Comparison of Three Tonometers in Measuring Intraocular Pressure in Eyes That Underwent Myopic Laser in situ Keratomileusis and Photorefractive Keratectomy

Ang, Robert Edward; Bargas, Neiman Vincent R; Martinez, Gladness Henna A; Sosuan, George Michael N; Umali, Maria Isabel N

doi:10.2147/opth.s362344

Cited by 5 publications

(8 citation statements)

References 47 publications

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“…A recent study from Ang et al [33 ▪▪ ] compared three different tonometers in measuring IOP in eyes that underwent myopic LASIK and PRK. Corrective applanation tonometer surface (CATS) and biomechanically corrected IOP of the Corvis ST tonometer (Corvis ST-bIOP) were compared with GAT.…”

Section: Postoperative Considerationsmentioning

confidence: 99%

Refractive surgery for the glaucoma suspect

Hein

Tauber

Shrivastava

2023

Current Opinion in Ophthalmology

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Purpose of reviewThe aim of this study was to provide an update on perioperative considerations in the evaluation and management of patients undergoing primary corneal and intraocular refractive procedures who are at risk for progressive glaucomatous optic neuropathy.Recent findingsThe necessity of a comprehensive baseline assessment prior to refractive procedures with structural and functional testing, along with documentation of preoperative intraocular pressure (IOP) measurements, is highlighted in recent literature. Substantiation of the increased risk of postoperative IOP elevation in keratorefractive procedures in patients with higher baseline IOP and lower baseline CCT, but not necessarily the degree of myopia, has been variably evidenced. Tonometry methods which are less influenced by postoperative corneal structural change should be considered in patients undergoing keratorefractive procedures. Vigilence in postoperative monitoring for progressive optic neuropathy is suggested given evidence of an increased risk of steroid-response glaucoma in these patients. Additional evidence for the IOP-lowering impact of cataract surgery in patients with an increased risk of glaucoma is provided, irrespective of intraocular lens choice.SummaryPerforming refractive procedures on patients at risk for glaucoma remains controversial. Definitive steps to optimize patient selection along with vigilance in disease state monitoring with longitudinal structural and functional testing can help mitigate potential adverse events.

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Section: Postoperative Considerationsmentioning

confidence: 99%

Refractive surgery for the glaucoma suspect

Hein

Tauber

Shrivastava

2023

Current Opinion in Ophthalmology

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“…The IOP can be evaluated using techniques such as applanation -Goldmann applanation tonometry (GAT) and surface correction (CATS, Reichert, USA)), indentation pneumotonometer (Pneumotonometer, Reichert, USA), both applanation and indentation (Tono-Pen, Reichert, USA), rebound (i-Care, USA), dynamic contour (dynamic contour tonometer (DCT), Pascale, Switzerland) and non-contact type (air breath tonometers such as Corvis ST (CVS, Oculus , Germany ) and ocular response analyzer (ORA, Reichert, USA) 7 . GAT is still the gold standard for measuring IOP in normal corneas 4 .…”

Section: Introductionmentioning

confidence: 99%

“…GAT is still the gold standard for measuring IOP in normal corneas 4 . Applanation tonometry is based on the Imbert-Fick law 8 which only applies to a sphere with an infinitely thin, perfectly flexible, elastic and dry limiting membrane, neither of which is true in the human eye 7,9 . Some studies report that the IOP measurement through the GAT may be influenced by the central corneal thickness (CCT), corneal curvature, tear film and biomechanical properties of the cornea 5,6,7 .…”

Section: Introductionmentioning

confidence: 99%

“…Applanation tonometry is based on the Imbert-Fick law 8 which only applies to a sphere with an infinitely thin, perfectly flexible, elastic and dry limiting membrane, neither of which is true in the human eye 7,9 . Some studies report that the IOP measurement through the GAT may be influenced by the central corneal thickness (CCT), corneal curvature, tear film and biomechanical properties of the cornea 5,6,7 . Measurement of IOP by GAT requires a regular spherical ocular surface, providing a correct IOP measurement for corneas of thickness 520μm 6,10 .…”

Section: Introductionmentioning

confidence: 99%

“…Femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK) involves the creation of a corneal flap by femtosecond laser and corneal reshaping by excimer laser to remove tissue from the underlying stromal bed. Thus, these changes in corneal morphology and biomechanics may affect IOP measurement by several methods patients 4,5,6,7,11 .…”

Section: Introductionmentioning

confidence: 99%

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Evaluation of Intraocular Pressure in Eyes After Femtolasik Surgery

Leite,

Ribeiro,

Abreu

et al. 2024

MRAJ

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Introduction: Femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK) surgery is a surgical procedure performed in the treatment of refractive errors. Given the changes in central corneal thickness, intraocular pressure may be lower and underestimated, which may lead to a late diagnosis of ocular hypertension/glaucoma. Aims: The aim of this study was to evaluate and compare intraocular pressure, by different methods, before and after FS-LASIK, for correction of myopia or myopic astigmatism. Methods: Retrospective and observational study, which included eyes undergoing FS-LASIK surgery (November 2020 to November 2022). The intraocular pressure values were measured (preoperatively, on the 1st, 3rd and 6th postoperative month) using contact tonometry (Goldmann applanation tonometry) and non-contact tonometry (by Corvis®ST according to the formulas: pachymetry – Ehlers, Shah, Dresden, Spoerl – and biomechanics – corrected and uncorrected). The intraocular pressure values obtained at 6 months with the different methods were compared with the Goldmann applanation tonometry intraocular pressure values obtained at baseline. Results: Ninety patients (of a total of 174 eyes) underwent FS-LASIK, with a preoperative spherical equivalent of -3.7±1.7. Preoperatively (mean ± standard deviation) Goldmann applanation tonometry was 15.0±1.9 mmHg; the intraocular pressure values obtained through the Corvis® ST (in mmHg) according pachymetry: Ehlers (13.5±2.6), Shah (14.3±2.3), Dresden (14.5±2.2) and Spoerl (14.5±2.1); and biomechanics: corrected (14.4±1.9) and not corrected (15.3±2.1), respectively. At 6 months postoperatively, all showed statistically significant differences, with the exception of Shah's formula (p=0.074); comparing the preoperative Goldmann applanation tonometry with each of the formulas at the end of the follow-up, the Ehlers formula did not present statistically significant differences (p=0.434), the Shah formula a value of p=0.047 and the others a value of p<0.001. Conclusion: Femtosecond laser-assisted laser in situ keratomileusis surgery underestimates intraocular pressure measurement by contact tonometry. In non-contact tonometry, at 6-month follow-up, the Shah formula appears to be less influenced by this bias. More studies are needed to evaluate the best method to assess I intraocular pressure measurement after FS-LASIK surgery.

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Intraocular Pressure Before and After Corneal Refractive Surgery: A Prospective Comparison of Corvis ST and Ocular Response Analyzer

Salouti,

Azimi,

Meshksar

et al. 2024

Journal of Glaucoma

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Precis: The study showed that Corvis ST’s bIOP and ORA’s IOPcc do not agree well, before or after PRK, and may not be used interchangeably. bIOP remained unchanged after PRK. Purpose: To evaluate the agreement between the biomechanically-corrected intraocular pressure (bIOP) measured by the Corvis-ST and the cornea-compensated IOP (IOPcc) measured by the Ocular Response Analyzer (ORA) before and after photorefractive keratectomy (PRK). Methods: In this prospective interventional study, a total of 53 patients (53 eyes) were included. Measurements were acquired using both the Corvis-ST and ORA devices before and 3 months post- PRK. The agreement between the two devices was evaluated using limits of agreement (LoA) and Bland-Altman plots. Results: The participants had a mean age of 29.6±5.21 years (range: 21 to 40), with 41 (77.4%) of them being female. Following the surgery, the average change in IOP was 0.3±1.7 mmHg for bIOP and −1.6±4.0 mmHg for IOPcc. The corresponding 95% LoA were −3.5 to 4.2 mmHg and −9.5 to 6.3 mmHg, respectively. The 95% LoA between bIOP and IOPcc after PRK was −2.3 to 8.5 mmHg. Notably, the bIOP values were higher for IOPs <20 mmHg and lower for IOPs >20 mmHg compared to IOPcc. Conclusions: The findings indicate a weak agreement between the Corvis ST-bIOP and the ORA- IOPcc both before and after PRK. These devices may not be used interchangeably for IOP measurement. bIOP exhibited less variation compared to the IOPcc, suggesting that the bIOP is a superior option for IOP reading following PRK.

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Comparison of Three Tonometers in Measuring Intraocular Pressure in Eyes That Underwent Myopic Laser in situ Keratomileusis and Photorefractive Keratectomy

Cited by 5 publications

References 47 publications

Refractive surgery for the glaucoma suspect

Refractive surgery for the glaucoma suspect

Evaluation of Intraocular Pressure in Eyes After Femtolasik Surgery

Intraocular Pressure Before and After Corneal Refractive Surgery: A Prospective Comparison of Corvis ST and Ocular Response Analyzer

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