Effect of cataract extraction and posterior chamber lens implantation on outflow facility and its response to pilocarpine in Korean subjects

Aim-To investigate the effect of the lens on outflow facility in Korean pat ients with cataracts. Methods-Intraocular pressure measured by Goldmann applanation tonometry in 42 patients with cataracts and outflow facility was determined by tonograph y preoperatively, before and after instillation of pilocarpine. All patient s received clear corneal phacoemulsification and silicone foldable intraocu lar lens implantation within the capsular bag by one surgeon. Two months af ter surgery, slit lamp examination and gonioscopy were performed and intrao cular pressure and outflow facility were again determined. Statistical anal ysis was carried out using the Student's paired t test. Results-There were no anterior chamber reactions and no visible trabecular meshwork damage 2 months after surgery. Intraocular pressure 2 months after lens extraction decreased by a mean of 2.4 (SE 0.4) mm Hg (p<0.001) compar ed with the preoperative value; postoperative outflow facility with and wit hout pilocarpine increased by 0.080 (0.019) mu l/min/mm Hg (p<0.001) and 0. 045 (0.014) mu l/min/mm Hg (p<0.001), respectively, at 2 months compared wi th preoperative values. The facility response to pilocarpine after lens ext raction, relative to the baseline value and preoperative response, increase d by 10.7 (7.1)% which was not statistically significant (p>0.1). Conclusion-Lens extraction causes a reduction in intraocular pressure and a n increase in outflow facility in Korean subjects. Pilocarpine causes an in crease in outflow facility which persists after cataract extraction and pos terior chamber lens implantation.