Glaucoma Home A-Z Health Information Health Library A-Z Glaucoma Overview Glaucoma comprises a group of eye conditions associated with damage to the optic nerve (the nerve that connects the eye to the brain) to the point where it detaches from the eye. It is one of the leading causes of vision loss globally. In the UK, approximately 2% of people aged > 40 years are reported to have glaucoma.While any vision loss resulting from glaucoma cannot be recovered, early diagnosis, routine monitoring, and accurate treatment strategies can greatly help suppress further loss of vision and preserve eyesight long-term in most patients. Glaucoma is usually difficult to detect as there are no warning sign. Routine eye examinations will help ascertain the onset and progression of this condition.Glaucoma may be categorised into the following four types:Primary open angle glaucoma, which develops very slowly, is the most common type of glaucoma. The risk of developing this condition is high among Black African or Black Caribbean populations.Angle closure glaucoma may develop slowly (chronic) or rapidly (acute) with a sudden, painful elevation of intraocular pressure. Asian populations show a higher risk for developing this condition than other ethnic groups. This is a rare condition.Secondary glaucoma occurs because of other eye conditions, such as uveitis (inflammation of the uvea: the middle layer of the eye), or eye injuries.Developmental (congenital) glaucoma is a serious abnormality of the eye. Usually, it develops at, or shortly after, birth. This is also a rare condition. Causes Most cases of glaucoma are caused by the increase in intraocular pressure resulting from the improper drainage of fluid within the eye, damaging the optic nerve. Although an exact cause has not yet been identified, certain factors have been reported to increase the risk for developing glaucoma:Age (glaucoma is more common with older age).Ethnicity (Caribbean, African, or Asian populations are at a higher risk).Family history.Other medical conditions, such as diabetes, hypertension, short-sightedness, and long-sightedness, may increase the risk for developing glaucoma. Symptoms Glaucoma rarely causes any symptoms. It develops slowly over several years, initially affecting the peripheral vision. Therefore, most people do not realise that they have glaucoma. This condition is often diagnosed only during a routine ophthalmic examination.The presence of the following symptoms may be observed:Blurry vision.Appearance of rainbow-coloured circles around bright objects/lights.Although both eyes are usually affected, glaucoma may be more severe in one eye. Occasionally, the sudden development of glaucoma has been noted along with the following symptoms:Redness.Blurred vision.Intense eye pain.Tenderness around the eyes.Appearance of rings around lights or bright objects.Headache, nausea, and vomiting. Diagnosis Glaucoma is diagnosed by two main tests:Optical coherence tomography (OCT) of the optic nerve head to rule out structural changes and thinning or loss of the retinal nerve fibre.Perimetry or Humphrey Field Analyser (HFA) to assess the peripheral visual field. Treatment Any loss of vision that has occurred before glaucoma is diagnosed cannot be reversed. However, specific glaucoma treatment methods can help stop the worsening of vision.The recommended treatment depends on the type of glaucoma and includes:Anti-glaucoma eyedrops to reduce the intraocular pressure.Laser treatments to reverse the blockage of drainage tubes or reduce fluid production within the eye.Trabeculectomy: A type of surgery to enhance the drainage of fluid out of the eye and reduce the intraocular pressure.Microinvasive glaucoma surgery (MIGS): A type of minimally invasive eye surgery in which the intraocular pressure is lowered via the creation of small incisions. This procedure improves the natural drainage, unlike the case for traditional glaucoma surgeries, in which the drainage system is bypassed.