One-year results of excimer laser photorefractive keratectomy for low to moderate myopia
S. Dutt, R. F. Steinert, M. B. Raizman and C. A. Puliafito
New England Eye Center, Tufts University School of Medicine, Boston, Mass.
OBJECTIVE: Excimer photorefractive keratectomy is a promising method to
reduce myopia. We evaluated the effectiveness, predictability, stability,
and safety of photorefractive keratectomy performed by two surgeons at a
single site with a 1-year follow-up. METHODS: An excimer laser (Summit
Excimed UV200, Summit Technology, Waltham, Mass) was used to treat 47 eyes.
Preoperative uncorrected visual acuity averaged 20/277 and ranged from
20/60 to 20/500. Spherical equivalent averaged -3.9 diopters and ranged
from -1.5 to -6.1 D. RESULTS: One year postoperatively, best corrected
visual acuity averaged 20/13 and ranged from 20/10 to 20/20. No patients
lost any of best corrected visual acuity. The uncorrected visual acuity at
1 year averaged 20/20 and ranged from 20/10 to 20/200. Ninety-four percent
of eyes had an uncorrected visual acuity of 20/40 or better; 83%, 20/25 or
better; and 74%, 20/20 or better. An initial hyperopic overcorrection is
followed by gradual regression to emmetropia during a 12-month period.
Refractive spherical equivalent averaged 0.44 D and ranged from -3 to +2.6
D at 1 year. The proportion of eyes within 1 D of emmetropia was 80% at 1
year. The most significant shifts in refraction occurred between the first
and second months, but small shifts occurred up to 12 months. Subgrouping
the results according to age revealed a significantly greater effect with
larger residual hyperopia in those older than 40 years. Patient
satisfaction with the procedure was high. CONCLUSION: During a 1-year
period, excimer photorefractive keratectomy appears to be an effective,
predictable, stable, and safe method to reduce myopia. Age may play a role
in the effectiveness of the procedure, with greater hyperopia resulting in
those older than 40 years.
