JIA AND UVEITIS

Knowing which patients are at highest risk of developing juvenile idiopathic arthritis (JIA)- associated uveitis, and which of those are greatest risk for severe disease is essential for optimal management of these hard to treat patients, according to Joke de Boer MD, a uveitis specialist at the Donders Institute of Ophthalmology in Utrecht, the Netherlands. This can be a tricky disease to diagnose, she reminded a Joint Session of the 2nd WCPOS and 12th EURETINA Congress. “Remember, JIA-associated uveitis is an anterior segment disease, so if you see chorioretinal lesions, you should consider another diagnosis,†she said.

Which patients are at risk of developing uveitis? She emphasised the importance of three risk factors. First, female gender, with a ratio of three to one female to male patients. Second, ANA positivity, since 90 per cent of patients with JIA who are ANA positive go on to develop uveitis. The third factor is oligoarthritis subtype of JIA, since 79 per cent of all patients with JIAassociated uveitis have the oligoarthritis subtype of JIA, she noted. However, these risk factors are distinct from those that predict a poor prognosis. Here, the focus is on those patients with a short interval between arthritis and uveitis; patients who present with severe uveitis at the first examination; patients who present with uveitis, as opposed to arthritis, as the initial manifestation of JIA, and patients who develop posterior synechiae.

More controversial is whether males with JIA-associated uveitis, and patients with a young age at onset, are at greater risk for severe disease. Dr de Boer highlighted the fact that there are several studies with conflicting results on these two risk factors. However, multivariate analysis suggests that male gender and development of uveitis prior to arthritis are independent prognostic factors for poor outcome. But why do patients with JIA-associated uveitis go blind? Dr de Boer highlighted the three main causes of blindness: glaucoma (50 per cent), cyclitic membranes (33 per cent); and cystoid macular oedema (25 per cent). Significantly, this progression to glaucoma is nearly four times as common in JIA-associated uveitis than in non- JIA-uveitis. The practical implication of this statistic is that IOP must always be measured in children with JIA-associated uveitis, despite the challenges presented by the difficulty of IOP measurement in this young population.

The next topic was a sobering account of the difficulty in preventing blindness in this condition. Dr de Boer referred to a study published by Cassidy in 1977 in which 15 per cent of eyes went blind, and then to another study by Kalinina-Ayuso, published in 2010, in which again 15 per cent of all eyes were blind. At first glance, this seems like a total lack of progress over 33 years. However, those patients analysed in Kalinina-Ayuso’s long-term study included a significant proportion of patients who were never treated with biological agents, which have since become the standard of care in refractory cases. Future studies, reporting only on patients during the biologicals era will likely show a lower percentage of blind eyes.

Dr de Boer closed her presentation with a short summary of the treatment of the disease. The main take-home messages on this topic were that methotrexate is still a mainstay in the treatment of the disease, and that longer inactivity during long-term treatment with methotrexate is independently protective against a relapse of uveitis. “Every year of inactivity under methotrexate treatment decreases the hazard of a new relapse by 93 per cent,†she said.