The Effects of Miotics on Accommodative Convergence/Accommodation (AC/A) Ratio of Nigerian Youths

Abstract

Miotics are autonomic effectors which are routinely used as diagnostic and therapeutic agents in ophthalmic practice, exerting actions on autonomic nervous control of the eye. This in turn controls changes in the pupil size, accommodation, convergence and aqueous humor dynamics.  Gradient AC/A ratios were assessed in Nigerian youths of both sexes with ages ranging between 18 and 30 years (mean 20.5± 2.6 yrs).  Initial values of the AC/A ratio were assessed on each volunteer and thereafter pilocarpine ophthalmic solution 4% and physostigmine ophthalmic solution 0.5% were applied topically, and the AC/A ratio re-assessed. Results showed that AC/A ratios were reduced after the application of the miotics relative to normal gradient AC/A ratios. The decrease in AC/A ratio following the use of the miotics was highly significant (p<0.01) and was associated with the normal gradient AC/A ratio.  In conclusion, the miotic–induced spasm of accommodation significantly decreased the AC/A ratio of Nigerian youths.