N-Acetylcarnosine Eyedrops for Corneal Disease
Q Can N-acetycarnosine eye drops be helpful for my 5-year-old dog, just diagnosed with the beginning of the autoimmune disease Pannus? I was given prednisone eye drops by my veterinarian, but I don’t want to keep my dog on something as strong as that for the rest of my dog’s life.
JOYCE, Las Cruces, NM
A Pannus is a serious disease that affects the cornea and can lead to blindness by causing an abnormal layer of fibrovascular tissue or granulation tissue to grow. While it may occur over a joint surface (as seen in rheumatoid arthritis), or on a prosthetic heart valve, a common site for pannus formation is over the cornea, the outer, clear, portion of the eye.
Normally, the cornea has no blood vessels, no pigmentation, and should be smooth and convex shaped. While Pannus is not painful and causes no eye discharge in its early stages, it is insidiously progressive. It is also thought to be an autoimmune disorder, worsened by exposure to ultraviolet radiation (sunlight).
A study using rats susceptible to diabetes indicates that eye drops containing carnosine may protect the cornea against the oxidative damage caused by diabetes. The results indicate that diabetes decreases the levels of thiols (from glutathione and proteins) in the cornea.
While N-acetylcarnosine has been proposed to treat ocular disorders that have the component of oxidative stress in their genesis (cataracts, glaucoma, retinal degeneration, corneal disorders, ocular inflammation, complications of diabetes mellitus, systemic diseases), there is no clear evidence to date that it can help with Pannus.
- Shi Q, Yan H. Changes of the thiol levels in the corneas of the diabetic rats: effect of carnosine, aspirin and a combination eye drops. Int J Ophthalmol 2010;3(3):211-5.