Custom vs conventional PRK: a prospective, randomized, contralateral eye comparison of postoperative visual function.
OBJECTIVE
To determine whether VISX S4 (VISX Inc) custom photorefractive keratectomy (PRK) results in better visual outcomes than VISX S4 conventional PRK.


METHODS
Photorefractive keratectomy was performed on 80 eyes from 40 patients in this randomized, prospective, contralateral eye study. Dominant eyes were randomized to one group with the fellow eye receiving the alternate treatment. Primary outcome measures included uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), contrast sensitivity, and root-mean-square (RMS) higher order aberrations.


RESULTS
Mean UDVA was -0.023±0.099 (20/19) in the custom group and -0.044±0.080 (20/18) in the conventional group 6 months after surgery (P=.293). Mean CDVA was -0.073±0.067 (20/17) in the custom group and -0.079±0.071 (20/17) in the conventional group 6 months after surgery (P=.659). Total higher order aberration RMS and spherical aberration increased in both groups compared to preoperative values (P<.05). Coma increased in the conventional group (P<.05) whereas it was similar to preoperative values in the custom group. No significant differences were noted in induction of trefoil.


CONCLUSIONS
Custom and conventional PRK were shown to be safe and effective with excellent visual acuity and contrast sensitivity performance at 6 and 12 months. Conventional PRK induced more coma than custom PRK; however, this did not seem to correlate with clinical outcomes.
University of Utah, Department of Ophthalmology and Visual Sciences, Salt Lake City, Utah, USA. mark.mifflin@hsc.utah.edu
Mark D
MD
Mifflin
Bryndon B
BB
Hatch
Shameema
S
Sikder
James
J
Bell
Christopher J
CJ
Kurz
Majid
M
Moshirfar
D015350:Contrast Sensitivity / Q000502:physiology; D006801:Humans; D054018:Lasers, Excimer / Q000627:therapeutic use*; D009216:Myopia / Q000601:surgery*; D018903:Photorefractive Keratectomy / Q000379:methods*; D011184:Postoperative Period; D011446:Prospective Studies; D016037:Single-Blind Method; D016896:Treatment Outcome; D014792:Visual Acuity / Q000502:physiology