Eating fish might reduce your chances of developing the potentially blinding eye disease glaucoma.
While it’s been known for some time that this healthy food reduces the risk of another vision threatening condition, macular degeneration, evidence is also building that it can help prevent glaucoma. A recent study found that those with low intakes of omega-3 polyunsaturated fatty acids are much more likely to have glaucoma than people with high amounts in their diet.
But the study also found that too much fatty acids overall (omega-6 and omega-3 combined) increases glaucoma risk, leading researchers to suggest a better mix of more omega-3 and less omega-6 may be the key to protecting against glaucoma.
University of Melbourne optometrist Dr Christine Nguyen said the modern western diet had an over-abundance of omega-6, found in many common vegetable oils, margarines and meats, and an insufficient intake of omega-3 fats, found in fish, walnuts, flaxseeds and green leafy vegetables.
“There is increasing evidence that omega-3 may play a beneficial role in eye diseases, including glaucoma, although more studies are required to conclusively link increased omega-3 to lowered glaucoma risk,” she said. “This would open the possibility for using diet as a modifiable risk factor for glaucoma, as currently eye-drops and surgical treatment to lower pressure in the eye is the only way we can modify the course of the disease.
“The current recommendation for maintaining a healthy balance of omega 3 is to consume 500mg per day, equating to two serves of fish per week or two fish oil capsules (2000mg/day) or one flaxseed oil capsule (1000mg/day.)”
Gingko biloba and exercise may also help
Glaucoma Australia says Ginkgo biloba may be beneficial in glaucoma management. But it warns that while generally safe and well-tolerated, Gingko can increase bleeding so should be used with caution in people taking anticoagulants or those with medical conditions associated with increased bleeding.
Other research indicates exercise may reduce your chance of developing glaucoma, with the latest study finding a 73 per cent decline in risk among the most physically active participants, compared with those who were the least active.
However experts warn that strenuous exercise may be harmful for glaucoma patients. Ophthalmologist Dr Hamish Dunn told mivision magazine that moderate intensity exercise appeared safe and likely beneficial but pressure fluctuations of strenuous exercise could put patients with normal tension or advanced glaucoma at risk of further optic nerve injury. He said they should develop a personalised exercise plan with their ophthalmologist and health care team.
Risk factors for glaucoma include a family history, high eye pressure, age over 50, African or Asian descent, diabetes, short or long sightedness, previous eye injury, prolonged use of steroids, migraine and high or low blood pressure.
Glaucoma is known as the ‘silent thief of sight’ because it affects side (peripheral) vision before central vision. Loss of side vision is not readily noticeable in day-to-day life. Left untreated, it can damage the eye’s optic nerve which transmits visual information to the brain, resulting in vision loss and blindness.
There is no cure but early diagnosis is vital because treatment can slow progression. The only way to know if you have glaucoma is to see your optometrist or ophthalmologist for a full examination. Optometrists have the skills and equipment to screen for glaucoma and are usually the first port of call to find out if you may have glaucoma.
Glaucoma Australia’s CEO Annie Gibbins said: “Sadly, 50 per cent of the estimated 300,000 Australians who have glaucoma are completely unaware they have it and consequently may suffer vision loss including irreversible blindness that may have been preventable. You are 10 times more likely to have glaucoma if you have a direct family member with glaucoma, so we are reaching out to the relatives in the first instance.
“A comprehensive eye exam can be conducted by an optometrist or ophthalmologist especially from age 40 for those with a family history or age 50 with no family history, and every two years ongoing.”
During World Glaucoma Week from March 11 to 17, Glaucoma Australia is promoting its Beat Invisible Glaucoma B.I.G. Breakfast fund-raising campaign.