Associations of cataract with antioxidant enzymes and other risk factors: The French Age-Related Eye Diseases (POLA) Prospective Study

Abstract

Purpose To determine the association of potential risk factors, including antioxidant enzymes, with the incidence of cataract. Design Cohort study. Participants At baseline, the Age-Related Eye Diseases (Pathologies Oculaires Liées à l'Âge, POLA) Study included 2584 residents of Sète (southern France) aged 60 years or older. From September 1998 to May 2000, a 3-year follow-up examination was performed on 1947 of the 2436 surviving participants (79.9%). Methods Cataract classification was based on a standardized lens examination at the slit lamp, according to Lens Opacities Classification System III. Biologic measurements were performed at baseline from fasting blood samples. Main outcome measures At baseline and follow-up, the presence of cataract was defined as: NC or nuclear opalescence (NO) ≥ 4 for nuclear cataract, C≥4 for cortical cataract, and P≥2 for posterior cataract (PSC) opacities, using opacity grades corrected for interobserver variability. Incidence rates were assessed separately for right and left eyes and for each type of cataract. Results In the multivariate model, the incidence of cortical cataract was increased in subjects with high red blood cell superoxide dismutase activity (odds ratio [OR] 4.2 [1.5–12.1], P = 0.007). The incidence of PSC cataract was increased in subjects with a high level of plasma glutathione peroxidase (OR 1.8 [1.0–3.3], P = 0.05). In addition to age, gender, and opacities at baseline, significant risk factors for incident cataract were: long-duration diabetes (OR 5.8, P = 0.001 for cortical cataract) and lifetime heavy smoking (OR 2.9, P = 0.006 for PSC cataract). Conclusions Consistent with the baseline analysis, the results of this prospective study suggest that antioxidant enzymes might be implicated in the etiology of cataract.