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A common question asked during the eye exam is, “When is the puff coming?”
Patients are referring to air-puff or non-contact tonometry. Tonometry is the procedure used to measure eye pressure, and this is important for diagnosing and monitoring glaucoma.
In non-contact tonometry, a puff of air is used to measure the pressure inside the eye. The benefit of this test is there is no actual contact with the eye, but the air puff is sometimes very startling for patients. Some people hate that test and it isn’t the most accurate way to measure your eye pressure.
Some doctors don’t even use the air-puff test. Instead, they place a yellow drop that consists of a numbing medicine and then shine a blue light on the eye. This is done in front of the slit lamp and a small tip gently touches the eye to measure the eye pressure. This procedure is called Goldmann tonometry and is considered the gold standard for measuring eye pressure.
Another method for checking eye pressure is the Tonopen. This is a portable, hand-held instrument that is useful when patients can’t sit in front of the slit lamp to have their eye pressure checked. The Tonopen also requires a numbing drop to be placed in the eye, and the tip gently touches the eye.
A common question related to tonometry is “what normal eye pressure?”
Normal eye pressure ranges from 10-21 mm Hg. Eye pressure doesn't have any relationship to blood pressure. Many times, people are surprised that their eye pressure is high, but they have normal blood pressure. In general, there is no diet or exercise that will significantly affect eye pressure. It is therefore important to have your eye pressure checked regularly because there are usually no symptoms of high eye pressure until it has affected your vision.
Article contributed by Dr. Jane Pan
This blog provides general information and discussion about eye health and related subjects. The words and other content provided in this blog, and in any linked materials, are not intended and should not be construed as medical advice. If the reader or any other person has a medical concern, he or she should consult with an appropriately licensed physician. The content of this blog cannot be reproduced or duplicated without the express written consent of Eye IQ.
Have you ever seen a temporary black spot in your vision? How about jagged white lines? Something that looks like heat waves shimmering in your peripheral vision?
If you have, you may have been experiencing what is known as an ocular migraine. Ocular migraines occur when blood vessels spasm in the visual center of the brain (the occipital lobe) or the retina.
These optical migraines can take on several different symptoms, but they typically last only from a few minutes to an hour. They can take on either positive or negative visual symptoms, meaning they can produce what looks like a black blocked-out area in your vision (negative symptom), or they can produce visual symptoms that you see but know aren’t really there, like heat waves or jagged white lines that look almost like lightning streaks (positive symptoms).
Some people do get a headache after the visual symptoms but most do not. They get the visual symptoms, which resolve on their own in under an hour, and then generally just feel slightly out of sorts after the episode but don’t get a significant headache. The majority of episodes last about 20 minutes but can go on for an hour. The hallmark of this problem is that once the visual phenomenon resolves the vision returns completely back to normal with no residual change or defect.
If you have this happen for the first time it can be scary and it is a good idea to have a thorough eye exam by your eye doctor soon after the episode to be sure there is nothing else causing the problem.
Many people who get ocular migraines tend to have them occur in clusters. They can have three or four episodes within a week and then may not have another one for several months or even years.
There are some characteristics that raise your risk for ocular migraines. The biggest one is a personal history of having migraine headaches. Having a family history of migraines also raises your risk, as does a history of motion sickness.
Although the symptoms can cause a great deal of anxiety, especially on the first occurrence, ocular migraines rarely cause any long-term problems and almost never require treatment as long as they are not accompanied by significant headaches.
So if symptoms like this suddenly occur in your vision, try to remain calm, pull over if you are driving, and wait for them to go away. If they persist for longer than an hour, you should seek immediate medical attention.
Article contributed by Dr. Brian Wnorowski, M.D.
This blog provides general information and discussion about eye health and related subjects. The words and other content provided in this blog, and in any linked materials, are not intended and should not be construed as medical advice. If the reader or any other person has a medical concern, he or she should consult with an appropriately licensed physician. The content of this blog cannot be reproduced or duplicated without the express written consent of Eye IQ.
