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. 2022 Feb 16;22(1):79.
doi: 10.1186/s12886-022-02309-x.

Intraocular pressure after myopic laser refractive surgery measured with a new Goldmann convex prism: correlations with GAT and ORA

María Iglesias  1 , Bachar Kudsieh  2 , Andrea Laiseca  3 , Cristina Santos  4 , Jeroni Nadal  3 , Rafael Barraquer  3   5 , Ricardo P Casaroli-Marano  6
Affiliations

Intraocular pressure after myopic laser refractive surgery measured with a new Goldmann convex prism: correlations with GAT and ORA

María Iglesias et al. BMC Ophthalmol. .

Abstract

Background: The purpose of this study is to describe measurements using a newly developed modified Goldmann convex tonometer (CT) 1 year after myopic laser refractive surgery. Intraocular pressure (IOP) measurements were compared with IOP values obtained by Goldmann applanation tonometer (GAT), and Ocular Response Analyzer (ORA).

Methods: Prospective double-masked study performed on thirty eyes of thirty patients that underwent laser in situ keratomileusis (LASIK; n = 19) or photorefractive keratectomy (PRK; n = 11). IOP was measured before and 3 and 12 months after surgery. Intraclass correlation coefficient (ICC) and Bland-Altman plot were calculated to assess the agreement between GAT, CT, IOPg (Goldmann-correlated IOP) and IOPcc (corneal-compensated IOP) from ORA.

Results: Twelve months after LASIK, IOP measured with CT showed the best correlation with IOP measured with GAT before surgery (GATpre) (ICC = 0.886, 95% CI: 0.703-0.956) (15.60 ± 3.27 vs 15.80 ± 3.22; p < 0.000). However, a moderate correlation was found for IOP measured with IOPcc and CT 12 months after LASIK (ICC = 0.568, 95% CI: - 0.185 - 0.843) (15.80 ± 3.22 vs 12.87 ± 2.77; p < 0.004). Twelve months after PRK, CT showed a weak correlation (ICC = - 0.266, 95% CI: - 3.896 - 0.663), compared to GATpre (17.30 ± 3.47 vs 16.01 ± 1.45; p < 0.642), as well as poor correlation (ICC = 0.256, 95% CI: - 0.332 - 0.719) with IOPcc (17.30 ± 3.47 vs 13.38 ± 1.65; p < 0.182).

Conclusions: Twelve months after LASIK, IOP measured with CT strongly correlated with GAT before surgery and could therefore provide an alternative method for measuring IOP after this surgery. More studies regarding this new convex prism are needed to assess its accuracy.

Keywords: Corneal biomechanics; Glaucoma; Intraocular pressure; LASIK; Myopia; PRK; Tonometry.

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Conflict of interest statement

Each of the co-authors has seen and agrees with the financial and non-financial competing interests statement presented by MI (as corresponding author) on behalf of all the authors of the paper:

MI has personal conflict of interest being the inventor of the new Goldmann “CT” applanation tonometer. She had full access to all the data in this study and takes complete responsibility for the integrity of the data and the accuracy of the data analysis. MI has exclusive personal rights to the intellectual property of this invention secured by the patents referred to above, and is the owner of every figure presented in this study.

The rest of the co-authors declare no financial competing interests.

MI and the rest of the co-authors declare they do not have non-financial competing interests.

Figures

Fig. 1
Fig. 1
Modified CT applanation tonometer. Observe the convex reflection in the tip (A) and in the side image (B, *) CT tonometer inserted in a handling tonometer device (B)
Fig. 2
Fig. 2
Mean IOP changes over time obtained using different tonometer devices in pre- and post-refractive surgery evaluations after 3 and 12 months. CX: L, LASIK (A); CX:P, PRK (B); GAT, Goldmann applanation tonometer; CT, convex tonometer; IOPg, Goldmann-correlated intraocular pressure and IOPcc, corneal-compensated IOP. M, months
See this image and copyright information in PMC

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