In vitro flow testing of glaucoma drainage devices.
OBJECTIVE
The study was intended to determine methods that could evaluate in vitro the flow characteristics of glaucoma drainage devices.


METHODS
Two test methods were used: (1) a gravity-driven flow test and (2) a syringe-pump-driven flow test. Eighteen devices, both valved and nonvalved, from 4 manufacturers were evaluated for their hydrodynamic resistance and the pressure at which the flow becomes 0.


RESULTS
Results show a wide variation in device performance, indicating a strong need for enhanced quality control procedures in the device manufacturing process.


CONCLUSIONS
A gravity-driven flow test provides a reasonably quick test of both resistance and closing pressure, which might be useful as a manufacturing line test. The syringe-driven flow test requires more time but provides additional insight into device performance, and, therefore, might be useful as a design validation test.
Porter
J M
JM
U.S. Food and Drug Administration, Rockville, Maryland 20852, USA.
Krawczyk
C H
CH
Carey
R F
RF
D004322:Drainage / Q000592:standards*; D018463:Filtering Surgery / Q000295:instrumentation*; D005901:Glaucoma / Q000601:surgery; D006112:Gravitation; D066298:In Vitro Techniques; D007260:Infusion Pumps; D007552:Isotonic Solutions; D011312:Pressure; D011786:Quality Control
D007552:Isotonic Solutions