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Excimer laser photorefractive keratectomy for hyperopia
Purpose:
To achieve less variation in the refractive outcome of hyperopic photorefractive keratectomy (PRK) by enlarging the treatment zone to 9.0 mm.
Setting:
Marienhospital, Amberg, Germany, and Klinika Ocni A Esteticke Chirurgie, Zlin, Czech Republic.
Methods:
This prospective clinical study was based on the results of PRK in 68 hyperopic eyes (62 patients) using an MEL 60 excimer laser. Mean attempted correction was +4.85 diopters (D) +/- 1.45 (SD) (range +2.00 to +8.25 D). Maximum follow-up was 12 months (68 eyes).
Results:
One year after PRK, 55 eyes (81%) were within 1.00 D and 40 eyes (59%) were within 0.50 D of the intended correction (predictability). Best corrected visual acuity was unchanged or improved in 62 eyes (92%) (safety). Four eyes (6%) lost one line, 1 eye (1%), two lines, and 1 eye (1%), three lines. Sixty-six eyes (97%) had an uncorrected visual acuity of 20/40 or better (efficacy) and 27 (40%), 20/20 or better.
Conclusion:
Photorefractive keratectomy with a 9.0 mm treatment zone was an efficient and relatively safe procedure for correcting hyperopia of up to 8.25 D. The predictability was good. Great care must be taken to improve the centration of the optical zone.