Compilation of Published Cases and a New Case Report of Corneal Ectasia After Keratorefractive Lenticule Extraction.

PURPOSE: To report a case of post-keratorefractive lenticule extraction (KLEx) ectasia in the United States followed by a comprehensive literature review of all published KLEx ectasia cases with an analysis of risk factors and prevalence rates. METHODS: A systematic literature search of PubMed, Embase, Google Scholar, and institutional databases for studies published between January 2008 and April 2026 was conducted. Studies reporting cases of post-KLEx ectasia and large cohort studies with a minimum of 3-year follow-up without ectasia were included. Demographic, tomographic, and surgical parameters were extracted. Comparative statistical analysis between cohorts with and without ectasia was performed. RESULTS: At our institution, a 34-year-old woman developed ectasia 4 years after KLEx, with borderline risk factors and possible subclinical keratoconus. Including this case, 69 eyes from 41 patients across 25 studies were identified with post-KLEx ectasia. Common preoperative abnormalities included elevated Belin/Ambrosio Display Deviation score, reduced Ambrosio Relational Thickness maximum, and tomographic abnormalities. Compared with international nonectatic cohorts, ectatic eyes were significantly younger, had thinner corneas, and higher astigmatism. Overall prevalence of post-KLEx ectasia at our institution was 0.3% over an 8-year period. CONCLUSIONS: Post-KLEx ectasia is a rare but recognized complication with several predisposing factors. Younger age, higher astigmatism, and tomographic abnormalities were more prevalent among the ectasia cohort, mirroring established risk factors for post-LASIK and post-PRK ectasia. The development of ectasia even in tomographically normal eyes poses the question of whether refractive surgery induces ectasia de novo or unmasks subclinical keratoconus.