Juvenile idiopathic arthritis uveitis is an inflammation of the inner part of the eye (uvea). It results as a complication of juvenile idiopathic arthritis (JIA), an inflammatory condition of the joints. The JIA associated uveitis is the most common eye disorder that results from arthritis in children under 16 years. Inflammation can occur to any of the following inner parts of the eye:
- Iris – This is the colored part that controls entry of light into the eye.
- Ciliary body – The ciliary body is the fluid that fills the front part of the eye. It gives shape to the lens to help focus light correctly.
- Vitreous humor – Clear gel that takes up space in the inside of the eye.
- Choroid – The layer of blood vessels located at the back of the eye.
- Retina – This is the tissue that lies at the back of the eye. Light is focused on the retina to produce images.
Uveitis that involves the anterior part of the eye is the most common type.
- Anterior uveitis – It affects the front parts of the eye such as the iris, anterior chamber and ciliary body. It can further be classified into iritis and iridocyclitis. Iritis is the most common type, involving the iris and the ciliary body. Iridocyclitis involves the iris and anterior chamber of the eye.
- Intermediate uveitis – Inflammation that involves the vitreous humor.
- Posterior uveitis – An inflammation of the choroid and/or retina
Causes and Risk Factors
Juvenile idiopathic arthritis uveitis occurs when the immune system attacks the inner parts of the eye. Like other autoimmune disorders, the cause of the attack is not clear. Factors that increase the risk of developing the condition include the following:
- Female gender
- Being below 7 years of age
- Positive antinuclear antibody (ANA) test - Individuals found to be ANA positive are at a higher risk than those who test negative
- Having oligoarthritis – Oligoarthritis is a common subtype of JIA where 5 or fewer joints are affected within the first six months of the condition
Signs & Symptoms
At the onset of the condition, there are no obvious symptoms in majority of the patients. However, symptoms such as redness, pain, photophobia and blurred vision appear later on. In most cases, the disease is usually advanced at this stage.
The diagnosis assesses inflammation as well as signs of complications. The tests may include:
- Visual acuity test – The test includes a chart which contains letters, shapes or pictures. The child is required to read out loud what they see. The test assesses clarity in vision.
- Slit lamp exam – Involves the use of a magnifying equipment known as a slit lamp microscope. After placing dilating eye drops inside the eye, an eye professional can use the slit lamp to look for signs of inflammation.
- Intraocular pressure measurement – This is done to check for complications that may have arisen, e.g. glaucoma.
Treatment is aimed at relieving the inflammation and reducing pain.
Medical treatment can include:
- Eye drops – The eye doctor may prescribe steroid drops such as prednisolone to aid in reducing inflammation. The patient may also be issued with mydiatrics which help to drain fluid from the eye when the intraocular pressure is too high.
- Immunosuppressive drugs – When eye drops fail, immunosuppressive drugs administered orally, intravenously or subcutaneously can be used. They include Infliximab, Adalimumab, Tacrolimus, Methotrexate (MTX) and some steroids.
Juvenile idiopathic arthritis uveitis can be well controlled with medication. Visual problems will arise in a small percentage of children when the condition is not detected early and treated. Likely complications expected from JIA uveitis include:
- Cataracts – Obstruction of the lens of the eye
- Glaucoma – Build up of intraocular pressure that results in damage to the optic nerve
- Band keratopathy – White discoloration of the usually clear cornea of the eye
- Macular edema – Swelling of the macula (center of retina) due to buildup of fluid.
There are no particular prevention strategies for juvenile idiopathic arthritis uveitis. However, regular eye check-ups, especially by those at risk, is important for early detection and treatment.