97th DOG Annual Meeting 1999
TRANSEPITHELIAL PHOTOTHERAPEUTIC KERATECTOMY FOR THE TREATMENT OF RECURRENT EROSION SYNDROME
A. Mutsch, W. Waller
Phototherapeutic keratectomy (PTK) with the 193-nm excimer laser is of increasing interest as therapeutic alternative in the treatment of the recurrent erosion syndrome. Usually, PTK is applied after epithelial debridement. Postoperative changes of refraction and irregular astigmatism were reported after this procedure. These complications could probably be avoided by choosing a transepithelial approach.
Methods: In a prospective study we evaluated the rate of recurrent erosion and visual acuity after transepithelial PTK (t-PTK). 25 eyes of 23 patients with recurrent erosion syndrome were included. The mean duration of recurrent erosion was 14,5 months (3-72 months), with 3 to 20 episodes of recurrent erosion (mean 7,6 episodes). 13 patients reported a history of trauma, in 4 patients an epithelial basement membrane dystrophy was diagnosed, in 6 patients no trauma or dystrophy was found. The size and localisation of the corneal erosion was documented.
We performed t-PTK after reepithelialization was complete (50 pulses, mean epithelial ablation depth 12.5 µm, ablation diameter = maximal diameter of corneal erosion). Mean follow-up time was 14.1 month (4 - 28 months).
Results: In 23 eyes (92%) of 21 patients no further corneal erosion occured during the follow-up period, in 2 eyes (8%) a new episode of erosion occured 6 and 12 weeks after t-PTK. All patients reported an improvement of complaints. Postoperative visual acuity was stable in all patients, it improved two lines in 2 patients with epithelial basement membrane dystrophy.
Discussion: The success rate after t-PTK is similar to the reported results of PTK after epithelial debridement. All patients reported on minimal postoperative pain. No change of refraction and visual acuity occured. Therefore t-PTK seems to be a possible alternative to the conventional PTK procedure and may be used as a "first step" procedure.
University Eye Hospital, Josef-Schneider-Strasse 11, 97080 Würzburg, Germany