Control of ocular disease in mucous membrane pemphigoid.

BACKGROUND: Mucous membrane pemphigoid is a rare immune-mediated disease. It is characterised by an abnormal binding of immunoglobulins to the basement membrane zone of mucous membranes and the skin. Conjunctival involvement in mucous membrane pemphigoid may lead to cicatrising conjunctivitis and eventually to corneal blindness. The factors that determine mild or progressive disease are not fully understood and need to be clarified. This study examines the features, progression and risk factors of patients with ocular involvement in mucous membrane pemphigoid. METHODS: 36 eyes of 18 patients with the diagnosis of ocular disease associated with MMP were identified. Fornix depth and keratopathy were repeatedly assessed using a standardised protocol to identify progression. MMP was diagnosed based on the characteristic clinical and laboratory features. Endpoints of the study were the incidence of progressive disease and the development of keratopathy with and without systemic immunomodulatory therapy. RESULTS: 12 eyes of 6 patients (33%) showed progressive conjunctival cicatrisation. Obvious progression was observed in 2 patients who had refused systemic treatment at an early stage. 10 eyes showed progression while on systemic treatment. In these patients, however, systemic treatment was started at an advanced stage of the ocular disease. None of the patients receiving systemic treatment developed persistent keratopathy. CONCLUSION: Systemic treatment with diaminodiphenyl sulfone and/or cyclophosphamide allows one to control the further progression of cicatrising conjunctivitis. It prevents keratopathy. To be efficient, however, treatment has to be started at an early stage of the ocular disease.

Simulation of ozone depletion using ambient irradiance supplemented with UV lamps.

In studies of the biological effects of UV radiation, ozone depletion can be mimicked by performing the study under ambient conditions and adding radiation with UV-B lamps. We evaluated this methodology at three different locations along a latitudinal gradient: Rimouski (Canada), Ubatuba (Brazil) and Ushuaia (Argentina). Experiments of the effect of potential ozone depletion on marine ecosystems were carried out in large outdoor enclosures (mesocosms). In all locations we simulated irradiances corresponding to 60% ozone depletion, which may produce a 130-1900% increase in 305 nm irradiance at noon, depending on site and season. Supplementation with a fixed percentage of ambient irradiance provides a better simulation of irradiance increase due to ozone depletion than supplementation with a fixed irradiance value, particularly near sunrise and sunset or under cloudy skies. Calculations performed for Ushuaia showed that, on very cloudy days, supplementation by the square-wave method may produce unrealistic irradiances. Differences between the spectra of the calculated supplementing irradiance and the lamp for a given site and date will be a function of the time of day and may become more or less pronounced according to the biological weighting function of the effect under study.