Anterior uveitis is inflammation in the anterior part of the uvea. The uvea involves the iris, ciliary body and choroid. The choroid is the layer between the retina and the sclera all the way around the eye. Sometimes anterior uveitis is referred to as iritis.
It involves inflammation and immune cells in the anterior chamber of the eye. The anterior chamber of the eye becomes infiltrated by neutrophils, lymphocytes and macrophages. This is usually caused by an autoimmune process but can be due to infection, trauma, ischaemia or malignancy. Inflammatory cells in the anterior chamber cause floaters in the patient’s vision.
Anterior uveitis can be acute or chronic. Chronic anterior uveitis is more granulomatous (has more macrophages) and has a less severe and longer duration of symptoms, lasting more than 3 months.
Acute anterior uveitis is associated with HLA B27 related conditions:
- Ankylosing spondylitis
- Inflammatory bowel disease
- Reactive arthritis
Chronic anterior uveitis is associated with:
- Lyme disease
- Herpes virus
Anterior uveitis usually presents with unilateral symptoms that start spontaneously without a history of trauma or precipitating events. They may occur with a flare of an associated disease such as reactive arthritis.
- Dull, aching, painful red eye
- Ciliary flush (a ring of red spreading from the cornea outwards)
- Reduced visual acuity
- Floaters and flashes
- Sphincter muscle contraction causing miosis (constricted pupil)
- Photophobia due to ciliary muscle spasm
- Pain on movement
- Excessive tear production (lacrimation)
- Abnormally shaped pupil due to posterior synechiae (adhesions) pulling the iris into abnormal shapes
- A hypopyon is a collection of white blood cells in the anterior chamber, seen as a yellowish fluid collection settled in front of the lower iris, with a fluid level
NICE Clinical Knowledge Summaries on red eye say patients with potentially sight threatening causes of red eye should be referred for same day assessment by an ophthalmologist. They need fully slit lamp assessment of the different structures of the eye and intraocular pressures to establish the diagnosis.
The ophthalmologist will guide treatment choices:
- Steroids (oral, topical or intravenous)
- Cycloplegic-mydriatic medications such as cyclopentolate or atropine eye drops. Cycloplegic means paralysing the ciliary muscles. Mydriatic means dilating the pupils. Cyclopentolate and atropine are antimuscarinic medications that blocks to the action of the iris sphincter muscles and ciliary body. These dilate the pupil and reduce pain associated with ciliary spasm by stopping the action of the ciliary body.
- Immunosuppressants such as DMARDS and TNF inhibitors
- Laser therapy, cryotherapy or surgery (vitrectomy) are also options in severe cases.
Last updated April 2019