Effect of intraoperative factors on IOP reduction after phacoemulsification

Abstract

The purpose of the study was to determine the independent predictors of long-term intraocular pressure (IOP) reduction after cataract surgery with phacoemulsification. This is a retrospective review of uncomplicated cataract surgeries from 2006 to 2008 at the Baltimore VA Medical Center with longitudinal follow-up. Demographic, clinical, biometric, and intraoperative variables including phacoemulsification parameters were recorded. Univariate and multivariate linear regression were used to analyze the relationship between these variables and postoperative IOP, which was the outcome variable. Analysis was performed in 115 eyes of 115 patients who underwent uncomplicated phacoemulsification during the study period. There was an average postoperative IOP reduction through 12, 24, and 36 months of −1.7 ± 3.1, −1.5 ± 3.8, and −1.3 ± 2.6 mmHg, respectively. Higher preoperative IOP (P < 0.001), a more anterior relative lens position (P < 0.05), and longer phaco time (P < 0.05) were significantly associated with greater postoperative decrease in IOP using univariate analysis. Using multivariate analysis, preoperative IOP (P <0.001), and phaco time (P = 0.038) were associated with greater postoperative IOP reduction through 24 months. Phaco time is independently associated with IOP reduction after adjusting for age and preoperative IOP. Higher preoperative IOP is associated with a greater IOP-lowering effect after phacoemulsification.

Microinvasive glaucoma surgery: an evidence-based assessment

“…The group with preoperative IOP ≤21mmHg had a success of 37.5% with a decrease in IOP of 11.5% (16.5 ±2.9 to 14.6 ±3.7mmHg, P=0.012) while 62.5% of those with preoperative IOPs >21mmHg achieved success with a decrease in IOP of 36.6% (25.8 ±2.9 to 16.4 ±5.4mmHg, P<0.001). This is consistent with other studies that find CE/IOL alone is more effective at IOP-lowering when performed in patients with higher preoperative IOPs[27]*. No serious complications were reported in this study.…”

“…Prior work has shown that each additional millimeter of mercury results in an 11% increase in the risk of glaucoma progression[88]*. Most MIGS studies are combined with cataract surgery, which can lower IOP in the short term by 2–4mmHg[27]*[89][90]. However, this effect wanes over time, thus studies focusing on long term data will be important moving forward.…”

Intraocular Pressure and Anterior Segment Morphometry Changes after Uneventful Phacoemulsification in Type 2 Diabetic and Nondiabetic Patients

“…Similar to Lee et al [17], our analysis failed to demonstrate any significant relationship between the amount of CDE and the IOP variations. A study by DeVience and colleagues [38] was able to show a significant correlation between phacoemulsification time and postoperative IOP reduction 24 months postoperatively. However, these findings were not confirmed by Pradhan et al [35].…”

Effect of phacoemulsification cataract surgery on intraocular pressure in early glaucoma: A prospective multi‐site study

“…Finally, the phacoemulsification ultrasound may improve trabecular meshwork aqueous drainage. DeVience et al reported that intraoperative phacoemulsification time was associated with greater IOP reduction in normal eyes . This is supported by an in‐vitro study of phacoemulsification ultrasound on trabecular meshwork cells activating cellular pathways leading to improved aqueous outflow and lower IOP .…”