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Abstract #9743 Published in IGR 5-3
Effect of soft contact lenses on the measurements of intraocular pressure with non-contact pneumotonometry
Schollmayer P; Hawlina MKlinische Monatsblätter für Augenheilkunde 2003; 840-842
PURPOSE: To evaluate the effect of soft contact lenses with different lens power on the measured value of intraocular pressure (IOP) with non-contact pneumotonometry. METHODS: One hundred and twenty (80 healthy volunteers: 50 females, 30 males, aged 22-61 years) were included in this study. IOP was measured with a pneumotonometer Canon X-10 before and after insertion of the Ciba Vision Focus Night&Day soft contact lens. The authors used contact lenses with different lens power of +0.25 D, +1.00 D, +4.00 D, -1.00 D, and -4.00 D. The averages of three measurements were taken as representative IOP values and were statistically evaluated. RESULTS: IOP measured over myopic lenses of -1.00 and -4.00 D showed lower values within the mean range of 1 mmHg. The difference between the measurements over the myopic lenses was mostly smaller than ± 2 mmHg (78% when using -1.00 D and 90% when using -4.00 D contact lens). All the differences using +0.25 D contact lens were smaller than ± 2 mmHg. The difference was considerably higher in measurements over +1.00 and +4.00 hyperopic contact lenses, and showed a strong increase with the lens power. CONCLUSIONS: In this study the authors showed that IOP can be reliably measured with non-contact pneumotonometry over myopic lenses or hypermetropic lenses with small lens power. This suggests that non-contact pneumotonometry is a useful method in patients wearing therapeutic contact lenses and contact lens wearers who, when measuring the eye pressure, would not need to remove the contact lenses before the examination.
Dr. P. Schollmayer, University Eye Clinic, Medical Centre Ljubljana, Ljubljana, Slovenia
Classification:
6.1 Intraocular pressure measurement; factors affecting IOP (Part of: 6 Clinical examination methods)