Any long term decrease or interruption of blood flow to the optic nerve can cause ocular damage leading to glaucoma. This would establish as candidates for glaucoma individuals with high or low blood pressure, blockage in the carotid, coronary disease or with a history of migraine headaches. Diabetics and heavy smokers are at high risk because of the negative effects of both the disease and the habit on blood circulation. Blacks are more at risk than whites because, for reasons unknown, their intraocular pressure is more difficult to control and they seem to sustain more nerve damage. They seem to scar faster after surgery, causing premature post-op drainage problems.
Experience also indicates that blacks are less compliant in following treatment instructions.
It should be noted also that individuals with myopia are more inclined than others to contract glaucoma. In the normal eye, aqueous humor circulates freely through the anterior and posterior chamber. The fluid, produced constantly by the ciliary body, drains through the trabecular meshwork, back into the bloodstream. Glaucoma develops when production of fluid increases, or filtration is no longer adequate. Pressure rises in the eye, causing damage to the optic nerve.