The visual outcomes and corneal biomechanical properties after PRK and SMILE in low to moderate myopia

Purpose: To compare the corneal biomechanical parameters, visual outcome, and epithelial remodeling after small-incision lenticule extraction (SMILE) and photorefractive keratectomy (PRK) for low to moderate myopia. Design: Prospective, interventional, randomized, comparative study. Methods: Eighty eyes of 40 patients undergoing bilateral SMILE or PRK for low to moderate myopia ( Results: At 6 months follow-up, the corrected distance visual acuity as well as the postoperative spherical equivalent of both the groups were comparable (P = 0.13 and P = 0.32, respectively). The biomechanical parameters like deformation amplitude ratio (P < 0.01), inverse concave radius (P = 0.006), integrated ratio (P < 0.01), stress-strain index (P < 0.01), Ambrosio's relational thickness (ArTH) (P < 0.01), and corneal biomechanical index-laser vision correction (P = 0.02) were altered more in the SMILE group than in the PRK group, while the biomechanically corrected intraocular pressure (P = 0.16) was comparable. Epithelial remodeling (P = 0.59), higher-order aberrations (P = 0.53), and stromal keratocyte loss (P = 0.16) in both the groups were comparable. Conclusion: Both SMILE and PRK are comparably effective procedures for correction of low to moderate myopia in terms of visual outcomes; however, the corneal biomechanical stability in PRK is superior than that in SMILE. Keywords: Corneal biomechanics, myopia, PRK, SMILE
Author(s): Shivani Joshi [1]; Aafreen Bari [1]; Chetan Shakkarwal [1]; Tushar Agarwal [1]; Tanuj Dada [1]; Rajesh Sinha [1]; Jeewan Singh Titiyal [1]; Namrata Sharma (corresponding author) [1] There are [...]