Excimer laser treatment for high and extreme myopia. The Melbourne Excimer Laser and Research Group
C. A. Carson and H. R. Taylor
Department of Ophthalmology, Royal Victorian Eye and Ear Hospital, University of Melboune, Australia.
OBJECTIVE: 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.
METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.
