Purpose: To compare the differences of optic disc topograph between normal and glaucomatous persons, and to establish the score classification pattern for glaucoma using Heidelberg Retina Topograph (HRT).
Methods: One hundred and sixteen eyes from 116 normal controls, 99 eyes from 63 consecutive primary open angle glaucoma(POAG) patients, and 75 eyes from 42 patients with POAG in early stage were included. All subjects underwent HRT exams. The topograph parameters of optic nerve head obtained from HRT were compared between normal and glaucoma, according to the 50%,95%,and 99% distribution of each parameter defining as score -4, -3, -2, -1, 1, 2, 3, 4. The total value of all parameters in one eye were calculated as a diagnostic index. And the cut-off points were determined by specificity of 95% for certain glaucoma and certain normal, the others were classified into suspects.
Results: The differences of optic disc topograph between normals and glaucomatous patients were significant. When consecutive glaucoma data were analyzed by the new score classification pattern, miss-diagnosis ratio was 6.1%, mis-diagnosis was 5.2%, correctly diagnostic ratio was 57.6%, suspects ratio was 36.4%. When POAG in early stage data were analyzed, the miss-diagnosis ratio and mis-diagnosis ratio were 5.2%, 5.2%, respectively; correctly diagnosis ratio is 36%, suspects ratio is 53.3%.
Conclusions: The differences of optic nerve head topograph between normals and glaucomatous patients are significant. The new diagnostic pattern which will classify subjects into normals, suspects, and glaucoma, may be useful to lower miss-and misdiagnosis rate clinically.