THE CYCLOPLEGIC EFFECTS OF CYCLOPENTOLATE AND TROPICAMIDE ON MYOPIC CHILDREN

Thirty-seven myopic children were given either 1-2 drops of 1% cyclope ntolate or 1% tropicamide twice with 5 min intervals to evaluate the t ime course and maximal cycloplegic effect of both agents. The other fi fteen subjects were given 1% tropicamide initially, then 1% cyclopento late given after 30 min of maximal effect of tropicamide appeared to e valuate whether the effect of cyclopentolate was superior to tropicami de. Cycloplegic refraction was measured with an auto-refractometer (To pcon RK-3000) before drug delivery and every 15 min thereafter, for 90 min. The maximal cy cycloplegic effect of cyclopentolate was around 4 5 min, then it remained stable until 90 min after the last instillatio n. The effect of tropicamide was faster than that of cyclopentolate. I t was around 30 min, then it stabilized until 75 min. The extra effect of cyclopentolate over tropicamide was minimal (only -0.1D). The powe r of cornea and astigmatism were not affected by either agent. However , a big variation in astigmatism was noted during the course, especial ly with cyclopentolate. This study suggests that 1% tropicamide should be a good agent for routine refractive status checking on myopic chil dren.