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The classic trabeculectomy technique using a rectangular scleral flap with two releasable sutures at the edges and viscoelastic to maintain the anterior chamber (AC) is most routinely used. 1 However, this technique has three weak points. Firstly, the amount of filtration is variable. Hyperfiltration can result in a flat AC, hypotony maculopathy, choroidal detachment or haemorrhage, aqueous misdirection or cataract. 2 On the other hand, ocular massage and/or laser suture lysis are frequently necessary to obtain a low postoperative intraocular pressure (IOP). Laser suture lysis is non-titratable, sometimes impossible to perform, and can result in subsequent overdrainage and hypotony. Secondly, peroperative flat chamber and hypotony during trabeculectomy augment the risk of vision threatening complications such as choroidal haemorrhage, macular wipeout, and corneal decompensation. Thirdly, debris that remains at the trabeculectomy site after surgery induces an inflammatory response that induces fibrosis.
A new trabeculectomy technique was developed by Peng Khaw 3 that implies the use of releasable and adjustable sutures, an AC maintainer, and a punch. This technique has several advantages. Firstly, the punch produces a standard trabeculectomy aperture, and postoperative adjustment of the sutures allows titration of filtration, resulting in a more controlled amount of outflow. Secondly, during the operation, the AC is maintained and hypotony is prevented. Thirdly, inflammatory factors are flushed away from the site of surgery, reducing the risk of bleb failure. Overall, this novel technique may result in a better and safer outcome after filtration surgery. This study was set up to evaluate the outcome and safety of this novel trabeculectomy procedure.
METHODS
Study design and patient inclusion
In this retrospective study, the files of patients who underwent trabeculectomy using the described technique between February and December 2003 were reviewed. Patients with a history of preceding filtering surgery were excluded. The main outcome measures were the postoperative IOP and the frequency of early postoperative complications. IOP was recorded on days 1-3, weeks 1-4, at 3 months after surgery, and 3 monthly thereafter.
Trabeculectomy technique and postoperative management
A corneal traction suture was placed with a silk 8/0 and a fornix based conjunctival flap was dissected. Antimetabolites were used when indicated. Gentle diathermy was performed. A scleral flap of 6x4 mm with side incisions at 0.5 mm from the cornea was...