Uveitis and neurological diseases.

S ystemic disease associations in uveitis are widespread, ranging from inflammatory bowel disease (IBD), such as ulcerative colitis or Crohn’s disease, to demyelinating diseases such as multiple sclerosis. In some cases, the systemic disease is diagnosed before onset of uveitis, whereas in others uveitis is the initial presentation of the underlying or associated condition. Two significant questions arise regarding neurological concomitants of uveitis. What is the incidence and identity of neurological diseases seen in individuals with uveitis? Are there particular clues in the clinical examination of an individual patient with uveitis that would help lead to diagnosing an associated neurological condition? In the current issue of BJO (p 1498), Smith and Rosenbaum attempt to address these important questions through a retrospective analysis of 1450 patients examined in a tertiary care uveitis clinic. Increased use of biological agents such as the tumour necrosis factor (TNF-a) inhibitors intensifies the relevance of this study. Targeted immunotherapy for specific immune mediated diseases is rapidly advancing. The immune tolerance network (ITN) is an international consortium with investigators from more than nine countries with the goal of developing clinical therapies for tolerance induction in transplantation, allergy and asthma, and autoimmune diseases. In contrast with the goals of tolerance, clinical trials in cancer therapy now include methods for boosting antitumour immunity through autologous dendritic cell delivery of recombinant tumour antigens or through inhibition of the negative regulatory T lymphocytes. 6 This is an exciting time in therapeutic development targeted towards immune regulation. However, unanticipated responses to these therapeutic agents provide us with clues about the unknown aspects of disease pathogenesis. For example, use of the TNF-a inhibitors, whose positive therapeutic utility was predicted for multiple sclerosis, may actually increase demyelinating events. Use of biological agents in uveitis therapy has received increasing attention and there is now evidence for the utility of specific agents in the therapy of refractory uveitis or for specific uveitis syndromes—for example, Behçet’s disease. 9 However, therapy using an anti-TNF-a medication should probably not be initiated in a patient with underlying multiple sclerosis. Additionally, immunosuppressive medications, commonly used in treatment of refractory uveitis, may mask or worsen certain infectious or neoplastic disease concomitants of uveitis. Understanding the magnitude of the neurological associates of uveitis and developing preferred patterns for the comprehensive evaluation of patients with specific uveitis syndromes is critical in this emerging therapeutic era. In the series presented here by Smith and Rosenbaum, almost 8% of all patients in their clinic had neurological disease underlying and associated with the ocular inflammatory disease. The authors note, but do not describe, cases with neurological diseases that were presumably unrelated to uveitis. These cases were excluded from the present report; however, additional descriptions of these patients may have been helpful to understanding the magnitude of neurological diseases in this patient group. For example, associations of HIV infection with both infectious diseases and uveitis are well characterised. 11 The absence of AIDS or HIV as a diagnosis in the present series probably reflects the exclusion of these patients from this report.