Glaucoma

Glaucoma is a disease that can affect your eyesight.

If untreated, it can lead to serious and permanent effects on your vision. It does this by damaging the nerve at the back of the eye.

This means that the information picked up by the eye isn’t able to get to the brain. Glaucoma tends to affect older people though it can even affect children and young people.

Glaucoma is usually associated with high pressure inside the eye though patients can also get damage to the nerve when the pressure is normal; this is called normal tension glaucoma.

There are other types of glaucoma, as summarised below:

Open angle glaucoma

Open angle glaucoma occurs when the drainage system of the eye is open but the fluid inside is unable to escape or leave the eye. This leads to a build up of pressure and subsequently leads to damage to the nerve.

Open angle glaucoma is the commonest type of glaucoma in the UK and patients tend to not be aware that their pressures are high or that their vision is affected. Treatment usually consists of eye drops, laser (selective laser trabeculoplasty) or surgery depending on the amount of nerve damage or severity of pressure.

For more information on primary open angle glaucoma a PDF leaflet from Glaucoma UK can be downloaded here.

Closed angle glaucoma

In this type of glaucoma the pressure is usually high, and it is this high pressure that causes damage to the optic nerve.

The “angle” is part of the drainage system of the eye and is where the iris meets the cornea and sclera. In closed angle glaucoma, the eyes natural drain system is blocked by the iris as can be seen in the image below. It is this blockage that causes the fluid inside the eye to build up causing a high pressure.

This condition can also present as an “acute attack” where the pressure goes up very rapidly. Symptoms for this range from severe eye pain, headache on one side, brow ache, blurring, whitening of vision, rainbow coloured haloes around lights, red eye, nausea and vomiting.

The symptoms usually last a few hours though rarely symptoms can last for a short time and resolve. Patients sometimes find these symptoms are worse at night and when reading. If concerned you should go to your nearest eye emergency service.

Depending on the pressure and the amount of nerve damage, treatments, range from laser iridotomy or cataract surgery. Sometimes cataract surgery is also combined with a procedure called goniosynechiolysis (this removes the iris from the drainage system). The ultimate aim of these treatments are to restore the natural drainage system of the eye.

If however the drainage system shows severe scarring then a procedure that bypasses the natural drainage system of the eye like a trabeculectomy may be necessary.

For more information on primary angle closure glaucoma a PDF from Glaucoma UK can be downloaded here.

Uveitic glaucoma

Neovascular glaucoma

Neovascular glaucoma or rubeotic glaucoma is a very aggressive form of glaucoma and is usually associated with diabetes or other retinal conditions such as retinal vein (sometimes retinal artery) occlusions, inflammation (uveitis) or even more rarely, tumours.

Retinal ischaemia (or a lack of blood in the eye) causes the eye to produce more blood vessels. However it does this in a rather rushed or “panicked” way, with the blood vessels growing in the wrong parts of the eye, one place being the drainage system. These blood vessels can block the drainage of fluid from the eye, increasing the pressure and cause damage to the optic nerve.

Treatments for this condition are complex and usually involve the treatment of the retinal disease in the form of laser and injections into the eye. The treatment for pressure can involve the use of drops, laser (cyclodiode) or insertions of tubes/ drainage implants inside the eye to drain the extra fluid out of the eye.