and intraocular inflammation was first noted by Ohm in 1918 and Blegvad in 1941; the association was firmly established after a publication by Vesterdal and Sury in 1950 [11]. It is now recognized that chronic arthritis in the pediatric population is not a single diagnosis but a group of diseases. Only a minority of patients will develop eye disease, with each ­disease subtype having a different propensity for ocular involvement.

The use of different systems and terminology to classify chronic juvenile arthritis can be a point of confusion for ophthalmologists. In 1997, the term juvenile idiopathic arthritis (JIA) was adopted by the International League of Associations of Rheumatologists (ILAR) in European countries to unify the classification and replace the formerly used terms juvenile chronic arthritis and juvenile rheumatoid arthritis (JRA). However, the American Rheumatism Association (ARA) has yet to accept the term JIA and continues to use the term JRA.

19.4.1.2  Clinical Findings/Natural History

Chronic juvenile arthritis is uncommon but not rare, with estimates of incidence varying based on geographic location and criteria for diagnosis. Overall, the incidence is around 10 per 100,000 children per year, with a prevalence of 113–150 per 100,000 children in the United States [12, 13].

JRA is divided into three subtypes.

Subtypes of JRA (Table 19.2) .

Systemic onset (Still disease) accounts for 20% of all JRA, with less than 6% of patients manifesting ocular involvement [14]. Patients are usually less than 5 years old, with the characteristic onset of fever, rash, lymphadenopathy, and hepatosplenomegaly.

Polyarticular disease accounts for 40% of JRA, but only 7–14% of it is JRA-associated uveitis. By definition, five or more joints are involved in the first 6 weeks of the disease. Large and small joints are affected, often symmetrically.

Pauciarticular or oligoarticular disease accounts for 80–90% of children with JRA uveitis, and is more commonly found in girls [15]. It is defined by 4 of fewer joints involved in first 6 weeks of the disease. Patients have a 10–30% chance of developing a

typically chronic insidious anterior uveitis [16], which usually occurs within the first 4 years of disease onset. There is a high frequency of nonspecific low-titer ANA, and rheumatoid factor is almost always absent.

JRA-associated uveitis generally develops within 5–7 years of joint disease. Occasionally, uveitis is diagnosed before joint disease and confers a poorer prognosis. Inflammation is bilateral in 75% [17], with both eyes involved simultaneously or within a few months. The inflammation is usually asymptomatic with the involved eye appearing white and non-injected, even with numerous cells in the anterior chamber. Often, there is no correlation between ocular and joint inflammation.

At the slit lamp, signs of inflammation include anterior chamber cell and flare, fine keratic precipitates and posterior synechiae. The inflammation is usually nongranulomatous, with keratic precipitates distributed on the inferior half of the corneal endothelium. Spill-over of cells into the anterior vitreous can occur if the inflammation is moderate to severe. Complications of long-standing inflammation include band keratopathy and cataracts (Fig. 19.1).

Screening Guidelines

Regular slit lamp examinations are essential to detect JRA-associated uveitis since the inflammation is usually asymptomatic and does not always correlate with joint disease. The screening guidelines are based on the type of arthritis, the age at onset, and the presence or absence of ANA [18] (see Table 19.2).

Fig. 19.1  Patients with juvenile rheumatoid arthritis-associated uveitis may present with a white cataract and band keratopathy because the inflammation is usually asymptomatic