Dry eye after refractive surgery: a meta-analysis

Objective: To examine and compare the rates of dry eye after various refractive surgeries, including laser-assisted in situ keratomileusis (LASIK), photorefractive keratectomy (PRK), femtosecond lamellar extraction (FLEx), and small incision lenticule extraction (SMILE). Design: Systematic review and meta-analysis. Methods: This systematic review and meta-analysis was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement guidelines. Databases searched included MEDLINE (Ovid), Embase, Cochrane Library, Cumulative Index of Nursing and Allied Health Literature, Web of Science, ProQuest Dissertations and Theses, and ClinicalTrials.gov. Meeting abstracts from European Society of Cataract and Refractive Surgeons, American Academy of Ophthalmology, Association for Research in Vision and Ophthalmology, and Canadian Ophthalmological Society were also examined. Articles underwent 3 stages of screening before data extraction and meta-analysis. Results: In total, 3232 studies were found; 261 remained after title screening, 92 remained after abstract screening, and 14 studies progressed to data extraction. Meta-analysis indicated a significant reduction in tear break-up time (TBUT) with LASIK (standardized mean difference [SMD] = -0.3; confidence interval [CI]: -0.53 to -0.08) and FLEx (SMD = -1.09; CI: -1.44 to -0.74), and a nonsignificant reduction in TBUT with SMILE (SMD = -0.34; CI: -0.95 to 0.27) and PRK (SMD = -0.11; CI: -0.29 to 0.08). Meta-analysis also indicated a significant reduction in tear production with LASIK (SMD = -0.23; CI: -0.46 to -0.01), and a nonsignificant reduction in tear production with SMILE (SMD = 0.04; CI: -0.28 to 0.36), FLEX (SMD = -0.05; CI: -0.37 to 0.28), and PRK (SMD = -0.07; CI: -0.32 to 0.19). Conclusions: Overall, a significant reduction in postoperative tear production as well as TBUT time was seen with LASIK, and a nonsignificant reduction in postoperative tear production and TBUT was seen with SMILE, FLEx, and PRK. Ultimately, more high-quality randomized controlled trials are required to make concrete conclusions about dry eye parameters after refractive surgery.