Cataract extraction and posterior chamber intraocular lens (PC-IOL) implantation was carried out in 45 glaucoma eyes that had undergone glaucoma filtering surgery (Group A), and in 47 glaucoma eyes in which intraocular pressure (IOP) was well controlled with medication (Group B). To analyze the effects of PC-IOL implantation on the control of IOP and the functioning of the filtering bleb, a life-table analysis using the Kaplan-Meier method was carried out. In Group A the probability that IOP control will not worsen at 2 years was 56 +/- 12 (SE)% in eyes where a functioning filtering bleb had existed preoperatively. The probability that the filtering bleb was not cicatrized at 2 years postoperatively was 44 +/- 11 (SE)%. In Group B the postoperative IOP on the first postoperative day was significantly higher than the preoperative level in primary open angle glaucoma (POAG) eyes, while no such difference was seen in primary angle closure glaucoma (PACG) eyes. The postoperative IOP was significantly lower than the preoperative level from 3 to 6 months postoperatively in POAG eyes and from 1 to 12 months postoperatively in PACG eyes. Medication did not differ significantly pre- and postoperatively. In 64 +/- 11 (SE)% of POAG and 63 +/- 15% of PACG eyes the IOP control did not worsen at 2 years. In 70% of the eyes the IOP control improved postoperatively, and was maintained for 2 years with the probability of 44 +/- 12 (SE)%.