Counteracting the effects of mydriatics. Does it benefit the patient?

The effect of 2% pilocarpine nitrate in countering mydriasis, cycloplegia, and change in visual acuity due to 0.5% tropicamide was studied in 23 healthy volunteers. There was no significant difference in the decrease in pupil size or the rate of return of accommodation between the eye that received pilocarpine and the control eye. The effect of tropicamide on visual acuity was slight. In four (17%) of 23 eyes that received pilocarpine, visual acuity was reduced to 6/36 or worse. It is suggested that the use of 2% pilocarpine in the attempted reversal of 0.5% tropicamide to improve a patient's vision is not helpful and may possibly be harmful.