97th DOG Annual Meeting 1999



H. Petersen, M. Mrochen, T. Seiler

Reduced suction force and minimizing the movement of intraocular structures during the operating procedure is considered advantageous during vitrectomy. High cutting rates and a reduced suction force enables a continuous vitrectomy, which was published previously.

Patients and Methods: 20 randomized eyes (20 patients) were operated and included in a prospective study. The follow up time was 3 months. 10 eyes were treated by a conventionally available mechanical vitrectomy unit (Prophaco, Fritz Ruck GmbH, Eschweiler). The operating parameters for cutting rate (7Hz), suction force (300mmHg) and aspiration flow (20ml/min) were fixed. For the Erbium:YAG-laser vitrectomy (10 eyes) we used a laser system with an improved handpiece (Adagio, WaveLight, Erlangen). The parameters: cutting rate (70Hz), suction force (50mmHg) and aspiration flow (20ml/min) were also predetermined. All surgery parameters were measured online and recorded , all procedures were video taped.

Results: The averaged suction force for the Er:YAG-laser vitrectomy was significantly decreased (p<0,001) compared to the mechanical vitrectomy. To quantify the amount of intraocular movements we used the rood-mean-square variation in suction. This parameter was significantly smaller in the laser vitrectomy group (p<<0,001).

Conclusions: The Erbium:YAG-laser technique provides a quasi continuous vitrectomy. This technique prevents periodical forces and movements of retinal structures and may provide therefore less damage. With our measurements we can confirm this observation from the video tapes.

Department of Ophthalmology, University Dresden, Fetscherstrasse 74, D-01307 Dresden