Reproducibility Among Residents in Evaluating Cup-disc Ratio Using Computer-aided Planimetry

ABSTRACT

PURPOSE: To investigate the intra-observer agreement and inter-observer agreement among observers assessing optic disc cup-disc ratio of glaucoma patients. METHODS: Fifty stereoscopic optic disc photographs of patients with glaucoma were digitized and five ophthalmology residents drew optic disc and cup margin in a masked random fashion. It was performed twice on same photographs weekly under monoscopic and stereoscopic conditions. The agreement was estimated by Pearson correlation coefficient r. RESULTS: Intra-observer agreement for estimating linear cup-disc ratio (LCDR) under monoscopic (0.84) and stereoscopic conditions (0.86) were high and inter-observer agreement was also high under monoscopic (0.81) and stereoscopic conditions (0.83) showing more perfect agreement under stereoscopic condition. The observers estimated smaller cup-disc ratio when evaluating under stereoscopic condition than under monoscopic condition. CONCLUSIONS: Evaluating optic disc stereoscopically with computer-aided planimetry can be clinically useful when managing patients with glaucoma since it has a high reproducibility.