Elsevier

Ophthalmology

Volume 105, Issue 3, 1 March 1998, Pages 441-447
Ophthalmology

High-risk characteristics of fellow eyes of patients with unilateral neovascular age-related macular degeneration1,

https://doi.org/10.1016/S0161-6420(98)93025-1Get rights and content

Abstract

Objective

This study aimed to determine whether clinical tests of ocular function and macular appearance independently can help to predict which patients with unilateral neovascular age-related macular degeneration (AMD) will have a choroidal neovascular membrane (CNVM) develop in their fellow eye.

Design

The study design was a prospective cohort study.

Participants

One hundred twenty-seven patients with unilateral neovascular AMD observed for up to 4.5 years participated.

Intervention

Functional measurements included visual acuity, macular visual field, glare recovery time, and foveal electroretinogram amplitude and implicit time.

Main outcome measure

The age-adjusted proportion of patients having a CNVM develop over follow-up assessed by the Cox proportional hazards model with stepwise selection was measured.

Results

On average, 8.8% of patients had a CNVM develop each year. Independent risk factors for the fellow eye were its glare recovery time in minutes (relative risk = 1.30, confidence interval = 1.10–1.54, P = 0.003) and its extent of visible macular abnormalities on a four-point scale (relative risk = 1.62, confidence interval = 1.06– 2.59, P = 0.03). Of the fellow eyes that converted, the interval to have a CNVM develop was inversely related to the foveal electroretinogram implicit time.

Conclusions

A slower recovery from glare and more extensive funduscopic changes appear to be independent risk factors for the development of a CNVM in the fellow eyes of patients with unilateral neovascular AMD. A slower foveal electroretinogram implicit time may be a sign of early stage CNVM development, perhaps because of outer retinal ischemia. These results have clinical management implications, particularly for those patients at high risk of having a potentially treatable form of AMD develop.

Section snippets

Enrollment

Patients with unilateral neovascular AMD were identified by referral from ophthalmologists in New England (87% of cases) or by self-referral in response to advertisement (13% of cases). Patients were informed that they would receive a screening-baseline examination and, if eligible, be asked to return for re-examination every 6 months thereafter for at least 3 years. Eligibility criteria were a corrected Snellen visual acuity of 20/ 60 or better in the fellow eye with sufficiently clear media

Overall rate of having a choroidal neovascular membrane develop

Table 1 lists by follow-up visit the cumulative proportion of patients who failed (i.e., in whom a CNVM developed), the number of patients who failed, the number of patients who were censored for the next visit (i.e., those subsequently lost to follow-up), and the number of at-risk patients (i.e., those who had not failed at a previous visit or been lost to follow-up). The table reflects that 19 patients (15%) were lost to follow-up by the third year; this number includes 14 who died. Based on

Discussion

The annual rate of having a CNVM develop in the fellow eye of patients with unilateral neovascular AMD studied for up to 4.5 years was 8.8% in the current prospective study, slightly higher than that (6%) found in a previous prospective study that observed patients for 5 years.10 Both rates of conversion lie within the range of rates reported by several retrospective studies.4, 5, 6, 7, 8, 9

We identified two independent, age-adjusted baseline predictors of choroidal neovascularization in the

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  • Cited by (0)

    Supported by grants from the National Eye Institute (EY08398), the Foundation Fighting Blindness, Baltimore, Maryland, and the Massachusetts Lions Eye Research Fund, Inc.

    1

    The authors have no proprietary interest in the products described in this article.

    2

    Asher Weiner currently is affiliated with the Division of Ophthalmology, Columbia-St. Luke’s Medical Center, Cleveland, Ohio.

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