Hypotony May Signal Severe Uveitis in Juvenile Idiopathic Arthritis Patients

The most common rheumatic disease among children is juvenile idiopathic arthritis (JIA), often manifested as sight-threatening uveitis. JIA-associated uveitis is most frequently the chronic anterior type, which often produces no symptoms. As a result, screening at-risk patients to ensure early detection and treatment is crucial.

A 30-year retrospective cohort study done at Johns Hopkins’ Wilmer Eye Institute indicates that hypotony may affect a clinically significant proportion of children with JIA-associated uveitis and appears to indicate active, severe uveitis. Thus, hypotony may be a particularly important finding when screening these often asymptomatic patients.

Regarding treatment, a growing body of evidence supports the early use of systemic immunosuppressants such as methotrexate or biological agents to reduce the use of glucocorticoids in these children. The Wilmer study provides further albeit limited support for aggressive control of inflammation.

In the study, patients who were receiving immunosuppressive drugs when they first came into the institute for evaluation had a slightly lower risk of hypotony that those who were not receiving these drugs (adjusted hazard ratio [aHR] 0.02; P = 0.002). As a result, the Wilmer team concluded that aggressive control of inflammation with immunosuppressive drugs may reduce the risk of hypotony in children with JIA-associated uveitis. Details of the study are being published in the September, 2016, issue of the American Journal of Ophthalmology.

The study enrolled 108 patients who had been evaluated and followed for JIA-associated uveitis at the institute from July 1984 through June 2014. The study aimed to determine the prevalence and incidence of hypotony and low intraocular pressure (IOP) as well as the risk factors for hypotony. The study team defined hypotony as an IOP of less than 5 mmHg and low IOP as an IOP of at least 5 mmHg but less than 8 mmHg.

When patients first came in for evaluation, 9.3% of 196 affected eyes were hypotonic. “During a median follow-up of 5.3 years, the rate of developing hypotony and low IOP were 0.04 per eye-year (/EY; 95% confidence interval [CI]: 0.02/EY, 0.05/EY) and 0.06/EY (95% CI: 0.04/EY, 0.08/EY),” according to the study, and the rate of development of low IOP was 0.06 per eye-year (95% CI 0.04/EY—0.08/EY).

Risk factors for the development of hypotony during follow-up were associated with more severe disease, including:

• panuveitis (aHR, 43.1; P = 0.004)
• anterior chamber cells or flare ≥ 3+ (aHR, 25.6; P < 0.001)
• posterior synechiae (aHR, 5.9; P = 0.02)
• use of an oral corticosteroid at first exam (aHR, 28.9; P = 0.003).