Glaucoma is the name given to a group of conditions that result in damage to the optic nerve that transmits information from the retina to cells in the brain. Commonly the damage results from a rise in pressure within the eye but pressure is not always involved and the damage can be due, for example, to a reduced blood flow to the nerve. Intraocular pressure (IOP) is not related to blood pressure.
The eye continuously produces ‘aqeous’, the fluid in the front section of the eye, that leaves via tiny holes in the angle of the eye, the trabecular meshwork. If the angle becomes blocked or partially blocked the intraocular pressure will rise. The angle can become gradually blocked with age as debris fills this area over the years. Certain secondary glaucomas also result from blockage of the angle, such pigment dispersion syndrome were pigment molecules cause a blockage, or advanced diabetes were blood vessels can grow into and block the drainage angle.
There is an increased risk of glaucoma if it runs in your family. Anyone 40 or over and with a direct relative suffering glaucoma has their eye examination fee covered by the NHS. Regular eye examinations are important as glaucoma can result in significant damage before any symptoms are noticed. Most glaucomas are relatively slowly progressing other than angle closure glaucoma. Here there is complete, or virtually complete, closure of the angle so little to no aqeous can escape. If this happens the symptoms are immediate and far more dramatic. Pain, redness, vomitting and haloes around lights are commonly experienced.
Treatment is usually in the form of drops to bring down the intraocular pressure. There are also operations available to relieve the pressure if drops are not successful.