High eye pressure - known as ocular hypertension - is typically caused when there is a build-up of fluid in the eye. In a healthy eye, a clear, gelatinous fluid called aqueous humour helps to maintain the eye's structure and maintain pressure. However, ocular hypertension can occur, which damages the optic nerves. This leads to significant vision problems and eventual blindness if left undiagnosed. As high pressure does not have any outward-showing symptoms such as pain, it's unlikely you will notice without regular eye checks. If you are experiencing pain and a feeling of pressure behind the eyes, this is much more likely to be sinusitis. When the sinuses become inflamed it can create a pressure headache, but this is not the same as intraocular pressure. Typically, sinusitis will clear up on its own without further treatment, however, in severe or complicated cases you may need to visit a GP.  There are a number of treatments for high eye pressure, but first let's cover some of the causes.

Excessive aqueous humour production

If the eye produces too much aqueous humour, this quickly builds up and raises intraocular pressure.Poor aqueous humour drainage: The fluid drains through a structure called the trabecular meshwork. Should this become blocked or dysfunctional, aqueous humour cannot drain properly, leading to a build-up of pressure.

Eye trauma

An injury to the eye - whether recent or years ago - can upset the balance between fluid production and drainage in the eye.Medications: Steroid-based treatments have been known to create high eye pressure and lead to glaucoma. Even eye drops after corrective surgery could cause problems.

Eye conditions

Some eye conditions have been linked to intraocular pressure. These include corneal arcus and pigment dispersion syndrome.

Other factors

There are a number of genetic and age factors that may contribute to high pressure levels in the eye. People aged over 40 and those with a family history of glaucoma or with African or Caribbean heritage are also more at risk.

What are the treatments for high eye pressure?

You are considered to have ocular hypertension if the pressure in your eye exceeds approximately 21 mmHg, which is millimetres of mercury. However, high pressure is not a disease on its own and is really only an indicator that you should be observed more closely for glaucoma as you get older. You may be given medications, usually eye drops, to treat high eye pressure to prevent a build-up that could eventually damage the optic nerve. It is important that you follow your optometrist's instructions closely.

The main aim is to reduce pressure before it becomes a risk to your eyesight. Initially, you will be asked to apply the drops to one eye to see if they have a positive impact before beginning treatment on both eyes. There could be side effects to medications, so you will be encouraged to attend frequent check-ups to ensure treatment is progressing normally. However, if intraocular hypertension fails to respond to these treatments, you may be experiencing early primary open-angle glaucoma already. If this is the case, your optometrist will advise you on suitable treatments. Laser surgery is an option, although it is not usually recommended as there is a risk you could develop glaucoma damage from the operation alone. Despite this, some people may be considered high risk for glaucoma or are not reacting well to medications.