Long-term outcomes of PRK, LASIK and SMILE

Background Patients and refractive surgeons have a legitimate interest in the long-term results of the most commonly used laser procedures for correction of ametropia. Objective To assess the safety, predictability, stability and late complications according to the current recommendations of the committee for refractive surgery (KRC). Methods Literature search in PubMed with the search term "long-term outcome" combined with either "PRK", "LASIK" or "SMILE". Articles about PRK and LASIK with a minimum follow-up of 10 years and SMILE with a minimum follow-up of 5 years were evaluated and duplications were eliminated. Results From a total of 440 articles that matched these search terms 15 articles were selected and analyzed. The results of PRK were described in 4 studies with a total of 666 eyes, 7 studies (566 eyes) described the results of LASIK and 5 studies (188 eyes) the results after SMILE. Conclusion Long-term studies with follow-up periods of at least 10 years have shown that PRK and LASIK treatment carried out in the early days of medical excimer lasers have a very high level of safety and late complications occurred only rarely. The effectiveness of particularly high corrections declined over time. In contrast, there was no clinically significant regression within the indications recommended by the KRC. The results of SMILE were not inferior to those of PRK and LASIK. In direct long-term comparisons no procedure showed a clear superiority. Due to technological improvements in hardware and software for both preoperative diagnostics and lasers, treatment performed nowadays is presumably even safer, more efficient and also more stable over a long period of time.