Do topical corticosteroids have a role following excimer laser photorefractive keratectomy?

The article reviews the evidence for and against the use of topical corticosteroids following PRK. Two significant problems after PRK are the development of corneal haze and unpredictability of the refractive outcome. These arise from changes in the anterior stroma, the deposition of new subepithelial tissue, and individual variations in the wound healing response. In rabbits, corticosteroids reduced corneal haze by limiting the synthesis of subepithelial collagen. However, in humans, controlled trials showed that corticosteroids had no lasting effect on either haze or regression, and were associated with an unacceptably high incidence of unwanted effects. The difference between species probably related to the relative absence of collagen and predominance of glycosaminoglycans during corneal wound healing in humans. Some human studies have shown rapid changes in refraction occurring within days of stopping or restarting corticosteroids. This suggests that their transient hyperopic effect is probably mediated by changes in the hydration of the tissue. Therefore, the role of corticosteroids in PRK is very limited. There is no justification for their routine use after PRK for low or moderate myopia. If corticosteroids have a role in improving haze or refractive outcome in selected patients, a means for their early identification must be found.