Posters

Variations of corrected intraocular pressure measurements using five correction equations against Goldmann Applanation Tonometer and Dynamic Contour Tonometer

Poster Details

First Author: W.Wan Abdul Halim MALAYSIA

Co Author(s): D. Kaur Gill                    

Abstract Details

Purpose:

To determine the agreement between corrected intraocular pressure (IOP) against Goldmann Applanation Tonometer (GAT) and Dynamic Contour Tonometer (DCT) and the agreement between GAT and DCT

Setting:

Department of Ophthalmology, Universiti Kebangsaan Malaysia Medical Centre, Jalan Yaacob Latiff, Cheras, Kuala Lumpur

Methods:

This was a prospective, cross sectional study by convenience sampling. 139 patients fulfilling inclusion criteria were enrolled and undilated fundus examination was performed to exclude glaucomatous changes. Then central corneal thickness (CCT) and corneal radius (R) measurements were taken from a randomly selected eye. Subsequently one IOP reading from the DCT was taken and five minutes later three readings from GAT were taken (the mean of which was used in analysis).

Results:

A total of 139 eyes studied, 80 subjects were females (58%) and 59 were males (42%). Subjects ethnicity distributions are Malay ethnicity (69%, 96 subjects), Chinese (20%, 28 subjects) and Indians (11%, 15 subjects). Excellent intra-class correlation coefficient (ICC) between the primary investigator and a specialist for both GAT (0.992) and DCT (0.975) readings were obtained at p<0.001. Cronbach Alpha (CA) values were 0.7 indicating high internal reliability of the measurement values. IOP correction formula by Orssengo et al showed good agreement with the GAT. However, none of the corrected IOP values were in agreement with DCT.

Conclusions:

The correction formulas were not able to calculate ‘true’ IOP values and cannot be used interchangeably with DCT.

Financial Disclosure:

None