Effect of cataract extraction on the visual fields of patients with glaucoma.

OBJECTIVE To investigate the effect of cataract extraction on the visual fields of patients with open-angle glaucoma. METHODS Patients in a prospective cohort study in a tertiary center underwent standard automated perimetry every 6 months. We compared the mean results of the 2 examinations immediately before and 2 examinations immediately after phacoemulsification cataract extraction and intraocular lens implant (effect analysis) and the mean results of the first 2 and last 2 examinations from 4 consecutive examinations obtained more than 1 year after the cataract surgery (control analysis). RESULTS Our sample contained 34 eyes of 26 patients (mean +/- SD age, 69.2 +/- 10.8 years). While the mean logMAR best-corrected visual acuity improved significantly by approximately 2 Snellen lines after surgery (P < .001), the average change in mean deviation in both the effect and control analyses was less than 0.1 dB and not statistically significant (P = .85). There was a strong correlation between change in foveal sensitivity and change in mean deviation in the effect analysis but not in the control analysis (r = 0.76 [P < .001] and r = 0.30 [P = .08], respectively). There was no relationship between change in visual acuity or initial mean deviation and change in mean deviation in either analysis. Change in pointwise total deviation was not systematically related to the respective baseline value in either analysis; however, the variance of the distribution of change in total deviation was significantly higher in the effect analysis (P < .001). CONCLUSION While there was an improvement in best-corrected visual acuity after cataract surgery, the changes in the visual field as a group were negligible.