Tube Obstruction of a Non valved Glaucoma Drainage Device by a Dislocated Soemmering’s Ring

We report a case of tube obstruction of a non valved glaucoma drainage device (Aurolab Aqueous Drainage Implant; AADI) with a dislocated Soemmering’s ring leading to a postoperative intraocular pressure (IOP) spike after an initial IOP reduction. A 24 year old male with bilateral aphakia, bilateral secondary glaucoma developed corneal decompensation in the left eye. The IOP in the left eye was 22▒mmHg with three IOP topical lowering medications (timolol 0.5%, brimonidine 0.2% and latanoprost 0.005%). To control the IOP prior to performing a penetrating keratoplasty, AADI was implanted. A good bleb and an IOP of 10▒mmHG was noted at 6.5 weeks postoperatively. The following day the patient developed an acute rise in IOP (42▒mmHg) due to tube obstruction of the AADI by a Soemmering’s ring. 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, Soemmering’s ring removal, penetrating keratoplasty, and tube trimming was performed. Following this, the patient had good IOP control, and a clear corneal graft at 1 year follow up. In aphakic eyes undergoing non valved glaucoma drainage device implantation, a complete pars plana vitrectomy combined with any lens remnant removal may be considered. It helps to avoid tube obstruction due to these lens remnants which can migrate anteriorly along with the aqueous currents.