Monkeys were treated twice daily with 5 μg 1,25-(OH)2D3 to both eyes. Prior to the 5th 1,25-(OH)2D3 treatment on day 3, one eye was treated with 1mg Pilo to contract the ciliary muscle and block uveoscleral outflow and after 30 min both eyes received the fifth 5 μg treatment of 1,25-(OH)2D3 (see Materials and Methods for details). White squares represent the IOP change in the eye treated with 1,25-(OH)2D3 only and black circles represent the IOP change in the eye pretreated first with pilocarpine and then treated with 1,25-(OH)2D3. After the 5th treatment with 1,25-(OH)2D3, there was no apparent suppression of the IOP response to 1,25-(OH)2D3 as a result of pilocarpine pretreatment. Data are mean ± sem. Significantly different from 0.0: *p<0.05, minimum. IOP (mmHg ± sem) prior to the first treatment on day 1 was: 1,25-(OH)2D3 = 18.9 ± 1.0; 1,25-(OH)2D3+Pilo = 19.1 ± 0.9.