Abstract
Purpose::
To compare photorefractive keratectomy with prophylactic use of mitomycin C (MMC-PRK) and laser in situ keratomileusis (LASIK) in custom surgeries for compound myopic astigmatism.
Methods::
Eighty-eight eyes of 44 patients with a minimum estimated ablation depth of 50 µm were randomized to PRK with MMC 0.002% for one minute in one eye and LASIK in the fellow eye. Uncorrected visual acuity (UCVA), best-spectacle-corrected visual acuity (BSCVA), cycloplegic refraction, biomicroscopy, contrast sensitivity, specular microscopy, aberrometry and a subjective questionnaire were evaluated. All patients completed 6 months follow-up.
Results::
Mean spherical equivalent (SE) error before surgery and mean ablation depth (AD) were -3.99 ± 1.20 diopters (D) and 73.09 ± 14.55 µm in LASIK and -3.85 ± 1.12 D and 70.7 ± 14.07 µm in MMC-PRK eyes. At six months postoperatively, the mean UCVAs (logMAR) were -0.10 ± 0.09 in LASIK eyes and -0.13 ± 0.10 in MMC-PRK eyes (p>0.05). The mean BSCVAs improved in both groups postoperatively (p=0.001), with no statistical difference between groups. The mean cycloplegic SE error was 0.52 ± 0.56 D and 0.56 ± 0.34 D in LASIK and MMC-PRK, respectively at last follow-up (p>0.05). Significant haze was not observed in any PRK eye. The mean higher-order aberrations (HOA) was higher in LASIK eyes postoperatively when compared with MMC-PRK eyes (p<0.04). MMC-PRK eyes showed better contrast sensitivity than LASIK eyes. The endothelial cell count did not differ significantly in the 2 groups (p>0.713). MMC-PRK eyes were better rated in terms of visual satisfaction.
Conclusions::
MMC-PRK may be more effective than LASIK in custom surgeries for myopic corrections. Our six months follow-up did not notice any evidence of MMC toxic effects. Further follow-up is necessary to attest long-term safety.
Clinical Trial::
www.clinicaltrials.gov NCT00365040
Keywords: refractive surgery: PRK • refractive surgery: LASIK • myopia