Photorefractive keratectomy for myopia of -8.00 to -24.00 diopters.

BACKGROUND

Sixty-eight highly myopic eyes (mean refraction, -11.17 diopters [D]; range, -8.00 D to -24.00 D) were treated with excimer laser photorefractive keratectomy and followed 1 year.

METHODS

A 193 nm Meditec excimer laser was used with a 5.0-mm ablation zone without peripheral taper. All patients were followed during a period of at least 1 year. All patients had a complete ophthalmological examination including videokeratography and documentation of haze.

RESULTS

After 1 year, uncorrected visual acuity was 20/20 or better in eight (13%) and 20/40 or better in 48% of eyes; 42% of eyes had a refraction within +0.50 D, 74% within +/-1.00 D, and 90% within +/-2.00 D of the planned correction. The eyes that needed only a single treatment obtained the best results. In 30% of eyes, two treatments were necessary in order to obtain acceptable results. A decrease of spectacle-corrected visual acuity, caused by the laser treatment, was exceptional, probably transient, and increased when a second treatment was necessary. Subjective complaints were present in four of 68 eyes. Eyes with clinically significant regression had more and longer lasting haze.

CONCLUSION

Excimer laser photorefractive keratectomy for myopia of -8.00 D and more give less predictable results than those achieved for less than -8.00 D. Two treatments improve the outcome but cause more loss of spectacle-corrected visual acuity.