Retinal Specialist Insight into Neovascular Age-Related Macular Degeneration Study

Abstract

Purpose : Monitoring patients for the onset of neovascular age-related macular degeneration (nAMD) is important for preventing vision loss. This study sought to determine if features observable on optical coherence tomography (OCT) scanning of the macula permit retinal specialists to assign a follow-up interval proportional to the risk of developing nAMD.

Methods : OCT scans were obtained from 30 eyes on the date nAMD was diagnosed and from two preceding visit dates (Cirrus OCT-HD, Carl Zeiss). Three retinal specialists, blinded to patient identifiers, graded anonymized images for signs of choroidal neovascularization (CNV) as single or paired scans. A recommended follow-up interval was also assigned to each study eye judged to be free of nAMD. Those scans were also scored for the presence or absence of subretinal fluid, intraretinal fluid, or subretinal hyperreflective material, as well as the size of any retinal pigment epithelial detachment and extent of drusen, both graded on a Likert scale. These observations were summed and used to assign an "AMD feature score" as being high or low if it was above or below the average for the population. Inter-rater reliability for final diagnoses, recommended follow-up intervals, and composite scores were assessed by using Cohen’s kappa coefficient.

Results : Based on OCT alone, 96% of scans with nAMD were correctly identified and 93% of scans obtained prior to conversion were confirmed as free of CNV. There was high inter-rater reliability for the diagnosis of nAMD (κ=0.83, 95% CI 0.71-0.95). For scans obtained prior to the onset of nAMD, a moderate inter-rater reliability was found for the composite AMD score (κ=0.49, 95% CI 0.32-0.66), as well as for recommended return intervals categorized into those that were <6 or ≥6 months (κ=0.88 95% CI 0.73-1.00). Importantly, when there was agreement, the follow-up intervals recommended by the retina specialist (241 ± 31 days) significantly correlated with the actual time to conversion to nAMD (321±130 days; r=0.308, p=0.010). The composite AMD score also significantly correlated with time to conversion to nAMD (r=-0.404, p=0.033).

Conclusions : Our study indicates that retina specialists are able to identify which eyes are more at risk of conversion to nAMD with a high degree of accuracy in the absence of any other clinical data. The extent of features observed on OCT scans correlated with the actual time to conversion to nAMD.

This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.