eyespy

A patient with severe retinal vasculitis performed a headstand, with immediate loss of vision in the left eye-from 6/5 to just being able to perceive light. T1 and T2 weighted magnetic resonance scans showed a vitreous haemorrhage, with a fluid level within the vitreous cavity. Retinal vasculitis is an inflammatory disease of the retinal circulation that can be associated with systemic inflammatory or infectious disorders such as Behçet's disease, sarcoidosis, tuberculosis, herpes, and toxoplasmosis. Retinal ischaemia as a result of this process produces neovascularisation within the posterior segment, and sudden head movements in such patients can cause intraocular bleeding.

Nishal Patel(drnish1975@yahoo.com) specialist registrar in ophthalmology, Genevieve Larkin consultant ophthalmologist, King's College Hospital, London SE5 9RS, Miles Stamford professor, medical eye unit, St Thomas' Hospital, London

Smoking a single cannabis joint can obstruct lung function as much as between two and a half and five cigarettes. Researchers took computed tomograms of 339 volunteers' lungs and conducted breathing tests to assess lung function. They found that users of the drug had reduced lung density and experienced wheeze and chest tightness but that they did not have a significantly higher incidence of macroscopic emphysema (Thorax 2007 Jul 31 doi: 10.1136/thx.2006.077081).

Chocoholics take note: your addiction may be good for you. One small square of dark chocolate a day could …