Serum Retinol Binding Protein as an Indicator of Vitamin A Status in Cirrhotic Patients with Night Blindness

BACKGROUND/AIM: Vitamin A deficiency is known to be associated with night blindness. Plasma retinol binding protein (RBP) estimation highly correlates with plasma retinol concentration to predict vitamin A status. Serum RBP estimation is reasonably simple, inexpensive, and highly applicable in less technologically developed settings. We studied the correlation of plasma vitamin A levels (by RBP estimation) and ocular manifestation in patients with liver cirrhosis. MATERIALS AND METHODS: This prospective, cohort study included 137 patients with liver cirrhosis. Ocular manifestations in these patients were recorded along with detailed history and clinical examination. Blood samples after overnight fasting were measured for RBP levels. The characteristics of cirrhotic patients with and without eye findings were compared. RESULTS: Out of 137 patients, 55% were males. The causes of cirrhosis were hepatitis C virus in 61%, hepatitis B virus in 32%, alcoholics in 3%, and primary biliary cirrhosis in 3%. Ocular manifestations were found in 47% patients. RBP levels were found to be low in 44%, normal in 40%, and relatively high in 16% patients. Low levels of RBP compared to normal were associated with opthalmological findings of hypovitaminosis A (P < 0.001). CONCLUSION: The measurement of plasma RBP as an alternative to serum retinol estimation to detect relative hypovitaminosis A is simple, easy and reliable. Vitamin A level is strongly related to the severity of liver disease. Opthalmological manifestations in patients with liver cirrhosis may be preventable by early detection of hypovitaminosis A with serum RBP level, but larger studies are required before recommendation of vitamin A supplementation.