Short-term changes in intraocular pressure after phacoemulsification in glaucoma patients.

PURPOSE: To evaluate short-term intraocular pressure (IOP) changes after phacoemulsification in glaucoma and normal patients and the effect of oral acetazolamide (Diamox) to control IOP in these patients.

METHODS

120 patients undergoing cataract surgery were included in this prospective multicenter study involving 6 University Eye Clinics: 60 patients with well-controlled primary open-angle glaucoma (POAG) and 60 controls. Half of the study participants received oral acetazolamide, 250 mg, 1 and 6 h after surgery. The treated and untreated groups were matched for age and density of cataract. All patients underwent a standard phacoemulsification procedure and were checked for IOP with Goldmann tonometry in the morning before surgery and then at 3, 6, 21 and 24 h postoperatively by a masked evaluator.

RESULTS

The group with POAG showed a significant postsurgical increase in IOP (p < 0.001) at all time points. Six of thirty (20%) untreated POAG patients showed at least 1 IOP reading above 30 mm Hg whereas acetazolamide significantly reduced postoperative IOP at all time points (p < 0.01) and in no case was IOP >30 mm Hg. The control group had high IOP during the first 6 h (p < 0.01), but normal values thereafter.

CONCLUSION

A significant short-term IOP increase may be found after phacoemulsification both in POAG and normal patients; this is not dangerous in normal subjects, but can be potentially dangerous in POAG patients. The use of systemic acetazolamide provided significant control of IOP and could be considered a 'possible standard' management of cataract surgery in POAG patients.