Night blindness in primary biliary cirrhosis

A 58-year-old woman was referred by her optician because of decreased clarity of vision in both eyes with poor night vision. Her medical history in - cluded late-stage primary biliary cirrhosis. Her visual acuity was 6/6 in both eyes and ocular examination was unremarkable. An electroretinogram showed a reduced am - plitude scotopic (dark-adapted) response (Figure 1A) with a normal photopic (lightadapted) response. This finding suggested a vitamin A deficiency, and subsequent testing showed serum vitamin A levels were low at 0.3 (normal 0.7.1.7) µmol/L. She was given high-dose vitamin A supplementation orally with improvement in her symptoms and electroretinogram trace (Figure 1B).