Intraocular Pressure Elevation within the First 24 Hours after Cataract Surgery in Patients with Glaucoma or Exfoliation Syndrome

Primary lens extraction for glaucoma management: A review article

Recently, primary lens extraction alone gained more acceptance as an alternative surgical approach for glaucoma management. This view was supported by the advances in phacoemulsification and intraocular lenses with greater safety and visual recovery, in addition to a substantial reduction of intraocular pressure and deepening of the anterior chamber and filtration angle. The decrease in IOP after cataract surgery in primary open-angle glaucoma (POAG) is mild, less predictable, related to baseline levels, and may return to presurgical values after an initial period of reduction. Therefore, the IOP-lowering effect of primary cataract extraction in POAG may be insufficient to achieve adequate IOP control. The IOP reduction after lens extraction is consistently greater in eyes with primary angle closure glaucoma (PACG) than in eyes with POAG. Primary lens extraction in acute PACG eliminates, or at least, reduces the risk of recurrence of acute attacks and deepens the anterior chamber and widens the angle which reduces the risk of progression of peripheral anterior synechiae and development of chronic PACG. Primary lens extraction may be more preferable to glaucoma incisional surgery in mild to moderate PACG eyes with appositional angle closure. The decision to do lens extraction as a primary treatment for glaucoma should be individualized based upon several factors other than the effect on IOP. These factors include patients' characteristics, surgeons' skills and preferences, status of glaucoma control, type of cataract and intraocular lens implanted, and potential harm of laser treatment for late capsular opacification and fibrosis.

Efficacy of brimonidine in preventing intraocular pressure spikes following phacoemulsification in glaucoma patients

PURPOSE

To measure intraocular pressure (IOP) elevation 6 and 24 hours after phacoemulsification in patients with glaucoma and to investigate the efficacy of brimonidine tartrate 0.2% in preventing IOP rise on the first postoperative day following cataract surgery.

METHODS

In this prospective randomized single-masked study, 86 eyes of 78 patients with well-controlled open-angle glaucoma were scheduled for phacoemulsification surgery. Patients were randomly assigned into 2 groups. Group A received 1 drop of brimonidine tartrate 0.2% and group B, which served as a control group, received 1 drop of artificial tears. Intraocular pressure was measured at baseline, before surgery, and 6 and 24 hours postoperatively.

RESULTS

Within each group, we found a statistically significant difference in IOP between baseline and 6 hours postoperatively (p<0.01) and between 6 and 24 hours (p<0.01). There was no statistically significant difference between baseline IOP and 24-hour values. Comparing the 2 groups, there was no statistically significant difference in preoperative and 24-hour postoperative IOP. Six hours after surgery, the mean IOP in the brimonidine group was 18.52±4.58 mmHg, compared with 20.86±3.79 mmHg in the control group. Treatment with brimonidine tartrate 0.2% significantly reduced postoperative IOP elevation 6 hours following cataract extraction (p=0.009).

CONCLUSIONS

Patients with medically well-controlled glaucoma may experience a substantial increase in IOP shortly after phacoemulsification surgery. Instillation of brimonidine tartrate 0.2%, although it significantly reduced IOP elevation following cataract operation, did not completely prevent IOP spikes.

Phacoemulsification versus phacoemulsification with micro-bypass stent implantation in primary open-angle glaucoma: randomized double-masked clinical trial

PURPOSE

To compare phacoemulsification alone and phacoemulsification with micro-bypass stent implantation in eyes with primary open-angle glaucoma.

SETTING

Instituto di Fisiopatologia Clinica, Clinica Oculistica, Universita' di Torino, Torino, Italy.

METHODS

In this prospective double-masked randomized clinical trial, patients had phacoemulsification alone (control group) or phacoemulsification with iStent implantation (combined group). Primary outcomes were intraocular pressure (IOP) and reduction in medication use over 15 months and IOP after a 1-month washout of ocular hypotensive agents (ie, 16 months postoperatively).

RESULTS

The baseline IOP was similar between groups (combined group: 17.9 mm Hg +/- 2.6 [SD]; control group: 17.3 +/- 3.0 mm Hg) (P = .512). Three patients in the control group were lost to follow-up. The mean IOP was 14.8 +/- 1.2 mm Hg in the combined group and 15.7 +/- 1.1 mm Hg in the control group at 15 months and 16.6 +/- 3.1 mm Hg and 19.2 +/- 3.5 mm Hg, respectively, after washout; the IOP was statistically significantly lower in the combined group than in the control group at both time points (P = .031 and P = .042, respectively). At 15 months, the mean number of medications was lower in the combined group than in the control group (0.4 +/- 0.7 and 1.3 +/- 1.0, respectively; P = .007), as was the proportion of patients on ocular hypotensive medication (33% and 76%, respectively).

CONCLUSIONS

Phacoemulsification with stent implantation was more effective in controlling IOP than phacoemulsification alone; the safety profiles were similar.

Cataract surgery to lower intraocular pressure

Cataract and glaucoma are common co morbidities. Cataract surgery is frequently performed in patients with glaucoma. In this study, a review of literature with search terms of cataract, glaucoma and intraocular pressure is followed by evaluation and synthesis of data to determine the effect of cataract surgery on intraocular pressure. Cataract surgery seems to lower intraocular pressure on a sustained basis, especially in patients with higher preoperative intraocular pressure. The mechanism of action of these finds remains speculative.