Yeo Kim-Teck, MD (Singapore, Singapore), Elaine Hz Huang, MD (Outram, Singapore)

PURPOSE:

To study the long-term results of pars plana glaucoma valve implants (GDI) in neovascular glaucoma in an Asian series.

METHODS:

We retrospectively reviewed the long-term outcome of 16 eyes from 16 patients with uncontrolled neovascular glaucoma operated between 1997 and 2006. Of these, 13 eyes were secondary to proliferative diabetic retinopathy, 2 were associated with central retinal vein occlusion and 1 had a central retinal artery occlusion. A total of 12 Baerveldt and 4 Ahmed glaucoma devices were implanted via the pars plana route during a combined trans pars plana vitrectomy and endolaser procedure. We define success as IOP of 21 mm Hg or less with or without medications. Failure includes phthisis bulbi, IOP of more than 21 mm
Hg,less than 6 mm Hg or additional glaucoma surgery.

RESULTS:

The mean follow-up time was 28.7 months. The IOP was controlled (21 mm Hg or less) in 15 of 16 eyes (93.75%). 10 eyes did not require additional antiglaucoma medications. The average IOP decreased from a mean of 46.1 mmHg (range, 31-66 mm Hg) before surgery to a mean of 13.9 mm Hg (range, 7-20 mm Hg) at the last postoperative visit. The average number of anti-glaucoma medications required decreased from a mean of 3.0 before surgery to 0.5 postoperatively. In the follow-up period the following were encountered: phthisis bulbi from retinal detachment in an eye with advanced diabetic retinopathy (1/16), tube exposure (2/16), tube blockage by fibrin (1/16) and hyphema (1/16). 1 eye had a choroidal detachment that resolved after 7 weeks. There were no tube-plate exposure, endophthalmitis, secondary glaucoma, or corneal decompensation over the entire follow-up period. An anterior chamber GDI in a contralateral eye of 1 patient subsequently had hyphema, tube blockage and phthisis bulbi.

CONCLUSION:

Pars plana insertion of glaucoma valve implants and simultaneous endolaser allow the inciting retinal ischemia to be treated and contributes to the overall 93.75% success rate. Significantly, the long term risk of corneal decompensation is also avoided. The use of a scleral tunnel and anchoring sutures in a prescribed fashion at the sclerostomy site serve to reduce the risk of hypotony.