Cataract Surgery and Rate of Visual Field Progression in Glaucoma

Abstract

Purpose : To test the hypothesis that cataract surgery would slow the apparent rate of glaucomatous visual field (VF) decay in open-angle glaucoma patients, as compared to rates measured during the progression of the cataract.

Methods : Two hundred eyes of open-angle glaucoma patients who underwent cataract surgery and who had ≥ 5 visual field measurements and at least 3 years of follow-up before and after cataract surgery were included. The point-wise rate of change (PRC) for each location was calculated with a pointwise exponential regression (PER) model and expressed as %/year change of the age- and location-matched normal values as previously published. PRCs were used to calculate the Glaucoma Rate Index (GRI) for each eye. The proportions of PRCs decaying, improving, and stable were compared before and after surgery. GRI, MD rate, and VFI rate were also compared before and after surgery.

Results : Patients were followed for 5.9 ± 2.5 years (mean ± SD) before and 12.8 ± 2.9 years after cataract surgery, with 9.3 ± 4.4 VFs before and 8.8 ± 4.0 VFs after surgery. The rate of change for all VF locations was -0.9 ± 3.8 %/year before surgery, and was -1.2 ± 4.0 %/year after surgery (P < 0.001). 12.2 % of locations decayed and 3.1 % improved preoperatively; postoperatively, 13.3 % decayed and 3.3 % improved. Mean GRI was -8.2 ± 16.8 preoperatively and -10.9 ± 19.8 postoperatively; there was no significant change after cataract surgery (P=0.12). There was no difference after surgery in MD rate (-0.26 ± 0.53 dB/year preoperatively and -0.35 ± 0.61 dB/year postoperatively, P=0.12), but the VFI rate significantly increased after cataract surgery (-0.65 ± 1.43 %/year preoperatively and -1.12 ± 1.80 %/year postoperatively, P=0.002).

Conclusions : The mean rate of VF decay was slightly faster after cataract surgery compared with before cataract surgery, and not slower, as expected. However, there was no significant change in GRI or MD rate after cataract surgery, while the VFI rate significantly worsened after cataract surgery. Cataract surgery does not appear to improve the apparent rates of glaucomatous VF decay as measured by these indices.

This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.