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Anterior uveitis denotes intraocular inflammation that involves the iris (iritis), anterior part of the ciliary body (anterior cyclitis), or both (iridocyclitis). Primary site of inflammation, as determined clinically, is the anterior chamber and/or anterior vitreous.1 The standardization of uveitis nomenclature (SUN) working group has categorized uveitis according to the onset, duration, and course of the disease.1 Anterior uveitis can be of an acute or insidious onset. The duration of anterior uveitis can be limited (less than or equal to three months) or persistent (more than three months). Anterior uveitis is also classified based on the disease course: It is classified as acute anterior uveitis when there is an episode of sudden onset and limited duration; recurrent anterior uveitis when repeated episodes occur separated by periods of inactivity for at least three months without treatment; and chronic anterior uveitis when it persists and relapses in less than three months after discontinuing treatment. Anterior uveitis may also be classified as granulomatous or non-granulomatous according to its clinical appearance, and infectious or non-infectious according to its etiology. A clear classificaton of uveitis helps clinician in performing investigations and laboratory tests. Anterior uveitis can be associated with various systemic diseases and further systemic physical examination and investigations should be carried out when required. With a systematic approach, including detailed history, ocular examination and ancillary investigations, a diagnosis can be established in up to 70 % of cases.2
Although causes of uveitis differ among the various regions of the world, anterior uveitis is the most common form of intraocular inflammation at uveitis centers worldwide.3–6 Anterior uveitis is usually the most easily managed form of uveitis. However, in some cases it can lead to sightthreatening and serious complicatons such as glaucoma, cataract, and cystoid macular edema. Complications can be prevented or managed earlier, if anterior uveitis is promptly diagnosed and appropriately treated.
Symptoms of Anterior Uveitis
As anterior uveitis can present with an acute, chronic, or recurrent form, the severity of symptoms ranges from no symptoms in chronic disease to very severe symptoms in acute uveitis. Patients with insidious-onset chronic anterior uveitis do not have symptoms until the development of complications that cause blurred vision. Young children with chronic anterior uveitis are typically asymptomatic.7 By contrast, patients with acute anterior uveitis associated with the HLA-B27 antigen are severely symptomatic and start feeling a dull ocular pain even before any evidence of an acute attack can be detected on clinical examination. Symptoms of acute anterior uveitis include pain, photophobia, redness, tearing, blurred vision and floaters.
The pain of anterior uveitis usually results from acute inflammaton of the iris and ciliary body and is most severe when the patient fixates at a near object, especially a light source. Ciliary and iris sphincter muscle spasm can cause varying degrees of pain that may be described as a dull aching type of pain or a throbbing sensation localized to the eye, but may also be a referred pain that seems to radiate over a larger area served by the trigeminal nerve. In contrast to the ocular pain associated with scleritis or papillitis, a nocturnal pain is not specifically reported and pain does not increase with eye movements.
Photophobia is usually caused by ciliary muscle spasm but can also be associated with pupillary muscle involvement or corneal epithelial edema.
Tearing is seen as a result of trigeminal nerve irritation.
Floaters and Blurred Vision
Inflammatory cells, fibrin, or opacities in the anterior vitreous can cause floaters. Corneal edema, occlusion of the pupillary area with a dense fibrin clot, opacities in the anterior vitreous, ciliary spasm, macular edema, and secondary cataract can cause blurred vision in anterior uveitis.