Sequential glaucoma drainage implants markedly reduce IOP, medication use
PHILADELPHIA — Second glaucoma drainage implants significantly reduced IOP and medication use but had a high failure rate, according to a study presented here.
“Trabeculectomies have always been the gold standard for glaucoma surgery … but the rates of tube shunt surgery have been going up in the past decade significantly, especially with publication of the Tube Versus Trabeculectomy Study, which showed that Baerveldt tube shunts have about the same IOP lowering as trabeculectomy,” Wanda D. Hu, MD, said at the Wills Eye Annual Conference.
The retrospective study included 65 eyes of 63 patients with a mean age of 62.5 years. Minimum follow-up was 3 months, and average follow-up was about 2 years.
Primary outcome measures were IOP reduction and failure rates. Secondary outcome measures were postoperative medication use, reoperation rates and complications. A majority of patients had primary open-angle glaucoma and previous tube shunt insertion or trabeculectomy.
The average interval from primary tube shunt insertion to secondary insertion was 32 months. Secondary insertions were primarily Ahmed glaucoma valves (New World Medical) and Baerveldt glaucoma implants (Abbott Medical Optics). Most secondary shunts were placed in the inferotemporal quadrant.
Mean IOP decreased 43%, from about 26 mm Hg before secondary tube shunt insertion to 15 mm Hg at 1 year.
Average medication use decreased significantly, from 3.59 preoperatively to 1.71 at 12 months.
The failure rate was 55.4% at a median interval of 2 years postoperatively. “The criteria for success was slightly more stringent in our study,” Hu said.
The most common complications were serous choroidal detachment, worsening corneal edema and diplopia, she said.
Disclosure: Hu has no relevant financial disclosures.