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When is it Glaucoma?
Chronically elevated intraocular pressure (IOP) is unhealthy for the optic nerve, the 'TV cable' that connects the eye with the brain. Pressure inside the eye is measured with a device called a tonometer. When the IOP number is higher than normal (typically greater than 21) the doctor considers the possibility of ocular hypertension. But is it glaucoma?
Glaucoma occurs when the high pressure damages optic nerve fibers. Each healthy adult eye has 1,200,000 nerve fibers. One borderline pressure measurement is insufficient to establish a diagnosis of glaucoma. It is merely a snapshot. The IOP trend is far more important. The doctor will want to collect multiple measurements. At the same time additional studies will be ordered to determine if any damage has occurred - damage that has not yet generated any visual symptoms. Visual field testing and a retinal imaging study called OCT are two good examples.
Once again, you may ask your doctor, "Well, do I have glaucoma?"? Don't be frustrated if the eye doctor replies, "I don't know!" It is not always wise to begin prescribing eyedrops. They are expensive and have a well-established risk profile. If the IOP is not dangerously high and the other tests are normal it is reasonable for the clinician to observe the patient conservatively and repeat the IOP measurements every few months.
Related Topics: Glaucoma: What Increases Your Risk, Glaucoma Screening Saves Sight
Glaucoma occurs when the high pressure damages optic nerve fibers. Each healthy adult eye has 1,200,000 nerve fibers. One borderline pressure measurement is insufficient to establish a diagnosis of glaucoma. It is merely a snapshot. The IOP trend is far more important. The doctor will want to collect multiple measurements. At the same time additional studies will be ordered to determine if any damage has occurred - damage that has not yet generated any visual symptoms. Visual field testing and a retinal imaging study called OCT are two good examples.
Once again, you may ask your doctor, "Well, do I have glaucoma?"? Don't be frustrated if the eye doctor replies, "I don't know!" It is not always wise to begin prescribing eyedrops. They are expensive and have a well-established risk profile. If the IOP is not dangerously high and the other tests are normal it is reasonable for the clinician to observe the patient conservatively and repeat the IOP measurements every few months.
Related Topics: Glaucoma: What Increases Your Risk, Glaucoma Screening Saves Sight
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