Associations between lens features assessed in the Oxford Clinical Cataract Classification and Grading System

Abstract

PURPOSE To study the associations between eleven lens features graded according to the Oxford Clinical Cataract Classification and Grading System (OCCCGS).

METHOD 560 subjects taking part in the Melton Eye Study had their lenses graded according to the OCCCGS by one of two examiners. Associations between features were examined using log-linear models for categorised grades. Adjustment was made for age, sex and grader.

RESULTS Within subjects, the two nuclear features, white nuclear scatter and brunescence, are closely related with one another, as are coronary flakes and focal-dots, but these two groupings are negatively associated. Cortical spoke, fibrefolds and waterclefts are all associated with one another and this group is positively associated with coronary flakes and focal-dots. Posterior subcapsular and anterior subcapsular opacity are associated with one another and with cortical spokes. A within-eye analysis gives similar results.

CONCLUSION These associations may be important in defining cataract subtypes and in identifying minor features that indicate early cataract development.

Key Words:

• lens opacity
• slit-lamp grading
• cataract classification
• Melton Eye Study