Transepithelial PTK/PRK over complicated LASIK flaps.

To the Editor: We read with interest the recent contribution by Dr. William Bond (Bond WI. PRK over incomplete LASIK flap [letter]. J Refract Surg 2000;16:483). We are convinced that some variant of the technique he described, which we think is probably more appropriately referred to as transepithelial PTK/PRK, will eventually become the procedure of choice for the treatment of some patients who suffer from flap complications from LASIK. Kapadia and Wilson have described a similar technique using transepithelial PRK for thin corneal caps or flap abnormalities after LASIK.1 In those cases, however, the transepithelial PTK/PRK treatment was administered weeks after the initial, complicated LASIK procedure, rather than immediately, as recommended by Bond. Although the additional waiting time may create anxiety for the patient, we think that delayed transepithelial PTK/PRK may allow the inflammatory component of the wound healing process to diminish, potentially reducing the incidence of lateonset corneal haze2 that is typically associated with PRK following LASIK, as in the case encountered by Dr. Bond’s colleague. In addition, performing a delayed transepithelial PRK treatment may also allow the epithelium time to remodel, and thereby “smooth” the corneal surface, especially in cases of bottonhole flaps. However, excessive waiting following the initial procedure may increase the risk of scar formation associated with the wound healing process, which would make subsequent laser treatment potentially less predictable. The optimal timing for the PTK/PRK procedure in this situation has yet to be determined. We have treated patients who developed significant haze following PRK after aborted LASIK procedures with mitomycin C, with excellent results.3 We suggest that adjunctive mitomycin C treatment, as we have described, be considered prophylactically following transepithelial PTK/PRK in this setting. Our experience and that of other researchers has shown that in this concentration and dosing scheme, mitomycin C has no toxic side effects. We are presently engaged in a prospective clinical trial in an attempt to determine the optimal timing for this treatment following aborted LASIK procedures. We commend Dr. Bond for his contribution and look forward to learning about his long-term results with these patients.