Juvenile rheumatoid arthritis (JRA) is a severe autoimmune disorder that causes both painful and disabling arthritis and ocular manifestations which can result in blindness.
The trademark of JRA is the development of chronic non-granulomatous anterior uveitis in both eyes. The uvea is the colored part of the eye, including the iris, ciliary body and the choroid layer underlying the retina, nourishing and renewing it.
Uveitis of this type in JRA is typically accompanied by the development of joint pain in children between the ages of 4 and 6 years. In contrast, acute uveitis occurs in children who develop arthritis later, between the ages of 7.5 and 9 years. Arthritis typically occurs months or years before the onset of ocular signs and symptoms. However, uveitis has been recorded to develop anywhere between a year before to 16 years after the condition manifests, or even several years after remission is achieved.
- JRA presenting with systemic involvement is not associated with uveitis in most cases.
- JRA with the involvement of multiple joints at onset shows a 5% incidence of uveitis.
- JRA in which few joints are initially involved shows a 20% incidence of uveitis. The risk of developing chronic iridocyclitis is highest in girls between 0 and 4 years of age, who test positive for antinuclear antibody, and who had mono-articular or pauci-articular forms of the disease. Of this group, approximately 30% developed uveitis after the age of 16 years.
JRA-associated iridocyclitis is often asymptomatic. However, almost 44% of patients present with symptoms such as:
- Redness of the eye
- Eye-associated pain
- Loss of visual acuity
- Intolerance to light, or photophobia
The following signs are present:
- Aqueous flare
- Keratic precipitates
- Cellular infiltrates in the anterior chamber
- No visual loss
In many cases of JRA, ocular involvement does not produce any symptoms. For this reason, all patients with JRA must undergo regular eye examinations with slit-lamp examination, to pick up signs of uveitis which can be promptly treated.
Topical corticosteroids are the initial choice of treatment and produce a good response in approximately 40% of patients following a short course.
In the remainder, the treatment needs to be carried on for a longer period. In addition to topical applications, peri-ocular injections of corticosteroids in depot or sustained-release form are often required. Short-term oral corticosteroids are also used, but long-term use of these drugs can produce devastating side effects for children. Posterior subcapsular cataracts also form in patients treated with systemic corticosteroids.
In patients with refractory forms of ocular disease in JRA, other forms of therapy need to be explored, such as TNF-alpha-inhibitors such as etanercept, oral or injected cytotoxic drugs such as methotrexate, or disease modifying drugs such as infliximab or adalimumab. In all cases, regular monitoring is necessary to ensure that neither the disease nor its treatment produce irreversible visual loss. However, prompt treatment of ocular involvement is required to prevent permanent loss of vision. Surgical management should be undertaken only with a full understanding of the high risk of inflammation following surgery in a patient with active JRA.
Complications of ocular involvement in JRA
Uveitis in JRA is associated with the onset of complications such as:
- Band keratopathy
- Anterior synechiae, or post-inflammatory adhesions between the cornea and the anterior surface of the iris
- Posterior synechiae, or adhesions between the posterior edge of the iris and the lens
- Cataract formation
- The development of a pupillary membrane
- Blinding complications of the affected eye
- Keratoconjunctivitis sicca, or dryness of the conjunctiva and cornea