Glaucoma: What Every Patient Should Know
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Controversial risk factors for open angle glaucoma

A recent study found that when the thickness of the cornea is measured by a test called pachymetry those with thinner corneas are more likely to go from suspect status to having evidence of open angle glaucoma damage. When we measure eye pressure, the instrument doing the measurement, the tonometer, pushes against the cornea. The higher the eye pressure, the harder it pushes back against the tonometer, giving a higher pressure reading. If the cornea is thin, the instrument will think that the pressure is lower than it really is because it is easier to flatten. So, part of the reason why eyes with thin corneas were more likely to develop glaucoma was that their eye pressure was really higher than the measured number. There is some controversy about whether eyes with thin corneas are more prone to glaucoma even after we take account of the falsely low pressure that is measured. It would make sense that such eyes would be more at risk if having a thin cornea meant that the eye wall all over was thin or that the optic nerve head was more susceptible to pressure. However, this hasn’t been shown to be the case (yet).

For many years, it was said that persons with various kinds of heart disease and blood vessel abnormalities were more likely to get glaucoma or to have worse glaucoma when they get it. This is logical, since as we already mentioned, having a low perfusion of blood into the eye (low blood pressure combined with higher eye pressure) is a contributing risk. But, some very extensive studies actually have failed to show that many aspects of cardiovascular disease make glaucoma more likely. This includes things like having had a heart attack, having migraine headaches, and having a constriction of blood vessels in the hands called Raynaud’s phenomenon. It may well be that small numbers of persons do have vascular disorders that make glaucoma worse. For example, a recent study found that glaucoma got worse much faster in people who have something in their blood stream called anti-cardiolipin antibodies. But, less than 5 in 100 glaucoma patients had these antibodies.

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Things that make open angle glaucoma more likely Table of Contents Things that aren’t risk factors for open angle glaucoma