Editor,—Flat anterior chamber (AC) is a significant complication following trabeculectomy, which can cause serious sequelae.1 Treatment of flat AC may include drugs, torpedo dressing, or megasoft contact lens and reformation using hyaluronic acid, BSS, expandable gases, or air.2 3

Between 1989 and 1996, 15 patients in our department underwent reformation of flat AC with sulphur hexafluoride (SF₆) following a first standard Cairns trabeculectomy. Nine patients had open angle glaucoma, three closed angle, two pseudoexfoliation, and one juvenile glaucoma. All eyes were phakic. Following the trabeculectomy, all patients suffered from flat AC and hypotony, and six of them also had corneal decompensation. Reformation was performed by injecting 25–100% SF₆ via a paracentesis, to fill two thirds of the AC. Three patients needed repeat reformation. All ACs eventually remained deep with normal intraocular pressure (IOP). The IOP values, with a gas bubble present in the AC, did not exceed 22 mm Hg, and are shown in Figure 1. None of the patients needed extraction of gas for any reason.

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Figure 1

Average intraocular pressure (IOP) among patients following reformation while gas present in the anterior chamber. Numbers within the columns represent number of patients. Numbers above the columns show range of IOP.

The mean follow up period was 13 months. There were no corneal complications. In four patients, a cataract developed or progressed. At the end of follow up, 11 patients had normal IOP without antiglaucoma treatment.

Successful reformation of the AC following filtration surgery by perfluoropropane, air, sodium hyaluronate, or SF₆ has been reported previously.4-6 We prefer SF₆ since it lasts in the AC for an optimal period of time (up to 10 days, depending on the concentration); it remains as a single bubble, deepening the AC until aqueous gradually replaces it. Although corneal toxicity with SF₆ has been previously reported,7 none of our patients developed corneal complications.

We find the use of SF₆ to be simple, safe, and effective. We recommend it in patients after trabeculectomy with prolonged hypotony, overfiltration, and flat AC, with or without corneal decompensation, in whom conservative treatment has failed.