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Abstract #15747 Published in IGR 2-3
Erbium-YAG laser-assisted preparation of deep sclerectomy
Klink T; Lieb W; Grehn FGraefe's Archive for Clinical and Experimental Ophthalmology 2000; 238: 792-796
BACKGROUND: Deep sclerectomy and viscocanalostomy are becoming more and more popular as non-penetrating filtering procedures. The purpose of the present study was to simplify the technique for this procedure and to reduce the rate of unintended perforations during the preparation of the deep lamella. METHODS: Twenty enucleated porcine eyes were used. A superficial lamellar scleral flap with an area of 5 x 5 mm as for trabeculectomy was surgically prepared. Using a pulsed erbium:YAG laser, the deep lamella (220 ± 40 μm) with an area of 4 x 3 mm was removed. Ablation was performed with an energy of 40-100 mJ, a frequency of 1-10 Hz, and a spot size of 500 μm and 1 mm (divergent beam). During the procedure, the intraocular pressure was kept constant by continuous infusion. Finally, the eyes were analyzed histologically. RESULTS: After the initial trials, it was possible to ablate the remaining deep corneoscleral lamella with the erbium:YAG laser without perforating into the anterior chamber. Starting with an energy of 70-85 mJ and a reduction to 40-60 mJ when reaching deeper layers, a spot size of 500 μm and a 10 Hz repetition rate gave the highest safety and efficiency in preparation. After a learning curve, it was possible to preserve Descemet's membrane and intact trabecular meshwork in ten consecutive operations, as demonstrated by histology. CONCLUSIONS: Erbium:YAG laser-assisted deep sclerectomy offers an alternative to microsurgical preparation of the deep scleral lamella. The thermal damage is minimal (10-40 μm), and therefore scarring may not be stimulated.
Dr. T. Klink, Universitäts-Augenklinik Würzburg, Germany. t.klink@mail.uni-wuerzburg.de
Classification:
12.8.3 Non-perforating (Part of: 12 Surgical treatment > 12.8 Filtering surgery)
