Anterior Uveitis Flashcards
What is anterior uveitis?
Uveitis is an inflammation of one or all parts of the uvea, or the vascular area between the retina and sclera of the eye. The anterior uvea is composed of the iris and ciliary body; an irritation of this segment, or anterior uveitis, leads to acute painful symptoms and photophobia.
Sometimes anterior uveitis is referred to as iritis.
Briefly describe the anatomy 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.
Briefly describe the pathophysiology of anterior uveitis
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.
Briefly differentiate between acute and chronic anterior uveitis
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.
What conditions are associated with acute anterior uveitis?
Acute anterior uveitis is associated with HLA B27 related conditions:
- Ankylosing spondylitis
- Inflammatory bowel disease
- Reactive arthritis
What conditions are associated with chronic anterior uveitis?
Chronic anterior uveitis is associated with:
- Sarcoidosis
- Syphilis
- Lyme disease
- Tuberculosis
- Herpes virus
What are the clinical features of anterior uveitis?
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.
Symptoms include:
- Dull, aching, painful red eye
- 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)
What are the signs of anterior uveitis on examination?
- Ciliary flush (a ring of red spreading from the cornea outwards
- 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
Briefly describe the management of anterior uveitis
The ophthalmologist will guide treatment choices:
- Steroids (oral, topical or intravenous)
- Cycloplegic-mydriatic medications such as cyclopentolate or atropine eye drops
- Immunosuppressants such as DMARDS and TNF inhibitors
- Laser therapy, cryotherapy or surgery (vitrectomy) are also options in severe cases
Briefly describe the mechanism of action of cycloplegic-mydriatic medications
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.
What are the complications of anterior uveitis
- Synechia
- Retinal scarring
- Cataract
- Macular oedema
- Glaucoma
Give differentials for a painless red eye
- Conjunctivitis
- Episcleritis
- Subconjunctival Haemorrhage
Give differentials for a painful red eye
- Glaucoma
- Anterior uveitis
- Scleritis
- Corneal abrasions or ulceration
- Keratitis
- Foreign body
- Traumatic or chemical injury
What is the NICE guidance for a patient presenting with a red eye?
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.
