EFFECT OF CATARACT TYPE AND SEVERITY ON LENS GRADING

Two sets of lens photogradings were used to investigate the effect of cataract type and severity on the intra- and interobserver agreement between two graders using the Lens Opacities Classification System III (LOCS III). The first set consisted of 193 eyes, largely of mild-to-moderate opacities for all cataract types. The second set consisted of a similar number of cataracts in each group subdivided into mild, moderate, and severe, a total of 159 lens photographs. Intraclass correlation coefficient (r(I)) was used to measure the intra- and interobserver reproducibility and 95% tolerance limit the intra- and interobserver variability. Results showed that more variability was seen in intra- and interobserver agreement when grading increasing posterior subcapsular opacities. Decreased reproducibility and increased variability in interobserver agreement were seen in increasing cortical gradings, and decreased reproducibility in interobserver agreement in more severe nuclear opacities. No difference was seen in nuclear color gradings. The results suggest that the effect of cataract severity on interobserver agreement should be taken into consideration in longitudinal studies requiring several photograders.