The perforation of the flap consisting of conjunctiva and Tenon's capsule is a serious complication in a glaucoma filtering operation. It results in a collapsed anterior chamber and hypotony. Closing the perforation is most difficult1-6 especially if it occurs at the limbus over the sclerectomy. At this point, the conjunctiva is so thin and friable that it is virtually impossible to achieve a watertight closure by suturing to the more rigid cornea. A second layer of conjunctiva, however, used as a tissue patch, will seal the hole effectively without the necessity for sutures in the immediate operative area.
In the posterior lip sclerectomy,7 the initial incision is 8 mm behind the limbus (Fig 1, A and B). The conjunctiva and Tenon's capsule are undermined as far as the Tenon's scleral reflection (Fig 2, A and B). It is at this point, the anterior limit of the undermined area,
ILIFF CE. Flap Perforation in Glaucoma Surgery Sealed by a Tissue Patch. Arch Ophthalmol. 1964;71(2):215-218. doi:10.1001/archopht.1964.00970010231016