Abstract
Purpose: :
To determine whether there is a difference in efficacy and safety between Laser in situ keratomileusis (LASIK) and photorefractive keratectomy (PRK) for correction of myopia.
Methods: :
A literature review was performed using the Cochrane protocol to identify published randomized controlled trials comparing LASIK and PRK for correction of myopia. A meta–analysis was performed on the results of these trials. Additional, previously unpublished data was obtained from trial authors to enable comparison of defined outcomes. A retrospective comparison of FDA approval trials for lasers used to perform LASIK or PRK for correction of myopia was also undertaken. Key efficacy (+/–0.50 of target refraction, uncorrected visual acuity – UCVA ≥20/20) and safety outcomes (loss of 2 or more lines of best spectacle corrected visual acuity – BSCVA) were compared between studies.
Results: :
Seven randomized controlled trials compared PRK (683 eyes) and LASIK (403 eyes) for correction of myopia. More LASIK patients achieved UCVA ≥20/20 at 6 months (p=0.009) and 12 months (p=0.01). Loss of ≥2 lines of BSCVA at 6 months was less frequent with LASIK (p=0.05). Data from 14 LASIK (7810 eyes) and 10 PRK (4414 eyes) FDA approval trials showed more LASIK patients achieved UCVA of 20/20 or better at 6 months (p=0.01), significantly more LASIK patients were within +/–0.50D of target refraction at 6 months post treatment (p<0.00001) and loss of ≥2 lines of BSCVA at 6 months was less frequent with LASIK (p<0.00001).
Conclusions: :
LASIK may have superior efficacy and safety to PRK. Further trials employing contemporary equipment and techniques are needed to re–evaluate these findings.
Keywords: refractive surgery: LASIK • refractive surgery: PRK • myopia