Which visual measures affect change in driving difficulty after first eye cataract surgery?

Abstract

Objective: To investigate self-reported driving difficulty before and after first eye cataract surgery and determine which visual measures are associated with changes in self-reported driving difficulty after surgery.

Methods: A cohort of 99 older drivers with bilateral cataract were assessed the week before and 12 weeks after first eye cataract surgery. Visual measures including visual acuity, contrast sensitivity, stereopsis and useful field of view were assessed. Self-reported driving difficulty was measured via the Driving Habits Questionnaire. Cognitive status was assessed using the Mini Mental State Examination. Regression analysis was undertaken to determine the association between changes in visual measures and self-reported driving difficulty after first eye cataract surgery.

Results: Overall, self-reported driving difficulty improved after first eye cataract surgery. However, 16% of participants did not improve and driving difficulty worsened in 11% following surgery. Improvement in driving difficulty score after first eye cataract surgery was associated with improved contrast sensitivity in the operated eye (p<0.001), new glasses after surgery (p<0.001), and fewer chronic health conditions (p=0.016).

Conclusion: Contrast sensitivity rather than visual acuity was a significant factor affecting change in self-reported driving difficulty after first eye cataract surgery for bilateral patients. This has implications for driver licensing authorities worldwide that rely heavily on visual acuity as a measure of visual fitness to drive.

Keywords: Cataract surgery; Driving difficulty; Visual measures.