Excimer photorefractive keratectomy for myopia

Ophthalmology. 1993 Sep;100(9):1335-45. doi: 10.1016/s0161-6420(13)31819-3.


Purpose: To study the safety, effectiveness, predictability, and stability of excimer laser photorefractive keratectomy (PRK) in 133 normally sighted eyes.

Methods: An excimer laser was used with a fluence of 160 mJ/cm2 at a frequency of 5 Hz and an ablation zone of 5.0 mm. The effects of nitrogen purge at surgery and postoperative steroids were evaluated.

Results: No significant complications occurred in any patient. After an initial over-correction, the refraction stabilized. The average results obtained at 6 months were maintained on successive examinations to 36 months. Analysis of their visual acuity in groups IIA, IIB, and III indicates that results at 6 months are predictive of final results at 1 to 3 years (P < 0.0001; r > 0.9). In myopia (1.00-6.00 diopters [D]) treated with the excimer laser, there was a trend toward improvement in results over the course of the study. In 60% in group IIA, 58% in group IIB, 71% in group III, and 88% in group III no nitrogen (no N2), +/- 1 D was obtained. For 20/40 or better uncorrected visual acuity, the outcome was 70% for group IIA, 67% for group IIB, 75% for group III, and 100% for group III no N2. Significant improvement was noted without nitrogen purge. No significant improvement was observed from steroid treatment as used.

Conclusion: In reducing myopia, PRK appears to be safe and effective. The results obtained are reasonably predictable and stable after 6 months. As more refinements are introduced, this procedure could become one of the most promising in refractive surgery.

MeSH terms

  • Adult
  • Astigmatism / etiology
  • Contrast Sensitivity
  • Cornea / surgery*
  • Corneal Opacity / etiology
  • Epithelium
  • Female
  • Fluorometholone / administration & dosage
  • Follow-Up Studies
  • Humans
  • Laser Therapy* / adverse effects
  • Male
  • Middle Aged
  • Myopia / surgery*
  • Prognosis
  • Visual Acuity
  • Wound Healing


  • Fluorometholone