Lens opacity AREDS score predicts progression

Researchers using the Age-Related Eye Disease Study (AREDS) lens grading scale have found that long-term clinically relevant outcomes can be predicted by 2-year changes in severity of lens opacities.

Reporting in Ophthalmology, researchers from the National Eye Institute, National Institutes of Health (US) and contract research organization EMMES Corp. conducted a prospective cohort study within a randomized clinical trial of oral supplements. The study enrolled AREDS participants who were free of late age-related macular

degeneration throughout the study, and whose eyes were phakic at baseline.

The researchers examined 3,466 baseline and annual lens photographs of AREDS participants and graded them for cataract severity. They then collected data on cataract surgery and visual acuity through semiannual clinical examinations. Adjusted Cox proportional hazard models were used to analyse the association of the change in lens opacities at 2 years with the incidence of cataract surgery and visual acuity loss of 2 lines or more at 5 years.

They found that the adjusted hazard ratios (HRs) for association of progression to cataract surgery at 5 years were:

• 2.77 HR for nuclear cataract increase of 1.0 unit or more at 2 years compared with less than 1.0 unit change

• 1.91 HR for cortical cataract increase of 5% or more in lens opacity in the central 5 mm of the lens at 2 years compared with less than 5% increase

• 8.25 HR for posterior subcapsular cataract increase of 5% or more versus less than 5% in the central 5 mm of the lens.

For vision loss of 2 lines or more at 5 years, the HRs were as follows:

• 1.83 HR for nuclear cataract increase of 1.0 unit or more at 2 years compared with less than 1.0 unit change

• 1.13 HR for cortical cataract increase of 5% or more in lens opacity in the central 5 mm of the lens at 2 years compared with less than 5% increase

• 3.05 HR for posterior subcapsular cataract increase of 5% or more versus less than 5% in the central 5 mm of the lens.