ESCRS refractive surgery guidelines navigate gray areas in which evidence is lacking
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BARCELONA, Spain — ESCRS guidelines for refractive surgery are a work in progress, expected to be released in 2025. Experts are using a structured methodology, but there are challenges and many unanswered questions.
Beatrice Cochener-Lamard, MD, PhD, said there are few randomized controlled trials for refractive surgery, and the quality of evidence is low.
Many identified results had limited scientific proof and leave remaining questions, so this required moving to what is called expert opinion, she said at the European Society of Cataract and Refractive Surgeons meeting.
She shared examples of topics in which there are expert opinions rather than evidence, such as the definitions and thresholds of ametropia and the new definitions of IOLs. Multifocal, extended depth of focus and full visual range IOLs will now be grouped under the term “simultaneous vision range lenses” and classified based on the level of pseudoaccommodation they can provide for near, intermediate and distance vision.
Other questions that are kept open by a lack of evidence are the role and potential risks of corneal cross-linking in refractive surgery, the rates of ectasia associated with surface ablation procedures, the benefits of topography-guided vs. wavefront-guided LASIK ablations, and the biomechanical advantages of kerato-lenticule extraction (KLEx) over LASIK.
“There is limited evidence [on the efficacy of KLEx] for hyperopia ... and astigmatism in the long term, and re-treatment management remains to be codified,” Cochener-Lamard said.
The guidelines will try to define a decision tree for corneal surgery. Current recommendations are to utilize PRK for myopia up to –6 D and hyperopia up to +3 D, both with astigmatism up to 4 D. LASIK for myopia is recommended for up to –10 D with astigmatism up to –5 D, hyperopia up to 5 D with astigmatism up to 3 D, and astigmatism up to +6 D. KLEx recommendations are now limited to myopia between –1 D and –10 D with astigmatism up to 2 D or 5 D with cyclotorsion compensation. The thresholds for myopic treatments can only be extended in thick corneas without any risk factors.
Concerning phakic IOLs, Cochener-Lamard said that the evidence is stronger for these lenses compared with other procedures. However, more evidence is needed for phakic IOLs in hyperopic and presbyopic patients.
“We have demonstrated that they are good for contrast sensitivity in high ametropia, but there is limited evidence for hyperopia with or without astigmatism,” she said.
Concerning safety, phakic IOLs are preferred to laser surgery in high myopia, with a higher risk for early cataract development but no risk for ectasia.
“Phakic IOLs are more than just the ICL (STAAR Surgical), so we need to get more evidence-based data on the other models available,” she said, such as the IPCL (Care Group) and iris-fixated phakic IOLs.
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Cochener-Lamard B, et al. ESCRS refractive surgery guidelines. Presented at: European Society of Cataract and Refractive Surgeons meeting; Sept. 6-10, 2024; Barcelona, Spain.
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