Sunday, November 29, 2015
Eye and Vision Care
Niacin and Glaucoma
Hello. I am in my mid-40s. My primary care doctor has prescribed Niaspan to improve my good cholesterol (my cholesterol levels aren’t that bad, but heart disease runs in my family, so he thought we should try to get them to be better).
We have not specifically tried dietary or exercise changes, although in general I am in good health, do not smoke, drink only socially, watch what I eat (although I’m sure I could do better), and exercise regularly (I take an exercise class--weights, lunges, squats, crunches, etc.-- twice a week and try to walk or bike ride on some other days).
The only prescription I take right now is Travatan Z for ocular hypertension, which I have been taking for two or three years. Glaucoma runs in my family, I have thin corneas, my IOP was slightly elevated, and my visual field test showed some minor changes from a previous test, so my optometrist thought it best to put me on the drops.
When I got my Niaspan prescription, however, I noticed that it was not recommended for people who have glaucoma. My PCP knows I have ocular hypertension. Why is Niacin not recommended for people who have glaucoma? Do I have to choose between treating the two conditions, high cholesterol and high IOP? Should I exercise more and meet with a dietitian to try to improve my diet as a way to address the cholesterol issue? Thanks.
Thanks for a great question.
One of the reported adverse side effects of Niaspan is flushing or rash. This means it can affect the caliber of blood vessels (i.e., it can dilate them). If the pupil of the eye is also dilated, and causes an obstruction of the eye's fluid outflow, then the eye's intraocular pressure could potentially rise.
And you already know that you have a higher-than-normal intraocular pressure (ocular hypertension), for which Travatan Z is a good eye drop to use. (IMPORTANT NOTE: ocular hypertension is a risk factor for glaucoma, but many people with ocular hypertension never progress to a diagnosis of glaucoma.)
There are two kinds of glaucoma: open angle and narrow/closed angle. Open angle is treated with eye drops, and closed angle is treated with laser surgery. So your higher-than-normal eye pressure is most likely NOT due to a narrow/closed angle; and therefore, from an eye doctor's perspective, it should be safe to take Niaspan.
In summary, since the angles of your eyes are probably open and you do not have a glaucoma diagnosis, you should have no problem with taking Niaspan. However, I would advise you to comply with your eye doctor's recommendations for follow-up visits to monitor your intraocular pressures.
Robert D Newcomb, OD, MPH, FAAO
Professor Emeritus of Clinical Optometry
College of Optometry
The Ohio State University