Clinical trial NCT00665756: Comparison of Efficacy Between Silicone Ahmed Glaucoma Valves and Second Trabeculectomy in Glaucoma Patients
Official title: Comparison of Efficacy Between Silicone Ahmed Glaucoma Valves and Second Trabeculectomy in Glaucoma Patients
Study type: INTERVENTIONAL
Overall status: UNKNOWN
Phase: NA
Conditions: Open Angle Glaucoma
Keywords: Glaucoma
Drainage implant
Ahmed valve
Second trabeculectomy
Lead sponsor: Federal University of São Paulo
Sponsor class: OTHER
First posted: 2008-04-24
Enrollment: 40
Sex: ALL
Minimum age (years): 18
Maximum age (years): 80
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

Brief summary: In the management of open angle glaucoma, frequently more then one procedure is necessary to control the intra ocular pressure. There is still no consensus whether this second intervention should be a second trabeculectomy or a shunt device. In the present study we compare a second trabeculectomy versus Ahmed silicone shunt device in open angle glaucoma patients with previous trabeculectomy without proper IOP control.

Detailed description: In the management of open angle glaucoma, frequently more then one procedure is necessary to control the intra ocular pressure. There is still no consensus whether this second intervention should be a second trabeculectomy or a shunt device. In the present study we compare a second trabeculectomy versus Ahmed silicone shunt device in open angle glaucoma patients with previous trabeculectomy without proper IOP control.

40 Patients with clinically uncontrolled open angle glaucoma with previous trabeculectomy surgery were selected from the glaucoma sector of Federal university of Sao Paulo. Patients were randomized to one of two groups:

1. Silicone Ahmed Implant
2. Second trabeculectomy

Surgery description:

Ahmed silicone tube implant: A fornix-based conjunctival flap was created between two adjacent recti muscles. Before placement of the tube implant body to the sclera, tube was irrigated with saline solution to open the valve mechanism. The implant's polypropylene body was sutured to sclera with 6.0 silk suture. The tube then trimmed and the anterior chamber was entered from 1mm posterior to corneoscleral limbus with 23-gauge needle. A human donor scleral flap was placed over the tube and sutured to the sclera with 10.0 nylon suture. The conjunctiva was sutured to the limbus.

Second Trabeculectomy: A fornix-based conjunctival flap was created in the opposite superior quadrant of the previous trabeculectomy. Mitomycin-C was used under the conjunctival flap for up to 4 minutes (0,3mg/mL) and rinsed with 30mL saline solution. Scleral flap with crescent bevel and sclerectomy with a punch. Iridectomy and flap suture with nylon 10-0. Conjunctival suture with nylon 10-0.

Follow up after surgery was in the 1st, 4th, 7th, 15th, 30th days and after that monthly or whenever needed for clinical reasons.

Eligibility criteria: Inclusion Criteria:

* Patients with open angle glaucoma and uncontrolled IOP despite the use of maximum tolerated glaucoma medication.
* Patients over 18 years old.
* Patients who can understand and sign the inform consent form.

Exclusion Criteria:

* Other forms of glaucoma other than open angle glaucoma; previous psiquiatric condition ;
* Patients who can understand and sign the inform consent form;
* visual acuity worse than hand motion;
* previous retina surgery with buckle implant

Primary outcomes:
measure: intra ocular pressure
timeFrame: Monthly
Secondary outcomes:
measure: number of hypotensive medications
timeFrame: monthly
Other outcomes:
Locations:
city: Sao Paulo
country: Brazil
facility: Federal University of Sao Paulo
state: SP
Study officials:
affiliation: Federal University of São Paulo
name: Augusto Paranhos JR, PHD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Gedde SJ, Schiffman JC, Feuer WJ, Parrish RK 2nd, Heuer DK, Brandt JD; Tube Versus Trabeculectomy Study Group. The tube versus trabeculectomy study: design and baseline characteristics of study patients. Am J Ophthalmol. 2005 Aug;140(2):275-87. doi: 10.1016/j.ajo.2005.03.031.
citation: Minckler DS, Vedula SS, Li TJ, Mathew MC, Ayyala RS, Francis BA. Aqueous shunts for glaucoma. Cochrane Database Syst Rev. 2006 Apr 19;(2):CD004918. doi: 10.1002/14651858.CD004918.pub2.
citation: Ishida K, Netland PA, Costa VP, Shiroma L, Khan B, Ahmed II. Comparison of polypropylene and silicone Ahmed Glaucoma Valves. Ophthalmology. 2006 Aug;113(8):1320-6. doi: 10.1016/j.ophtha.2006.04.020.