VV 520
Use of the Er:YAG laser in viscocanalostomy
W. Wetzel
Introduction: In the new non-fistulating glaucoma procedures like viscocanalostomy, preparation and excision of deep scleral tissue is necessary, but it may be difficult to avoid injuries of adjacent structures. As shown in other applications, the Er:YAG laser radiation should be feasible to ablate small tissue lamellas from the surface due to its very low thermal penetration depth of only a few micrometers. Here are the first clinical results of this application.
Materials and Methods: We used a commercially available Er:YAG laser (Phacolase, Fa. Asclepion-Meditec, Jena, Germany). This pulsed laser (2940nm wavelength) works in free-running mode with 200µs pulse length. On lower pulse energies up to 20mJ, repetition rates of up to 100Hz are possible. Viscocanalostomy was performed in 5 patients with chronic open-angle glaucoma. Varying the original technique of Stegman, the deep sclerectomy was carried out with the Er:YAG laser using an application probe with rectangular down emitting tip.
Results: In all 5 cases, deep sclerectomy was successfully done without any problems. Schlemms canal could be found and the integrity of the anterior chamber could be preserved. Only in one case, limited hemorrhage occurred out of a chorioid vessel. The intended IOP reduction was achieved in all cases.
Discussion: The Er:YAG laser is very feasible for deep sclerectomy. As compared to the traditional cutting instruments like diamond blades, expense is higher, but also control and therefore safety of the cutting process are better. Unintended to deep preparation can be avoided.
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