Excimer laser treatment for high and extreme myopia. The Melbourne Excimer Laser and Research Group

The excimer laser allows the controlled ablation of corneal tissue to correct refractive error. We assessed the efficacy of excimer laser treatment for persons with high (spherical equivalent between -5 and -10 diopters) and extreme (spherical equivalent greater than -10D) myopia.

Patients were assessed 1, 3, and 6 months postoperatively. A VisX Twenty/Twenty laser was used. Visual acuity, refraction, corneal clarity, and adverse reactions were evaluated at each visit.

Six month follow-up data were available for 194 high myopes and 53 extreme myopes. Postoperative healing was similar for the two groups. Six months postoperatively, 89.2% of high myopes and 49% of extreme myopes were within 2D of planned refraction. At 6 months, 28% of high myopes had an uncorrected visual acuity of 20/20 and 71% had an uncorrected visual acuity of 20/40. Of extreme myopes, 4% had an uncorrected visual acuity of 20/20 and 30% had an uncorrected visual acuity of 20/40. Significantly more corneal haze was observed in the extreme myopes. Loss of 2 or more lines of best corrected visual acuity was observed in 13% of high myopes and 13% of extreme myopes at 6 months.

Excimer laser photorefractive keratectomy is an alternative means of treating high and extreme myopia and can cause a significant reduction in myopia. There is a need to gather further information as more patients are followed up for greater time.