Objective: To examine the occurrence and characteristics of uveitis in patients with recently diagnosed juvenile chronic arthritis (JCA).
Design: A prospective observational case series.
Participants/methods: The study covered the new cases detected with JCA (426 children), all of whom were referred to an ophthalmologic consultation during 1989 to 1996 at the Pediatric Department of the Rheumatism Foundation Hospital, Heinola, Finland.
Main outcome measures: The children with JCA were followed by ophthalmologic and pediatric examinations two to four times a year. The type and course of arthritis and presentation and characteristics of uveitis were examined prospectively.
Results: Uveitis was detected in 104 of 426 children (24%). Two thirds of all patients and the same proportion of those with uveitis were girls. Proportionally, uveitis was found to be as common among children with oligoarthritis (27%) as among those with seronegative polyarthritis (25%). Antinuclear antibodies (ANA) were detected significantly more frequently in patients with uveitis (66%) than among those without uveitis (37%) (P < 0.001). The uveitis was asymptomatic in 99 cases; only 5 children had episodes of acute anterior symptomatic uveitis. Uveitis was found before or within 3 months from the onset of recent arthritis in 51 of 104 children (49%) and later on in 53 of 104 children (51%). The mean age at diagnosis of uveitis was 5.9 years (range, 1.1-17.7; median, 4.9 years). The mean period from the diagnosis of JCA to the diagnosis of uveitis was 1.1 years (range, -2.4-6.5; median, 0.3 years). The mean age at diagnosis of JCA was 4.8 years (range, 0.6-15; median, 3.2 years) among those with uveitis and 7.3 years (range, 0.9-16; median, 6.7 years) among those who did not have it (P < 0.001). Uveitis was ongoing in 63 children at the end of the follow-up period. The mean follow-up time was 4.5 years (range, 0-9.7) for all children and 5.6 years (range, 1.3-9.6) for those with uveitis. In most instances, the visual prognosis was good. In 25 of 104 patients (24%) one or more complications of uveitis were found, but in only three children did the visual acuity decrease to 20/60 or less, and none became blind. All the other patients had visual acuity > or = 20/40.
Conclusions: In this patient group, uveitis in JCA frequently appeared very early after the onset of arthritis. The uveitis was significantly more common in patients with an early onset of arthritis combined with ANA positivity. The proportion of children with uveitis was as large in those with polyarthritis as in those with oligoarthritis, with no predilection to girls.