Effect of topical interferon-alpha 2b on corneal haze after excimer laser photorefractive keratectomy in rabbits.

BACKGROUND

Anterior corneal stromal keratocytes are activated by excimer laser photorefractive keratectomy resulting in haze with healing of the ablated area. In some eyes, this causes a visible haze or scar on the cornea, and an unpredictable regression of the myopic correction following refractive ablations.

METHODS

Following a 6.00-diopter excimer laser photorefractive keratectomy to both eyes, 16 rabbits were treated for 5 weeks with interferon-alpha 2b drops four times a day to one eye only. Eight of these rabbits were treated with dexamethasone drops four times a day to both eyes. Using a standard grading scale for haze, the corneas were examined and the haze graded weekly.

RESULTS

The observed corneal haze was significantly reduced in the treated eyes by the application of topical interferon-alpha 2b drops (p = .004), and topical dexamethasone drops (p < .001). Topical dexamethasone also produced less haze in combination with interferon-alpha 2b than when used alone (p = .035). There was continuing resolution of the corneal haze in those rabbits observed for 7 weeks after the cessation of the drops. Topical interferon-alpha therapy was not toxic to the rabbit eye and was not associated with delayed reepithelialization after the laser procedure.

CONCLUSION

Topical interferon-alpha 2b appears to reduce the corneal haze produced by excimer laser photorefractive keratectomy in rabbits.