Glaucoma is a complicated disease in which damage to the optic nerve leads to damaging vision, and progressive, permanent and irreversible vision loss, if left untreated.
Glaucoma is the second leading cause of blindness. In England, about 480,000 people have chronic open-angle glaucoma. Of these about 1 in 50 above 40 years old and 1 in 10 people above 75 years old.
It is a category of eye disorders, which is often associated with dangerous build-up of internal eye pressure (intraocular pressure or IOP). The pressures cause damage to the eye’s optic nerves, which normally transmits the visual information to your brain.
If untreated, initially the peripheral vision is affected, causing inability to see at the edges of vision, then progressively leading to damage causing blindness. Visual field testing is an eye examination method used to measure your peripheral vision and to determine if you have eye diseases such as glaucoma .
Symptoms Of Glaucoma
There are two main types of glaucoma:
Approximately 90% of cases are open-angle. It is painless and does not have acute attacks. The only signs are gradually progressive visual field loss as the optic nerve changes.
Approximately 10% of cases are closed-cases. 10% of these closed-angle cases tend to be characterized by sudden ocular pain, seeing halos around lights, red eye, very high intraocular pressure, nausea and vomiting, sudden decreased vision and fixed mid-dilated pupil. This is treated ocular emergency.
Causes Of Glaucoma
There is a constant flow of fluid through the eye to ensure that the eye maintains its round shape and does not become too hard or soft. The fluid is called ‘aqueous humour’ and is secreted from behind the iris around through the pupil then drains through several microscopic channels. Glaucoma develops usually when the flow is obstructed and causing a build-up of pressure within the eye.
People with a history of glaucoma have about 6% chance of developing it. People of African descent are three times more likely to develop primary open-angle glaucoma, and elderly people have a higher risk of developing glaucoma due to a thinner corneal thickness.
Treatments For Glaucoma
Early diagnosis is important because any damage to the eyes cannot be reversed. The treatment is aimed to control the condition and minimize future damage. The treatment involved could be: eye drops, laser treatment or surgery.
- Eye drops / medicine
These work by increasing the drainage of fluid out of the eye, or they reduce the amount of fluid secreted into the eye for open-angled glaucoma. For closed-angled medicine is given rapidly into circulation through a vein to reduce pressure quite quickly.
- Laser treatment
For open-angled glaucoma this is used to increase of flow of fluid from the eye. It is normally considered to be a temporary treatment method. For closed-angled glaucoma, a hole in the iris is made using a laser to prevent condition happening again.
- Eye surgery
This operation allows drainage of fluid from inside the eye to the outside of the eye. The surgery may result in a small blister on eye, hidden under upper eyelid and medicine used to reduce risk of scarring.