Increased intraocular pressure after cataract surgery

different time sequences for measuring pressure. Ten percent to 55% of nonglaucomatous eyes develop a 7- to 10-mm Hg increase in intraocular pressure after extracapsular cataract extraction and posterior chamber intraocular lens implantation.8J' Approximately 7% of normal eyes reach intraocular pressure levels greater than 40 mm Hg after cataract surgery." In these normal eyes, most episodes of intraocular pressure increase occur within the first 24 hours after surgeryI2 and typically resolve in 24 to 72 hours. The intraocular pressure increase is usually well tolerated and has little long-term significance. Hayreh,I3 however, described a group of nonglaucomatous, normal individuals who are susceptible to the effects of a postoperative intraocular pressure increase. These patients develop anterior ischemic optic neuropathy associated with the postoperative intraocular pressure increase. Hayreh13 postulated that a transient intraocular pressure elevation in patients with cardiovascular disease, atherosclerosis, or arteriosclerosis could further compromise an already marginal optic nerve head circulation. This situation could be exacerbated by substantial reductions in systemic blood pressure, which would also jeopardize perfusion to the optic nerve. Eyes with preexisting glaucoma are more likely to develop increased intraocular pressure and are more susceptible to visual loss during a postoperative intraocular pressure elevation.I4-lh The increase in intraocular pressure is not only more frequent and sustained in glaucoma patient~,'~,~'-*~ but may subject an already compromised optic nerve to further visual ~OSS.'~J~-~~ In fact, 70% to 100% of glaucoma patients may experience a significant increase in intraocular pressure after cataract extraction.I8 Savage et all8 found that glaucomatous eyes that underwent extracapsular cataract extraction with posterior chamber intraocular lens implantation were at greater risk of a postsurgical intraocular pressure increase than nonglaucomatous eyes undergoing the same procedure. They further reported that 9.7% of these glaucomatous eyes suffered additional visual field loss in the perioperative period.I8 The eyes at greatest risk of visual loss were those with preexisting extensive visual field loss or split fixati~n.'~,'~ McGuigan et all2 reported that combined cataract extraction-glaucoma filtering procedures reduced the frequency and magnitude of the postoperative intraocular pressure increase in glaucomatous eyes. However, combined surgery did not prevent this intraocular pressure increase. Krupin et a120 noted that 14% of glaucomatous eyes undergoing combined cataract-glaucoma procedures had an increase in intraocular pressure of 10 mm Hg or more, and that 21% of these patients had an intraocular pressure greater than 25 mm Hg 15 to 18 hours postoperatively. Early recognition and accurate diagnosis of intraocular pressure increase after cataract extraction is vital to the correct management of the condition in normal and glaucomatous eyes. This article will briefly review the clinical findings, diagnostic considerat ions, and therapeutic management of elevated intraocular pressure after cataract surgery.