Association between corneal hysteresis and the magnitude of intraocular pressure decrease after cataract surgery

Abstract

To evaluate the relationship between baseline corneal hysteresis (CH) and the change in intraocular pressure (IOP) before and after cataract extraction in patients without glaucoma. Private practice, New York City, New York, USA. Retrospective cohort study. Charts of consecutive patients who had phacoemulsification cataract extraction with posterior chamber intraocular lens implantation were analyzed. All included patients had preoperative and postoperative measurements with the Ocular Response Analyzer 2 to 4 months and 10 to 12 months postoperatively. Data collected included age, baseline CH, baseline central corneal thickness (CCT), and IOP. Thirty nine (65 eyes) of the 230 patients met the inclusion criteria. The mean patient age was 70.8 years ± 8.6 (SD). The mean preoperative, 2- to 4-month and 10- to 12- month postoperative IOP values were 14.8 ± 3.5 mm Hg, 11.9 ± 3.4 mm Hg, and 12.6 ± 3.1 mm Hg, respectively (P < .05 for comparisons with preoperative IOP). The baseline CH was not predictive of the IOP reduction at 2 to 4 months (β = -0.3; 95% confidence interval [CI], -0.7 to 0.01; P = .06). However, the baseline CH (but not the baseline CCT) was statistically associated with the magnitude of IOP reduction at 10 to 12 months when controlling for patient age (β = -0.5; 95% CI, -0.8 to -0.1; P = .01). A low baseline CH was associated with a larger magnitude of IOP reduction after cataract extraction. Dr. Radcliffe is a consultant to Reichert Technologies and Glaukos Corp.; a consultant to and speaker for Allergan, Inc., Alcon Laboratories, Inc., Iridex Corp., Merge Healthcare, Carl Zeiss Meditec AG; and a speaker for Merck Pharmaceuticals. No other author has a financial or proprietary interest in any material or method mentioned.