Dark adaptation in early primary biliary cirrhosis.
BACKGROUND
The role of vitamin A in early primary biliary cirrhosis (PBC) remains uncertain.


METHODS
We assessed dark adaptation and assayed vitamin-A-related compounds in 10 patients with early PBC and a group of age- and sex-matched controls.


RESULTS
In patients compared with controls: (i) mean final light threshold value was 11.8% greater (p < 0.004), (ii) time taken to see the first light stimulus was longer (2.8 +/- 0.6 vs 1.4 +/- 0.2 min, mean +/- SEM; p < 0.03) and (iii) sensitivity to light stimuli was impaired after 6 min in the dark (p < 0.03). Three patients had an abnormal final light threshold despite receiving regular vitamin A; two had a low serum vitamin A. Raised serum bilirubin and increased age were the most important determinants of impaired dark adaptation.


CONCLUSIONS
Patients with early PBC have modestly impaired dark adaptation, despite standard vitamin A supplementation, although these changes may not have a significant effect on visual function. Vitamin A supplementation should be recommended for older patients with jaundice, but its effect should be carefully monitored.
Academic Division of Medicine, St James's University Hospital, Leeds, UK. s.h.hussaini@leeds.ac.uk
S H
SH
Hussaini
T
T
Henderson
A J
AJ
Morrell
M S
MS
Losowsky
D000284:Administration, Oral; D000287:Administration, Topical; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology*; D000368:Aged; D000369:Aged, 80 and over; D000959:Antihypertensive Agents / Q000494:pharmacology*; D016084:Bronchoconstriction / Q000187:drug effects; D018592:Cross-Over Studies; D004311:Double-Blind Method; D005260:Female; D005541:Forced Expiratory Volume / Q000187:drug effects; D006801:Humans; D008875:Middle Aged; D009798:Ocular Hypertension / Q000188:drug therapy*; D010366:Peak Expiratory Flow Rate / Q000187:drug effects; D015656:Respiratory Mechanics / Q000187:drug effects*; D013999:Timolol / Q000494:pharmacology*; D014797:Vital Capacity / Q000187:drug effects
D000319:Adrenergic beta-Antagonists; D000959:Antihypertensive Agents; D013999:Timolol