[Phototherapeutic keratectomy in recurrences of granular corneal dystrophy after keratoplasty].

BACKGROUND

Recurrences of granular corneal dystrophy (Groenouw type I dystrophy) after penetrating keratoplasty have been often reported in the literature. Up to now the therapy of these recurrences consists in performing a lamellar or penetrating re-keratoplasty. As those recurrent opacities at first are located in the area of Bowman's membrane and the superficial corneal stroma, a phototherapeutic keratectomy (PTK) with an excimer laser offers a therapeutic alternative to re-keratoplasty.

PATIENTS AND METHODS

We describe three eyes of two patients with recurrent opacities on the transplant after successful keratoplasty because of granular corneal dystrophy. In all eyes we performed an excimer-laser PTK (Keratom of Schwind Company, Kleinostheim/Germany, wave length 193 nm) after abrasion of the epithelium with a hockey-knife. The depth of ablation depended on the location of the opacities and was between 7 microns and 35 microns. During the excimer-laser treatment several biomicroscopical slit-lamp controls were performed to make sure whether a sufficient depth of ablation was obtained.

RESULTS

The opacities could be totally removed in all eyes by excimer-laser PTK. Postoperatively the visual acuity increased and the patient's photophobia decreased. At the same time a slight progression of hyperopia developed depending on the depth of ablation. During the follow-up period of 5 to 12 months no recurrent opacities could be found until now.

CONCLUSIONS

Phototherapeutic keratectomy with the excimer laser seems to be a good alternative to re-keratoplasty in superficially located recurrences of granular corneal dystrophy in a graft after keratoplasty. A slight progression of hyperopia depending on the depth of ablation has to be accepted. The future will show whether there will develops recurrent opacities of the dystrophy after an excimer laser treatment.