Ultrasound biomicroscopy in uveitis

Ultrasound Biomicroscopy (UBM) is an imaging technique using ultrasound waves to produce a two-dimensional real time view of the anterior segment of the eye up to a depth of five millimeters. The cross section images are obtained using a high frequency ultrasound (50 to 100 MHz) transducer, incorporated into a B-mode clinical scanner. Axial and lateral resolutions of the anterior segment structures are within 20 to 60 mm. This is ten times the resolution achieved by the conventional ophthalmic ultrasound imaging frequencies. As a relation exists between image resolution and waves, tissue penetration ultrasound biomicroscopy has a penetration depth of only five millimeters, but can be increased to 15 mm using an orbital cup filled with methylcellulose that allows a shorter work transducer distance. Commerically available scanners produce a 5 X 5-mm transducer field with 256 image lines at a scan rate of 8 frames per second. This system generates images of the anterior segment of the eye, the pars plana and peripheral retina. Clincial applications of UBM have been previously described, including imaging in cases of glaucoma, anterior segment and peripheral choroidal tumours, ocular trauma, corneoscleral phakic and pseudophakic pathologies. With UBM, the anterior segment of the eye can be better observed in cases of corneal opacities, cataract, hyphaema and intraocular anterior membranes. UBM also provides information that cannot be obtained with the clinical examination alone. This talk highlights some of the findings of ultrasound biomicroscopy in anterior uveitis. UBM provides a view of the inferior angle in cases of hypopyon. Sometimes what looks like a hypopyon can be a cyst filled with inflammatory cells. A sign of granulomatous inflammation that can be observed with UBM is a localized thickening of the interior peripheral cornea at the six o'clock position (prismatic effect). Many cases that present this prismatic effect will be associated with sarcoidosis. Inflammation of the ciliary body and the vitreous base can be observed in ways that are not possible with the direct ophthalmoscope and the tree mirror contact lens. Circumscribed areas of reflectivity and thickness changes in UBM images resembing nodules are often seen in the ciliary bodies in cases of sarcoidosis or in severe chronic granulomatous uveitis.(AU)

Treatment of uveitis: past, future and present

This presentation will review the different treatments of uveitis. The use of corticosteroids, immunosuppressive medications and the upcoming newer modalities for treatment will be reviewed. The discoveries of the different types of immune reactions, the T helper subset functions (Th1 and Th2), the understanding of ACAID (anterior chamber associated immune deviation), the identification of the intraocular immune cell types, and the role of cytokines in the pathogenesis of inflammation, result in a better understanding of autoimmune diseases such as non-infectious uveitis. This improved understanding has allowed the development of new experimental uveitis treatments that may become the standard of care. For example, processing of specific antigens in the gut was demonstrated to induce tolerance by the release of suppressor cytokines like tumour growth factor-B, interleukin (IL)-4 and IL10. Therapeutic approaches like immune modulation with interferon, the use of soluble tumour necrosis factor receptor, anti-Tac, monoclonal antibodies against cell adhesion molecules, and antisense therapies are becoming useful in the treatment of severe uveitis. Intervitreal sustained release devices for the delivery of drugs like corticosteroids, cyclosporins and other immunosuppressive medications will soon become commercially availble. Gene somatic therapy appears another promising therapeutic approach. The use of viral and non viral vectors, and the host immune response against modifies adenoviruses, are solved.(AU)

Human T cell lymphotropic virus (HTLV-1): cutaneous manifestations

Skin manifestations are a common feature of HTLV-1 associated disorders and of HTLV-1 infection itself. These include the lymphomatous skin infiltrates in adult T-cell lymphoma/leukaemia, most commonly manifesting as persistent, generalised papules, nodules and plaques with later ulceration, acquired ichthyosis and xeroderma in HAM/TSP, infective dermatitis of children, dermatomyositis, crusted (Norwegian) scabies, psoriasiform rashes which may precede one of the more serious disease associations, and possibly also seborrhoeic dermatitis. Disorders typically associated with immunosuppression such as disseminated herpes zoster, and ulcerative non-healing herpes simplex may also be seen occasionally both in ATK as well as in other wise asymptomatic HTLV-1 infection (AU)

Clinical manifestations of ocular toxocariasis - abstract

Fifteen symptomatic patients were seen at the Eye Clinic, General Hospital, Port-of-Spain from December, 1988 to October, 1989 and 12 cases were available for review. A complete eye examination was done, and serum IgG and IgM (to Toxocara) levels were measured by an ELISA method. There were 5 females and 7 males with ages ranging from 4 to 61 years. Toxocara titres ranged from 1:00 to 1:3, 200 with the most frequent value being 1:200. The commonest presenting complaint was a moderate to severe visual impairment (8/11 or 73 per cent). Two patients had sudden onset of visual loss due to lesions at the posterior poles with macular involvement. Other presenting features were pain and redness of the eye associated with anterior uveitis (2 patients) and 4-year old patient had a white reflex in the pupil (leucocoria) for which an important differential diagnosis is retinoblastoma. Overall, Toxocara granulomas were seen on 9 of 12 patients. Therapy consisted essentially of steroids, topical and systemic and a non-steroidal anti-inflammatory preparation (indomethacin). All patients available for follow-up (n = 11) showed significant improvement and none required surgery. These results emphasize that ocular Toxocariasis must be considered in cases of posterior uveitis in Trinidad (AU)