. Results The study included 71 eyes (52.1% right eye) of 71 patients. At baseline, there was a correlation between the size of the EZ and ELM damaged area and BCVA (R = -0.39,p = 0.001 andR = -0.47,p < 0.001, respectively). The EZ and ELM damaged areas maintained correlation with BCVA at 6 months (R = -0.28,p = 0.01 andR = -0.39,p = 0.001, respectively). Central retinal thickness did not correlate with BCVA at the time of switch (p = 0.38) or at 6 months (p = 0.36). Conclusions The extent of damage to the EZ and ELM correlates with BCVA following a switch in treatment.