Changes in lens opacities on the age-related eye disease study grading scale predict progression to cataract surgery and vision loss: age-related eye disease study report no. 34.
PURPOSE: To investigate whether the 2-year change in lens opacity severity on the Age-Related Eye Disease Study (AREDS) lens grading scale predicts progression to cataract surgery or loss of visual acuity by 5 years.
DESIGN: Prospective cohort study within a randomized clinical trial of oral supplements.
PARTICIPANTS: The AREDS participants whose eyes were phakic at baseline and free of late age-related macular degeneration throughout the study.
METHODS: Baseline and annual lens photographs of AREDS participants (n = 3466/4757; 73%) were graded for severity of cataracts using the AREDS system for classifying cataracts from photographs. Clinical examinations conducted semiannually collected data on cataract surgery and visual acuity. Association of the change in lens opacities at 2 years with these outcomes at 5 years was analyzed with adjusted Cox proportional hazard models.
MAIN OUTCOME MEASUREMENTS: Progression of lens opacities on stereoscopic lens photographs at 2 years, cataract surgery, and visual acuity loss of 2 lines or more at 5 years.
RESULTS: The adjusted hazard ratios (HRs) for association of progression to cataract surgery at 5 years were: nuclear cataract increase of 1.0 unit or more compared with less than 1.0-unit change at 2 years, 2.77 (95% confidence interval [CI], 2.07-3.70; P < 0.001); cortical cataract increase of 5% or more in lens opacity in the central 5 mm of the lens compared with less than 5% increase at 2 years, 1.91 (95% CI, 1.27-2.87; P = 0.002); and posterior subcapsular cataract increase of 5% or more versus less than 5% in the central 5 mm of the lens, 8.25 (95% CI, 5.55-12.29; P < 0.001). Similarly, HRs of vision loss of 2 lines or more at 5 years for this degree of lens changes at 2 years were the following: nuclear, 1.83 (95% CI, 1.49-2.25; P < 0.001); cortical, 1.13 (95% CI, 0.78-1.65; P = 0.519); and posterior subcapsular cataract, 3.05 (95% CI, 1.79-5.19; P < 0.001).
CONCLUSIONS: Two-year changes in severity of lens opacities on the AREDS lens grading scale are predictive of long-term clinically relevant outcomes, making them potential surrogate end points in follow-up studies.