Evaluation of automated pupillometry for early detection of ethambutol-induced optic neuropathy

Automated pupillometry (AP) has been studied in established optic neuropathies. This prospective, sequential AP evaluation of 62 newly diagnosed adult patients with pulmonary/extra-pulmonary tuberculosis, showed a statistically significant change in the amplitude of contraction (p=0.018), percent pupillary contraction and velocity of dilation (p=0.003). Although there was a significant decrease in retinal nerve fibre layer thickness in three quadrants (p<0.001) and an increase in the latency of pattern visual evoked potential (p<0.001), none of these changes reached the pre-defined cut-off values for subclinical ethambutol-induced optic neuropathy. Temporal quadrant retinal nerve fibre layer change is correlated with pupillometry changes. AP holds promise for the early detection of ethambutol-induced optic neuropathy.