Why you should avoid excess coffeeA new study suggests limiting caffeine intake to avoid developing serious eye disease and vision loss after finding a link between coffee drinking habits and glaucoma.

Based on previously reported findings among Scandinavian populations, US researchers from Harvard University carried out a meta-analysis examining the profiles of about 120,180 men and women aged 40 and older who provided information on their caffeinated beverage intake.

Responses were compared against their medical records to determine the cases of exfoliation glaucoma, which contributes to elevated pressure and can lead to damage of the optic nerve.

Exfoliation glaucoma occurs when a whitish material builds up on the lens of the eye and, as its name implies, exfoliates or rubs off the color of the iris, blocking fluids from leaving the eye.

Results showed that compared to non-caffeinated coffee drinkers, participants who drank three or more cups a day were at an increased risk of developing the eye disease. Interestingly, scientists say they found no associations with the consumption of other caffeinated beverages such as soda, tea, chocolate or decaffeinated coffee.

The US study, published in the journal Investigative Ophthalmology & Visual Science, builds on previously reported studies which found a link between the caffeinated coffee consumption of Scandinavians and the increased risk of developing eye disease: Scandinavian populations have the highest rates of exfoliation glaucoma and also happen to be the highest coffee consumers in the world, researchers said.

The health findings surrounding coffee are mixed, as another study suggests that caffeinated coffee could lower the risk of the most common form of skin cancer, basal cell carcinoma, while another study claims that coffee drinkers have a lower rate of death from heart disease.