Should we be considering selenium in glaucoma?
- Correspondence to Mr Anthony J King, Department of Ophthalmology, Queen’s Medical Centre, Nottingham NG7 2UH, UK;
- Accepted 7 May 2009
Rarely does a glaucoma clinic go by without a patient asking, “Is there anything I can do to help my glaucoma?” Apart from encouraging compliance with their medications and regular clinic attendance, occasionally the use of gingko biloba,1 and some limited lifestyle changes for those wearing neck ties,2 3 swimming goggles4 or suffering from pigment dispersion syndrome,5 my advice regarding this question is limited.
The paper by Bruhn and colleagues6 in the current issue of the British Journal of Ophthalmology (see page 1155) may be of interest to those who would like to consider lifestyle changes to minimise visual loss related to glaucoma.
Selenium is an essential trace element required in small amounts for good health. Once ingested, selenium is incorporated into selenoproteins, which are important antioxidant enzymes helping to prevent cellular damage from free radicals.7 Free radicals are an essential component of cellular physiology; however, when an excess of free radicals occurs, which may result from a reduction in the normal neutralising molecules within the cell or a reduction in the activity of enzymes systems mediating neutralisation of free radicals, these molecules may inflict damage upon cells. Oxidative stress refers to damage that occurs to cellular components when there is excessive activity of oxidising agents. The aqueous humour contains free radicals, and it has been demonstrated that antioxidant activity in patients with primary open-angle glaucoma is reduced,8 9 and these oxidative effects have been shown to decrease trabecular meshwork (TM) cell adhesion and integrity10 and promote apoptosis.11
Glutathione peroxidase is an important enzyme species responsible for managing oxidative stress: it mediates the activity of the antioxidant glutathione in reducing hydrogen peroxide to water. Selenium is …