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Leaks may follow trabeculectomy surgery, particularly where antimetabolite useage has resulted in thin or avascular filtration blebs. Leaking blebs are associated with endophthalmitis, low intraocular pressure (IOP), hypotony maculopathy and choroidal haemorrhage. Treatment aims to stop the leak while preserving filtration.
Conservative management of bleb leaks involves aqueous suppressants, pressure patching, contact lens application or topical autologous serum drops.1 Surgical treatments include application of trichloracetic acid, cyanoacrylate glue, autologous fibrin tissue glue, cryotherapy and argon laser or Nd YAG Laser “remodelling” of the bleb. Intrableb injection of autologous blood2 has been successful in sealing bleb leaks, although blood can track into the anterior chamber (AC). Compression sutures3 have been used to control overdraining blebs but are used less often for bleb leaks. More major procedures include conjunctival autografts or amniotic membrane, scleral or processed pericardial tissue transplantation.
Haynes and Alward4 used compression sutures in conjunction with autologous blood injection to enhance their efficacy in the treatment of postfiltration hypotony maculopathy. We have successfully used compression sutures for some years to remodel overdraining blebs in the absence of leakage.5 We then proceeded to utilise compression sutures with autologous blood injection as the initial surgical intervention for leaking filtering blebs.
MATERIALS AND METHODS
A retrospective study of patients who had compression sutures and autologous blood injection for leaking trabeculectomy blebs over a 5-year period between April 1999 and April 2003 was carried out. All patients with leaking blebs during this period were recruited for the study with no exclusion. A single spatulated 8/0 or 9/0 nylon compression suture was placed over the leak as either a “rectangular” mattress or an “X-shaped” suture with bites just anterior to the limbus at 50% of the corneal stromal depth and posteriorly in the episclera to achieve a satisfactory compression (fig 1, table 1).
Up to 0.75 ml of autologous venous blood was injected within the filtering bleb. Postoperative antibiotic drops but no steroids were prescribed. Patients were followed up weekly for the first month.
Sutures were removed after 8 weeks or more, once scarring lines were seen in the conjunctiva or if the sutures had come loose. Most sutures embedded into the conjunctiva with time. Repeat blood injections were used if the leak persisted. Data collected included control of the leak, visual outcome, further procedures, final IOP and complications. Surgical success was identified as resolution of the bleb leak, a target pressure between 10 and 20 mm Hg with or without topical medication, non-worsening of vision and a non-requirement of further procedures.
Fourteen eyes of 12 patients underwent compression sutures for bleb leaks over a period of 5 years. Five were male and seven female, with the mean age being 59.5 years (range 33–89 years). The mean period between trabeculectomy and identification of bleb leak was 17.9 months (range 1 week to 5 years 8 months). None of the leaks was from the wound edge. The mean duration of the leak prior to treatment was 4 months (range 2 weeks to 18 months). Ten eyes had antimetabolites during the original trabeculectomy (71.4%). All had a single suture over the leak site with concurrent autologous blood injection, while seven patients had further top-up of blood injections.
The mean follow-up period following compression suture was 3.9 years (range 5 months to 7 years). There were two patients with a follow-up period of only 5 months, as they had moved away from the area. The bleb leak stopped in eight cases (57.1%) without further intervention, while additional intervention to control persistent leak was required in six (42.9%). Further procedures included Tisseel glue injection (two cases, 33%), and formal bleb revision with or without conjunctival autograft (all six cases requiring revision).
The leak was controlled in eight cases undergoing compression suture with a mean rise in IOP of 3.9 mm Hg, from 9.3 mm Hg to 13.2 mm Hg (range 0–7 mm Hg). Visual acuity remained the same or was better in all patients. Complications included hyphaema in four patients (which spontaneously resolved). There was no significant anterior chamber inflammation.
Given the range of treatments available for bleb leaks, it is likely that no single method will be effective for every case. In this study, compression sutures with autologous blood injection were effective in 57.1% of bleb leaks. Similar studies in future with larger number of cases might make it possible to analyse the influence of age, race or type of antimetabolite used in filtering surgery on the success of this procedure. Euswas et al6 have reported success in five out of seven eyes (71.4%) treated with compression sutures for bleb leaks. However, our study is the largest in terms of patient numbers and follow-up period reported to date. Given their simplicity compared with more major procedures, we recommend that they be considered the first line of surgical intervention for bleb leaks.
Competing interests: None.
Presented as a poster at the International Glaucoma Symposium, Athens, March 2007.
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