Small incision lenticule extraction and femtosecond-assisted laser in situ keratomileusis in patients with deep corneal opacity: case series

? AIM: To report the safety, efficacy, and accuracy of small-incision lenticule extraction (SMILE) or femtosecond-assisted laser in situ keratomileusis (FS-LASIK) for the correction of myopia or myopic astigmatism in patients with deep corneal opacity denoted by anterior segment optical coherence tomography (AS-OCT).? METHODS: Four patients with monocular corneal opacity (3 due to mechanical injury, 1 due to a firecracker wound) were recruited and treated with refractive surgery (3 for SMILE, 1 for FS-LASIK combined with limbal relaxing incision (LRI). Preoperative ocular manifestations, surgical details, postoperative visual outcomes, corneal opacity parameters, and corneal topography were analyzed.? RESULTS: Preoperatively, spherical diopter ranged from-3.0 D to-4.75 D with cylinder ranging from-0.75 to-5.0 D, and corrected distance visual acuity (CDVA) ranging from 20/25 to 20/20. One eye's corneal opacity was located in the central zone and three were in the mid-peripheral optical zone. Three patients underwent uneventful SMILE in both eyes, whilst one patient underwent FS-LASIK for high astigmatism in both eyes and LRI in the right eye. CDVA of the eye with corneal opacity ranged from 20/22 to 20/20 one to six weeks postoperatively. Two patients achieved better CDVA and no patients lost Snellen lines. The postoperative diopter was within +/- 0.75 D for all eyes. Significant edema existed above the corneal opacity in one eye and dissipated soon. No eccentric corneal topographyor morphological anomaly of the corneal cap or flap was observed.? CONCLUSION: The cases demonstrate that SMILE or FS-LASIK is safe and effective to treat myopic astigmatism combined with deep corneal opacity lesions after comprehensive preoperative evaluation and appropriate candidate selection. FS-LASIK combined with LRI is also sufficient for correcting high astigmatism due to corneal scarring.