One sealant (ReSure Sealant, Ocular Therapeutix) is a hydrogel formed in situ. Polyethylene glycol is mixed with trilysine amine to create a polymeric crosslink. It is applied while still in a liquid state and specifically adheres to de-epithelialized tissue on the eye. It then sloughs off as underlying epithelium grows. This material was adapted from neurosurgery applications and has a proven track record for safety and efficacy.
The sealant is a good preventative measure, as well as a lifesaver, for many unexpected situations, he noted.
Good flow versus bad flow
The goal with trabeculectomy (shunt surgery) is to get aqueous to flow out of the eye and into the subconjunctival space, thus lowering pressure.
However, unexpected leaks exaggerate flow causing serious complications. The goal is to keep IOP in a reasonable range—usually double digits—in the early postoperative period. This way, the eye functions normally, the patient sees well, and postoperative management is straightforward.
Unfortunately, even the best glaucoma surgeons get leaks with a certain frequency. Sometimes a patient’s tissue shreds during suturing, making the surgeon alert to issues. Other times, a case seems to have finished very well, but every time the patient blinks there is a miniscule gap between sutures that leaks.
I have begun applying this sealant as the last step of every filtering procedure. Instead of creating a long-running suture, I most often put in one interrupted suture to secure the conjunctiva back together. I then mix the sealant and apply it to the patient’s eye after the surface is dried. It is ideal for glaucoma surgeries because the sealant automatically migrates to areas that do not have the epithelium attached, even if you cannot visualize the hole.