Validity of tono-pachymetry for measuring corrected intraocular pressure in non-surgical and post-photorefractive keratectomy eyes

Session Details

Session Title: LASIK and Imaging

Session Date/Time: Tuesday 10/10/2017 | 14:00-15:20

Paper Time: 14:06

Venue: Room 4.1

First Author: : H.Kim SOUTH KOREA

Co Author(s): :    C. Moon   C. Lee   J. Lee   J. Kim   M. Kim   H. Tchah     

Abstract Details

Purpose:

To assess the validity of central corneal thickness (CCT) and corrected intraocular pressure (IOP) values obtained by tono-pachymetry in non-surgical and post-photorefractive keratectomy (PRK) eyes.

Setting:

Department of Ophthalmology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea, and Department of Ophthalmology, Aerospace Medical Center, Republic of Korea Air Force, Cheongju, Korea

Methods:

For the study, 108 young healthy participants and 108 patients who had PRK were enrolled. Measurements were randomly performed by tono-pachymetry, ultrasonic (US) pachymetry, and Goldmann applanation tonometry (GAT). CCT measurement by tono-pachymetry was compared to that of US pachymetry. The corrected IOP value obtained by tono-pachymetry was compared to that obtained by US pachymetry and GAT. The corrected IOP from US pachymetry and GAT was calculated using the identical compensation formula built into the tono-pachymetry. Bland-Altman plot and paired t-test were conducted to evaluate the between-method agreements.

Results:

The mean CCT measurement using tono-pachymetry was significantly greater by 7.3 μm in non-surgical eyes (p < 0.001) and 17.8 μm in post-PRK eyes (p < 0.001) compared with US pachymetry. Differences were significant in both Bland-Altman plot and paired t-test. The mean difference of corrected IOP values obtained by tono-pachymetry and calculated from measurements by US pachymetry and GAT was 0.33 ± 0.87 mmHg in non-surgical eyes and 0.57 ± 1.08 mmHg in post-PRK eyes. The differences in the Bland-Altman plot were not significant.

Conclusions:

The CCT measurement determined using tono-pachymetrywas significantly thicker than that of US pachymetry. The difference in CCT was greater in post-PRK eyes than in non-surgical eyes. However, the corrected IOP value obtained by tono-pachymetry showed reasonable agreement with that calculated from US pachymetry and GAT measurements.

Financial Disclosure:

NONE