Understand risk factors to limit endothelial cell loss after glaucoma surgery
WASHINGTON — Traditional glaucoma surgery will result in endothelial cell loss, but surgeons can be aware of potential risk factors and take steps to help limit the amount of loss, a speaker said here.
“You see trabeculectomy and tube shunt studies show some endothelial cell loss, but most studies are limited to about 2 to 3 years’ follow-up. Take steps to minimize hypotony and intervene if it occurs,” Douglas J. Rhee, MD, said at the American Glaucoma Society annual meeting.
Data from the literature have shown traditional tube shunts, glaucoma drainage devices and trabeculectomies all lead to endothelial cell loss. Rhee shared data from a 2007 study that showed 9% endothelial cell loss at 12 months in 62 eyes that underwent trabeculectomy. A separate retrospective study showed 72 eyes that underwent Ahmed glaucoma valve (New World Medical) implantation experienced rapid endothelial cell loss 1 to 2 years postoperatively but stabilized from years 2 to 5, he said.
Risk factors such as iridocorneal touch can further endothelial cell loss in patients undergoing trabeculectomy. Pseudoexfoliation and narrow tube-cornea angles found on OCT can similarly hasten cell loss in patients receiving tube shunts, he said.
“The main risk factor for endothelial cell density loss with tube shunts is just how close the tube is to the cornea. ... Mechanically you want that tube to not be close to the cornea,” Rhee said.
Avoiding hypotony is the best way to manage risk factors. If choroidal detachment or iridocorneal touch is observed, surgeons should intervene, he said. Surgeons should also monitor endothelial cell loss through clinical examination by slit lamp biomicroscopy and gonioscopy.
“I would intervene if there were symptomatic and observable changes in the cornea,” he said. – by Robert Linnehan
Rhee DJ. Managing endothelial loss after traditional glaucoma surgery. Presented at: American Glaucoma Society annual meeting; Feb. 27-March 1, 2020; Washington.
Disclosure: Rhee reports he receives research funding from Allergan, Glaukos, Ivantis, National Eye Institute and Research to Prevent Blindness; is an ad hoc consultant for Aerie, Alcon, Allergan and Ivantis; is on the data safety and monitoring board of Ocular Therapeutix and the scientific advisory board for Aerie; and is on the speakers bureau for Aerie and Bausch + Lomb.