Late-onset corneal haze and myopic regression after photorefractive keratectomy (PRK).
OBJECTIVE
To report the incidence and clinical course of a series of patients who developed both delayed-onset, clinically significant progressive haze and myopic regression after photorefractive keratectomy (PRK).


METHODS
In this retrospective case series, the charts of 542 consecutive patients who had undergone PRK with the VISX Star Excimer or Nidek EC-5000 laser between July 1996 and October 1998 and who had a minimum of 6 months of follow-up were reviewed. Ten eyes of 8 patients developed progressive haze to greater than 1+ and myopic regression equal to or more than -1 D 3 months or more after PRK. The historical and clinical features were reviewed.


RESULTS
The incidence of combined progressive haze and myopic regression was 1.8%. The average age was 40.5 years. Three of the 8 patients were female. The median spherical equivalent (SE) attempted correction was -6.69 D (range -4.00 to -12.25 D). Five patients who underwent bilateral PRK had unilateral involvement. The mean SE regression was -2.01 +/- 0.79 D (range -1.00 to -3.00 D). Regression plateaued at a mean of 9.8 months. Haze ranging up to 4+ peaked at a mean of 7.4 months. Topical steroid treatment and/or epithelial scraping was attempted in 3 eyes but was ineffective.


CONCLUSIONS
Combined delayed-onset progressive haze and myopic regression can occur after PRK. In such cases, the amount of haze appears to correlate with the magnitude of attempted initial correction (r = 0.639, P = 0.046) although not with the magnitude of subsequent regression. Patients may need at least 10 months of follow-up to achieve a stable refraction and level of haze. These observations suggest a need for improved understanding of corneal wound healing following PRK and of biologic factors that may contribute to variability in outcomes.
Kuo
Irene C
IC
Cornea and Refractive Surgery Service of the Department of Ophthalmology, University of California, San Francisco, San Francisco, CA 94143, USA. ickuo@jhmi.edu
Lee
Salena M
SM
Hwang
David G
DG
D000328:Adult; D003318:Corneal Opacity / Q000209:etiology*; D019781:Corneal Topography; D018450:Disease Progression; D005260:Female; D006801:Humans; D015994:Incidence; D054018:Lasers, Excimer; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000209:etiology*; D018903:Photorefractive Keratectomy; D011183:Postoperative Complications; D012189:Retrospective Studies; D014786:Vision Disorders / Q000209:etiology; D014792:Visual Acuity