Source: DGNews  |  Posted 2 years ago

By Louise Gagnon

TORONTO -- June 30, 2009 -- Buccal mucous membrane grafts can be used as conjunctival substitutes to repair leaking trabeculectomy blebs and exposed glaucoma drainage devices, according to a study presented here at the 72nd Annual Meeting and Exhibition of the Canadian Ophthalmological Society (COS).

Trabeculectomy and the use of a glaucoma drainage device are measures used to lower intraocular pressure in patients with glaucoma, explained Dan Rootman, MD, University of Toronto, Toronto, Ontario.

Because trabeculectomy and the use of a glaucoma drainage device involve remodelling local conjunctiva to form a filtering space, the potential exists for the conjunctiva to erode and for intraocular infection to develop.

"It's rare, but it is possible that the conjunctiva can erode because of the presence of a foreign body or infection," explained Dr. Rootman.

Moreover, conjunctival repairs can fail, and clinicians can be left with only scarred conjunctiva, forcing them to look for other tissue.

"The buccal membrane is a mucous membrane that acts like conjunctiva and is pretty available as an autologous graft," explained Dr. Rootman. "It is pretty easy to harvest and is tolerated quite well."

Dr. Rootman and colleagues used buccal mucous membranes to repair the blebs or cover the glaucoma drainage devices. They defined failure of the use of buccal membranes as repeat bleb leaks requiring surgical intervention or erosion of the glaucoma drainage device despite efforts to cover the device.

The buccal membrane was used to control leaking blebs in 4 eyes of 4 patients. One patient requiring minor procedures to control postoperative leaking. Three cases were considered a success, and the fourth case was considered a qualified success.

In 5 patients, 3 exposed tubes, 2 plates, and a pars plana clip were repaired with a corneal patch graft and buccal mucous membrane. Buccal membrane repairs were regarded successful in 5 of 6 cases (83%). One case, which had a mean follow-up of 18 months, was considered a failure.

The need for conjunctival substitutes arises from a complication that is not so rare in glaucoma management, said Dr. Rootman.

"It is not as uncommon in managing advanced glaucoma cases as you would hope," he added. "The use of a buccal mucous membrane appears robust."

[Presentation title: Buccal Mucous Membrane Grafts for the Repair of Leaking Trabeculectomy Blebs and Exposed Glaucoma Drainage Devices. Abstract P5]