J Korean Ophthalmol Soc.  2000 Jun;41(6):1310-1316.

Seven Year Results of Excimer Laser Photore fractive Keratecto my for Myopia

• Shin JH
• Park JS
• Lee HY

Abstract

To evaluate the long term efficacy of excimer laser photorefractive kerate-ctomy (PRK)for myopia, 37 eyes of 20 patients were observed for 7 years after PRK.The patients were divided into three groups according to preop-erative myopia :group 1 with diopters between -2.00 and -5.75, group 2with diopters between -6.00 and -9.75, group 3 with myopia over -10.0 diopter.During the follow up period, 6 months, 1 year, 2 years and 7 years, refractive error, uncorrected and best corrected visual acuity and corneal opacity were examined. Mean refractive errors seven years after PRK were changed significantly. In group 1 and group 3, long-term regression occured between 2 and 7 years (paired t test:p=0.01, p=0.01, respectively).In group 2, long-term regression occured between 1 and 7 years (p=0.02).At 7 years, in group 1, 92%of eyes, in group 2, 69%of eyes, and in group 3, 20%of eyes achieved uncorrected visual acuity of 0.5 or better.The group 3 showed a trend toward greater regression. With these results we thought that excimer PRK was effective for mild-to-moderate myopia, while less effective for high myopia.Despite the effi-cacy, we believe that slow myopic regression can continue up to 7 years and further follow-up is essential to assess long-term effect.

Keyword

Excimer laser; Myopic regression; Photorefractive keratectomy; Seven year clinical results

MeSH Terms

Corneal Opacity
Follow-Up Studies
Humans
Lasers, Excimer*
Myopia*
Photorefractive Keratectomy
Refractive Errors
Visual Acuity