Photorefractive Keratectomy for Correction of Hyperopia Over 3 Diopters after 1 Year

Photorefractive keratectomy or PRK is a good way to correct mild, moderate and severe myopia and astigmatism. Because of several reports about the sight threatening of Hyperopic PRK, it’s effectiveness is less known. This study was done to characterize the refractive changes after excimer laser PRK for correction of hyperopia > 3 diopters and to assess refractive state and changes in astigmatism after 1year.

In an interventional study, thirty eyes of nineteen patients were participated. Their mean refractive error was +5.45 diopters and mean astigmatism was -1.42D. All of the patients were treated by Technolas 217-z excimer laser. Post operative SE (sphere equivalent), UNCVA (uncorrected visual acuity), BCVA (best corrected visual acuity) and all of the complications examined at 12 months later.

The mean post operative refraction was +1.00D (range-2.00 to +5.00), the mean SE was 0.55D and mean astigmatism was -0.95D (range -0.25 to-2.00D). Mean BCVA was unchanged or improved in 83.4% of cases (pre op log MAR = 0.10 and post op log MAR = 0.11) but five eyes (16.6%) lost 1 or 2 lines of snellen BCVA. In 46.6% refraction was within +/-1.00D and 80% was within +/-2.00 from target refraction. The grade corneal haze in eighteen eyes (66%) was 0 or 0.5 and in one eye was 3 and neither developed to grade 4.

Hyperopic PRK has a low predictability for high hyperopia but it is effective for low hyperopia. We do not recomended PRK in highly hyperopic-astigmatic eyes.