The effect of cataract extraction with implant in glaucomatous eyes

The effect of cataract surgery in patients with glaucoma controlled by either topical medication or surgery was assessed in 64 patients. At one year there was a small significant fall in intraocular pressure (IOP) for eyes without previous surgery (preoperative IOP 18.9 +/- 4.7, range 12 to 35 mmHg; postoperative IOP 16.3 +/- 3.4, range 10 to 26 mmHg; P < 0.01) and also for those with previous surgery (preoperative IOP 15.0 +/- 4.3, range 3 to 22 mmHg; postoperative IOP 14.2 +/- 3.7, range 6 to 22 mmHg, P < 0.05). There was a significantly greater incidence of high rise in IOP to 30 mmHg or more immediately after operation in patients without (32%) than those with previous surgery (13%) (chi 2 = 3.9; P < 0.05). Complications were minimal in each group. Iridotomy to deliver the nucleus was necessary in nine eyes without and 21 with previous surgery. Cataract extraction usually causes only a small fall in IOP in glaucomatous patients. If a separate corneal section is used there is no loss of function of the filtering bleb in patients with previous glaucoma surgery.