Levels of melatonin in serum of patients with retinitis pigmentosa

PURPOSE: To elucidate melatonin secretion through the pineal gland in patients with night blindness. MATERIAL AND METHODS: Blood samples for melatonin RIA assay were taken from 14 patients at 8 o'clock a.m. and p.m., before and after 3 weeks therapy with Trental, Cocarboxylase and vitamin B12. RESULTS: Usual rhythm of melatonin secretion was demonstrated. The applied treatment influenced melatonin secretion in the youngest group of patients. CONCLUSION: Damage of the photoreceptors in the retina affects melatonin secretion and its circadian rhythm.