The Association Between Visual Field Reliability Indices and Cognitive Impairment in Glaucoma Patients

PRECIS: This prospective cross-sectional study found that patients with cognitive impairment (CI) are more likely to produce unreliable visual field (VF) tests, especially with higher false-negative (FN) responses and consequent overestimation of mean deviation (MD).

AIM: Aging-associated CI can impair the ability of individuals to perform a VF test and compromise the reliability of the results. We evaluated the association between neurocognitive impairment and VF reliability indices in glaucoma patients.

METHODS: This prospective, cross-sectional study was conducted in the Ophthalmology Department, Hospital Kuala Pilah, Malaysia, and included 113 eyes of 60 glaucoma patients with no prior diagnosis of dementia. Patients were monitored with the Humphrey Visual Field Analyzer using a 30-2 SITA, standard protocol, and CI was assessed using the clock drawing test (CDT). The relationships between the CDT score, MD, pattern standard deviation, Visual Field Index (VFI), fixation loss (FL), false-positive values, and FN values were analyzed using the ordinal regression model.

RESULTS: Glaucoma patients older than 65 years had a higher prevalence of CI. There was a statistically significant correlation between CDT scores and glaucoma severity, FL, FN, and VFI values (rs=-0.20, P=0.03; rs=-0.20, P=0.04; rs=-0.28, P=0.003; rs=0.21, P=0.03, respectively). In a multivariate model adjusted for age and glaucoma severity, patients with lower FN were significantly less likely to have CI (odds ratio, 0.91; 95% confidence interval, 0.89-0.93) and patients with higher MD were more likely to have CI (odds ratio, 1.10; 95% confidence interval, 1.05-1.16); false positive, FL, pattern standard deviation, and VFI showed no significant correlation.

CONCLUSION: Cognitive decline is associated with reduced VF reliability, especially with higher FN rate and overestimated MD. Screening and monitoring of CI may be important in the assessment of VF progression in glaucoma patients.