Twenty-Year Follow-Up of Excimer Laser Photorefractive Keratectomy: A Retrospective Observational Study

Abstract

Introduction: Photorefractive keratectomy (PRK) was introduced in the late 1980s to correct myopia. The purpose of this study was to assess its long-term efficacy and safety, analyzing patients with at least 20-year follow-up. Methods: This retrospective observational study was carried out on 85 eyes of 54 patients (33 females) that underwent PRK between 1991 and 1998 (mean age 32.62 ± 9.74, range 18-55 years). Both preoperatively and postoperatively, patients underwent a complete ophthalmological evaluation, including uncorrected and corrected distance visual acuity, slitlamp, intraocular pressure, dilated fundus, and corneal topographic examinations. The outcome assessment was made by comparing the preoperative refraction, as spherical equivalent, with the postoperative ones, taking into account the planned refractive correction. Safety and efficacy indices were also calculated. All the data were evaluated with a paired t test. Results: The mean attempted correction as spherical equivalent was-5.64 ± 3.01 D (range-1.00 to-15.00 D), while the mean achieved correction after 20 years was-4.30 ± 3.13 D (range-1.88 to-14.25 D), with a significant statistical difference (p \ 0.01).The mean expected refractive outcome was-0.27 ± 0.81 D (range-4.00 to ? 1.25 D). The mean difference between achieved and attempted treatment was 1.33 ± 1.92 D (range-4.25 to ? 6.25 D), with a significant difference (p \ 0.01).The safety index was 1.00 and the efficacy index was 0.63. Conclusion: The results provided by this study highlight that the procedure could be considered safe, with no long-term sight-threatening complications such as late ectasia or haze.

Ten-Year Outcome of Topography-Guided Transepithelial Surface Ablation for Refractive Myopia Treatment

“…Das manifeste SE lag bei 86 % der Augen nach 10 Jahren innerhalb von ± 1,0 dpt der Zielrefraktion. Die Background Photorefractive keratectomy (PRK) was introduced in the 1980s to correct myopia and subsequentially different commercial laser systems and treatment algorithms have evolved [1,2]. Advantages of PRK over other refractive methods such as laser in situ keratomileusis (LASIK) include less dry eye symptoms, postoperative corneal ectasias, and avoidance of flap-related complications [2].…”

Long-Term Visual and Refractive Stability and Ocular Biometric Changes after Laser-Assisted Subepithelial Keratomileusis for Correction of Myopia

“…Limited studies reported long-term (one-decade or more) results of excimer laser surface ablation procedures including LASIK and PRK for the correction of myopia. 1 2 3 4 5 6 7 In a 12-year study of LASIK for moderate-to-high myopia, Ikeda et al 1 found a refractive regression of 0.7 D from 3 months to 12 years, postoperatively. They found a significant correlation of refractive regression with the changes in keratometry, but not with the changes in CCT from 3 months to 12 years.…”

“… 2 Similarly, a recent retrospective study reported the safety of 1.00 and the efficacy of 0.63 at a 20-year follow-up after PRK. 7 Rajan et al 3 evaluated long-term refractive stability for myopic PRK and reported stability of refraction at 12 years, with no significant change in mean spherical equivalent between 1, 6, and 12 years and no late regression in the long-term. 3 Other studies of myopic refractive surgeries with PRK have also shown mild regression of <0.5 D at 10–16 years.…”

“…Some studies reported the one- or two-decade results of photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK) showing mild regression in subjects without postsurgery ectasia. 1 2 3 4 5 6 7 However, no study has evaluated the efficacy and safety of excimer laser-assisted subepithelial keratomileusis (LASEK) in the long-term.…”

Unexpected ocular morphological changes after corneal refractive surgery: A review

“…Since the first studies performed in the 80's of last century, corneal refractive surgery (CRS) has been adopted as a leading method to correct refractive errors (1,2). Thanks to its reliability and effectiveness, today it is considered a worldwide diffuse and accepted method (3)(4)(5)(6)(7). It is well-known that the refractive effect is related to the corneal flattening and thinning, and several authors evaluated these induced changes (8)(9)(10)(11).…”