Glaucoma - Diagnosis
Glaucoma is usually diagnosed during a routine visit to an eye specialist. Because of its mild symptoms, patients are less likely to visit a doctor about the condition.
The fastest test for glaucoma is a measurement of the IOP. The eye specialist first numbs the patient's eye with eye drops that have a yellow coloring. The pressure inside the eyeball is then measured with an instrument called a tonometer (pronounced toe-NAHM-etter). The test takes only a few seconds and provides a fast diagnosis of glaucoma.
If glaucoma is suspected, the eye specialist can then examine the back of the patient's eye for possible damage or changes. The specialist uses an ophthalmoscope (pronounced ahf-THAL-muh-skope) for this purpose. An ophthalmoscope is a device that shines light on the retina. The eye specialist is able to see if the retina and optic nerve are damaged in any way.
An interesting footnote in the history of medicine is the role played by the study of the eye, ear, nose, and throat. These parts of the body are now regarded as important special fields of medicine. However, until the nineteenth century, they were not regarded as legitimate topics of medical study. They were left to "quacks." A quack is someone who treats human disease without having adequate medical preparation.
Thus, the first scientific discussion of glaucoma appeared around 1850. At that time, the German physician Albrecht von Graefe (1787–1840) described a surgical method for treating glaucoma.
He tells of operating on patient's whose vision was "perfectly restored in all cases."
At about the same time, drugs were being developed for treatment of the disorder. The first such drugs were actually discovered by Christian missionaries. The missionaries were introduced by native people to plants that had the effect of reducing the worst symptoms of glaucoma. Those plants were later found to contain a chemical known as physostigmine. Nearly a century later, the great black American chemist Percy Julian (1899–1975) discovered a way to make physostigmine synthetically in the laboratory. Physostigmine has now largely been replaced by other drugs for the treatment of glaucoma.
Visual tests can also be used to find blind spots in the patient's field of vision. The patient is asked to look at cards with various geometric patterns on them. Difficulty in seeing any one part of a pattern tells the eye specialist where a blind spot may be.
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