Laser Activated Flow Regulator for Glaucoma Drainage Devices.
OBJECTIVE
To assess the capabilities of a new glaucoma drainage device regulator in controlling fluid flow as well as to demonstrate that this effect may be titratable by noninvasive means.


METHODS
A rigid eye model with two main ports was used. On the first port, we placed a saline solution column. On the second, we placed a glaucoma shunt. We then measured the flow and flow rate through the system. After placing the regulator device on the tip of the tube, we measured again with the intact membrane and with the membrane open 50% and 100%. For the ex vivo testing we used a similar setting, using a cadaveric porcine eye, we measured again the flow and flow rate. However, this time we opened the membrane gradually using laser shots. A one-way analysis of variance and a Fisher's Least Significant Difference test were used for statistical significance. We also calculated the correlation between the numbers of laser shots applied and the main outcomes.


RESULTS
The flow through the system with the glaucoma drainage device regulator (membrane intact and 50% open) was statistically lower than with the membrane open 100% and without device (P< 0.05). The flow was successfully controlled by the number of laser shots applied, and showed a positive correlation (+ 0.9). The flow rate was almost doubled every 10 shots and statistically lower than without device at all time (P< 0.05).


CONCLUSIONS
The glaucoma drainage device regulator can be controlled noninvasively with laser, and allows titratable control of aqueous flow.


CONCLUSIONS
Initial results and evidence from this experiment will justify the initiation of in vivo animal trials with the glaucoma drainage device regulator; which brings us closer to possible human trials and the chance to significantly improve the existing technology to treat glaucoma surgically.
Ophthalmology Department, University of Colorado School of Medicine, Rocky Mountain Lions Eye Institute, Aurora, CO, USA.
Jeffrey L
JL
Olson
Ophthalmology Department, University of Colorado School of Medicine, Rocky Mountain Lions Eye Institute, Aurora, CO, USA.
Raul
R
Velez-Montoya
Department of Ophthalmology, Springfield Clinic, Springfield, IL, USA.
Ramanath
R
Bhandari
aqueous flow; glaucoma drainage device; intraocular pressure; surgical complications