Cataract Surgery and Rate of Visual Field Progression in Primary Open-Angle Glaucoma

Purpose: To test the hypothesis that cataract surgery slows the apparent rate of visual field (VF) decay in primary open-angle glaucoma patients compared with rates measured during cataract progression. Design: Retrospective cohort study. Methods: Consecutive open-angle glaucoma patients who underwent cataract surgery and who had ≥4 VFs and ≥3 years of follow-up before and after surgery were retrospectively reviewed. Mean deviation (MD) rate, visual field index (VFI) rate, pointwise linear regression (PLR), pointwise rate of change (PRC), and the Glaucoma Rate Index (GRI) were compared before and after cataract surgery. Results: A total of 134 eyes of 99 patients were included. Median (interquartile range) follow-up was 6.5 (4.7-8.1) and 5.3 (4.0-7.3) years before and after cataract surgery, respectively. All intraocular pressure (IOP) parameters (mean IOP, standard deviation of IOP, and peak IOP) significantly improved (P <.001) after cataract surgery. All VF indices indicated an accelerated VF decay rate after cataract surgery: MD rate (-0.18 ± 0.40 dB/year vs -0.40 ± 0.62 dB/year, P <.001), VFI rate (-0.44% ± 1.09%/year vs -1.19% ± 1.85%/year, P <.001), GRI (-5.5 ± 10.8 vs -13.5 ± 21.5; P <.001), and PRC (-0.62% ± 2.47%/year before and -1.35% ± 3.71%/year after surgery; P <.001) and PLR (-0.20 ± 0.82 dB/year before and -0.42 ± 1.16 dB/year after surgery; P <.001) for all VF locations. Worse baseline MD and postoperative peak IOP were significantly associated with the postoperative VF decay rate and the change in the decay rate after cataract surgery. Conclusion: Although all IOP parameters improved after cataract surgery, VFs continued to progress. Cataract surgery does not slow the apparent rate of glaucomatous VF decay as compared to rates measured during the progression of the cataract.