Assessment of Tonometry Methods in Keratoconic Eyes Following Intracorneal Ring Segments Implantation: A Comparative Study
- Author:
Siamak ZAREI-GHANAVATI
1
;
Seyed Mehdi TABATABAEI
;
Samaneh GHOLAMHOSEINPOUR-OMRAN
;
Hamed HOSSEINIKHAH-MANSHADI
;
Saeed BANAN
;
Mehdi AMINIZADE
;
Kosar ESMAILI
;
Ebrahim AZARIPOUR
Author Information
- Publication Type:Original Article
- From:Korean Journal of Ophthalmology 2025;39(3):231-240
- CountryRepublic of Korea
- Language:English
-
Abstract:
Purpose:To compare intraocular pressure (IOP) readings from corneas with intracorneal corneal ring segments (ICRS) using various methods, including Goldmann applanation tonometry (GAT), Tonopen, corneal-compensated IOP from the Ocular Response Analyzer (ORA), and biomechanically corrected IOP from the Corneal Visualization Scheimpflug Technology (Corvis ST).
Methods:This cross-sectional observational study included participants who had undergone ICRS implantation with KeraRing at least 3 months before the study. The mean IOP recorded by different instruments was compared using analysis of variance. Agreement among the methods was assessed with Bland-Altman plots.
Results:A total of 54 eyes from 27 participants were enrolled. The mean IOP measured by Tonopen was significantly lower in the center compared to the peripheral quadrants (p < 0.001). IOP measured by GAT was significantly lower than that measured by Tonopen (13.02 ± 2.31 mmHg vs. 14.50 ± 2.91 mmHg, p = 0.021). There were no significant differences between the IOP measurements provided by Tonopen, ORA, and Corvis ST. The corneal-compensated IOP from ORA and biomechanically corrected IOP from Corvis ST had the highest correlation, with a weak intraclass correlation coefficient of 0.38.
Conclusions:IOP measurements using Tonopen were significantly lower in the central 5-mm zone compared to other quadrants. GAT measurements were significantly lower than those from Tonopen. Different measurement tools did not show a strong correlation. Corvis ST (biomechanically corrected IOP) tended to present lower readings at higher IOP levels in eyes with ICRS.
