Abstract
Purpose :
To describe the frequency of fibrosis and macular atrophy (MA) detected by optical coherence tomography (OCT) and to characterize associations with visual acuity (VA) after exit from the inhibition of VEGF in age-related choroidal neovascularization (IVAN: ISRCTN92166560) trial.
Methods :
Participants in the IVAN trial were randomized to either ranibizumab or bevacizumab and after exit received usual care consisting of treatment with licensed anti VEGF agents and followed for up to 7 years after enrolment. Visual acuity (VA) and image grading of the most recent OCT in 372 surviving participants were obtained from a study visit or from usual care records. Fibrosis was inferred from presence of hyperreflective material (HRM) on OCT and location categorized into none, subretinal only , subretinal pigment epithelial (sub-RPE) only, or combined (subretinal plus sub-RPE) Figure 1. Graders assigned the latter two categories only when they detected an intact RPE layer with HRM on its outer and or inner aspect. MA was identified from subsidence of the inner nuclear and or outer plexiform layer, thinning of the outer nuclear layer, or a band of hypertransmission of OCT signal. Observations were excluded from VA descriptives when VA was unavailable within 30 days of the OCT image.
Results :
Tabulations of MA and HRM shown in Figure 1. MA was present in 90%, HRM in 82% and either in 96%. When MA was absent (n = 39) one third of study eyes had no HRM. Whereas when MA was present (n = 333) around one-fifth had no HRM. When HRM was subretinal, MA was detectable in 95.4% and absent in 4.6%. When HRM was sub-RPE only, MA was present in 85.8% and absent in 14.2%. Both VA and OCT were available in 319 (86%) study eyes. Examining associations of MA and HRM with VA, VA was best when MA was present with no HRM (median VA 65.0, IQR 45.0, 75.0) or MA present with HRM sub-RPE only (median VA 64.5, IQR 43.0, 72.0). In eyes with MA when HRM was subretinal, median VA was 33.0 letters (IQR 18.0, 62.0). In the absence of MA, VA was similar across the HRM groups.
Conclusions :
High proportions of neovascular AMD eyes treated with anti VEGF agents over a sustained period that have subretinal fibrosis exhibit MA. A visible RPE layer was associated with a lower risk of an eye having MA and better VA.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.