The putative therapeutic value of high-dose selenium in proliferative retinopathies may reflect down-regulation of VEGF production by the hypoxic retina.

Two decades ago, Crary reported his anecdotal observation that a supplemental antioxidant regimen including high-dose selenium (500 mcg daily) appeared to slow the progression of visual loss in diabetic retinopathy and macular degeneration. Recently, selenium has been shown to down-regulate VEGF production by rodent cancer cells, both in vivo and in vitro; this effect is dose-dependent and, like the anticarcinogenic activity of selenium, is mediated by methyselenol. If increased selenium exposure can likewise suppress VEGF production in the hypoxic retina, a straightforward explanation for Crary's observation may be at hand. Since selenium is inexpensive and non-toxic in the dose employed by Crary, an effort to replicate his findings is warranted.