Visual acuity outcomes after cataract surgery in patients with age-related macular degeneration: age-related eye disease study report no. 27

Abstract

Objective: To evaluate visual acuity outcomes after cataract surgery in patients with varying degrees of age-related macular degeneration (AMD).

Design: Cohort study.

Participants: A total of 4757 participants enrolled in the Age-Related Eye Disease Study (AREDS), a prospective, multicenter, epidemiological study of the clinical course of cataract and AMD and a randomized controlled trial of antioxidants and minerals.

Methods: Standardized lens and fundus photographs, performed at baseline and annual visits, were graded by a centralized reading center using standardized protocols for severity of AMD and lens opacities. History of cataract surgery was obtained every 6 months. Analyses were conducted using multivariate logistic regression.

Main outcome measure: The change in best-corrected visual acuity (BCVA) after cataract surgery compared with preoperative BCVA.

Results: Visual acuity results were analyzed for 1939 eyes that had cataract surgery during AREDS. The mean time from cataract surgery to measurement of postoperative BCVA was 6.9 months. After adjustment for age at surgery, gender, type, and severity of cataract, the mean change in visual acuity at the next study visit after the cataract surgery was as follows: Eyes without AMD gained 8.4 letters of acuity (P<0.0001), eyes with mild AMD gained 6.1 letters of visual acuity (P<0.0001), eyes with moderate AMD gained 3.9 letters (P<0.0001), and eyes with advanced AMD gained 1.9 letters (P = 0.04). The statistically significant gain in visual acuity after cataract surgery was maintained an average of 1.4 years after cataract surgery.

Conclusions: On average, participants with varying severity of AMD benefited from cataract surgery with an increase in visual acuity postoperatively. This average gain in visual acuity persisted for at least 18 months.

Figure 1

Baseline visual acuity and cataract severity of eyes in the primary analysis. Cataract grade is shown as a function of visual acuity in eyes with no AMD and mild AMD, as well as intermediate AMD and advanced AMD. The visual acuity score is represented as Snellen equivalents. AMD = age-related macular degeneration.

Figure 2

Comparison of preoperative visual acuity of eyes analyzed in both primary and secondary analyses. Percentages are shown for eyes with varying degrees of preoperative visual acuity and AMD severity used in primary and secondary analyses. The visual acuity score is represented as Snellen equivalents. AMD = age-related macular degeneration.

Figure 3

Visual acuity scores before and after cataract surgery in the primary analysis. Visual acuity scores and the corresponding Snellen equivalents are represented in the preoperative (x-axis) and postoperative (y-axis) visits. The diagonal lines intersecting at the origin represent no change in visual acuity, whereas those values below the diagonal demonstrate a decrease in visual acuity postoperatively.

Figure 4

Change in visual acuity after cataract surgery in patients with varying severity of AMD. Percentage of patients with gain or loss of letters on the logarithm of the minimal angle of resolution visual acuity chart is shown for eyes with no AMD, mild AMD, intermediate AMD, and advanced AMD. AMD = age-related macular degeneration; ETDRS = Early Treatment Diabetic Retinopathy Study.