Effect of Corticosteroids in Postoperative Care Following Photorefractive Keratectomies

Since the start of photorefractive keratectomy (PRK) Seiler has recommended the use of topical corticosteroids during the first 3 months after surgery.1 The rationale for this treatment was to diminish the inflammatory reaction as well as to control the keratocytes from producing collagen and creating scars. Our knowledge of corneal wound healing in general, and after PRK in particular, is very limited and the action of corticosteroids is still unclear. Corticosteroids, when given in comparatively large topical doses, create problems. Between 15 and 30% of patients are corticosteroid responders with increased intraocular pressure. This is a threat to the eye, and also a burden for the doctor as intraocular pressure has to be checked during the treatment. The risk for cataract formation after longer periods of topically administered corticosteroids also has been discussed. In order to decrease the rise in intraocular pressure, FML has been used in place of dexamethasone. During the 4 years follow up after PRK it has been reported that a number of patients do not regress or get a scar formation if they have not used corticosteroids in the postoperative period. The reasons to avoid topical corticosteroids in some patients are a misunderstanding of their instructions, or those who have had a history of herpes infection or glaucoma. A double-masked study of the effects of corticosteroids after PRK was performed by Gartry, et al in a small group of patients. After 6 months, the results revealed that there were no differences between the corticosteroid and the non-corticosteroid group. However, the standard deviation was high. As a result of these findings, our group stopped the use of dexamethasone in the postoperative care of PRK patients. The result of this was very dramatic. Within a month's time, a myopic regression started in a majority of the patients. This regression was greater than that seen in earlier experience. At 3 months, the regression increased and it was impossible to avoid corticosteroids in these patients. As a consquence of these results we did two retrospective studies. (Refract Corneal Surg (suppl) 1993;9:S61-S64.)