Progression from Early/Intermediate to Advanced Forms of Age-Related Macular Degeneration in a Large UK Cohort: Rates and Risk Factors

Abstract

Purpose: To estimate rates and risk factors for progression to geographic atrophy (GA) or choroidal neovascularization (CNV) among eyes diagnosed with early or intermediate age-related macular degeneration (AMD) in clinical practice.

Design: Retrospective cohort analysis of a multicenter electronic medical record (EMR) database from the United Kingdom.

Participants: Patients aged 50 years or more with diagnosis of early/intermediate AMD in at least 1 eye (the study eye) and no evidence of CNV or GA in the study eye, from 10 clinical sites using the EMR.

Methods: Anonymized data for 40 543 patients with a diagnosis of early/intermediate AMD were extracted between October 2000 and February 2016 from EMR database records held in the 10 sites. A sample of records randomly selected from each center was used to validate disease definitions. Records were analyzed by subgroup, based on the AMD status of the fellow eye. Multivariate Cox regression models identified other predictors of disease progression.

Main outcome measures: Progression rate (per 100 person-years) to GA or CNV in study eyes with early/intermediate AMD by fellow eye status and identified risk factors for progression.

Results: Study eyes with early/intermediate AMD and a diagnosis of CNV in the fellow eye progressed to CNV fastest (at a rate of 15.2 per 100 person-years), and those with a diagnosis of GA in the fellow eye progressed to GA fastest (11.2 per 100 person-years), compared with the rates per 100 person-years of progression to CNV (3.2-11.9) or GA (2.0-7.8) in the other subgroups. In individuals with bilateral early/intermediate AMD, rates of progression to GA or CNV were 2.0 and 3.2 per 100 person-years, respectively. In the multivariate model, age, female sex, and cardiovascular disease were associated with an increased risk for progression to advanced AMD, whereas diabetes and glaucoma were associated with a decreased rate of progression (hazard ratios, 0.45 and 0.64, respectively).

Conclusions: Progression to GA or CNV was observed frequently in eyes with early/intermediate AMD, with the status of the fellow eye affecting the rate of progression. Novel associations with risk factors were observed and require replication in other cohorts.