Refractive surgery for myopic astigmatism: systematic review for assessing efficacy, stability, and complication

Astigmatism is a common refractive error characterized by meridional asymmetry in corneal or lenticular curvature, often coexisting with myopia. It significantly impacts visual function and quality of life. Refractive surgery offers a promising solution, with several techniques available, including LASIK, small incision lenticule extraction (SMILE), and phakic intraocular lens (pIOL) implantation. This systematic review aims to evaluate the efficacy, stability, and safety of various refractive surgeries specifically for myopic astigmatism. A literature search was conducted across PubMed, Embase, Cochrane Library, and Google Scholar. Risk of Bias-2 and the Newcastle-Ottawa Scale were used for quality assessment. Seven studies met inclusion criteria: four randomized controlled trials and three retrospective analyses. Outcomes included changes in manifest refractive astigmatism, spherical equivalent, visual acuity, postoperative stability, and complications. Wavefront-guided LASIK showed superior correction of astigmatism and spherical equivalent compared to SMILE in several studies. However, other comparisons found FS-LASIK and SMILE to offer similar results. All techniques improved visual acuity, with LASIK demonstrating slightly better outcomes in some cases. SMILE, while less effective in higher astigmatism due to limited cyclotorsion control, had fewer flap-related issues and a lower risk of dry eye. Toric pIOLs showed better astigmatism correction than non-toric variants with limbal relaxing incisions, which remained a cost-effective alternative. All procedures showed stable postoperative results and acceptable safety profiles. Most complications were minor and specific to the surgical technique. In conclusion, wavefront-guided LASIK offers the most consistent refractive correction for myopic astigmatism. However, SMILE and pIOLs are viable options depending on individual patient factors. Personalized preoperative evaluation remains key, and further high-quality randomized trials are warranted to refine treatment strategies.