Association of ARMS2 genotype with bilateral involvement of exudative age-related macular degeneration.

PURPOSE To study the association of ARMS2 A69S genotype with the development of exudative age-related macular degeneration (AMD) in the unaffected fellow eye and to estimate the duration until the development of AMD in the second eye. DESIGN Retrospective cohort study. METHODS We retrospectively reviewed 326 patients who had exudative AMD in at least 1 eye, genotyping of ARMS2 A69S, and a minimum follow-up of 2 years. Survival analysis and Cox proportional hazard regression analysis were used to examine the association between candidate factors and the duration until the development of AMD in the second eye. RESULTS One hundred nineteen patients (36.5%) had bilateral exudative AMD at the initial visit. A risk allele of ARMS2 A69S was more frequently seen in patients with bilateral AMD (P = .0270) than in those with unilateral AMD. Of the 207 unilateral AMD patients, 23 (11.1%) had AMD in the fellow eye after a mean duration of 56.3 ± 40.4 months. Fellow-eye involvement was associated with ARMS2 A69S genotype (hazard ratio [HR], 2.673; P = .0013), age (HR, 1.102; P = .0005), and smoking history (HR, 0.680; P = .3663). As HRs indicate, correlation of genotype (2.673) was as high as that of 10-year aging (1.102(10) = 2.641). Survival analysis revealed that patients with risk homozygous (TT) genotype had second-eye involvement significantly earlier than those with other genotypes (P = .0028). When the observation duration reached 120 months, second-eye involvement had developed in 50%, 6.6%, and 11.2% of the TT, GT, and GG cohorts, respectively. CONCLUSION ARMS2 A69S genotype is associated with second-eye involvement of exudative AMD and with the period between first- and second-eye involvements.