Factors Influencing Intraocular Pressure Changes after Laser In Situ Keratomileusis with Flaps Created by Femtosecond Laser or Mechanical Microkeratome

Lin, Ming-Hsiu; Chang, David C. K.; Shen, Yun-Dun; Lin, Yen‐Kuang; Lin, Chang‐Ping; Wang, I‐Jong

doi:10.1371/journal.pone.0147699

Cited by 11 publications

(6 citation statements)

References 36 publications

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“…16,17 To overcome this problem, many authors have developed either formulas to correct the GAT IOP readings obtained after surgery [18][19][20][21][22][23][24][25] or they tried to utilize different methods. [26][27][28][29][30][31][32][33][34][35][36] These methods can be divided in:…”

Section: Introductionmentioning

confidence: 99%

Reliability of Intraocular Pressure Measurement by Goldmann Applanation Tonometry After Refractive Surgery: A Review of Different Correction Formulas

Bernardo

Cembalo

Rosa

2020

OPTH

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Myopia is one of the main risk factors for the onset of open-angle glaucoma. One of the first steps to assess glaucoma occurrence is the measurement of the intraocular pressure (IOP) by the Goldmann applanation tonometry (GAT). Even if this device is considered to be the gold standard for such measurements, it is affected by several sources of errors. Among these, there are the corneal thickness and curvature, both modified by corneal refractive surgery (CRS), that nowadays has become a very popular method to treat refractive errors. Indeed, CRS, by modifying the corneal shape and structure, causes an underestimation of the IOP measurements. In the literature, several IOP correction formulas to utilize with different devices have been proposed to overcome this problem. This paper aims to review the various correction formulas applied to the GAT in the attempt to improve the reliability of this measurement.

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Section: Introductionmentioning

confidence: 99%

Reliability of Intraocular Pressure Measurement by Goldmann Applanation Tonometry After Refractive Surgery: A Review of Different Correction Formulas

Bernardo

Cembalo

Rosa

2020

OPTH

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“…This fact was confirmed in a femtosecond laser or microkeratome flap created by LASIK. 22 In the current study, the IOP calculation started 6 months postoperatively, when all postoperative treatments including steroids had been completed and discontinued to avoid steroid-induced glaucoma. This coincides with the observation of authors that steroid-induced glaucoma and pressure-induced keratopathy may appear as acute or lateonset events, and may disrupt the reliability of readings and subsequent equations.…”

Section: Discussionmentioning

confidence: 99%

Intraocular Pressure Calculation in Myopic Patients After Laser-Assisted In Situ Keratomileusis

Helmy¹,

Hashem²

2020

OPTH

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Background: Corneal refractive surgery is widely used worldwide. Myopia is the most common reason for laser-assisted corneal refractive surgery (LASIK) and one of the risk factors for glaucoma. Intraocular pressure (IOP) measurement becomes variable postoperatively as the results are affected by the decrease in corneal thickness and biomechanics. This prospective clinical case study attempted to establish a simple correction formula for the calculation of IOP in post-LASIK myopic patients. Methods: This study included 300 eyes of 150 patients with myopia and myopic astigmatism as a refractive error who underwent LASIK. IOP was measured preoperatively and 6 months postoperatively. Preoperative and postoperative corneal thickness as well as ablation depth were measured. Statistical analysis was performed to detect the relationship between ablation depth and change in IOP. An attempt was made to construct a correction formula for the calculation of post-LASIK IOP. Results: The age of the patients ranged between 18 and 50 (mean ± SD 34.78±8.8) years. The spherical equivalent of refractive error ranged between −1.5 and −10 diopters. The mean IOP decreased significantly from 15.72±2.37 mmHg preoperatively to 11.71±2.24 mmHg postoperatively, with a mean difference of 4±1.75 mmHg (p˂0.001). A positive correlation was detected between corneal thickness and IOP difference among patients both preoperatively and postoperatively (p˂0.001). A positive correlation was identified between ablation depth and IOP change (p˂0.001). The correction formula for IOP was established: Real IOP=4+0.7(preoperative IOP)−0.3(ablation depth). Conclusion: IOP measurements change after corneal refractive surgery with LASIK. A corrected formula may be a good option for the proper calculation of post-LASIK IOP.

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“…Several researches during the last 15 years have found that non-contact pneumatonometry (air-puff ) also exhi-bits a large reduction after LASIK [27][28][29][30]33].…”

Section: Patients With History Of Corneal Refractive Surgery With Exc...mentioning

confidence: 99%

“…Secondarily, it alters the precision of the IOP measurement, especially with applanation tonometers. Goldman tonometry has been widely shown to underestimate IOP after corneal photorefractive surgery [17,19,[20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38]. This underestimation of IOP may at some point delay the diagnosis of de novo glaucoma in patients with a history of refractive surgery [39][40][41][42][43][44].…”

Section: Introductionmentioning

confidence: 99%

Photorefractive surgery with excimer laser and its impact on the diagnosis and follow-up of glaucoma. A review

Arango¹,

Tello²,

Parra³

et al. 2021

CSO

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Excimer laser refractive surgery is a procedure performed worldwide to solve refractive errors and reduce dependence on glasses or contact lenses. There has been an increase in the number of procedures performed around the world. Myopia is the most common indication for corneal photorefractive surgery. Myopic patients have a higher risk of developing some type of glaucoma in their lifetime, such as primary open-angle glaucoma and others. Refractive surgery ablates central corneal stromal tissue, altering its thickness and biomechanics, which in turn makes it difficult to accurately measure intraocular pressure (IOP), since it underestimates it. This underestimation of IOP may delay the diagnosis of de novo glaucoma in patients with a history of refractive surgery. Each patient who wishes to undergo corneal refractive surgery should undergo a thorough glaucoma examination in order to monitor and detect the possible development and / or progression of glaucoma. A very useful practical approach is to perform a series of IOP measurements before and after surgery, when the eye is already stable, and the difference between the averages of the two sets of readings can then be used as a personalised correction factor for postoperative IOP monitoring in that eye. Also, if there is any suspicion of a possible glaucoma, paraclinical tests, such as coherent optical tomography of the retinal nerve fibre layer (RNFL), visual fields and photos of the optic nerve should be requested. All this data prior to refractive surgery should be provided to these patients, so that they can save it and give it to their treating ophthalmologists in the future.

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Factors Influencing Intraocular Pressure Changes after Laser In Situ Keratomileusis with Flaps Created by Femtosecond Laser or Mechanical Microkeratome

Cited by 11 publications

References 36 publications

<p>Reliability of Intraocular Pressure Measurement by Goldmann Applanation Tonometry After Refractive Surgery: A Review of Different Correction Formulas</p>

<p>Reliability of Intraocular Pressure Measurement by Goldmann Applanation Tonometry After Refractive Surgery: A Review of Different Correction Formulas</p>

<p>Intraocular Pressure Calculation in Myopic Patients After Laser-Assisted In Situ Keratomileusis</p>

Photorefractive surgery with excimer laser and its impact on the diagnosis and follow-up of glaucoma. A review

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