Glaucoma is the general term for a group of diseases that proceed unnoticed and that cause damage to the optic nerve. There is no cure for glaucoma yet and it can lead to blindness if it is not recognised and treated accordingly. In most cases the highest risk factor is an individually increased intraocular pressure, which is responsible for the development and progression of glaucoma. However, people with normal intraocular pressure can also develop glaucoma. Their eyes are either particularly sensitive or the blood supply to their optic nerve is insufficient. Nerve fibres die off in the course of the illness. As a result, there are partial losses to the field of vision that only become noticeable when there is massive damage to the optic nerve. The central vision acuity only diminishes or ceases completely at this stage. The loss of nerve fibres is irretrievable, yet further loss can be prevented. The affected patients at first do not realise they are suffering from glaucoma as they experience neither pain nor visual distortions.
The most frequent type of glaucoma is open angle glaucoma with few symptoms, which patients only recognise at a late stage. Another type of open angle glaucoma is normal pressure glaucoma in which there is no excessive intraocular pressure. With angle-closure glaucoma (acute glaucoma, glaucoma seizure), the intraocular pressure increases quickly and reaches high levels. As opposed to the other types of glaucoma, in this case there are typically acute symptoms such as intense pain, visual impairment and nausea. Secondary glaucoma, such as PEX glaucoma (pseudoexfoliation glaucoma) is caused by another eye or general illness.
Glaucoma is the second most prevalent cause of blindness around the world, irrespective of the level of development of the country concerned. The risk of developing glaucoma increases with age. This is why regular check-ups starting at the age of 40 are important for the early detection of glaucoma formation. When detected early, the course of a glaucoma can be slowed down with eye drops or surgery.