Neurocognitive Decline Linked to Visual Field Variability
JAMA Ophthalmology, July 2017
Diniz-Filho et al. sought to determine whether cognitive dysfunction is associated with visual field (VF) variability in glaucoma. They found that global neurocognitive impairment is linked to increasing VF changes in patients with glaucoma as well as in glaucoma suspects.
For this prospective observational study, the researchers evaluated 115 patients (211 eyes) with a mean age of 67 years. The patients were followed for a mean of 2.5 years and were monitored with standard automated perimetry (SAP) during each visit. They also received longitudinal evaluation of cognitive ability with the Montreal Cognitive Assessment (MoCA), a multidomain tool designed to detect mild cognitive dysfunction.
Changes in cognitive scores were determined by calculating differences in MoCA scores from baseline to the latest follow-up visit. Hence, scores lower than baseline values indicated a decline in cognitive function. VF variability was estimated by standard deviation (SD) of the residuals of ordinary least-squares linear regressions of SAP mean deviation (MD) values over time. Linear regression models were applied to determine the potential association between cognitive decline and VF variability, with adjustment for possible confounding factors.
There was a strong association between change in MoCA scores and visual field variability over time. In a univariable model, a 5-point decline in MoCA score was associated with an increase of 0.18 dB in the SD of residuals of SAP MD values. In a multivariable model with adjustment for baseline characteristics and test results, each 5-point decline in MoCA score coincided with an increase of 0.23 dB in the SD of residuals of SAP MD values.
The researchers concluded that the correlation between cognitive decline and increased variability of the VF suggests that monitoring cognitive function is important in the assessment of VF progression in patients with existing or suspected glaucoma. Studies with longer follow-up and more sensitive tests are warranted to gain greater understanding of this relationship and to comprehensively assess neuropsychological function. (Also see related commentary by Joshua R. Erlich, MD, MPH, and Sayoko E. Moroi, MD, PhD, in the same issue.)
The original article can be found here.