Baerveldt (BGI) Valve Versus Ahmed(AGV) Valve in Management of Difficult Glaucoma Cases

Study Overview
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Brief Summary
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Refractory glaucoma is a difficult subject as many glaucoma devices attempt to reduce IOP. Baerveldt implant is considered as a large implant, and, on the contrary, Ahmed implant is considered a small implant as many comparisons have showed. Investigators have previously used two models S2 and FP7 Ahmed implant. Currently, investigators use Baerveldt implant in refractory glaucoma cases in order to compare it with the Ahmed implant.

Detailed Description
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Eighty-one participants with glaucoma after ocular surgery or secondary glaucoma with persistent and uncontrolled IOP > 21 mmHg were randomized for placement of Baerveldt implant or Ahmed implant models using a standardized surgical technique. The primary outcome was failure, which was defined as IOP >16 mmHg with glaucoma medication on 2 consecutive study visits. Secondary outcomes were IOP, medication use, visual acuity, complications, and interventions.

Official Title
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Baerveldt Glaucoma Implant Versus Ahmed Glaucoma Implant in One- Year Follow up, Comparative Study

Conditions
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Glaucoma, Open-Angle, Glaucoma Secondary, Glaucoma, Neovascular, Glaucoma, Angle-Closure

Intervention / Treatment
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* Device: glaucoma implant procedure (Baerveldt)
* Device: glaucoma implant procedure (Ahmed)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 1 - patients with glaucoma who underwent a previous failed trabeculectomy or other intraocular surgery. 2- patients who had secondary glaucoma and are known to have a high failure rate with trabeculectomy such as neovascular, uveitis, or iridocorneal endothelial syndrome-associated glaucoma, were included in the study. Exclusion Criteria: 1 - patients lacked light perception, unwilling or unable to give informed consent, were expected to be unavailable for follow-up visits. 2-had previous aqueous shunt implanted in the same eye, other external impediment to supero-temporal drainage device implantation. 3- presence of silicone oil, vitreous in the anterior chamber sufficient to require a vitrectomy. 4-uveitis associated with a systemic condition like juvenile rheumatoid arthritis, nanophthalmos, Sturge-Weber syndrome or other conditions associated with elevated episcleral venous pressure.

Ages Eligible for Study
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Minimum Age: 40 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: Participants were randomized to BGI model 101-350 placement (BGI group) or an AGV model FP7or S2 placement (AGV group). Follow-up visits were scheduled 1 day, 1 week, 1 month, 3 months, 6 months, 1 year postoperatively. The primary outcome measure was failure that defined as IOP >16 mmHg or less than a 20% reduction below baseline on 2 consecutive study visits.The IOP, the use of glaucoma medications, visual acuity (VA), visual fields, bleb morphology and rates of surgical complications were secondary outcome measures.
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: BGI model 101-350 placement (BGI group)<br>A 350 mm2 Baerveldt glaucoma implant was placed. Follow-up visits were scheduled 1 day, 1 week, 1 month, 3 months, 6 months, 1 year postoperatively. The primary outcome measure was failure that defined as IOP >16 mmHg or less than a 20% reduction below baseline on 2 consecutive study visits.The IOP, the use of glaucoma medications, visual acuity (VA), visual fields, bleb morphology and rates of surgical complications were secondary outcome measures. | Device: glaucoma implant procedure (Baerveldt)<br>* A 350 mm2 Baerveldt glaucoma implant was placed in the superotemporal quadrant in 25 patients randomized to BGI group. A limbus-based conjunctival flap was dissected, and the implant was sutured to sclera 10 mm posterior to the limbus. A scleral graft was used to cover the limbal portion of the tube, and the conjunctiva was closed.<br>* Other names: glaucoma valve surgery;|
| Experimental: AGV model FP7 or S2 placement (AGV group)<br>A 184 mm2 Ahmed glaucoma implant was placed. Follow-up visits were scheduled 1 day, 1 week, 1 month, 3 months, 6 months, 1 year postoperatively. The primary outcome measure was failure that defined as IOP >16 mmHg or less than a 20% reduction below baseline on 2 consecutive study visits. The IOP, the use of glaucoma medications, visual acuity (VA), visual fields, bleb morphology and rates of surgical complications were secondary outcome measures | Device: glaucoma implant procedure (Ahmed)<br>* A 184 mm2 Ahmed glaucoma implant was placed in the superotemporal quadrant in 56 patients randomized to AGV group. A fornix-based conjunctival flap was dissected, and the implant was sutured to sclera 10 mm posterior to the limbus. The Ahmed tube left patent and viscoelastic substance injected into anterior chamber. A scleral graft was used to cover the limbal portion of the tube, and the conjunctiva was closed.<br>* Other names: glaucoma valve surgery;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| IOP | mean IOPs | one year follow up | 
| glaucoma medications | mean number of glaucoma medications | one year follow up | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| visual acuity | log MAR Snellen median and interquartile Range values | one year follow up |