Abstract
Purpose :
To examine the prevalence age-related macular degeneration (AMD) in Northern Ireland Cohort of the Longitudinal Study of Aging (NICOLA Study) participants using colour fundus photography(CFP) and spectral-domain optical coherence tomography (SD-OCT).
Methods :
The Northern Ireland Cohort for the Longitudinal Study of Aging (NICOLA Study) is a multidisciplinary longitudinal population-based study of ageing. Retinal imaging at the NICOLA study health assessment included stereo CFP (Canon CX-1, Tokyo, Japan) and SD-OCT ((HRA+OCT; Heidelberg Engineering, Heidelberg, Germany). Each modality was graded independently for AMD features by NetwORC UK Ophthalmic Reading Centre and incidences of discordance arbitrated by Senior graders, with late AMD verified by Clinicians. Medical history and demographic information was obtained during a home interview. Descriptive statistics were used to describe the prevalence of AMD in terms of the Beckman Clinical Classification and explore the differences in AMD stage and case status by modality.
Results :
Retinal images from 3393 participants were available for analysis. Mean age of the sample was 63.44 (sd. 9.013 range. 36-99). Prevalence of AMD using arbitrated colour grading was: No drusen:59.0%, drusen<63mm:16.8%, drusen 63-125mm:12.1%, drusen>125mm or pigmentary changes: 7.8%, late AMD:0.8%. Prevalence of nodular drusen in eyes on OCT was 34.8% and prevalence of focal atrophy on OCT was 6.1%. There were 1317(19%) eyes in which drusen was initially graded as present on colour but absent on OCT, arbitration using both modalities simultaneously revealed this was commonly caused by: over calling small drusen on CFP (19%), image quality on either modality (31%), subretinal drusenoid deposits on OCT (5%), other pathology causing drusen-like lesions (10%), vitreous changes (2%), drusen outside field of view of OCT (~8%), single drusen on OCT (5%), drusen missed on OCT 11% and 10% in which drusen-like lesions were clearly visible on colour but OCT looked healthy.
Conclusions :
This is the largest epidemiological study to date examining the burden of AMD in Northern Ireland and one of a few worldwide that has included OCT grading of AMD. Given the substantial discordance between colour alone versus both together there will be challenges in comparing prevalence data with historical cohorts.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.