Ultrasonic study to see the effect of topical pilocarpine and homatropine on anterior chamber depth in phakic cases.

Pilocarpine and Homatropine are the drugs having known effect on the depth of anterior chamber. The purpose of this study was to demonstrate the time of onset, peak effect and its duration of action as well as shallowing/deepening of the anterior chamber, after single instillation of pilocarpine 2% or homatropine bromide 2%, topically in one eye. Also we tried to see if there is any effect on the contralateral eye, due to systemic absorption of pilocarpine, homatropine after topical instillation of the drug in one eye. Pilocarpine causes a measurable shallowing of the anterior chamber with onset of effect with in 20 minutes and a peak in 60 minutes, the average narrowing being 0.26 mm. (range 0.20-0.29 mm.). Homatropine has a measurable deepening effect on the anterior chamber, due to axial flattening of the lens because of cycloplegia, with a range of 0.33 to 0.36 mm. In 70% of the cases the effect passes away with in 24 hours., but in 30% it comes to normal in 48 hours.