Posters

Comparison of iCare tonometer, Goldmann applanation tonometry and Tono-Pen XL in abnormal corneas or in eyes with penetrating keratoplasty

Poster Details

First Author: C.Altan TURKEY

Co Author(s):    B. Satana   B. Basarir   C. Ocal   N. Alagoz   C. Ozturker   A. Demirok

Abstract Details

Purpose:

To evaluate the agreement and practicability of Icare rebound tonometer, Goldmann applanation tonometer (GAT) and Tono-Pen XL for measuring intraocular pressure (IOP) in pathologic and post-keratoplasty corneas.

Setting:

Beyoglu Eye Training and Research Hospital,Istanbul, Turkey

Methods:

Fifty-seven consecutive eyes were included in this observational, cross-sectional study. Of these, 41 eyes had a previous keratoplasty; 16 eyes had corneal scars. IOP was measured in a sitting position and always in the same order: Firstly Icare and, after the application of the topical anesthetic, Tono-Pen XL and GAT; to avoid IOP reduction by applanation tonometry. GAT reading was subsequently obtained by another ophthalmologist, without the knowledge of the Icare readings.

Results:

Although IOP was successfully measured using Icare and Tono-Pen XL in all study eyes, successful measurement of IOP was only possible in 33,3% when using the GAT. Mean IOP for all enrolled eyes was 20,6±7,2 (range 8-36) mmHg for Icare, 20,1±9,4 (range 7-45) mmHg for Tono-Pen XL and 21,3±9,1 (range 8-35) mmHg for GAT in successfully measured eyes. The mean difference between Icare and GAT was 1,47±6,91 mmHg; and Icare and TonoPen XL was 0,51±6,72 mmHg (Paired-sample t-test, p=0,36; p=0,57, consecutively). IOP measurements with ICare were positively correlated with both GAT and TonoPen XL.

Conclusions:

In pathologic corneas, IOP was difficult to obtain with GAT, whereas Icare and Tono-Pen XL were able to determine IOP in all pathologic and post-keratoplasty corneas. The agreement between GAT and Icare and Tono-Pen XL were clinically acceptable in these eyes. The Icare instrument was easy to use and it seems to be more comfortable than GAT and obviates the need for topical anesthesia. ICare rebound tonometry could be an appropriate tonometry method for altered corneas. FINANCIAL INTEREST: NONE