Kareem Sadek

Topic: Keratorefractive lenticule extraction (KLEx) treats myopia and myopic astigmatism while preserving corneal biomechanics better than flap-based procedures. KLEx with prophylactic accelerated corneal crosslinking (KLEx–CXL) has been proposed for thinner corneas, higher myopia, or borderline tomography, but its incremental value remains uncertain. Clinical Relevance: KLEx–CXL may reduce biomechanical instability but adds operative time, cost, and protocol variability. Comparative evidence is needed to determine whether it improves outcomes over KLEx alone. Methods: MEDLINE, Embase, Scopus, Web of Science, CENTRAL, and CINAHL were searched to July 2, 2026. Comparative adult studies with at least 6-month follow-up reporting refractive or visual outcomes were included. 2 reviewers extracted data, assessed risk of bias, and rated certainty using Grading of Recommendations, Assessment, Development, and Evaluation. Random-effects meta-analyses pooled mean differences (MDs). Results: 9 studies included 730 eyes: 386 KLEx and 344 KLEx–CXL. Residual manifest refraction spherical equivalent was similar overall (MD 0.03 diopters [D]; 95% CI, −0.01 to 0.06; P = .17), with no consistent timepoint-specific difference. A small residual difference was confined to moderate-myopia cohorts (0.09 D; 95% CI, 0.04-0.15) and absent in high myopia. KLEx showed a 1-month advantage in uncorrected distance vision (MD −0.04 logMAR), safety index (MD 0.07), and efficacy index (MD 0.08), resolving by 12 months. Corrected vision was similar throughout. Biomechanical measures favored KLEx–CXL. Early haze was transient; no ectasia occurred. Certainty was low. Conclusions: KLEx and KLEx–CXL achieved similar residual refraction and corrected visual acuity. KLEx–CXL produced measurable biomechanical reinforcement but transiently delayed early uncorrected visual recovery. Current evidence supports reserving prophylactic crosslinking for higher-risk eyes.

Background: Large language models (LLMs) are increasingly embedded in medical education and clinical care settings, yet limited empirical data describe medical students in Canada’s use and perceptions of these tools. We aimed to characterize student engagement including LLMs used, frequency, purposes, trust, accuracy, perceived impacts, and attitudes toward educational and clinical integration. Methods: We conducted a national survey of medical students in Canada distributed between November and December 2025. We summarized responses using descriptive statistics and compared results between students in preclerkship versus clerkship using Fisher’s exact test. Results: Among 286 respondents from 10 medical schools, 96.50% reported using at least one LLM. The most commonly used LLMs were ChatGPT (93.36%) and OpenEvidence (57.69%). Daily/weekly use was most frequent for coursework assistance (60.22%) and clinical questions (57.14%). Most respondents reported positive impacts on efficiency (81.62%), learning (77.01%), and academic performance (59.49%). Students commonly reported encountering inaccurate information (90.18%). Formal instruction on LLM use was uncommon (10.95%), though 67.67% of students agreed medical schools should integrate formal instruction on LLMs. Only 21.43% of respondents felt adequately educated on data privacy regulations applicable to these tools. Conclusions: LLM use among surveyed medical students in Canada was nearly universal and perceived favourably. However, students reported exposure to inaccurate outputs and substantial gaps in formal training and privacy literacy. These findings support the development of structured curricular guidance on appropriate application of these tools, including information verification practices and ethical, privacy-aware engagement.