Will it help or hinder your glaucoma?

Jed Lusthaus, Glaucoma Fellow at Addenbrooke’s Hospital in Cambridge looks at a range of things we do in everyday life, from going for a swim to enjoying a cup of coffee and advises on whether they could make glaucoma better or worse.

None of us can do anything about our family history or how our eyes develop but we can alter our lifestyle. So is there any evidence that changing our diet, the kind of exercise we take or even how we lie in bed might affect glaucoma? We know for sure that glaucoma is made worse by uncontrolled high pressure in the eye or a reduced flow of blood to the optic nerve at the back of the eye so anything we do that increases or decreases eye pressure (IOP) or blood pressure might have an effect.

Drinking coffee is something many of us do and it turns out that taking in a lot of caffeine raises IOP: that’s not good news for coffee-loving glaucoma patients. Coffee drinkers increase their risk if they are on five or more cups a day, or have a family history of glaucoma. So the advice is to drink coffee in moderation and to avoid caffeine before a clinic appointment as it can affect your IOP measurement.

What might be more surprising is that even drinking plain water can raise IOP but that’s only if you gulp down several glasses of it in just a few minutes so don’t be put off drinking water. We all need enough to stay healthy. Just try to spread your fluid intake through the day.

Not many of us are yoga enthusiasts and regularly stand on our heads but if you do, this finding is for you: any position where the heart is above the eyes causes IOP to double, though it returns to normal in five minutes. Standing on your head is definitely not recommended if you have glaucoma!

Other things that raise IOP temporarily include lifting weights, playing wind instruments, wearing a tight necktie or using swimming goggles, but there’s no proof that any of these things worsen glaucoma as a consequence.

What about things that lower IOP? Exercise can certainly have that effect – the more intense it is the greater the reduction in IOP. But at the same time it’s likely to reduce blood pressure and the supply of blood to the optic nerve, so overall there are both pluses and minuses, though of course exercise is good for general health and well-being. Drinking modest amounts of alcohol may have some beneficial effect on IOP but excessive drinking damages the optic nerve along with having many other adverse effects on health.

On general diet and dietary supplements, there is no specific advice at present. No-one has identified anything that will either help glaucoma patients or be detrimental for them, though Omega-3 oils are beneficial for general eye health. And the only thing to avoid is large amounts of caffeine.

One dietary supplement does warrant a special mention, and that is gingko biloba. It’s a herbal extract that’s thought to improve blood flow, including to the optic nerve. Though it’s a natural product, it’s powerful, can interact with various medicines and may not suit everyone. It’s really important to see your GP first if you’re thinking about taking it. Anyone on gingko biloba should stop it before having surgery because it reduces the ability of the blood to clot.

Smoking seems to have little effect on IOP, though it can affect the optic nerve and has an impact on health in general so it’s always better not to smoke.

It’s worth keeping your blood pressure in check because both high and low blood pressure are linked to optic nerve damage, particularly if your blood pressure goes down a lot over night. And even how you lie in bed could be relevant. Sleeping with your head propped up on a pillow reduces IOP but burying your eye in your pillow may not be so good.

So what’s the overall message? As with so many things in life the key is ‘moderation’. What’s good for general health is also good for glaucoma patients: a balanced diet, regular exercise, not smoking and not being overweight. And above all, there is no substitute for conventional treatments. Keep up with the drops and take your consultant’s advice on what treatments you need.

This article is based on a talk given at the IGA Glaucoma Support Group meeting at Addenbrookes Hospital, Cambridge, in October 2015.