Retina Today - Assessing Uveitis: Beyond Vitreous Haze (October 2016)

摘要

The presentations of uveitis are as varied as the brands of artificial tears at your local drug store. A case of panuevitis can just as easily present with choroidal thickening and headaches as it can with 4+ cell, 2+ vitreous haze, and macular edema. The myriad presentations of even a single entity of uveitis, such as sarcoid uveitis, makes uveitis difficult to diagnose and manage, as each case must be evaluated and followed by its particular attributes. Treatment may be as straightforward as using local topical steroid formulations, or as involved as placing patients on long-term intravenous immunotherapy in addition to longer-acting local corticosteroids. AT A GLANCE • The presentation of uveitis is highly variable. • The standard means of assessment, vitreous haze, is subjective and may not correlate with disease activity. • A composite scoring system, as has been used in some investigator-initiated clinical trials, may allow improved communication among specialists and facilitate development of new therapies. Given the diversity of diseases and presentations of uveitis, there are a number of parameters by which patients are assessed. Certainly, it is important to assess, record, and follow anterior chamber and vitreous cavity cells, as well as vitreous haze. However, given our increasing capability to image the eye, macular edema, the extent of retinal vasculitis, autofluorescence imaging, and choroidal thickening are also important measures of disease activity. Additionally, it is vital to assess the patient’s symptoms, as a complaint of photopsia can indicate ongoing, uncontrolled disease activity. GETTING ON THE SAME PAGE This variability, along with the low prevalence of uveitis, makes it a difficult entity to study. This is all the more important in this day and age, as more localized, less toxic therapies are being developed for the treatment of our patients. Not long ago, a group of leading uveitis specialists gathered to discuss the various ways we describe our patients, in an effort to foster better communication about our cases to one another so that we can more meaningfully learn from one another. This initiative led to the Standardization of Uveitis Nomenclature, which has enabled better disease classification and an improved ability to teach and communicate with one another.1 Figure. Although the US Food and Drug Administration relies on vitreous haze as the primary surrogate endpoint for uveitis, this clinical finding is not always the primary feature of the condition and is thus an unreliable sign. The 1 to 2+ vitreous haze in this image is so borderline that different clinicians could easily interpret it differently. However, there were unforeseen consequences to this effort as well. Given the difficulty of describing various posterior findings of uveitis and the relative infancy of ocular imaging, a consensus could not be achieved on the quantification of many posterior parameters beyond vitreous haze (Figure). This, unfortunately, has led to the over-reliance on vitreous haze as a marker of disease activity, especially in clinical trials regarding intermediate, posterior, and panuveitis. Vitreous haze has become the primary surrogate endpoint for these types of uveitis as far as the US Food and Drug Administration is concerned. Most ophthalmologists are aware of cases in which vitreous haze was not the primary feature of disease, and they understand how unreliable vitreous haze can be in this regard. The inherent variability in measurement of vitreous haze also makes it a problematic endpoint. The grading of vitreous haze is based on comparison of indirect ophthalmoscopy with a series of photographs produced from a single image with diffusion filters by the National Eye Institute.2 This leads to a somewhat subjective measure with inter-observer variability. In addition, grading may not correlate well with disease activity, especially at the lower