Indiana University ophthalmologist and surgeon Dr. Darrell WuDunn responds:

“I, as well as other glaucoma specialists, have inserted and removed these devices. However, the more relevant question is whether removing the Ahmed Valve will relieve the tearing. These devices do not typically cause tearing, and other eye conditions, such as ocular surface disease or eyelid abnormalities, are more likely to blame. If the eye no longer sees, then it may be undergoing changes such as surface calcification or shrinkage of the globe. These conditions should be excluded as the cause of the tearing before considering removal of the Ahmed Valve. Your eye surgeon should be able to make an assessment of the cause of the tearing and recommend, or refer you for, the necessary care.”

Persistent Tearing The Saturday Evening Post