Aqueous humour and plasma amino acids in tapeto-retinal degenerations

The concentration of 18 amino acids and related compounds has been determined in plasma and aqueous humour in 17 patients with tapeto-retinal degenerations, among them 10 patients with retinitis pigmentosa. When compared with a previously obtained reference series of 40 patients abnormal aqueous concentrations (Caq) were found for taurine, glutamine, glutamic acid, proline, glycine, alpha-ANBA and cystine. As regards the plasma concentrations (Cpl) only glutamic acid and alpha-ANBA showed abnormal values. Several of the substances showing abnormal concentrations are possible neurotransmittors or inhibitors. The results suggest that aqueous humour analysis will be a useful way of studying retinal degenerations.