Glucosamine supplements may increase IOP.

study published in Eye investigated the link between oral glucosamine and increased IOP.

What’s the theory behind the IOP increase?
Glucosamine (widely used for osteoarthritis treatment) is found in the corneal stroma and plays a role in the structure and function of the trabecular meshwork.  Glycosaminoglycans (stay with me) are found in the outermost part of the trabecular meshwork and when many of them interact with each other, it can act like a gel and contribute to outflow resistance.

Tell me about the study.
In a small study of 88 patients with osteoarthritis, half took a glucosamine supplement (750mg) and half were given a placebo.  In the glucosamine group, “34% of patients had an increase of more than 2 mmHG compared to 23.5% of patients in the placebo group”.

The take home:
Although this study had a short follow-up period and too few glaucoma patients to really evaluate the glucosamine effects in that population, the authors suggest it’s wise to ask about glucosamine use in patients with uncontrolled IOP’s.  (via)