ABSTRACT
The purpose of this study is to establish the criteria to discriminate whether the difference of the optic disc parameters compared actually reflects the progress of the disease or it is merely caused by the intraexaminer or interexaminer error. Using the confocal scanning laser ophthalmoscope (TopSS), one eye of each of 20 healthy adults were exmained by the same examiner and one eye of each of 10 adults were examined by different examiners for two consecutive days. The results out of these repeated examinations were analysed to obtain 95%confidence intervals by analysis of the change of the 12 optic disc parameters, and to determine whether the results have been influenced by the disc size or the disc tilt. The criteria to differentiate actual progression of disease from potential errors of the test were obtained. In addition, it was confirmed that changes in the parameters were not influenced by the disc size or the contour tilt. In conclusion,the outcomes of this study can be utilized as a guiding criteria when judging the relevance of the parameter changes to the progress of the disease.