Intraocular pressure increments after cataract extraction in glaucomatous eyes with functioning filtering blebs

BACKGROUND AND OBJECTIVE: The effects of cataract extraction on intraocular pressure (IOP) were studied in glaucoma patients who had previously undergone trabeculectomy. PATIENTS AND METHODS: The files of 22 patients with 25 glaucomatous eyes with functioning filtering blebs who underwent cataract extraction were retrospectively reviewed. All patients had undergone pretrabeculectomy examination and had at least 18 months of follow- up after cataract surgery. Visual acuity, IOP, status of the filtering bleb, and the number of medications applied were recorded. RESULTS: The mean increase in IOP was 3.63 mm Hg, 3.84 mm Hg, 5.4 mm Hg, and 2.8 mm Hg at 3, 6, 12, and 18 months after cataract extraction, respectively. This elevation was statistically significant 3 months postoperatively (P < .001) and remained relatively constant thereafter. The postoperative IOP was still significantly lower than the pretrabeculectomy IOP (P < .001). CONCLUSIONS: Cataract extraction through corneal incisions in patients with functioning filtering blebs is followed by an increase in IOP. Cataract surgery in these patients does not neutralize the pressure-lowering effect achieved by the trabeculectomy, but it tends to elevate the post-trabeculectomy baseline pressure.