The proper production and drainage of aqueous
humor from the eye maintains an intraocular pressure (IOP) in a normal range of
10 to 21 mmHg. Glaucoma management involves either decreasing the aqueous humor
production or promoting its drainage out of the eye to achieve the required
target IOP.
Glaucoma Drainage Devices (GDDs) reduce IOP
by bypassing the normal aqueous humor outflow pathway and allowing the aqueous
humor to drain freely through the device's drainage channels. However, some GDDs
have a problem with increased flow in the early postoperative phase, causing
hypotony.
In a study by Kim et al., 3D printing
technology was used to improve conventional aqueous drainage devices. They fabricated
a double-layered aqueous drainage tube using polycaprolactone (PCL) with
different molecular weights. The high-molecular-weight PCL (for the outer
layer) and low-molecular-weight PCL (for the inner layer) were used to
fabricate an aqueous drainage tube with an inner diameter that could be
expanded via biodegradation.
After 2 days of exposure to sodium
hydroxide, the inner layer degraded with a decrease in the cross-sectional area
and a corresponding increase in the average diameter.
The inner diameter expansion is possible by
using low-molecular-weight PCL inside the tube. Therefore, it can drain less
aqueous humor when the IOP is low during the early postoperative period, and
the drainage is increased when the IOP is high during the late postoperative
period.
This approach can avoid some of the
complications seen with commonly used GDDs.
REFERENCE:
Kim, J.-S.; Jeong, H.-J.; Park, J.-W.; Gwak, S.-J.; Han, J.-S.; Jung, K.I.; Lee, S.-J. A 3D-Printed Aqueous Drainage Tube with an Expandable Inner Diameter to Accommodate the Intraocular Pressure (IOP) Fluctuations After Glaucoma Surgery. Polymers 2025, 17, 118. https:// doi.org/10.3390/polym17010118.
