[Cyclocryocoagulation in treatment of therapy refractory glaucoma: a retrospective analysis of 185 cryocoagulation procedures].

BACKGROUND

For several years it has been discussed whether cyclocryotherapy is still an up-to-date treatment of resistant inadequately controlled glaucoma. This retrospective study investigates the clinical aspects of 185 cyclocryotherapies between 1988 and 1997.

PATIENTS AND METHODS

At the University Eye Clinic of Tübingen, 114 patients received in 119 eyes (64.3%) one cyclocryotherapy, and in 66 eyes (35.7%) multiple cyclocryotherapies. The standard surgical techniques for cyclocryotherapy can be summarized as followed: probe placements per eye, 4 to 6; location of probe placement, inferior circumference (63.9%); distance of the applicator from limbus, 3 mm (50.7%); temperature of the probe tip, -70 degrees C (34.2%); and time of the treatment, 60 seconds (89.9%).

RESULTS

Intraocular pressure was on average 33.8 mm Hg before treatment. In all analysed glaucoma types intraocular pressure was lowered to 10.2 mm Hg (30%). The most frequent type of glaucoma was the neovascular glaucoma (55%). One year after treatment, this type showed on average, relative to all other types of glaucoma, the highest intraocular pressure (28.1 mm Hg) and a lowering of intraocular pressure by 8.3 mm Hg (22.7%). Half a year after cyclocryotherapy, a highly significant (p < 0.002) reduction of antiglaucomatous medication was achieved in comparison to the preoperative medication.

CONCLUSION

Despite the fact that cyclocryotherapy is not always effective, it is an ambulant surgical technique easy to apply, non-invasive, cost-effective and can be repeated to lower intraocular pressure in resistant chronic glaucoma. We conclude that cyclocryotherapy will remain useful until new techniques, like the diode laser cyclophototherapy (especially ultrasonic controlled), are developed as alternative therapies.