Surgical revision for leaking blebs highly effective, one surgeon says

Conservative management options are often discouraging.

Issue: June 1, 2000

ByBob Kronemyer

WAILEA, Hawaii — Glaucoma patients with leaking filtering blebs will most likely benefit from returning to the operating room, according to one surgeon.

“Pulling healthy conjunctiva over the thin area of the bleb to cover it has been shown to be extremely effective,” said L. Jay Katz, MD, an attending surgeon at Wills Eye Hospital in Philadelphia. “But it is invasive.”

Dr. Katz, who spoke here at the Hawaii 2000 meeting, sponsored by Ocular Surgery News and the New England Eye Center, said that “leaking blebs are an increasing problem that need to be recognized because of its potential to progress toward more serious problems — either hypotony, which can result in decreased vision, or even more ominous are bleb infections, which can lead to endophthalmitis and permanently affect vision.”

Early wound leaks can be managed either by using aqueous suppressants, an oversized contact lens that fits over the bleb and the bleb leak to provide a slight tamponade effect or by gluing. “We may even suture the bleb directly in these early wound leaks,” Dr. Katz said. On the other hand, a late leak may be treated conservatively, “watching it and hoping that it will close off spontaneously.” If this is not successful, “there are means to induce subconjunctival healing by autologous blood injections.”

A tamponade suture, YAG laser in the thermal mode, cryotherapy or trichloroacetic acid application are four other options. “Although there are lots of choices, none works particularly well, and the leaking bleb may recur,” said Dr. Katz, a professor of ophthalmology at Jefferson Medical College in Philadelphia.

Pressure control trade-off

Returning to the operating room may be the wisest decision, Dr. Katz said. A study from the Bascom Palmer Eye Institute looked at 26 eyes that had revision surgically, with indications being hypotony, decreased vision and previous bleb infections. About 20 months after surgical revision, 50% of these patients required glaucoma medications. “So the price you pay for doing a revision is that you may lose some pressure control,” Dr. Katz said. “And on occasion, you even have to go back to the operating room to do yet another filtration procedure or another glaucoma procedure for that eye.”

Dr. Katz’s revised surgical technique begins by using scissors to cut along the edge of the filtration bleb and the demarcation line between avascular and vascular conjunctiva. “We cut through conjunctiva and Tenon’s layer all the way down to the sclera,” he said. “When I started performing this procedure, I always thought the bleb would leak along the incision, but it typically doesn’t. The bleb is walled off at the juncture.” The surgeon cuts “all the way around the edge of the bleb and frees up the adjacent conjunctiva. Try not to incise right into the wall of the bleb itself.”

In addition, “you have to really dissect the conjunctiva extensively to mobilize it,” Dr. Katz said. “If you have traction on the conjunctiva pulling it back off the bleb area, it will retract with time. Then you are back to where you started with a leaking bleb.” Scissors are usually used bluntly and sometimes sharply “to make the conjunctival flap very relaxed so you can easily hood it over the bleb,” he added.

Cauterization necessary

By cauterizing the bleb wall “to de-epithelialize the bleb surface, the conjunctival flap will adhere more firmly with healing,” Dr. Katz said.

Some of the epithelium also is peeled off the cornea to achieve better adherence of the anterior conjunctival flap edge, Dr. Katz said. “The epithelium almost peels off like a capsulorrhexis, so you have denudement of the corneal epithelium in that zone,” he said. Two sutures are then employed on either edge of the filtration bleb to bring the conjunctival flap over the bleb site. Several interrupted sutures along the anterior margin anchor the conjunctival flap over the bleb.

After suturing and filling up the anterior chamber with fluid, “we check for wound leaks,” Dr. Katz said. “The conjunctiva over the bleb is a fleshy tone and vascular. Since it is a thicker wall bleb, we often end up with a higher pressure. But it is usually worth the price.” In essence, “surgical revision is a very acceptable method now for providing a better, long-lasting solution to a condition that could be visually disabling and potentially blinding,” he said.

Very thin, avascular bleb.	Seidel positive bleb leak.
Surgical revision of a leaking bleb: using the cautery to remove the surface epithelium of the bleb.	Surgical revision of a leaking bleb: freeing up the conjunctiva adjacent to the filtering bleb.
Surgical revision of a leaking bleb: conjunctival flap hooded over the pre-existing bleb and anchored into position with sutures.

For Your Information:

L. Jay Katz, MD, can be reached at 900 Walnut St., Philadelphia, PA 19107; (215) 928-3197; fax: (215) 928-0166; e-mail: ljk22222@aol.com. Dr. Katz is professor of ophthalmology at Jefferson Medical College of Pennsylvania. Dr. Katz has no direct financial interest in any of the products mentioned in this article, nor is he a paid consultant for any companies mentioned.