Evidence-Based Guidelines for Keratorefractive Lenticule Extraction Surgery

Abstract

Topic: Development of evidence-based guidelines for keratorefractive lenticule extraction (KLEx).

Clinical relevance: Keratorefractive lenticule extraction refers to various corneal refractive procedures involving removal of refractive lenticules of intrastromal corneal tissue, typically through a small incision, eliminating creation of a corneal flap. This technique has gained popularity rapidly; however, no clinical practice guidelines exist.

Methods: These evidence-based guidelines were developed following the World Health Organization guidebook using the Appraisal of Guidelines for Research and Evaluation II tool and adhering to the Reporting Items for Practice Guideline in Healthcare statement. The body of evidence was drawn from 8 literature databases, 5 clinical guideline databases, and 2 academic organizations. Recommendations were developed via a Delphi consensus of 44 global experts in refractive surgery, cornea, retina, glaucoma, and optometry. The certainty of evidence, balance of benefits and harms, patient preferences and values, and economic evaluations were considered fully. The Grading of Recommendations Assessment, Development, and Evaluation approach was used to assess evidence quality and recommendation strengths.

Results: From 385 initial clinical questions, 15 were identified, prompting a review of 250 717 studies, with 609 included for conducting and updating 26 and 2 systematic reviews, respectively. Subsequently, consensus was reached on 38 recommendations for preoperative screening, candidate selection, intraoperative quality control, operating principles, postoperative monitoring, and complication management. For KLEx, an effective and accurate refractive correction is attributed to various factors such as corneal thickness, degree of myopia, treatment nomogram, and optical zone. For complications that could affect vision, comprehensive and effective management strategies were proposed, particularly for wrong-plane dissection and difficult lenticule removal, suction loss, and perioperative infection. Customized surgical planning protocols and operative techniques were analyzed. Among all recommendations, 29 (76%) were labelled as strong, each externally reviewed. The corneal biomechanical properties may help to improve safety and predictability, although they need further validation. Several research gaps for enhancing KLEx safety were also revealed.

Conclusions: These guidelines provide evidence-based recommendations for KLEx in clinical practice, such as for preoperative screening for keratoconus, surgical planning, and management and prevention of complications and infection. The guidelines are expected to minimize the complications and achieve better outcomes.

Financial disclosure(s): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Keywords: Complication; Corneal biomechanics; Keratorefractive lenticule extraction; Refractive surgery; Small-incision lenticule extraction.