Refractive Surgery for the Glaucoma Suspect

Abstract and Introduction

Abstract

Purpose of Review: The 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 Findings: The 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.

Summary: Performing 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.

Introduction

Although glaucoma is widely regarded as a relative contraindication to elective refractive procedures, specific guidelines for patient selection and management are not readily available. Given the subjective nature of diagnostic criteria, and the innate challenge of determining rates of disease progression without longitudinal data, refractive surgeons may be reluctant to operate on such patients. Although most refractive surgeons generally avoid keratorefractive procedures in patients with advanced disease and so on the decision to operate on patients earlier in the spectrum may be more subjective. In a 2008 survey of 100 glaucoma surgeons and 100 corneal refractive surgeons, 80% of glaucoma specialists indicated that they would recommend against laser-assisted in situ keratomileusis (LASIK) or photorefractive keratectomy (PRK) for patients diagnosed with glaucoma, while only 50% of cornea specialists would choose not to operate. However, for patients who were glaucoma suspects, two-thirds of glaucoma specialists and three-fourths of cornea specialists agreed that they would offer the procedure.^[1] Further clarifications are additionally required to determine the risks, benefits, alternatives and postoperative considerations of refractive procedures such as refractive lens exchange with or without microinvasive glaucoma procedures (MIGS).

Table 1. Tonometer summary
Tonometry method	Brand/Device	Findings	References
Noncontact: Air Puff	Corvis ST	More reliable than other tonometry methods after various keratorefractive procedures including myopic LASIK and PRK.	Arango et al. [30], Hong et al. [31], Lanza et al. [32], Ang et al. [33], Salouti et al. [34]
	Cannon Full Auto Tonometer TX-F	More reliable than RT in eyes with low IOP following ICL implantation.	Ye et al. [44]
Noncontact: Ocular response analyser (ORA)	Reichert	Less reliable than the Corvis ST, and the two methods should not be used interchangeably following femtosecond laser-assisted LASIK.	Salouti et al. [34]
	–	More reliable than GAT following myopic PRK.	Lanza et al. [32]
Dynamic contour tonometry (DCT)	Pascal	More reliable than GAT following photorefractive surgery with excimer laser.	Arango et al. [30]
	–	More reliable than GAT following myopic PRK.	Lanza et al. [32]
Rebound tonometry (RT)	iCare HOME	Good agreement with noncontact tonometry (Cannon TX-F) following ICL implantation, except in cases of low IOP.	Ye et al. [44]
	iCare ic100	More reliable than GAT following myopic LASIK.	Gomez et al. [36]
	–	More reliable than GAT following myopic PRK.	Lanza et al. [32]
Applanation tonometry	Goldmann applanation (GAT)	Not recommended for use after corneal refractive surgery as this method has been shown to underestimate true IOP in eyes with altered corneal biometry.	Lanza et al. [32], Ang et al. [33], Iglesias et al. [35], Gomez et al. [36]
	Corrective Applanation Tonometer Surface (CATS)	Less reliable than noncontact tonometry (Corvis ST) following myopic LASIK and PRK, and may overestimate IOP. However, may be more accurate than GAT.	Ang et al. [33]
	New Goldmann Convex Prism	May be an accurate method for IOP measurement after LASIK, but notably unreliable in nonsurgical and post- PRK eyes.	Iglesias et al. [35]

Table 1. Tonometer summary

Tonometry method

Brand/Device

Findings

References

Noncontact: Air Puff

Corvis ST

More reliable than other tonometry methods after various keratorefractive procedures including myopic LASIK and PRK.

Arango et al. [30], Hong et al. [31], Lanza et al. [32], Ang et al. [33], Salouti et al. [34]

Cannon Full Auto Tonometer TX-F

More reliable than RT in eyes with low IOP following ICL implantation.

Ye et al. [44]

Noncontact: Ocular response analyser (ORA)

Reichert

Less reliable than the Corvis ST, and the two methods should not be used interchangeably following femtosecond laser-assisted LASIK.

Salouti et al. [34]

–

More reliable than GAT following myopic PRK.

Lanza et al. [32]

Dynamic contour tonometry (DCT)

Pascal

More reliable than GAT following photorefractive surgery with excimer laser.

Arango et al. [30]

–

More reliable than GAT following myopic PRK.

Lanza et al. [32]

Rebound tonometry (RT)

iCare HOME

Good agreement with noncontact tonometry (Cannon TX-F) following ICL implantation, except in cases of low IOP.

Ye et al. [44]

iCare ic100

More reliable than GAT following myopic LASIK.

Gomez et al. [36]

–

More reliable than GAT following myopic PRK.

Lanza et al. [32]

Applanation tonometry

Goldmann applanation (GAT)

Not recommended for use after corneal refractive surgery as this method has been shown to underestimate true IOP in eyes with altered corneal biometry.

Lanza et al. [32], Ang et al. [33], Iglesias et al. [35], Gomez et al. [36]

Corrective Applanation Tonometer Surface (CATS)

Less reliable than noncontact tonometry (Corvis ST) following myopic LASIK and PRK, and may overestimate IOP. However, may be more accurate than GAT.

Ang et al. [33]

New Goldmann Convex Prism

May be an accurate method for IOP measurement after LASIK, but notably unreliable in nonsurgical and post- PRK eyes.

Iglesias et al. [35]