Abstract
Purpose :
Recent advances in intraocular pressure (IOP)-lowering surgeries aim to maintain efficacy while optimizing safety and minimizing complications. Subconjunctival surgeries that bypass the physiologic aqueous outflow system (e.g. trabeculectomy, tube implants) lower IOP by diverting aqueous out of the anterior chamber into a filtering bleb. During postop healing, IOP typically fluctuates around the ultimate target. Several techniques are used to titrate flow and IOP postoperatively (e.g. trab suture release), but none of these titration techniques are predictably consistent or reversible. We present a novel titratable aqueous shunt that enables reversible titration of postoperative bleb resistance and outflow resistance that can be individualized to the patient. We hypothesized that our novel shunt for surgical management of glaucoma could be safely implanted and adjusted to titrate flow states postoperatively.
Methods :
The novel shunt is designed to have one open channel and two valve-controlled channels, which are actuated into the open or closed position with a transcorneal green laser. There are four different flow states (i.e. resistances) that can be achieved postoperatively. Shunts were implanted in 7 New Zealand White rabbits (14 eyes). The valves were actuated between the open and closed positions during the study. IOP was measured over 32 days.
Results :
Shunts were successfully implanted and blebs were observed in all eyes for 32 days. Surgeons successfully performed laser titration at the slit lamp and were able to observe the valves move between open and closed positions from Day 9 through Day 29. A decrease in IOP was sustained from a mean baseline of 19 mmHg to 11 mmHg at Day 32. None of the eyes became hypotonous.
Conclusions :
Our novel shunt was successfully implanted in rabbits. Laser actuation of the valves was achieved. Blebs formed and IOP-lowering was achieved. First-in-human trial has been initiated and is currently ongoing.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.