Excimer photorefractive keratectomy for low myopia and astigmatism with the Coherent-Schwind Keratom.
OBJECTIVE
To summarize the initial results of excimer laser photorefractive keratectomy (PRK) in 114 eyes of 89 patients using the Coherent-Schwind system and assess its safety, efficacy, and predictability.


METHODS
Hospital San Jose de Monterrey-ITESM, Mexico.


METHODS
The Coherent-Schwind Keratom excimer laser was used to correct low myopia (manifest spherical equivalent from -1.00 to -6.00 diopters [D], with manifest cylinder of -1.00 D or less) or myopic astigmatism (manifest spherical equivalent from -2.75 to -6.75 D, with manifest cylinder from -1.00 to -4.50 D) with standard settings. Ablation zone diameters were from 5.9 to 6.3 mm (low myopia) and 5.9 to 8.2 mm (astigmatism) with a repetition rate of 12 Hz. Follow-up was from 1 month (low myopia, n = 71; astigmatism, n = 35) to 6 months (low myopia, n = 36; astigmatism, n = 17).


RESULTS
Six months after PRK, uncorrected visual acuity was 20/40 or better in 94% of the low myopia eyes (n = 36) and 77% of the astigmatism eyes (n = 17). Intended correction was within 1.00 D of the target spherical equivalent in 81 and 88% of eyes, respectively. No eyes in the low myopia group lost two lines of best corrected visual acuity, although 12% in the astigmatism group did.


CONCLUSIONS
The Coherent-Schwind excimer laser appears to be effective in the treatment of low myopia and astigmatism, with results comparable to those of other laser systems after 6 months of follow-up. Further study of best corrected visual acuity loss after treatment of compound myopic astigmatism with this laser is warranted.
Cornea Service, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, USA.
J S
JS
Vidaurri-Leal
M C
MC
Helena
J H
JH
Talamo
J C
JC
Abad
G
G
Alexandrakis
C
C
Cantu-Charles
D000293:Adolescent; D000328:Adult; D001251:Astigmatism / Q000503:physiopathology / Q000601:surgery*; D003315:Cornea / Q000503:physiopathology / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007429:Intraocular Pressure; D054018:Lasers, Excimer; D008297:Male; D009216:Myopia / Q000503:physiopathology / Q000601:surgery*; D018903:Photorefractive Keratectomy / Q000295:instrumentation*; D011183:Postoperative Complications; D011446:Prospective Studies; D016896:Treatment Outcome; D014792:Visual Acuity