Introduction
Juvenile idiopathic arthritis is considered to be an arthritis (joint pain) condition that affects children (below the age of sixteen) without any identifiable cause. Uveitis, the inflammation of the middle layer of the eye called the uvea, is an extra-articular manifestation of juvenile idiopathic arthritis and this condition seems to be the most common kind of uveitis seen in children.
What Is Juvenile Idiopathic Arthritis?
Juvenile idiopathic arthritis is an autoimmune disease, where the tissues and cells of the human body are attacked by the immune system. This causes inflammation in the joints making them painful and difficult to mobilize. The exact cause of this mechanism is unknown, however, it could be due to multifactorial like genes, a trigger factor, and the body’s immune system. There are several types of juvenile idiopathic arthritis and uveitis which are seen commonly in:
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Polyarticular Juvenile Idiopathic Arthritis-Arthritis is five or more joints.
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Oligoarticular Juvenile Idiopathic Arthritis- Arthritis in four or fewer joints.
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Enthesitis-Related Juvenile Idiopathic Arthritis- Arthritis in children with enthesis (inflammation of the site where tendons and ligaments meet).
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Psoriatic Juvenile Idiopathic Arthritis- Arthritis in children with psoriasis.
What Is Uveitis?
The human eye has various parts. The part of the eye that one can see and is white in color is called the sclera. The uvea is made up of the eye's internal structures that lie beneath the sclera. It has three parts:
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Iris- It is the pigmented part of the eye which gives it its color.
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Ciliary Body- It is behind the iris structure in the eye and secretes the transparent liquid within the front of the eye
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Choroid- Between the sclera and the retina of the eye lies a layer of blood vessels which is termed the choroid.
The retina is part of the eye which receives the images that we see. It lies at the back of the eye. A gel-like liquid called vitreous fills the back of the eye.
What Is Uveitis in Juvenile Idiopathic Arthritis?
Uveitis is a complication seen in a child with arthritis of unknown origin. Juvenile idiopathic arthritis-associated uveitis has a poor prognosis and various risks of complications. Early diagnosis and rapid adequate treatment are important for the long-term prognosis. Children usually do not complain about the eye and adults may not see any visible irritant. However, once diagnosed close monitoring by an ophthalmologist is necessary.
What Are the Types of Uveitis?
Depending on the site of the uvea affected, uveitis can be of three types:
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Anterior Uveitis- The part of the eye present between the cornea as well as the iris and that of the ciliary body is affected.
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Intermediate Uveitis- The retina, the blood vessels located immediately behind the lens, and the vitreous gel are affected.
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Posterior Uveitis- The retina or the choroid is affected.
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Panuveitis- It is a condition when the iris, ciliary body, and choroid are inflamed.
What Are the Symptoms of Uveitis?
The symptoms usually present gradually but in some instances, they may be sudden in onset and worsen quickly. Individuals may present with unilateral or bilateral affected eyes. The symptoms of uveitis are as follows:
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Redness of the eye.
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Pain in the eye.
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Sensitive to light (photophobia).
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Visibility of dark floating spots (floaters).
Individuals with idiopathic arthritis do not always show these classic symptoms of uveitis unless it is late into the disease which can put them at risk for irreparable damage to the eye.
Who Is at Risk for Developing Uveitis in Juvenile Idiopathic Arthritis?
Some of the factors that may put a child with idiopathic arthritis at risk for developing uveitis are as follows:
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Arthritis before the age of 4 years old.
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Having a negative rheumatoid factor result.
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Female children with arthritis tend to have a higher tendency of developing uveitis.
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Individuals with a positive antinuclear antibody blood test.
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Individuals with a negative rheumatoid factor test.
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Prolonged use of immunosuppressant medications.
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Presence of human leukocyte antigen B27 (HLA-B27)- a protein present on the surface of white blood cells.
How to Diagnose Uveitis?
On diagnosis of juvenile idiopathic arthritis, uveitis is suspected even when the child does not present any symptoms with respect to the eye. Since uveitis can become very serious without warning, a thorough routine examination of the eye is advised when diagnosed with juvenile idiopathic arthritis. The diagnostic tests are as follows:
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Assessment of vision and the response of pupils to light is done after dilating with a pupil dilating drop.
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Intraocular pressure inside the eye is measured using tonometry after numbing the eye.
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The presence of inflammatory cells is checked using a microscope that magnifies and illuminates the front of the eye with an intense line of light (a slit lamp).
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The back of the eye is examined by shining a bright light into the eye, after pupil dilation using eye drops (ophthalmoscopy).
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Cycloplegic refraction is a procedure done to determine the clarity of vision using eye drops that temporarily paralyze the muscle in order to prevent the patient from straining to focus which can cause an error in determining the clarity of one’s vision.
Several other complications that may cause visual impairments may arise for individuals diagnosed with juvenile idiopathic arthritis. It is important to monitor the children for such complications closely. One may observe wandering of the eye, this may be due to reduced vision in the eye caused by abnormal visual development called a lazy eye (amblyopia). Ophthalmologists need to keep a close watch on the posterior segment of the eye to observe inflammation that could affect the retina, the macula of the eye (cystoid macular edema), or the optic nerve
How to Treat Uveitis Associated With Juvenile Idiopathic Arthritis?
Uveitis associated with juvenile idiopathic arthritis is one of the most difficult eye diseases to manage. In order to avoid the need for surgeries or probable complications of uveitis, one must get appropriate treatment to control uveitis.
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Topical corticosteroid eye drops are used to help relieve symptoms of redness, and pain and to prevent further damage to the eye as part of uveitis.
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Individuals who use 1 to 2 drops per day for persistent uveitis control are advised to undergo systemic immunosuppression therapy.
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Immune-modulating drugs (Methotrexate) or disease-modifying anti-rheumatic drugs (DMARDs- Azathioprine, Cyclosporine) help in managing uveitis as these drugs give relief pain and inflammation by modulating the immune system to heal.
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Biologics such as adalimumab along with methotrexate have shown better results in managing intraocular inflammations. Adalimumab and infliximab are safer and more effective as they are made from living cells and target specific functions of the immune system.
What Are the Complications of Uveitis Associated With Juvenile Idiopathic Arthritis?
Studies have shown approximately 67 percent risk of ocular complications in children with juvenile idiopathic arthritis-associated uveitis. Some of them are as follows
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Cataract- A clouding of the otherwise normal clear lens. another complication associated with uveitis in such children. Prolonged use of fewer than three drops per day of corticosteroid eye drops has shown a lesser incidence of cataracts compared to children using higher doses. The presence of other complications in the eye can only complicate the extraction of the cataract. Cataract surgery is very challenging and hence individual needs to control eye inflammation using medications for a minimum of three months prior to the surgery.
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Postoperative Posterior Capsular Opacification (PCO)- It is a complication of cataract surgery where a cloudy layer of scar tissue is formed behind the lens implant.
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Band Keratopathy- The appearance of a band across the cornea causing discoloration of the cornea.
- Glaucoma- Damage to the optic nerve caused due to high eye pressure. Treatment of uveitis with prolonged use of corticosteroids can cause an increase in eye pressure. Without proper follow-up, it can cause glaucoma in children.
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Macular Edema- Swelling in the center of the retina caused by a leak from blood vessels. This condition causes blurry vision.
Conclusion
Uveitis screening should start immediately when juvenile idiopathic arthritis is diagnosed. Since uveitis associated with juvenile idiopathic arthritis is usually asymptomatic a routine ophthalmology screening can help detect and treat the condition at the earliest. A delay in the same has been shown to cause complications that can affect the vision and thereby the quality of life for the child. Studies have shown relapse of uveitis on discontinuation or tapering of medications. A continued routine follow-up with an ophthalmologist can also help prevent a relapse of uveitis.
