Ocular hypertension (high eye pressure)
Jan 16, 2025 in Eye Care
Ocular hypertension, also known as high eye pressure or OHT, is a condition in which the pressure inside your eyeball is higher than it should be. You probably won’t notice any symptoms when you have OHT, but it can cause problems later if it goes undiagnosed and untreated. Read on to learn more about high eye pressure, the causes, and how it’s treated.
What is ocular hypertension?
Ocular hypertension is when the pressure inside the eye (also called intraocular pressure or IOP) is higher than it should be. Inside your eyes, there is a fluid called aqueous humour. This fluid helps your eye retain shape, helps focus light and provides nourishment to your eyes. Your aqueous humour flows freely through the anterior chamber in the eye and is drained out via a drainage system (the trabecular meshwork). The pressure inside the eye can build and cause ocular hypertension if aqueous is overproduced or if it cannot drain adequately.
The correct eye pressure is important for maintaining proper eye health – too high pressure can cause issues later on, such as glaucoma (a condition where the optic nerve becomes damaged) and loss of sight.
Ocular hypertension and glaucoma
Glaucoma is a condition in which the ocular nerve becomes damaged and causes sight loss. It can be caused by many things, but ocular hypertension is one of the main risk factors. Constant pressure on the optic nerve as a result of high eye pressure can result in damage, which can lead to blindness and sight loss. Therefore, if you’ve been diagnosed with ocular hypertension it is important that you have regular eye health checks.
The symptoms of ocular hypertension
Ocular hypertension doesn’t cause any symptoms. It’s unlikely that you will know if you have it unless it’s caught by your optometrist which makes it all the more important to attend regular eye check ups.
If you experience any halos, eye pain, or changes in your vision, it’s vital that you see your optometrist or doctor as soon as possible for diagnosis.
What causes ocular hypertension?
High eye pressure is caused by having too much aqueous humour – the liquid in your eye that helps to keep your eyeballs round and delivers nutrients to your eyes. If there is an overproduction of this fluid or if there is a fault or blockage of the drainage system that carries waste aqueous humour away, this can cause higher pressure in your eye than is normal.
Risk factors of ocular hypertension
Anyone can develop ocular hypertension, but there are a few factors that can increase the risk. These include:
- Family history of high eye pressure or glaucoma
- Age – chances increase with age
- Ethnicity – you’re more likely to develop this condition if you are from African-Caribbean descent
- Very high myopia (short-sightedness)
- Some medications can raise eye pressure as a side effect
- Eye injuries – even old injuries can affect your intraocular pressure
Diagnosing ocular hypertension
OHT is diagnosed via an eye test. During your test, the optometrist will perform multiple checks to determine the overall health of your eye and your prescription. Some of these tests will check your intraocular pressure and can tell if the pressure is too high or not.
Your eye pressure will be measured using a tonometer. For a normal, average eye pressure, they’ll be looking for a reading between 10mmHg and 21mmHG. Anything that is consistently above this level could indicate ocular hypertension.
They will also check the health of your optic nerve and your peripheral vision, to find other signs of glaucoma, as well as look for any other eye conditions that are related to increased eye pressure.
How is ocular hypertension treated?
The treatment of ocular hypertension will depend on the severity of the condition.
Often, the first line of treatment that your optometrist will recommend is a quick laser procedure called SLT. This procedure helps to reduce eye pressure
If your eye pressure is only slightly raised, your optometrist might decide to just monitor it with regular testing rather than start treatment right away. However, they may decide to refer you to an ophthalmologist or specialist. Often, the first line of treatment that they will recommend is a quick laser procedure called SLT. This procedure helps to reduce eye pressure. Alternatively, they may decide to prescribe eye drops to help lower your eye pressure, however, with an SLT treatment, ongoing use of drops is not required.
It’s important to follow instructions closer and to have regular eye tests so that your optometrist can closely monitor your eye pressure and look for the signs of glaucoma starting to develop. Treatment for glaucoma is most effective when caught early.
Takeaway
High eye pressure, also called ocular hypertension, occurs when there is a buildup of fluid inside your eye. If the fluid isn’t given the chance to drain as normal, either due to a blockage or problem with the drainage system, it can cause high intraocular pressure. Although it doesn’t present any symptoms, high eye pressure can cause damage to the ocular nerve over time (glaucoma) which can result in blindness. Regular eye tests are recommended, especially if you have any specific risk factors, as catching it early can help preserve your eyesight for a sling as possible.
Ocular hypertension FAQs
Can high blood pressure cause ocular hypertension?
Yes. Very high blood pressure can lead to an increase in intraocular pressure (pressure inside the eye), which is one of the main causes of glaucoma.
Can stress cause high eye pressure?
Yes. Stress is a common factor of high blood pressure, which can, in turn, cause high eye pressure.
What is considered dangerously high eye pressure?
Eye pressure is measured in millimetres of mercury (or mmHg). Normal eye pressure is between 10–21 mmHg and can vary throughout the day, week, or month.
If you have an eye pressure of 21-30 mmHg, this is considered high and puts you at risk of glaucoma. An eye pressure of 40-50 mmHg is considered dangerously high and needs immediate treatment.
Can you fly with high eye pressure?
Yes. Flying with high eye pressure isn’t dangerous thanks to the planes’ systems balancing out the air pressure while you fly. However, it’s always important to listen to your optometrist's advice.