Determinants of Fixation in Eyes With Neovascular Age-Related Macular Degeneration Treated With Intravitreal Ranibizumab

Abstract

To correlate the anatomic features of the macula with functional parameters like location and stability of fixation in patients with neovascular age-related macular degeneration treated with intravitreal ranibizumab injections. Retrospective analysis. The location and stability of fixation were determined in 41 eyes of 41 patients treated with ranibizumab for neovascular age-related macular degeneration for at least 12 months. All patients underwent 3 injections of ranibizumab 1 month apart and were retreated according to predefined criteria. The fixation parameters measured with microperimetry were correlated to visual acuity, qualitative measures on optical coherence tomography, and patterns of autofluorescence. The location of fixation was predominantly central in 68.29%, poor central in 2.4%, and predominantly eccentric in 29.27%. The fixation was stable in 80.5%, relatively unstable in 7.3%, and unstable in 12.2%. The factors that determined central and stable location of fixation were better visual acuity (P = .004), absence of subretinal thickening (P = .003), intact subfoveal third hyperreflective band (P = .006), and intact external limiting membrane (P = .036). Autofluorescence pattern within the 4-degree circle of fovea did not correlate with fixation characteristics. However, complete absence of autofluorescence in this area was a poor prognostic indicator for central fixation. Anatomic characteristics of the macula determine fixation patterns in patients with neovascular age-related macular degeneration treated with intravitreal ranibizumab injections. Further studies focused on eyes with complete absence of autofluorescence in the central 4-degree circle of fovea may help to define the disease characteristics in this group.