Comparison of Silicone and Porous Plate Ahmed Glaucoma Valves

The purpose of this study is to evaluate and compare the clinical outcomes after
implantation of the porous plate (polyethylene) (Model M4) Ahmed Glaucoma Valve with the
silicone plate Ahmed Glaucoma Valve (Model FP7) in participants with refractory glaucoma.
Participation will last for 12 months.

Inclusion Criteria:

- Male or female of any race ≥ 18 years and ≤ 80 years of age.

- Diagnosis of intractable glaucoma in the study eye, with the exception of silicone
oil endotamponade induced glaucoma, which has not responded to conventional medical
and surgical therapy.

- Elevated intraocular pressure > 21 mmHg in the study eye. Two consecutive
measurements using Goldmann Applanation Tonometry will be obtained and the mean of
those two measurements will be considered the subject's baseline intraocular
pressure.

- Subject is a candidate for surgery in the study eye with a glaucoma drainage device.

- Subject is willing and able to sign the informed consent.

Exclusion Criteria:

- Diagnosis of silicone oil endotamponade induced glaucoma in the study eye.

- History of prior drainage implant surgery in the study eye.

- History of cyclophotocoagulation of the study eye.

- Pregnancy.

- Prisoner.