RESUMEN
In order to assess the course of methadone (Heptadone) substitution therapy, 29 inpatients at the Vienna Psychiatric University Clinic (21 males, mean age = 27 years, SD 4 years; 8 females, mean age 29.75 years, SD 5.28 years) who were addicted to opium tea or to a mixture of opium and heroin were investigated by means of computer-assisted "static"- and "light-evoked dynamic" pupillometry. Pupillary measurements were carried out before the start of withdrawal, on the 2nd day 48 h after the administration of 10 mg methadone, and again after the maximum and half of the maximum dose of methadone had been administered. The constricted pupils (the effect of opiate) showed dilatation after the withdrawal syndrome appeared, but immediately after the start of the detoxification treatment, as well as 1 day after administration of the maximum methadone dose a decrease of pupillary diameter was observed. The narrowing of the pupil was followed by an increase in pupillary diameter, which peaked 48 h after the last minimal dose of methadone and nearly reached the normal level. The widening of the pupil reflects an increase of noradrenergic activity under conditions of opiate withdrawal. An increase of spontaneous fluctuations was observed during withdrawal and was only inhibited by the maximum dose of methadone. Finally, pupillary dynamics (shortening of latency time and increase of relative changes) improved during therapy. The pupillary measurement corresponded with clinical observations as well as with self-evaluation during treatment. Thus pupillometry seems to be a useful instrument for assessment of treatment of opiate-addicted patients.