Safety, efficacy, and stability indices of LASEK correction in moderate myopia and astigmatism.
OBJECTIVE
To evaluate the visual outcomes and complications in low to moderate levels of myopia and astigmatism treated with laser-assisted subepithelial keratectomy (LASEK) with a focus on postoperative recovery.


METHODS
Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Massachusetts, USA.


METHODS
A retrospective analysis of a case series of eyes treated with LASEK from 1996 to July 2002 with a follow-up of 2 years was performed. The LASEK technique involved creating an epithelial flap with 25 to 45 seconds of exposure to 20% alcohol, ablating the corneal surface using 3 different excimer lasers and nomogram adjustment, and repositioning the flap and applying a bandage contact lens. The main outcome measures were uncorrected visual acuity (UCVA), efficacy index, manifest refraction, best spectacle-corrected visual acuity (BSCVA), safety index, retreatment rate, and complications.


RESULTS
One hundred seventy-one eyes (85 right eyes and 86 left eyes) of 105 patients were studied. Preoperatively, the mean spherical equivalent was -2.99 diopters (D) +/- 1.43 (SD) (range -0.38 to -7.75 D) and the mean cylinder, -0.78 +/- 0.73 D. The UCVA ranged from 20/800 to 20/32, and the BSCVA ranged from 20/63 to 20/16; the median was 20/20. One week postoperatively, 96% of eyes had a UCVA of 20/40 or better but definitive visual recovery took more than 4 weeks in some eyes. Approximately 95% of eyes were within +/-1.0 D of emmetropia after 4 to 52 weeks; the remaining 5% did not show major deviations. At 4 to 52 weeks, only 1 eye was overcorrected by more than 1.0 D of manifest refraction. The safety index remained close to 1.0 for the follow-up after 4 weeks. The efficacy index displayed a plateau at 0.9 from 1 month to 1 year. No serious complication (including recurrent erosion syndrome) was encountered. The mean follow-up was 31 weeks, and the retreatment rate was 2.9% up to 2 years of follow-up.


CONCLUSIONS
The long-term safety and effectiveness of LASEK for the correction of low to moderate myopia and astigmatism were demonstrated. The treatment effect stabilized after 4 weeks.
Department of Ophthalmology, Massachusetts Eye and Ear Infirmary and the Schepens Eye Research Institute, Harvard Medical School, Boston, MA 02114, USA.
Suphi
S
Taneri
Rachel
R
Feit
Dimitri T
DT
Azar
D000328:Adult; D000368:Aged; D001251:Astigmatism / Q000503:physiopathology / Q000601:surgery*; D019573:Epithelium, Corneal / Q000503:physiopathology / Q000601:surgery*; D005260:Female; D006801:Humans; D020731:Keratomileusis, Laser In Situ / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000503:physiopathology / Q000601:surgery*; D012189:Retrospective Studies; D012449:Safety; D013524:Surgical Flaps; D016896:Treatment Outcome; D014792:Visual Acuity / Q000502:physiology