Reversal of progressive nyctalopia in a patient with Crohn's disease.

A 51-year-old man who had undergone several partial bowel resections for Crohn's disease presented with progressively decreased night vision. Electroretinography showed a flat scotopic response and a diminished, delayed photopic response. Measurement of stool fat showed marked fat malabsorption. Treatment with parenteral nutrition, including administration of vitamin A, resulted in marked improvement in the scotopic and photopic response and subjective improvement in his night vision. Patients with malabsorption states should be followed to avoid irreversible visual loss.