Predictability of excimer laser treatment of myopia. Melbourne Excimer Laser Group
H. R. Taylor, C. A. McCarty and G. F. Aldred
Department of Ophthalmology, University of Melbourne, Australia.
OBJECTIVE: To prospectively examine the predictability of excimer laser
photorefractive keratectomy and photoastigmatic refractive keratectomy for
myopia that ranged from -1 to -18 diopters (D). METHODS: Patients were
treated with an excimer laser and followed up prospectively for 12 months.
Low myopia was treated in one ablation zone (6.0 mm), high myopia in two
ablation zones (5.0 and 6.0 mm), and extreme myopia in three ablation zones
(4.5, 5.0, and 6.0 mm) with a maximum treatment of 15 D. Data were analyzed
to determine the distribution of the various postoperative outcomes by
preoperative myopia. RESULTS: Two hundred seventy-four low myopes, 189 high
myopes, and 41 extreme myopes were available for 12-month follow-up. The
re-treatment rate increased with preoperative myopia. The predictability of
refraction and uncorrected and best corrected visual acuity progressively
decreased with increasing myopia. The likelihood of losing lines of best
corrected visual acuity and corneal haze increased with increasing myopia.
CONCLUSION: These data should help in the counseling of patients about the
likely outcome if they have excimer laser surgery to correct myopia.
