Ahmed Valve Technology:
How Does the Ahmed Valve Work?
This animation demonstrates how the Ahmed Valve system works.
Valve Sheet Opening
Mathew Rickard, Ph.D.
Associate Professor in Bioengineering
California Baptist University
Physicians Experience with The Ahmed Glaucoma Valve
This video shows testimonials by physicians using The Ahmed Glaucoma Valve. It also explains some of the implications for use of the valve.
Valve Surgical Videos:
FP7 Surgical Video with Animation
Implantation technique for Ahmed Glaucoma Valve model FP7 with Animation of the video. Surgery Performed by Dr. Lama Al-Aswad
S2 Surgical Video
Ahmed Glaucoma Valve Mode S2 Implantation by Dr. Steven Cohen
Tube Irrigation from vitreous
How to overcome occluding tube by Lama Al-Aswad, MD
Combined Cataract Surgery Inferonasal Ahmed Glaucoma Valve
Ahmed Glaucoma Valve model FP7 Surgery Combined with Cataract Surgery. Performed by Dr. Ike Ahmed.
Ahmed Valve, a simple faster technique for insertion
This video demonstrates a simple, fast technique for insertion of The Ahmed Glaucoma Valve by Tarek AboulNasr.
Verifying Ahmed Valve fluid outflow using triamcinolone
Use of Triamcinolone to Verify Fluid Outflow via Ahmed Valve by Uday Devgan, MD, FACS.
Ahmed Valve intravitreal Avastin for Neovascular Glaucoma
Surgery performed by Khaled AG Shalaby, MD.
Ahmed Glaucoma Valve under scleral tunnel modified Dr. Gdih technique
Ahmed Glaucoma Valve under scleral tunnel modified Dr. Gdih technique by Rob Schertzer, MD, MEd, FRCSC.
Ahmed FP7 Surgery with Ologen Implant
Ahmed Glaucoma Valve FP7 Surgery with Ologen Implant performed by Chris Teng, MD.
New York Eye & Ear infirmary
Model FP7 with Amniotic Membrane Patch
Ahmed FP7 Implant Amnioguard Patch Graft
Celso Tello, MD
Christopher Teng, MD
PC7 Surgical Video with Animation
This video demonstrates the surgical procedure of The Ahmed Glaucoma Valve, model FP7 with Pars Plana Clip with a combination of surgery video clips and animation.
Kahook Dual Blade Surgical Videos
Leonard Seibold, MD
University of Colorado - School of Medicine
John Berdahl, MD
Vance Thompson Vision
Valve Technology: Mechanics of the Ahmed Glaucoma Valve
Flow resistance, R, is the inverse of flow facility, F, and is the key element in controlling eye pressure. For steady, laminar flow, R can be thought of as the rise in pressure associated with a rise in flow rate, i.e. the slope of the pressure vs. flow curve:
The Ahmed Glaucoma Valve naturally varies its critical flow path dimension with pressure, which provides (1) reduced risk of hypotony at low pressures and (2) increased flow facility at moderate pressures.
Non-Obstructive, Self-Regulating Valve Mechanism:
The Ahmed® Glaucoma Valve has no obstruction in its path of fluid flow. For the flow to be non-obstructive, a particle large enough to pass through the lumen of the tube, will easily pass through the much larger opening of the Venturi-Flow chamber. The elastic membranes help to regulate fluid flow at all times, consistently by changing their shape. The tension on these membranes is responsible of reducing hypotony.