Can preoperative anterior chamber angle width predict magnitude of intraocular pressure change after cataract surgery?

Objective: To determine whether preoperative anterior chamber angle width, captured by anterior segment optical coherence tomography (AS-OCT), can be a predictor of intraocular pressure (IOP) change following cataract surgery.

Design: Prospective comparative observational study.

Participants: Fifty-three eyes of 53 patients awaiting cataract surgery were included.

Methods: Measurement of anterior chamber angle width and IOP using AS-OCT and Goldmann's applanation tonometry, respectively, were performed before and 6 months after phacoemulsification and intraocular lens implantation. Preoperative and postoperative measurements were compared using paired t test. The prediction rule defined success as > or =20% IOP reduction from the baseline preoperative IOP measurement. Multivariate regression analysis was performed to assess the association of postoperative IOP with independent variables, including age, sex, systemic hypertension, diabetes mellitus, glaucoma, and preoperative anterior chamber angle width.

Results: Data were collected from 32 females and 21 males with visually significant cataract. Mean age was 73.3 (SD 8.2) years. Mean IOP dropped from 15.1 (SD 3.1) mm Hg to 12.8 (SD 2.5) mm Hg (p < 0.0001) after cataract extraction. Mean anterior chamber angle width increased from 24.7 degrees (SD 7.1 degrees ) to 38.1 degrees (SD 6.0 degrees ) after surgery (p < 0.001). Multivariate regression analysis did not identify preoperative variables to be significantly associated with > or =20% postoperative IOP reduction.

Conclusions: Cataract surgery results in significant and sustained mean reductions in IOP and concurrent increases in anterior chamber angle width for a period of at least 6 months after surgery. However, measurements of the preoperative anterior chamber angle width did not predict the IOP-lowering effect of cataract surgery.