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Abstract #18486 Published in IGR 3-3
Agreement among clinicians in the recognition of patterns of optic disc damage in glaucoma
Nicolela MT; Drance SM; Broadway DC; Chauhan BC; McCormick TA; Leblanc RPAmerican Journal of Ophthalmology 2001; 132: 836-844
PURPOSE: To determine the interobserver and intraobserver agreement in the recognition of different patterns of glaucomatous optic disc damage, and to evaluate whether these patterns changed over time in patients followed for a number of years. METHODS: Patients with early to moderate glaucoma (n = 105) were consecutively enroled to participate in a prospective observational study. In the first part of the present study, optic disc photographs obtained closest to the patient's entry date in the prospective study were classified in a masked fashion by three observers, according to the pattern of optic disc damage, into one of the following: (1) focal, (2) myopic, (3) senile sclerotic, (4) concentric cup enlargement, (5) normal appearance, or (6) miscellaneous (those discs that did not qualify for any of the other groups). The observers were also asked to assign a confidence score for each classification, ranging from 1 (low confidence) to 5 (highest confidence). The three observers reclassified the photographs after a minimum period of two months, in order to assess intraobserver agreement. In a second part of the study, one observer reviewed, in a masked fashion, all the optic disc photographs that had been taken during the routine follow-up of the 105 patients, in order to evaluate whether the classification of disc pattern changed over time. RESULTS: Intraobserver agreement yielded kappa values (95% confidence interval (CI)) from 0.51 (CI, 0.40-0.62) to 0.85 (CI, 0.77-0.93), depending on the observer. Interobserver agreement kappa value between all three observers was 0.40 (CI, 0.35-0.46), but it improved if photographs classified with moderate or higher degrees of confidence were included (0.52 (CI, 0.44-0.60)). During a mean follow-up period of 8.2 ± 4.8 years, 41.6% of the eyes were always classified into the same group, and 23.6% of the eyes were classified at least once into two or more of the four patterns of damage (groups 1-4). CONCLUSIONS: Intraobserver agreement on the pattern of optic disc damage was generally very good, with some variation among the observers. Interobserver agreement was reasonable and increased proportionally with the confidence in the classification. During long-term follow-up, the pattern of optic disc damage usually did not change. This type of classification can probably be used accurately in clinical practice.
Dr M.T. Nicolela, Eye Care Centre, 1278 Tower Road, Halifax, NS, B3H 2Y9 Canada. nicolela@is.dal.ca
Classification:
2.14 Optic disc (Part of: 2 Anatomical structures in glaucoma)
