Glaucoma Awareness week: Eye pressure and glaucoma -- everything you need to know!

Does high eye pressure always indicate glaucoma? How can it be treated and prevented? Read to find out.

A person with elevated intraocular pressure, commonly known as eye pressure, is suspected for glaucoma as it could potentially lead to the eye condition later in life. What is eye pressure? How can it be diagnosed? How can one lower their risk of glaucoma? Well, here's our expert Dr Rajesh Mishra, Consultant (Glaucoma and Cataract), Advanced Eye Hospital, Navi Mumbai explains everything about eye pressure and glaucoma.

What is eye pressure?

Intraocular pressure (IOP) or eye pressure is the fluid pressure inside an eye and is calculated in millimeters of mercury (mm Hg). If the pressure eye is between 12 - 22 mm Hg, it is considered normal. Eye pressure can be measured with the help of tonometry, which is also a screening test for glaucoma. Here's everything you need to know about glaucoma.

What happens when eye pressure rises?

If the eye pressure increases beyond 22 mm Hg, then it is considered abnormal and could signify ocular hypertension or glaucoma. If the IOP is higher than normal but the person fails to show any signs of glaucoma, it is known as ocular hypertension. However, if the pressure is high, coupled with symptoms of glaucoma, the person is suspected for glaucoma, which has to be confirmed with diagnosis.

Can eye pressure lead to vision loss?

Vision loss can occur when the eye pressure is too high than usual, damaging the optic nerve, which cannot be reversed. In such cases, the peripheral vision is first affected, which is unnoticed as the changes in vision occur very slowly. If this is not detected on time, the central vision is affected, which leads to visual impairment and then loss of vision. However, glaucoma, if detected early, can be managed with medical or surgical treatment and hence, loss of sight can be delayed. If you are suffering from glaucoma, stop performing these yoga asanas.

Does low eye pressure indicate no risk of glaucoma?

Although the normal intraocular pressure is less than 21 mm Hg, there are cases in which the pressure can be falsely elevated due to a thick and rigid cornea. The ocular hypertension treatment study [1] revealed that people with elevated pressure of more than 24 mm Hg and thick cornea were less likely to suffer from glaucoma as compared with those having normal or thin cornea. For example, people with thin cornea (say 400 ), might show a pressure of 20 mm Hg but in reality, it could be 27 mm Hg, which is higher than normal. Similarly, if the cornea is thick (say 640 ), the pressure of 18 mm Hg might, in reality, be equivalent to 12. Your doctor might recommend a pachymetry test to evaluate the thickness of the cornea to determine IOP reading and plan the treatment accordingly.

For example, people with thin cornea (say 400 ), might show a pressure of 20 mm Hg but in reality, it could be 27 mm Hg, which is higher than normal. Similarly, if the cornea is thick (say 640 ), the pressure of 18 mm Hg might, in reality, be equivalent to 12. Your doctor might recommend a pachymetry test to evaluate the thickness of the cornea to determine IOP reading and plan the treatment accordingly.

What are the early signs of an increased eye pressure?

The symptoms of increased eye pressure depend on the type of glaucoma. In most cases, open-angle glaucoma is asymptomatic as it affects the optic nerve slowly and painlessly. It doesn't show any signs until the optic nerve is severely damaged and the only symptom you might notice is loss of peripheral vision. Whereas angle closure glaucoma manifests as blurred vision, which lasts only for a short time during the initial stages. As the condition progresses, you might experience long lasting episodes of blurred vision, pain in or around the eyes, colored halos around lights, red eyes and vomiting. Here are 8 answers that could save your eyes!

How is it diagnosed?

An increase in eye pressure can be diagnosed during routine physical examination by an ophthalmologist. And if your doctor suspects glaucoma, your might be advised to visit a glaucoma specialist for further diagnosis.

How can it be treated?

Glaucoma cannot be cured but eye pressure can be controlled by preventing the optic nerve from further damage. Depending upon your condition, your doctor might recommend medication (eye drops), which should be taken daily, or laser treatment or surgery. Read more about medicines for glaucoma dosage, side effects, contraindications and precautions.

Are there any tips to control high eye pressure?

A diet rich in omega-3 fatty acids like green leafy vegetables and fish might improve your eye health, but do not prevent glaucoma, whereas exercising regularly might reduce eye pressure in open-angle glaucoma. Apart from this, here are a few things to keep in mind.

• Limit your intake of caffeine as drinking beverages loaded with caffeine increase your eye pressure.
• Sip fluids every few hours during the day and not all at once, because drinking more within a short span of time might temporarily increase the pressure within eyes.
• Sleep with your head elevated as it might reduce intraocular pressure in eyes as you sleep. Use a wedge pillow to raise your head slightly, about 20 degrees.
• And lastly, take medicines and eye drops as prescribed by your doctor as not doing so might further worsen the condition.

How to ensure that the eye pressure remains normal?

High eye pressure is not the sole cause of glaucoma although it a critical risk factor. Hence, people diagnosed with a high eye pressure should go for a regular eye examination to check the onset of glaucoma.

Reference 1. Kass, M. A. (1994). The ocular hypertension treatment study. Journal of glaucoma, 3(2), 97-100. Image source: Shutterstock

Image source: Shutterstock

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