Abstract
Purpose: :
To examine whether central corneal thickness and corneal curvature have an influence on an intraocular pressure (IOP) value measured by non–contact tonometer (NCT) and Goldmann applanation tonometer (GAT).
Methods: :
Ninety two eyes from 92 patients without a history of intraocular operation were included in the present study. They comprised of 19 primary open angle glaucoma, 7 normal–tension glaucoma, 6 chronic angle–closure glaucoma, 10 ocular hypertension, and 50 non–glaucoma eyes. We measured IOP using NCT and GAT, and calculated a difference of IOP value between the two methods (NCT–GAT). We examined relations between the IOP value and central corneal thickness and radius of corneal curvature using linear regression line. The same examiner measured corneal curvature radius, IOP using NCT and GAT and central corneal thickness. Right eyes were used for statistical examination.
Results: :
Central corneal thickness significantly correlated with IOP measured by NCT (r=0.507, p<0.0001) and that measured by GAT (r=0.233, p<0.05). Corneal curvature radius significantly correlated with IOP measured by GAT (r=–0.239, p<0.05), however not significantly correlated with that measured with NCT (r=–0.099, p=0.3457). There was significant correlation between central corneal thickness and IOP value of (NCT–GAT) (r =0.663, p <0.0001), and significant correlation between corneal curvature radius and IOP value of (NCT–GAT) (r =0.214, p<0.05).
Conclusions: :
The difference of IOP value between NCT and GAT significantly correlated with central corneal thickness and corneal curvature radius.
Keywords: intraocular pressure • cornea: clinical science