Purpose: To determine the safety and efficacy of photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK) early in a surgeon's experience.
Setting: Ophthalmology Department, John A. Moran Eye Center, Salt Lake City, Utah, USA.
Methods: Between October 1995 and April 1997, a retrospective analysis was performed of 200 eyes in 128 patients who had PRK or LASIK with a follow-up of at least 3 months. The mean age was 38.1 years +/- 10.4 (SD) in the PRK group and 42.3 +/- 10.1 years in the LASIK group. There were 36 women and 30 men in the former and 32 women and 30 men in the latter. Photorefractive keratectomy, PRK/astigmatic keratotomy (AK), LASIK, or LASIK/AK was performed with the Summit Omnimed excimer laser. Preoperative evaluation included uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), cycloplegic refraction, tonometry, and computerized videokeratography. At 1, 3, and 6 months, UCVA, BSCVA, mean spherical equivalent (SE), astigmatism, corneal haze, subjective vision (day, night, glare, and halo), and complications were measured.
Results: Mean SE was 0.16 +/- 0.82 diopter (D) in the PRK group and -0.09 +/- 0.63 D in the LASIK group at 1 month (P < .05), -0.18 +/- 0.66 D and -0.16 +/- 0.58 D, respectively, at 3 months, and -0.33 +/- 0.73 D and -0.09 +/- 0.62 D, respectively, at 6 months. Achieved correction was similar in the 2 groups. Mean BSCVA was 22.8 +/- 6.0 in the PRK group and 22.2 +/- 5.3 in the LASIK group at 1 month, 21.1 +/- 6.0 and 21.1 +/- 3.1, respectively, at 3 months, and 19.8 +/- 3.5 and 22.9 +/- 5.2, respectively, at 6 months (P < .005). Mean surface regularity index was 0.68 +/- 0.40 in the PRK group and 0.86 +/- 0.41 in the LASIK group at 1 month, 0.54 +/- 0.26 and 0.72 +/- 0.37, respectively, at 3 months (P < .05), and 0.49 +/- 0.27 and 0.84 +/- 0.42, respectively, at 6 months. Mean surface asymmetry index was 0.71 +/- 0.43 in the PRK group and 0.55 +/- 0.21 in the LASIK group at 1 month (P < .05), 0.53 +/- 0.24 and 0.51 +/- 0.23, respectively, at 3 months, and 0.46 +/- 0.19 and 0.64 +/- 0.54, respectively, at 6 months. The subjective parameters between the groups were significantly different only at 6 months; patients in the PRK group reported better day and night vision.
Conclusion: With careful preparation and proper training, PRK and LASIK appear to be safe and efficacious even during the surgeon's early learning phases.