gms | German Medical Science

The uveoscleral shunt surgery consists of an 8 mm silicone tube, similar to the tubes of drainage implants. After preparation of a scleral flap it is implanted in the supraciliary space and connects the anterior chamber with the suprachoroidal space. This drains the aqueous humour under the choroid.

In 31 eyes from 31 humans with therapy refractory glaucoma after multiple surgery an uveoscleral shunt was implanted. The follow-up time was at least 24 months. The surgery was similarly performed in rabbits. Two different types of tubes were used: open and closed systems (group 1 + 2). The eyes were enucleated for histopathologic examination at days 4, 6, 10 and 21.

In patients, no severe complications occurred. No cases of postoperative hypotony were noted. After 12 months more than 60% and after 24 months more than 40 % of the eyes were regulated without antiglaucomatous therapy. In two eyes the tubes were explanted due to dislocation. In the rabbits, complications regarding the anterior part of the tube were noted including damage of the corneal endothelium and iris stroma, iris incarceration and endothelialisation of the tube. Following implantation, fibrous tissue surrounded the posterior part of the tube in the suprachoroidal space. This process started earlier with closed tubes as compared to open tubes. Neither in humans nor in animals a foreign body reaction was observed.

The uveoscleral shunt implant is a new approach to treat eyes with refractory glaucoma. In many patients, the IOP could be regulated for more than 24 months. The shunt tube was well tolerated by the surrounding tissues as examined by histopathology. The long-term function of the shunt seems to be related to the flow of aqueous humour.