Visual Field Loss and Self-Reported Driving Restriction in Glaucoma

Background: To evaluate the association between glaucomatous visual field loss and self-reported driving limitation, and to explore potential threshold ranges of visual field loss associated with an increased likelihood of driving restriction. Methods: In this cross-sectional study, 100 patients with primary open-angle glaucoma underwent standard automated perimetry. Visual function was assessed using Mean Deviation (MD) and Visual Field Index (VFI) from the better eye. Driving status, driving limitation, and self-reported driving difficulties were assessed using a structured questionnaire. Multivariable logistic regression was performed to determine independent associations between visual field parameters and driving limitation, adjusting for age, sex, cataract status, and systemic comorbidities. Because MD and VFI are closely related indices of visual field loss, separate multivariable models were constructed for each parameter. Receiver operating characteristic (ROC) analysis was used to explore threshold values associated with driving limitation. Results: Driving limitation increased progressively with worsening functional severity, affecting 17% of participants with preserved function, 48% of those with borderline impairment, and 72% of those with definite impairment (p < 0.001). Reduced VFI was independently associated with driving limitation (OR = 0.972, 95% CI: 0.948–0.996; p = 0.021). In a separate model, more negative MD was also independently associated with driving limitation (OR = 0.924, 95% CI: 0.875–0.976; p = 0.004). Male sex was associated with a lower likelihood of driving limitation. ROC analysis identified threshold values of VFI ≤ 71% (AUC = 0.663) and MD ≤ −13.36 dB (AUC = 0.650), both characterized by high specificity but limited sensitivity. Participants who had ceased driving demonstrated worse visual field indices than active drivers, whereas never-drivers showed no consistent association with visual field loss. Conclusions: Glaucomatous visual field loss was significantly associated with self-reported driving limitation and behavioural self-regulation. Objective perimetric parameters, particularly VFI and MD in the better eye, may help identify patients more likely to report driving difficulties. The reported threshold values should be interpreted as exploratory reference points rather than clinically actionable criteria and require further validation before clinical application.