Sleep disturbances are common among patients with liver cirrhosis, but the reasons are not well understood. In this project the investigators evaluated whether an increase in blood ammonia in patients with cirrhosis had an impact on sleep quality and the function of retinal ganglion cells measured by pupillary response to blue light.

Inclusion Criteria:

• Patients with a clinical diagnosis of Child Pugh Class A or B cirrhosis
• Written informed consent
• >20 and <80 years of age

Exclusion Criteria:

• Misuse of alcohol in the preceding 6 months,
• Episodes of hepatic decompensation leading to in-patient admissions during the previous month
• History or clinical signs of overt HE or severe sleep-wake disturbances
• On anti-HE treatment (lactulose, rifaximin, Hepa-Merz, Generaid, Bramino)
• History of significant head injury
• Neurological/psychiatric comorbidity needing medical treatment
• Taking neuroactive medication/medication known to affect sleep
• Travel across more than two time zones in the preceding 3 months
• Shift work in the preceding 5 years
• Contraindications for arterial puncture (negative collateral circulation test, wrist infection or vascular abnormalities).