Cataract surgery in the myope: What you should know

Authors

  • Joshua Teichman, MD, MPH, FRCSC

DOI:

https://doi.org/10.58931/cect.2022.119

Abstract

Improvements in technology have led to an increased safety profile in cataract surgery. Accordingly, in recent decades there has been an increasing clinical focus on providing improved refractive outcomes.

Initially using manual keratometers and ultrasound biometry, advances in intraocular lens (IOL) formulae lead to increased precision and accuracy of IOL calculations. This manifested in the form of decreased requirement for spectacle correction, usually at a distance target.

Later, optical biometry supplanted ultrasound as a more accurate method for the measurement of axial length and anterior chamber depth; it may also be useful in the measurement of lens thickness and white-to-white limbal distance. Newer biometers have built-in topographers with accurate keratometry.

It is beneficial to have an experienced ultrasonographer to perform testing in myopes, but it should be noted that posterior staphyloma can cause issues for the most experienced technicians. Some of the newer optical biometers capture a small OCT image at the time of testing to be used to test for foveal alignment, which is especially important in staphylomatous eyes.

More accurate testing, combined with newer-generation IOL formulae, has resulted in further improvement in the accuracy and precision of IOL calculation and increased spectacle independence for patients, commonly at distance. Moreover, newer intraocular lenses including multifocal and trifocal IOLs have increased the probability of spectacle independence at both distance and near. Furthermore, extended range of vision IOLs can provide distance and intermediate vision, with less dysphotopsia than current multifocal lenses.

Despite these advances, there are patient populations in which special attention is required to achieve improved refractive outcomes. Patients with increased axial length (myopes) have suffered from systematic errors in IOL calculation. Initially, modifications to previously developed IOL formulae were developed to compensate for this. The Wang-Koch correction (including its newer-generation correction) to various formulae would be an example of this.

Currently, the newest generation of IOL formulae perform better, without correction, than the previous generation of formulae, with or without correction.

Author Biography

Joshua Teichman, MD, MPH, FRCSC

Dr. Joshua Teichman received his Bachelor of Science from Queen’s University then earned his Doctor of Medicine from Western University. He completed a Residency in Ophthalmology at McMaster University, a Research Fellowship at the University of Toronto, a Master of Public Health focusing on Clinical Epidemiology and Biostatistics from the University of Newcastle, and a Surgical Fellowship in Cornea, External Disease, Anterior Segment and Refractive Surgery at the University of Ottawa. Dr. Teichman has won numerous awards from the American Academy of Ophthalmology, the American Society of Cataract and Refractive Surgery, the Canadian Ophthalmological Society and the University of Toronto/Trillium Health Partners. Dr. Teichman is a Cornea Section Editor at the Canadian Journal of Ophthalmology and a Co-Director of the Cornea, External Disease and Refractive Surgery Fellowship at the University of Toronto.

References

Wang L et al. Optimizing intraocular lens power calculations in eyes with axial lengths above 25.0 mm. J Cataract Refract Surg. 2011 Nov;37(11):2018-27. DOI: https://doi.org/10.1016/j.jcrs.2011.05.042

Melles RB et al. Accuracy of Intraocular Lens Calculation Formulas. Ophthalmology 2018;125:169-178. DOI: https://doi.org/10.1016/j.ophtha.2017.08.027

Published

2022-06-01

How to Cite

1.
Teichman J. Cataract surgery in the myope: What you should know. Can Eye Care Today [Internet]. 2022 Jun. 1 [cited 2024 Dec. 13];1(1):27–29. Available from: https://canadianeyecaretoday.com/article/view/1-1-4

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Section

Articles