Development and validation of a new intraocular pressure estimate for patients with soft corneas

Chen, Kai-Jung ORCID: 0000-0003-4940-6856, Eliasy, Ashkan ORCID: 0000-0002-4473-1900, Vinciguerra, Riccardo, Abass, Ahmed ORCID: 0000-0002-8622-4632, Lopes, Bernardo T, Vinciguerra, Paolo, Ambrosio, Renato Jr, Roberts, Cynthia J and Elsheikh, Ahmed ORCID: 0000-0001-7456-1749 (2019) Development and validation of a new intraocular pressure estimate for patients with soft corneas. JOURNAL OF CATARACT AND REFRACTIVE SURGERY, 45 (9). pp. 1316-1323.

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Official URL: http://dx.doi.org/10.1016/j.jcrs.2019.04.004

Abstract

<h4>Purpose</h4>To introduce and clinically validate a new method of estimating intraocular pressure (IOP) in patients with keratoconus and soft corneas with the aim of significantly reducing dependence on corneal biomechanics.<h4>Setting</h4>Vincieye Clinic, Milan, Italy, and Rio de Janeiro Corneal Tomography and Biomechanics Study Group, Brazil.<h4>Design</h4>Retrospective case series.<h4>Method</h4>This study comprised participants enrolled at two hospitals on two continents. Numerical analysis based on the finite element method was performed to simulate the effect of tonometric air pressure of the Corvis ST dynamic Scheimpflug analyzer on eye globes with wide variations in thickness, geometry, and tissue. The numerical predictions of ocular behavior were used to develop a new algorithm to produce predictions of the biomechanically corrected IOP (bIOP) in eyes with a soft cornea (bIOP<sub>s</sub>). Predictions of the bIOP<sub>s</sub> were assessed in the keratoconic clinical datasets (because on average these corneas are softer) and compared with the previously developed bIOP algorithm predictions obtained for normal healthy eyes.<h4>Results</h4>The study comprised 722 eyes (722 participants). The main outcome was the absence of a significant difference in IOP between healthy eyes and keratoconic eyes when the bIOP and bIOP<sub>s</sub> algorithms were used (P > .05). There was, however, a significant difference with the uncorrected Scheimpflug analyzer IOP in both groups (P < .001). Furthermore, the bIOP<sub>s</sub> predictions were significantly less affected by corneal thickness and patient age than the Scheimpflug analyzer IOP.<h4>Conclusion</h4>The bIOP<sub>s</sub> algorithm was more reliable at estimating the IOP in eyes with a soft cornea and was validated for use in eyes with keratoconus.

Item Type:	Article
Uncontrolled Keywords:	Cornea, Humans, Keratoconus, Corneal Topography, Tonometry, Ocular, Retrospective Studies, Reproducibility of Results, Intraocular Pressure, Algorithms, Adolescent, Adult, Aged, Middle Aged, Female, Male, Young Adult, Corneal Pachymetry, Healthy Volunteers, Biomechanical Phenomena, Datasets as Topic
Depositing User:	Symplectic Admin
Date Deposited:	04 Apr 2019 09:59
Last Modified:	19 Jan 2023 00:55
DOI:	10.1016/j.jcrs.2019.04.004
Related URLs:	Author Publisher
URI:	https://livrepository.liverpool.ac.uk/id/eprint/3035801