Tube Obstruction of a Nonvalved Glaucoma Drainage Device by a Dislocated Soemmering's Ring.

Abstract

The authors report a case of tube obstruction of a nonvalved glaucoma drainage device (Aurolab aqueous drainage implant; AADI) with a dislocated Soemmering's ring (SR) leading to a postoperative intraocular pressure (IOP) spike after an initial IOP reduction. A 24-year-old man with bilateral aphakia, bilateral secondary glaucoma developed corneal decompensation in the left eye. The IOP in the left eye was 22 mm Hg with 3 topical IOP-lowering medications (timolol 0.5%, brimonidine 0.2%, and latanoprost 0.005%). To control the IOP before performing a penetrating keratoplasty, AADI was implanted. A good bleb and an IOP of 10 mm Hg were noted at 6.5 weeks postoperatively. The following day the patient developed an acute rise in IOP (42 mm Hg) because of tube obstruction of the AADI by a SR. The IOP spike was initially controlled with oral acetazolamide and topical IOP-lowering medications (fixed combination of timolol 0.5% and brimonidine 0.2%). Six days later, pars plana vitrectomy, SR removal, penetrating keratoplasty, and tube trimming were performed. Following this, the patient had good IOP control and a clear corneal graft at 1-year follow-up. In aphakic eyes undergoing nonvalved glaucoma drainage device implantation, a complete pars plana vitrectomy combined with any lens remnant removal may be considered. It helps to avoid tube obstruction because of these lens remnants, which can migrate anteriorly along with the aqueous currents.