General Medical Information

Iritis and Iridocyclitis

Jean Edwards Holt

The iris and ciliary body anatomically constitute the anterior uveal tract. Uveitis is a general term that describes inflammation of the iris (iritis), ciliary body (cyclitis), or most commonly both (iridocyclitis). Acute iridocyclitis causes severe aching of the eye, intense photophobia, tearing, and in many instances, decreased vision. The redness usually is most evident around the limbus over the ciliary body (ciliary flush), unlike the diffuse redness of conjunctivitis. The pupil is constricted owing to direct irritation of the iris sphincter muscle, and the anterior chamber fluid is cloudy owing to the presence of inflammatory exudate and cells entering the aqueous. Severe secondary glaucoma can occur if clumps of this debris block the filtration angle. In most acute cases of iritis not associated with severe corneal disease or trauma, the cause is unknown but the condition may be associated with tuberculosis, sarcoidosis, ankylosing spondylitis, rheumatic diseases, gonorrhea, or Reiter syndrome.

The objective in managing iritis is suppressing inflammation and easing pain due to spasm in the ciliary body. This is achieved with topical glucocorticoids and a cycloplegic agent. Systemic analgesics often are needed. Herpes zoster can involve the iris and produce marked iridocyclitis. This appears to be more common with involvement of the external nasal nerve, a branch of the ethmoid nerve, which is related to the innervation of the iris. The herald sign of this disorder is a painful eye, usually red, which is associated with herpetic eruption along the ipsilateral lower half of the nose. This is considered an urgent ophthalmologic condition and should be managed by an ophthalmologist. Herpes zoster ophthalmicus is a frequent first manifestation of acquired immunodeficiency syndrome (AIDS) or human immunodeficiency virus infection. Acute retinal necrosis also may be present. Herpetic lesions of the face have the highest association with AIDS. An underlying immunodeficiency syndrome should be suspected and investigated when herpetic lesions involve the eye.