Abstract
Purpose :
Glaucoma and cataract are two leading causes of vision impairment worldwide. Previous studies report a long-term decrease in intraocular pressure (IOP) after cataract surgery in patients with and without glaucoma. Higher preoperative IOPs have been reported to predict a greater drop in IOP postoperatively. However, past literature lacks a consensus about the precise timing of postoperative IOP reduction and has yet to show other significant factors that may affect IOP reduction. Our study examines the timing of IOP reduction following cataract extraction (CE) and additional patient-related variables that may contribute to this postoperative IOP-lowering effect of CE.
Methods :
Retrospective chart review data was collected from 101 patients with primary open angle glaucoma, ocular hypertension, or normal-tension glaucoma, who had CE in one or both eyes (140 total eyes). IOP was analyzed at 1, 3, 6, and 12 months after CE. Preoperative IOP, effect of time after CE, body mass index (BMI), number of IOP-lowering drops at time of CE, hypertension, diabetes, smoking history, age, race, and history of selective laser trabeculoplasty (SLT) were tested as explanatory variables for IOP reduction following CE.
Results :
Average IOP at time of CE was 15.62 [95% CI, 14.84 to 16.4]. After adjusting for preoperative values and history of ocular surgery, the predicted drop in IOP after 1 month was -1.04 [95% CI, -1.78 to -0.29], p=0.006; and after 12 months, -2.84 [95% CI, -3.79 to -1.9], p<0.001. IOP changes at 3 and 6 months were not significantly different from those achieved at 1 month postoperatively. A significant difference compared to the changes after 1 month was only predicted at 12 months (p<0.001) postoperatively. BMI, number of IOP-lowering drops at time of cataract surgery, hypertension, diabetes, smoking, age, race, and history of SLT did not predict IOP reduction after cataract surgery.
Conclusions :
Effect of time significantly influenced IOP reduction after CE, with the first significant drop in IOP occurring at 1 month and the next significant drop occurring at 12 months. Our data confirm the findings of previous studies that greater preoperative IOP levels are predictive of post-cataract surgery IOP reduction. None of the other variables appeared to predict IOP reduction after CE.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.