Retinol-binding protein (RBP) and pigmentary dystrophy of the retina

Abstract

Retinol-binding protein has been estimated for the first time in the serum of patients with retinal dystrophy. Of the 5I patients examined, 82 per cent. showed a low level of RBP, the average being 76 per cent. of the mean normal adult value. It is possible that low levels of RBP could lead to low plasma values for retinol and a consequent poor supply to the retina, leading to chronic tissue starvation and degeneration. A low RBP value could also lead to an accumulation of free retinol in the circulation with an eventual higher concentration in the pigment epithelium of the retina; this could damage the labile lysosomes, leading to tissue destruction. How the low levels of RBP could be aetiologically related to retinal degeneration is purely conjectural and further work is required before any definite explanation can be offered.