Uvea Flashcards
Uvea
Greek for grape due to its appearance when dissected. The uvea has three components, the iris, ciliary body and choroid. The uvea is synonymous with the vascular tunic (layer) of the globe
Aqueous flare
A pathognomonic sign of anterior uveitis in which proteins (and cells) are suspended in the anterior chamber. This debris scatters light and can be visualized when a bright focused beam of light is passed through it, like a headlights through fog. This optical phenomenon is known as the Tyndall effect. The presence of aqueous flare signals active inflammation.
Keratic precipitates
Another pathognomonic sign of uveitis which consists of cellular debris that adheres to the corneal endothelium as a result of constantly cycling convection currents within the eye.
Fibrin
Pathognomonic for uveitis. Fibrin develops within the eye like it would anywhere else in the body. Fibrin is very good at adhering delicate structures to one another within the eye and is often responsible for synechia
Miosis
Constriction of the pupil. When you see inappropriate miosis, uveitis should be on your short list of rule outs
Dyscoria
An abnormally shaped iris. Most commonly observed with posterior synechia
Synechia
adhesion of the iris to the lens (posterior synechia) or to the cornea (anterior synechia)
Iris Bombe
360 degree posterior synechia. Aqueous humor becomes entrapped within the posterior chamber which causes the iris to bulge forward like a donut.
Hyphema
Blood that settles within the anterior chamber. Common with uveitis and indicative of a large breakdown in the blood ocular barrier. Note that hypertension and coagulopathies can also cause hyphema
Hypotony
Decreased intraocular pressure. Hypotonyis consistent with acute uveitis.
Cycloplegia
paralysis of the ciliary body. Induced by atropine and useful at alleviating pain from uveitis (ciliary body spasm)
