Raised eye pressure
Raised eye pressure – how to know if there is a problem
Most people have an eye pressure that measures between 10mm and 20mmHg. However, this number can be lower or higher and still be fine for your eye. Normal pressure is said to be less than 21mmHg, but the number can be higher and your eye still be normal.
Ocular Hypertension (OHT) means raised pressure (over 21mmHg) but no damage to the nerve and full visual fields. If the pressure in your eye is over 21mmHg then you may be told you have raised pressure. If it less than 30mmHg you may not be advised to have treatment, as long as everything else is healthy with your eyes and your general health. If you have a family history of definite glaucoma you may want to consider starting pressure-lowering treatment.
Only a small number of people with OHT develop glaucoma over the following five years
This means you can decide to have a regular examination of visual fields once a year or every two years. As long as your visual field is full and your nerves are unchanged in appearance, then you are fine at that time, but further checks are sensible.
There are exceptions and some people have pressure less than 20mmHg, yet still develop glaucoma, which confirms that glaucoma is about more than just pressure in the eye.
Normal pressure is the pressure at which no damage occurs to the nerve. For some people this is as high as 30mmHg. The higher the pressure the more likely that, in time, damage will occur to the eye and vision. Below is a table to help you describe what the level of pressure means.
Using the best words to describe pressure
Low pressure | less than 8mmHg |
Normal pressure | level with no damage to eye |
Slightly raised pressure | over 22 mmHg |
High pressure | over 30mmHg |
Very high pressure | over 40mmHg |
Dangerous sight threatening | over 50mmHg |
Points to remember
- A normal pressure is a level of pressure that is causing no damage.
- People with very raised pressure have a variety of options to reduce the pressure and probably reduce the chance of damage to the optic nerve.
- Options include drops, laser or surgery, each with their own pros and cons. A plan will be discussed with each patient on the most appropriate course of action.
- Regular eye checks after 45 years of age can help pick up early glaucoma or raised pressure. You may only need intermittent checks, but treatment may be advised.
