Abstract
Abstract: :
Purpose:To investigate the accuracy of intraocular pressure (IOP) measurements through a therapeutic silicone hydrogel contact lens using applanation tonometry. Silicone hydrogel has a reduced affinity for the uptake of fluorescein, which will reduce lens staining during applanation tonometry. Methods:In a cohort study the IOP was measured with a Goldmann applanation tonometer without a contact lens and then repeated with a –0.50DS Bausch and Lomb Purevision silicone hydrogel contact lens in situ, this lens power is commonly used as a bandage contact lens. Goldmann tonometry, proxymetacaine and fluorescein mixed single use vials, utilising the same tonometer, slit lamp and operator on every occasion to standardize testing. Results:The IOP of twenty eyes of ten volunteers with no ocular pathology was measured (age range 21–48). The mean difference (±SD) found between IOP measurement with (mean 15.55 ±1.70mmHg) and without (mean 16.05 ± 1.90mmHg) contact lens was found to be –0.5 ± 0.89mmHg. Analysis was performed which revealed a correlation coefficient of 0.89. No significant statistical difference was found between the two groups with paired t–test (p=0.19). Conclusions:Accurate measurement of IOP by applanation tonometry can be achieved through a silicone hydrogel contact lens.
Keywords: contact lens • intraocular pressure