The U.S. Army Surface Ablation Study: comparison of PRK, MMC-PRK, and LASEK in moderate to high myopia.
OBJECTIVE
To compare visual outcomes following photorefractive keratectomy (PRK), PRK with mitomycin C (MMC-PRK), and LASEK in moderate and high myopia in military personnel.


METHODS
This prospective, randomized contralateral eye study included 167 patients 21 years or older with manifest spherical equivalent -5.99 ± 1.40 diopters (D) (range: -3.88 to -9.38 D) randomized to either MMC-PRK or LASEK treatment in their dominant eye and conventional PRK without MMC in the fellow eye. All procedures were performed using the LADARVision 4000 Excimer Laser System (Alcon Surgical Inc., Ft. Worth, TX). High- and low-contrast visual acuities, manifest refraction, endothelial cell count, and corneal haze were evaluated up to 12 months postoperatively.


RESULTS
At 12 months postoperatively, visual outcomes were comparable among the treatment groups. Corneal haze of any grade was less common in MMC-PRK compared to PRK at 1 month (21.4% vs 31.0%; P < .01) and 3 months (12.8% vs 35.9%; P = .03) postoperatively; it was also less common in MMC-PRK compared to LASEK at 1 month (21.4% vs 55.9%; P < .01), 3 months (12.8% vs 42.4%; P < .01), and 6 months (12.2% vs 36.4%; P = .03) postoperatively. Haze rate (grade 0.5 or higher) was comparable between LASEK and PRK. Clinically significant haze (grade 2 or higher) developed after PRK (4 eyes) and LASEK (2 eyes), but not after MMC-PRK.


CONCLUSIONS
MMC-PRK showed some benefits in minimizing corneal haze formation. One year after surgery, there was no discernible difference in the postoperative refractive outcomes among the three methods.
Rose K
RK
Sia
Denise S
DS
Ryan
Jayson D
JD
Edwards
Richard D
RD
Stutzman
Kraig S
KS
Bower
D000328:Adult; D000477:Alkylating Agents / Q000008:administration & dosage*; D002452:Cell Count; D003131:Combined Modality Therapy; D003315:Cornea / Q000503:physiopathology; D004728:Endothelium, Corneal / Q000473:pathology; D005260:Female; D006772:Hospitals, Military; D006801:Humans; D049008:Keratectomy, Subepithelial, Laser-Assisted / Q000379:methods*; D054018:Lasers, Excimer / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D008889:Military Personnel; D016685:Mitomycin / Q000008:administration & dosage*; D009216:Myopia / Q000503:physiopathology / Q000601:surgery*; D047728:Myopia, Degenerative / Q000503:physiopathology / Q000601:surgery; D018903:Photorefractive Keratectomy / Q000379:methods*; D011446:Prospective Studies; D012029:Refraction, Ocular / Q000502:physiology; D016896:Treatment Outcome; D014481:United States; D014792:Visual Acuity / Q000502:physiology; D014945:Wound Healing; D055815:Young Adult
D000477:Alkylating Agents; D016685:Mitomycin