Glaucoma is a disease which is generally gradual and painless in the early stages. Nerve fibres in the optic nerve slowly die, leading to an increasing restriction of the visual field. These restrictions in visual field are hardly noticed at the start, the head simply needs to be rotated a little more when looking sideways. Only when the disease is in the advanced stage are the losses also noticeable in the when looking straight ahead. An increased ocular pressure plays a significant role in glaucoma.
The risk of developing glaucoma increases from the age of 50. Further risk factors include familial predisposition and diabetes.
TYPES OF GLAUCOMA
Damage to the optic nerve fibres can be caused by various types of glaucoma.
Wide angle glaucoma is the most common type of glaucoma (approx. 90%) and is the result of degenerative changes in the eye, so is a sign of ageing. In a healthy eye there is a balance between the production and outflow of intraocular fluid (the liquid in your eye). If this balance is disrupted, in other words the outflow of excess fluid is slowed, this results in a pressure on the structures in the eye such as the retina and optic nerve. This causes increased pressure in the eye. If this is not treated, it can lead to glaucoma.
Normal intraocular pressure is between 10 and 21 mm Hg. Fluctuations over the course of a day of up to 5 mm Hg are deemed to be physiological, with the highest values generally occurring at night or in the early hours of the morning.
In normal-tension glaucoma, glaucoma develops without the intraocular pressure being elevated. It is as yet not entirely clear what the cause of this is, but circulation at the papilla (the place where the optic nerve leaves the eye) is restricted, leading to damage to the optic nerve fibres.
In narrow-angle glaucoma, also known as an acute glaucoma attack, the intraocular pressure increases rapidly to up to 70 mm Hg. This type of glaucoma is always an emergency. A doctor should be contacted as soon as possible if the following symptoms occur: a veil in front of the eyes, severe eye pain or headaches, coloured rings of light around sources of light and nausea and vomiting.
Congenital glaucoma is rare and mostly occurs within the first year of life. Secondary glaucoma is also a rare form and is caused by other eye diseases and injuries.
The measurement of the pressure in the eye is an important indication of the possible existence of glaucoma. Early identification and rapid, effective treatment enable many problems to be ruled out. At Optiker Fischer, the measurement of the pressure in the eye is part of the daily routine. Glaucoma is one of the most common causes of blindness in high-income countries. Regular measurements enable changes in intraocular pressure to be identified at an early stage.
Measuring the intraocular pressure alone is not sufficient to diagnose glaucoma. If the pressure in the eye is too high, the ophthalmologist will examine the ocular fundus and carry out a visual field test. The visual field is the entire field of vision without moving the head or eyes.
Increased intraocular pressure will be reduced by the ophthalmologist using eye drops. If this is not sufficient, operations or laser treatment can be considered to treat the condition.