ABSTRACT
Background: Ahmed glaucoma valve (AGV) is an useful modality in the management of medically refractory glaucoma. Human donor scleral patch graft (SPG) can be employed to cover the external portion of the tube to prevent its exposure and associated sight?threatening complication. Purpose: To report the management of a case of AGV tube exposure due to SPG shrinkage in the right eye (RE) of a patient. Synopsis: Under peribulbar anesthesia, the conjunctiva is undermined posteriorly, on either side of the exposed tube. The AGV tube is noted to lay firmly against the sclera without any excessive movement. The shrunk and displaced SPG is excised, and a larger, 6 × 8 mm, full?thickness, human donor SPG is placed on the episcleral bed, over the exposed segment of the tube, to ensure its adequate coverage. The SPG is sutured with four interrupted, 10?0 nylon sutures. The SPG is adequately covered with conjunctiva, by conjunctival mobilization and advancement to avoid excessive tension over the tube and closed with interrupted, 8?0 Vicryl suture. Highlights: SPG shrinkage and overlying conjunctival erosion can occur after AGV implantation. This can cause AGV tube exposure, which can be managed by donor SPG to cover the exposed tube
ABSTRACT
Objective To evaluate the effectiveness and safety of modified scleral tunnel for the prevention of Ahmed valve tube exposure in Ahmed valve implantation for refractory glaucoma.Methods A retrospective study was conducted in 72 patients with Ahmed glaucoma valve implantation for refractory glaucoma.All the patients were divided into unmodified and modified scleral tunnel group.In the unmodified scleral tunnel group,38 patients (38 eyes) underwent traditional scleral tunnel in Ahmed valve implantation,while in the modified scleral tunnel group,34 patients (34 eyes) received modified scleral tunnel in the procedures.The changes in intraocular pressure and visual acuity after operation were observed,and the incidence of drainage tube exposure and other complications were compared between the two methods after Ahmed valve implantation.The patients were followed up for 6 to 36 months with an average of 18 months.Results The intraocular pressure was (16.30 ±5.73) mmHg (1kPa =7.5 mmHg) in the unmodified scleral tunnel group and (15.80 ± 6.12)mmHg in the modified scleral tunnel group,with no significant difference between the two groups (P ＞ 0.05),but there was significant difference with the preoperative data (48.4 ± 5.79) mmHg (P ＜ 0.01).During the follow-up,conjunctival tube exposure was seen in 3 eyes (7.9％) in the unmodified scleral tunnel group,whereas there was no tube exposure in the modified scleral tunnel group.Conclusion The modified scleral tunnel is capable to prevent conjunctival tube exposure in patients with refractory glaucoma,which is more efficient and safe than traditional scleral tunnel in Ahmed glaucoma valve implantation.