Mechanics of the Ahmed™ Glaucoma Valve

• The Venturi Effect: To reduce internal friction within the valve system, the Ahmed™ Glaucoma Valve (AGV™) utilizes a specially designed, tapered trapezoidal chamber to create a Venturi effect to help aqueous flow through the device. As demonstrated by Bernoulli’s equation of hydrodynamic principle, the inlet velocity of aqueous entering the larger port of the Venturi chamber increases significantly as it exits the smaller outlet port of the tapered chamber. In an AGV™ this increased exit velocity greatly helps in evacuating aqueous from the valve, thereby helping to reduce valve friction.
• 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 for reducing hypotony.

Polypropylene Glaucoma Implants : S2 (Ahmed™ Glaucoma Valve)

Features:
- Made of medical grade silicone
- Immediate reduction of intraocular pressure
- Unique, non-obstructive valve system to prevent excessive drainage and chamber collapse
- Implanted in a true, single-stage procedure
- Tapered profile for easy insertion
- Silicone plate
- Aqueous percolation holes
- Thinner Plate

Plate/Valve Specifications:
Thickness: 0.9mm
Width: 13.00mm
Length: 16.00mm
Surface Area: 184.00mm2

Tube Specifications:
Length: 25.00mm
Inner Diameter: 0.305mm
Other Diameter: 0.635mm

Materials:
Valved Plate Body: medical-grade polypropylene
Drainage Tube: medical-grade silicone
Valve: medical-grade silicone, elastomer membrane

Ordering Information:
Model: S2 (Ahmed™ Glaucoma Valve)