a condition in which loss of vision occurs because of an abnormally high pressure in the eye. In most cases there is no other ocular disease. This is known as primary glaucoma and there are two pathologically distinct types: acute and chronic simple. In acute (or angle-closure) glaucoma, there is an abrupt rise in pressure due to sudden closure of the angle between the cornea and iris where aqueous humour usually drains from the eye. This is accompanied by pain and marked blurring of vision associated with inflammation of the anterior segment. In the more common chronic simple (or open-angle) glaucoma, the pressure increases gradually, usually without producing pain, and the visual loss is insidious. The same type of visual loss may rarely occur in eyes with a normal pressure: this is called low-tension glaucoma. Primary glaucoma occurs increasingly with age and is an important cause of blindness. Secondary glaucoma may occur when other ocular disease impairs the normal circulation of the aqueous humour and causes the intraocular pressure to rise.
In all types of glaucoma the eventual problem is to reduce the intraocular pressure. Drops are inserted into the eye at regular intervals to improve the outflow of aqueous humour from the eye and/or to reduce the production of aqueous humour. Drugs used for this purpose include beta blockers (e.g. timolol, levobunolol, carteolol), carbonic anhydrase inhibitors (e.g. brinzolamide, dorzolamide), alpha-receptor stimulants (e.g. apraclonidine, brimonidine), and prostaglandin analogues (e.g. latanoprost). If this treatment is ineffective, surgery may be performed to make a new channel through which the aqueous humour may drain from the eye in sufficient quantities to allow the pressure to return to normal. Such operations are known as drainage or filtering operations.

The new mediacal dictionary. 2014.

Игры ⚽ Нужен реферат?

Look at other dictionaries:

  • Glaucoma — Classification and external resources Acute angle closure glaucoma of the right eye. Note the mid sized pupil, which was nonreactive to light, and injection of the conjunctiva. ICD 10 …   Wikipedia

  • glaucoma — m. oftalm. Enfermedad ocular que se caracteriza por un aumento de la presión intraocular, dureza del globo ocular, alteraciones del campo visual y atrofia de la papila óptica. Suele estar provocada por una producción excesiva de humores oculares… …   Diccionario médico

  • glaucoma — 1640s, from Gk. glaukoma cataract, opacity of the lens (cataracts and glaucoma not distinguished until c.1705), from OMA (Cf. oma) + glaukos, an adj. of uncertain origin (see GLAUCOUS (Cf. glaucous)) …   Etymology dictionary

  • glaucoma — (Del lat. glaucōma, y este del gr. γλαύκωμα, der. de γλαυκός, verde claro, por el color verdoso que toma la pupila en esta afección). m. Med. Enfermedad del ojo, caracterizada por el aumento de la presión intraocular, dureza del globo del ojo,… …   Diccionario de la lengua española

  • Glaucoma — Glau*co ma, n. [L., fr. Gr. glay kwma, fr. glayko s light gray, blue gray.] (Med.) Dimness or abolition of sight, with a diminution of transparency, a bluish or greenish tinge of the refracting media of the eye, and a hard inelastic condition of… …   The Collaborative International Dictionary of English

  • Glaucōma — (Med.), s. Glaukom …   Pierer's Universal-Lexikon

  • Glaucoma — vgl. Glaukom …   Das Wörterbuch medizinischer Fachausdrücke

  • glaucoma — |ô| s. m. Endurecimento do globo ocular, por excesso da tensão interna, que provoca uma diminuição da visão e dores de cabeça …   Dicionário da Língua Portuguesa

  • glaucoma — sustantivo masculino 1. (no contable) Área: medicina Enfermedad ocular que se caracteriza por un aumento de la presión dentro del ojo y la atrofia de la retina …   Diccionario Salamanca de la Lengua Española

  • glaucoma — ► NOUN Medicine ▪ a condition of increased pressure within the eyeball, causing gradual loss of sight. ORIGIN Greek glauk ma, from glaukos bluish green or grey (because of the grey green haze in the pupil) …   English terms dictionary

  • glaucoma — [glô kō′mə, gloukō′mə] n. [L < Gr glaukōma < glaukos (see GLAUCO ) + OMA] any of a group of related eye disorders characterized by increased pressure within the eye which impairs the vision and may slowly cause eye damage and total loss of… …   English World dictionary

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”