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Erbium YAG-Laser assisted deep sclerectomyW. E. Lieb, T. Klink, F. Grehn
Purpose: Deep sclerectomy and viscocanalostomy are popular non-filtering glaucoma procedures. Purpose of this study was to simplify the procedures to reduce the rate of unpretended perforations which do occur during the preparation of the deep lamella.
Patients and Methods: We surgically prepared a lamellar sclerectomy with an area of 5x5 mm as with a standard trabeculectomy procedure in 8 patients (5 men/3 women, age 65,6 ±7,2 y) with pseudoexfoliation glaucoma and POAG, followed by preparation of the smaller deep lamella using a pulsed Erbium YAG-Laser (Wavelight Laser Technologie GmbH, Adagio). Ablation was performed with an energy of 40-80 mJ and a spot size of 500 µm. Schlemmm´s canal was selectively opened and a thin corneo-scleral lamella which allowed aqueous percolation remained. The scleral flap was secured with 2 - 4 sutures after a hyaluronic acid depot (Healon GV) was placed.
Results: After initial trials it was possible to systematically ablate the remaining cornea and sclera with the Erbium YAG-Laser without perforations. Intraoperatively energy levels of 40-80 mJ, a spot size of 500 µm and single pulse mode gave highest safety and efficiency in preparation. In one case a perforation occured which required surgical iridectomy. In 2 cases Nd-Yag laser goniopuncture was performed. In 7 cases the IOP 3 months postoperatively was below 21 mmHg without medications.
Conclusions: The Erbium YAG-Laser assisted deep sclerectomy offers an safe alternative to microsurgical preparation of the deep scleral lamella. Perforations can be avoided because of the very selective tissue ablation. The thermal damage is so minimal (10-30 µm) that additional scarring should not be stimulated.
Dept. of Ophthalmology, Julius Maximilians University, Josef-Schneider-Str. 11, D-97080 Wuerzburg