Recurrent episodes of night blindness in a patient with short bowel syndrome.
OBJECTIVE
To describe clinical characteristics in a patient with recurrent episodes of night blindness due to vitamin A deficiency caused by short bowel syndrome in Crohn disease.


METHODS
Retrospective analysis of best-corrected visual acuity (BCVA), kinetic perimetry, slit-lamp biomicroscopy, ophthalmoscopy, fundus photography, fundus autofluorescence (FAF), spectral domain optical coherence tomography (SD-OCT), dark adaptometry (DA) and electroretinography (ERG). Serum vitamin A level was measured.


RESULTS
A 44-year-old man with a 3-year history of night blindness suffered from a short bowel syndrome with chronic malabsorption due to ileocecal resection in Crohn disease. Both eyes had a BCVA of 0.9, Bitot's spots of the conjunctiva and no significant fundus abnormalities. SD-OCT showed no remarkable changes, whereas FAF was brighter than normal in the center of the fovea. DA showed normal cone and a lack of rod function. The dark-adapted 0.01 ERG was non-detectable, the dark-adapted 3.0 ERG severely diminished, but the light-adapted 3.0 and 30 Hz flicker ERGs were within normal limits. Serum vitamin A level was 0.11 µg/ml (normal 0.30-0.65 µg/ml). Treatment with intravenous vitamin A caused a rapid recovery of night vision and ERG. However, during the following 3 years, he had three further episodes of night blindness with loss of rod function. During each period, parenteral vitamin A substitution brought complete recovery of night vision and rod function. BCVA, fundus, FAF findings and SD-OCT remained unchanged during the course.


CONCLUSIONS
In patients with known chronic malabsorption serum vitamin A level should be regularly checked to avoid recurrent night blindness episodes. ERG might be more sensitive than serum vitamin A level and is recommended in case of night blindness but still normal vitamin A level.
Klinik und Poliklinik für Augenheilkunde, Universitätsklinikum Regensburg, Franz-Josef-Strauss-Allee 11, 93053, Regensburg, Germany. a.renner@berlin.de.
Agnes B
AB
Renner
Klinik und Poliklinik für Augenheilkunde, Universitätsklinikum Regensburg, Franz-Josef-Strauss-Allee 11, 93053, Regensburg, Germany.|Klinik für Augenheilkunde, Charité Universitätsmedizin Berlin, Campus Virchow-Klinikum, Mittelallee 4, Augustenburgerplatz 1, 13353, Berlin, Germany.
Tina
T
Dietrich-Ntoukas
Klinik und Poliklinik für Augenheilkunde, Universitätsklinikum Regensburg, Franz-Josef-Strauss-Allee 11, 93053, Regensburg, Germany.
Herbert
H
Jägle
D000328:Adult; D003623:Dark Adaptation / Q000502:physiology; D004596:Electroretinography; D006801:Humans; D008297:Male; D009755:Night Blindness / Q000209:etiology / Q000503:physiopathology*; D009887:Ophthalmoscopy; D012008:Recurrence; D017948:Retinal Rod Photoreceptor Cells / Q000502:physiology*; D012189:Retrospective Studies; D012778:Short Bowel Syndrome / Q000150:complications* / Q000503:physiopathology; D041623:Tomography, Optical Coherence; D014792:Visual Acuity / Q000502:physiology; D058609:Visual Field Tests; D014801:Vitamin A / Q000008:administration & dosage / Q000097:blood; D014802:Vitamin A Deficiency / Q000209:etiology / Q000503:physiopathology*
D014801:Vitamin A
Bitot’s spots; Dark adaptometry; Electroretinography; Fundus autofluorescence; Short bowel syndrome; Vitamin A deficiency