Detection of changes of the optic disc in glaucomatous eyes: Clinical examination and image analysis with the Topcon Imagenet system

Purpose: This study was designed to evaluate the clinical agreement in the detection of optic disc changes and the ability of computerized image analy sis to detect glaucomatous deterioration of the optic disc. Methods: Pairs of stereophotographs of 35 glaucomatous optic discs taken 5 years apart and of 5 glaucomatous discs photographed twice on the same day. Two glaucoma specialists examined the pairs of stereophotographs (35 cases and 5 controls) in a masked manner and judged whether the optic disc showe d changes in the optic disc compatible with progression of glaucomatous dam age. The stereophotographs of the five optic discs photographed twice on th e same day (which by definition did not change) and of five cases judged to have deteriorated by both glaucoma specialists were analyzed by computeriz ed image analysis with the Topcon ImageNet system. Intra- and inter-observe r agreement in the detection of optic disc changes (evaluated using kappa s tatistic), and changes in the rim area to disc area ratio (evaluated using descriptive statistics and paired t-test). Results: Intra-observer agreement had a kappa value of 0.75 for observer 1 and 0.60 for the observer 2. Inter-observer agreement between the glaucoma specialists had a kappa value of 0.60. The image analyzer did not discrimin ate between controls and cases with clinically apparent glaucomatous change of the optic disc. Conclusion: Clinical agreement in detecting changes in the optic disc was m oderate to substantial. Computerized image analysis with the Topcon ImageNe t system appeared not to be useful in detecting glaucomatous changes of the optic disc.