[Does a correlation exist between Myambutol dosage and occurrence of optic neuritis].

The frequency of retrobulbar neuritis during a long lasting myambutol therapy increases proportionally with the increased doses. This may be seen in retrospection on 2007 cases divided into 16 groups with doses from 15 till 60 mg per kg of bodyweight. Graphically a function may be established between myambutol doses and frequency of optic neuritis (y = -23.2 + 1.1 x). This shows for 20 mg/kg: 0%, for 25 mg/kg: 5%, for 30 mg/kg: 10% frequency of optic neuritis. Those findings allow a rough evaluation of neuritis risk and confirm clinical observations. A planed examination of patients groups with different myambutol doses checked by myambutol serum levels estimations would help in establishing optimal doses of myambutol.