AIM: To evaluate the characteristics of pupillo-accommodative functions in patients with idiopathic tonic pupil according to the time of onset, gender, and age.METHODS:Totally, 15 males and 19 females were divided into 2 groups depending on the time of disease onset:group Ⅰ (onset <2 months, n=20) and group Ⅱ (onset >2 months, n=14). A supersensivity test was conducted by applying diluted pilocarpine 0.125% to the eye and accommodative functions were evaluated using the near-point of accommodation (NPA) as the cutoff point, at which the patient experienced blurred vision. Pupil size and the ratio of decrease in the affected pupilafter instillation of 0.125% pilocarpine were investigated.RESULTS:There was no significant difference between the 2 groups regarding the various pupillary reflex results, including data on the affected pupil size before and after 0.125% pilocarpine, anisocoria, and ratio of pupil decrease. No significant difference in NPA was found between the 2 groups. However, female patients were noted to have greater anisocoria and a faster constriction ratio than those of the male patients (P=0.02 and P=0.04). On subgroup analysis, female patients from group Ⅱ had larger affected-pupil sizes before 0.125% pilocarpine instillation and longer NPAs than those of the male patients.CONCLUSION: No relationship was found between time of onset and dysfunction of pupillo-accommodative functions. Pupillo-accommodative functions and age were not related, except for the NPA.