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Abstract #9158 Published in IGR 5-2
Repeatability of ocular blood flow pneumotonometry
Bhan A; Bhargava J; Vernon SA; Armstrong S; Bhan K; Tong L; Sung VOphthalmology 2003; 110: 1551-1554
PURPOSE: To establish the repeatability of ocular blood flow (OBF) pneumotonometry and its agreement with Goldmann tonometry. DESIGN: Instrument evaluation study. PARTICIPANTS: Ten female healthcare professionals. METHODS: Intraocular pressure (IOP) was measured by one experienced ophthalmologist in both eyes of ten healthy female subjects on ten different occasions at the same time of day. The two methods were performed by alternate allocation, and laterality was chosen by random order. Repeatability coefficients and agreement plots were calculated by using the Bland-Altman method. MAIN OUTCOME MEASURES: IOP repeatability coefficients. RESULTS: Mean IOP was 15.6 mmHg (right) and 15.1 mmHg (left) by OBF pneumotonometry and 12.6 mmHg (right) and 12.4 mmHg (left) by Goldmann tonometry (p < 0.001). The repeatability coefficients were 7.06 (right) and 7.66 (left) for the OBF pneumotonometer and 4.81 (right) and 3.87 (left) for the Goldmann tonometer. With regard to agreement, the OBF pneumotonometer read significantly higher than did the Goldmann tonometer. The mean bias for the right eye was 2.92 (95% limits of agreement, -4.37 to 10.20), and for the left eye it was 2.68 (95% limits of agreement, -3.93 to 9.28). CONCLUSIONS: In this group of healthy females, the repeatability of the OBF pneumotonometer was worse than that of the Goldmann tonometer. This casts doubt on the value of the OBF pneumotonometer as a tool for measuring IOP. The agreement plots indicate that the OBF pneumotonometer may produce significant numbers of false-positive results in screening programs.
Dr. S.A. Vernon, Department of Ophthalmology, Queens Medical Centre, Derby Road, Nottingham, NG7 2UH UK. abhan9@hotmail.com
Classification:
6.1 Intraocular pressure measurement; factors affecting IOP (Part of: 6 Clinical examination methods)
