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Editor,—In a previously reported technique of free conjunctival autograft for the repair of leaking blebs,1 2 the distance from the limbus to the harvesting site was not specified. In these reports, the paralimbal conjunctiva could have been excised, which makes future filtration surgery difficult at that site. We believe that even in the contralateral eye or the inferior quadrant of the same eye, paralimbal conjunctiva are sites for potential future filtration surgery in most cases. Buxtonet al stated that grafts should not be taken from the fornix because this can induce foreshortening and lid malposition if both palpebral and bulbar conjunctiva are excised.2 We found that grafts can be harvested from the fornix with no complications, thus preserving the potential filtration sites.
CASE REPORTS
In six eyes of four patients, we repaired persistent leaking blebs after trabeculectomy by transplanting free conjunctival autografts harvested from the fornix. Grafts were harvested from the fornix side of the leaking blebs when possible. When the intact conjunctiva of the fornix side of a leaking bleb was very narrow, the graft was harvested from the other quadrant, 5–6 mm away from the limbus. The procedure followed the previously reported technique,1 2 except for the site from which the graft was harvested. The aqueous leaks were repaired successfully, and filtering function was maintained in all cases. Two eyes of two patients required β blocker treatment to maintain satisfactory intraocular pressure after the repair surgery. Over an average follow up of 9 months (range 6–12 months), none of the six eyes had any significant complications including either adhesion between palpebral and bulbar conjunctiva or lid malposition. The case series are described in Table 1.
Clinical characteristics of the case series
COMMENT
We believe that the optimal site for harvesting conjunctival autografts is the fornix side of the leaking bleb, because it has almost no potential as a future filtration site. The paralimbal conjunctiva of the contralateral eye is often a potential future filtration site, since glaucoma is often bilateral. Even with a diagnosis of “unilateral glaucoma” at the time of bleb reconstruction, the potential for development of glaucoma in the contralateral eye cannot be completely excluded. A persistent bleb leak that requires total reconstruction is frequently encountered in eyes that have undergone multiple procedures2 and treatment with adjunctive antimetabolites.1 3 4 These situations are mostly encountered in eyes with refractory glaucoma, which often have little intact paralimbal conjunctiva remaining but have a high potential for multiple filtration surgeries. We believe that intact conjunctiva within 5 mm from the limbus is needed to perform a successful filtration surgery. The reported distances of the conjunctival fornix from the limbus are as follows5: upper, 8–10 mm; temporal, 14 mm; lower, 8–10 mm; nasal, 7 mm. These data indicate that conjunctiva may be taken from the upper or lower quadrant, and is most easily taken from the temporal quadrant when harvesting a graft 5 mm away from the limbus. No special attention was required to avoid excising the palpebral conjunctiva during this procedure. Excising the palpebral conjunctiva may be technically difficult during this procedure. We conclude that harvesting a graft from the fornix should be considered when reconstruction surgery is performed with free conjunctival autografts for leaking blebs.