{'fraction_non_alphanumeric': 0.023023255813953487, 'fraction_numerical': 0.005813953488372093, 'mean_word_length': 5.428998505231689, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Riding the wave: challenges in the management of serpiginous choroiditis

Serpiginous choroiditis is a posterior uveitis, which characteristically begins adjacent to the optic disc and takes a serpentine course that may threaten the macula; the diagnosis is ‘descriptive’, and thus it may include cases that are immune-mediated or infectious. Toniolo et al. summarize the clinical presentation and course of 18 Australian and New Zealand patients, presenting with the disease over a fixed time interval. Key findings of their report include: a disease prevalence of 1 per 1.5 million persons in the region; the possible association with tuberculosis in approximately one quarter of patients diagnosed with serpiginous choroiditis; and a high relapse incidence rate (i.e. 22.8 per 100 person-years overall). Because of its rare occurrence, serpiginous choroiditis is an extremely difficult disease to study. The report by Toniolo et al. highlights the value of the Australian & New Zealand Ophthalmic Surveillance Unit in coordinating the collection of populationbased, clinical data on eye diseases with a predicted annual incidence of less than 1 in 100 000. With the cooperation of the local body of ophthalmologists in identifying and reporting relevant cases in a standardized fashion, the Unit, and similar organizations internationally, provide the best opportunity to increase knowledge on natural history and treatment outcomes of rare eye diseases. Among other difficulties in studying serpiginous choroiditis is the lack of established diagnostic criteria for the disease. Toniolo et al. defined serpiginous choroiditis as a ‘chronic relapsing remitting uveitis characterized by large areas of serpentine or geographical contiguous or semi-contiguous choroidal scarring or atrophy’ that is ‘predominantly around the posterior pole’. This definition is consistent with what many, but not all, ophthalmologists follow in diagnosing the disease. To address the problem of inconsistency in diagnostic vocabulary, which is common to most uveitic diseases, the international group of uveitis specialists known as the Standardization of Uveitis Nomenclature Working Group is presently developing classification criteria for 28 forms of uveitis, including serpiginous choroiditis. An additional challenge for Toniolo et al. was how to determine the clinical outcome in patients with serpiginous choroiditis. They chose to report relapse incidence rate (in 100 person-years). The selection of a non-visual acuity-based outcome parameter was very sensible. Particularly in the early course of disease, the macula may be spared, and visual acuity may be well preserved despite active and destructive inflammation. Five of the 18 patients studied by Toniolo et al. tested positively with one or more investigations for tuberculosis. A serpiginous-like choroiditis associated with latent or active systemic tuberculosis has been emphasized in the ophthalmic literature recently. The term, ‘multifocal serpiginoid choroiditis’, has been proposed as a name for this entity. Clinical signs that are characteristic of the condition include multifocality, peripapillary sparing and prominent aqueous and/or vitreous inflammation, as well as a personal history of extended residence in an endemic region or contact with TB-infected persons. In general, multifocal serpiginoid choroiditis responds to treatment with a combination of anti-tuberculous and anti-inflammatory drugs. Key descriptions of multifocal serpiginoid choroiditis come from India, where tuberculosis (TB) is endemic, but other papers show this to be a cause of choroiditis in countries non-endemic for TB, such as Australia and New Zealand. A related practical issue is how best to screen a patient with uveitis for latent TB. This is an important consideration for those individuals who will be treated with systemic immunosuppression, since such treatment may precipitate active infection. Australia’s National Tuberculosis Advisory Committee recommends that either an interferon-gamma release assay (i.e. QuantiFERON-TB gold In-Tube test or T-SPOT TB test) or the tuberculin skin test be used to screen for latent tuberculosis in persons with immune-mediated inflammatory diseases; if the risk of latent infection is high, both tests may