High resolution ultrasonic biometry was performed on ten eyes of five normal young volunteers (ages 21 to 26 years) prior to and at regular intervals following topical administration of 1%, 4%, and 8% pilocarpine hydrochloride. All eyes showed a narrowing of the anterior chamber and axial lens thickening following pilocarpine administration. There was a dose-related response of maximal anterior chamber depth and lens thickness changes, but comparison of the means of maximal changes of the two dimensions did not reveal statistically significant differences.
Increasing concentrations of pilocarpine had a more rapid onset of action, greater peak effect, and prolonged duration of action. A statistically significant prolongation of effect on anterior chember depth and lens thickness after instillation of the drug was obtained with the higher concentrations of pilocarpine.
Abramson DH, Chang S, Coleman DJ, Smith ME. Pilocarpine-Induced Lens ChangesAn Ultrasonic Biometric Evaluation of Dose Response. Arch Ophthalmol. 1974;92(6):464-469. doi:10.1001/archopht.1974.01010010478003