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Giant filtration pads and glaucoma

Alexey Kryvenko, medical expert
Last reviewed: 08.07.2025

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Giant pads can grow on the cornea, occupying the central zone and inducing asymmetric astigmatism with the impossibility of correcting visual acuity. Treatment of giant pads should be progressive, starting with the simplest methods and moving on to more complex ones.

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Treatment of giant pads

Separation and extrusion technique. Using a blunt spatula, determine the plane of delamination of the hanging pad, then move it back toward the limbus.
The technique of separation and extrusion when applying compression sutures. Then they use the same technique, applying compression sutures in the limbus area, which constantly press on the pad.
Removal of the corneal portion of the porous filtration pad. This approach is used for pads hanging over the cornea, similar to a sponge. The excess portion is excised with Vannas scissors.
As a rule, removing the entire filter pad is completely unnecessary.

The following case report is an exception to the general rule. The patient is a 55-year-old African American man with a history of multiple surgeries in his only sighted eye. The most recent surgery was a successful trabeculectomy with mitomycin for advanced glaucoma. The other eye was lost to glaucoma.

The patient developed corneal edema, underwent corneal transplantation, and visual acuity in the only functioning eye dropped from 20/30 to 20/200. After corneal transplantation, visual acuity increased to the initial 20/30 after 6 months.

The trabeculectomy remained functional, maintaining good intraocular pressure throughout the postoperative period. After 1 year, the patient developed a giant filtration pad that covered the entire cornea and significantly reduced visual acuity.

The patient was treated as described above, but the filter pad kept returning to its original state, growing larger. Eventually, visual acuity deteriorated to 20/400, and the eye barely functioned. After discussing the risks of the operation with the patient, it was decided to take the unusual step of revising the entire pad.

In this case, the patient had a different problem - excess free conjunctiva without scars surrounding the filter pad. As a result, after removal of the filter pad, it was reconstructed using a double layer of amniotic membrane from a donor transplant. A small filter pad with minimal vascularization was formed, which maintained good intraocular pressure for more than 4 years.