Trachoma in Australia: an update

In 2001, one of the authors wrote in the Medical Journal of Australia about trachoma explaining that Australia is the only developed country in the world where blinding trachoma still exists. Ten years later, the same is still true, but there is some progress and the situation in Australia is starting to change. However, this progress has been somewhat glacial, especially compared with the rapid changes being made in other ‘undeveloped’ parts of the world.     

Toxoplasmosis: new challenges for an old disease

More than a century after the identification of Toxoplasma gondii, major issues need to be addressed for the optimal management of ocular disease. Toxoplasmic retinochoroiditis is the main cause of posterior uveitis in several geographical areas. The parasite establishes a love-hate relationship with the eye, manipulating the immune response and inducing variable initial lesions and further relapses. It is now well established that most cases are acquired after birth and not congenital. The severity of the disease is mainly due to the parasite genotype and the host immune status. Diagnosis is based on clinical features, but may be confirmed by biological tools applied to ocular fluids. Combining several techniques improves the diagnostic yield in equivocal cases. Therapeutic management is the most important challenge. Even though evidence-based data on the efficacy of anti-parasitic drugs are still missing, new strategies with a good safety profile are available and may be proposed earlier during the course of the disease, but also in selected cases, to reduce sight-threatening relapses. Revisiting the therapeutic options and indications may be an important step towards long-term maintenance of the visual function and avoidance of major complications.     

Assessment of Trachoma in Cambodia: Trachoma Is Not a Public Health Problem

ABSTRACT

Purpose: To determine whether trachoma is a public health problem requiring intervention in Cambodia.

Methods: Based on historical evidence and reports, 14 evaluation units (EUs) in Cambodia, judged to be most likely to harbor trachoma, were selected. The Global Trachoma Mapping Project methodology was used to carry out rigorous surveys to determine the prevalence of trachomatous inflammation–follicular (TF) and trichiasis in each EU.

Results: The EU-level prevalence of TF among 25,801 1–9-year-old children examined ranged from 0% to 0.2%. Among the 24,502 adults aged 15+ years examined, trichiasis was found in 59 people. Age- and sex-adjusted prevalences of trichiasis in all ages in the EUs studied ranged from 0% to 0.14%; five EUs had a prevalence of trichiasis ≥0.1%.

Conclusions: There appears to be no need nor justification at this time for implementing public health measures to control trachoma in Cambodia.     

Trachoma control: the SAFE strategy

As a contagious bacterial infection that affects the conjunctival covering of the eye, the cornea and the eyelids, trachoma is controlled by an endorsed integrated strategy consisting of surgery for trichiasis, antibiotic therapy, facial cleanliness and environmental improvement, namely, the SAFE strategy developed by World Health Organization. Developed based on evidence from previous field trials and constantly modified in practice, SAFE strategy has greatly boosted the progress in trachoma control. Regardless of the fact that there are still many pending questions, national program coordinators are convinced that trachoma control initiative based on SAFE strategy would be effective.     

Corticosteroids in posterior segment disease: an update on new delivery systems and new indications

PURPOSE OF REVIEW: Corticosteroids are traditionally used for inflammatory disorders because of their ability to diminish neutrophil transmigration, limit access to sites of inflammation, and decrease cytokine production. More recently, however, investigators have focused on the angiostatic and antipermeability properties of corticosteroids for posterior segment diseases such as age-related macular degeneration (AMD), diabetic retinopathy, and macular edema. Both new angiostatic and traditional corticosteroids are currently undergoing evaluation as new delivery techniques such as intravitreal injection and intraocular sustained-release devices facilitate high local angiostatic and antipermeability concentrations while minimizing extraocular toxicity. The purpose of this review is to discuss recent work concerning both the mechanism and effectiveness of these newer treatments. RECENT FINDINGS: Steroids may exert a beneficial effect in AMD-related choroidal neovascular membranes (CNVM) through inhibition of CNVM-promoting macrophages and direct inhibition of angiogenic growth factors. They may also alter extracellular matrix turnover and inhibit matrix metalloproteinases involved in CNVM formation. Intravitreal steroid injections potently inhibit experimental CNVM in primates and rats and have shown promise in some early human pilot trials. In proliferative diabetic retinopathy, steroids may directly inhibit growth factors such as vascular endothelial derived growth factor and inhibit leukocytes that play an important role in early microvascular alterations. Intravitreal steroid injections inhibit experimental preretinal neovascularization in pigs and rats, and rubeosis in some early human studies. In addition, the effect of steroids on vascular permeability has led to their use for macular edema from many causes such as diabetes and venous occlusive disease. SUMMARY: The use of steroids to treat a number of retinal diseases is gaining wide spread acceptance. The apparent short-term success must be balanced by the fact that the long-term safety and efficacy have yet to be determined for any of these approaches. A number of large randomized prospective clinical trials of steroid compounds and new delivery systems are currently under way for AMD, diabetic retinopathy, uveitis, and other retinovascular diseases, and hopefully these studies will provide guidance about the use of these new modalities.