Phenylthiourea Taste Testing and Glaucoma

In population studies taste sensitivity for phenylthiourea (phenylthiocarbamide or PTC) has been found to be distributed bimodally. In Caucasian groups approximately 30% were found to be relatively insensitive to the bitter taste of PTC and were classified as nontasters.¹,²In Negroes a much lower prevalence of nontasters has been reported.³,⁴Evidence has been accumulated that nontasters are homozygous for a single recessive gene.⁵The ability to taste phenylthiourea has been used as a convenient genetic marker, and associations have been reported between taste insensitivity to PTC and nodular goiter,²,⁶cretinism,⁷,⁸and diabetes.⁹ The primary glaucomas, both angle-closure and open-angle, have been reported to be genetically determined diseases.¹⁰⁻¹³The association between PTC taste insensitivity and primary glaucomas has been studied, and it is the subject of this report. Method Solutions of phenylthiourea were prepared in the manner described by Harris and Kalmus.¹Solution