ABSTRACT
This chapter describes preliminary observations on the effect of anaesthesia on ocular microtremor (OMT). The return of OMT activity in patients under halothane and nitrous oxide anaesthesia is of interest. The level of activity gradually increased as anaesthesia became less deep. Lightening of the level of anaesthesia was accompanied by a recovery of innervation beginning with small single units. N. Sakatani et al. recorded clear discharge activity even during deep anaesthesia from the extraocular muscle in man. This correlates with the findings which show OMT activity in patients while anaesthetised with halothane, nitrous oxide, and trichloroethylene. Barbiturates also produce a well-recognized series of changes in the electroencephalogram during anaesthesia. A. E. Guedel suggested that the degree of oscillation of the eye reflected depth of anaesthesia, light anaesthesia leading to oscillation entirely across the palpebral slit and deeper anaesthesia causing movement just off center.
