Long-Term Followup of Laser In Situ Keratomileusis for Hyperopia Using a 213？nm Wavelength Solid-State Laser

Purpose. To evaluate the long-term efficacy, accuracy, stability, and safety of hyperopic laser in situ keratomileusis (LASIK) using a 213？nm wavelength solid-state laser. Methods. This prospective noncomparative case series consisted of 34 eyes of 17 patients which underwent hyperopic LASIK using a 213？nm solid-state laser (Pulzar Z1, CustomVis) at an outpatient refractive surgery center in Manila, Philippines. The preoperative and postoperative examinations included uncorrected distance visual acuity (UDVA), subjective manifest refraction, corrected distance visual acuity (CDVA), cycloplegic refraction, slitlamp biomicroscopy, and keratometry ( ). Main Outcome Measures. Accuracy, efficacy, stability, and safety of the refractive procedure. Results. Mean follow-up was months. At the end of follow-up, 26.47% had a UDVA of 20/20 and 94.12% had a UDVA of ≥20/40. Manifest refractive spherical equivalent (MRSE) was within ±0.50？D of the target refraction in 55.88% and within ±1.0？D in 85.30% of the study eyes. Refractive stability was noted in the 1st postoperative month while hyperopic regression was noted after the 3rd postoperative year. No eye lost more than 2 lines of CDVA. Conclusion. Our results show that the 213？nm solid state laser system is safe, effective, accurate, and predictable for the treatment of hyperopia. 1. Introduction Laser in situ keratomileusis is approved by the US Food and Drug Administration (FDA) for the treatment of myopia, hyperopia, and astigmatism and has been a popular choice among refractive surgeons for almost 2 decades now [1, 2]. Hyperopic LASIK consists of an annular zone of ablation to cause a relative flattening of the corneal periphery and a concomitant relative steepening of the center (optical zone) to achieve the desired refractive effect. Early attempts to correct hyperopia included techniques such as hexagonal keratotomy, thermokeratoplasty, keratophakia, and keratomileusis but have met with only limited success. With the advent of the excimer laser technology, reshaping of the corneal surface to a desired contour with submicron precision and reproducibility became a reality [3]. With the prototype ophthalmic excimer lasers, the visual and refractive outcomes of LASIK for hyperopia were less predictable due to challenges arising from the need to use larger ablation diameters and the relative difficulty to deliver uniformly distributed laser energy in ablation zones larger than 6？mm [1]. Newer models have permitted larger ablation diameters and the development of various microkeratomes facilitated the