AQUEOUS TUBE SHUNT TO A PREEXISTING EPISCLERAL ENCIRCLING ELEMENT IN THE TREATMENT OF COMPLICATED GLAUCOMAS

Purpose: The treatment of glaucoma after scleral buckling surgery is o ften problematic. The authors investigated a series of patients in who m a silicone tube was implanted to shunt aqueous from the anterior seg ment to the fibrous capsule surrounding a previously placed silicone e piscleral encircling element. Methods: Thirteen patients were retrospe ctively reviewed. In each patient, a silicone tube was inserted throug h a small incision into the fibrous capsule overlying the scleral expl ant. In most patients, no attempt was made to secure the distal end of the tube to the silicone band. The proximal end of the tube was inser ted into the eye via a needle track. Results: Successful control of in traocular pressure (IOP) (6 mmHg less than or equal to final IOP I 21 mmHg with or without medication) was ultimately achieved in 11 (85%) o f 13 patients (3 of the successful patients underwent one or more surg ical revisions to relieve obstruction of the proximal and/or distal tu be opening). Follow-up in these patients ranged from 8 to 49 months (m ean +/- standard deviation, 21.7+/-14.1 months). The final postoperati ve visual acuities were within one line of the preoperative visual acu ities or had improved in 11 (85%) patients. Complications included ser ous choroidal detachment (3 patients; 23%), conjunctival wound leak (2 patients; 15%), hyphema (1 patient; 8%), and tube obstruction by lens , iris, vitreous, or episcleral fibrous tissue (4 patients; 31%). Conc lusion: Aqueous tube shunt to a pre-existing episcleral encircling ele ment is useful in treating complicated glaucomas after scleral bucklin g surgery. Fibrous obstruction of the external tube opening is a frequ ent complication in the early postoperative period, but it may be reli eved by surgical revision.