Authors: Shikha Gupta Gautam Sinha Reetika Sharma Bhagabat Nayak Bharat Patil Bibhuti Kashyap Abdul Shameer Tanuj Dada
Publish Date: 2015/03/28
Volume: 36, Issue: 1, Pages: 9-15
Abstract
To estimate agreement in diurnal variations of intraocular pressure IOP by TonoPen TP and Goldmann applanation tonometer GAT in glaucoma patients on topical antiglaucoma medications IOP was measured at every 3 h from 7 am to 10 am in 50 eyes of glaucoma patients on topical medications Diurnal fluctuation of IOP by each method was calculated as maximum–minimum IOP in a day Central corneal thickness CCT was measured by ultrasonic pachymeter There was good correlation between TP and GAT at all times during a day minimum and maximum IOPs during a day Correlation coefficient 0706 at 7 am 0624 at 10 am 0682 at 1 pm 0814 at 4 pm 0652 at 7 pm 0572 at 10 pm 0668 minimum IOP 0689 maximum IOP Mean IOPs by TP were always higher than GAT at all times during a day Bland–Altman plots suggested a close relationship between the two sets of readings and that this relationship was consistent at different times in a day in maximum IOPs minimum IOPs and also in fluctuation of IOPs Linear regression analysis between the differences of diurnal fluctuation diurnal fluctuation by GATdiurnal fluctuation by TP and CCT showed strong association R 2 = 0857 p 0001 The mean change in difference of diurnal fluctuation GAT–TP for a 10micron increase in CCT was 069 mmHg TP can be considered a reliable alternative to GAT in glaucoma patients for knowing the diurnal control of IOP however these two methods should not be used interchangeably Difference of diurnal fluctuation between two methods is dependent on CCT
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