COGEVIS: A New Scale to Evaluate Cognition in Patients with Visual Deficiency

Abstract

We evaluated the cognitive status of visually impaired patients referred to low vision rehabilitation (LVR) based on a standard cognitive battery and a new evaluation tool, named the COGEVIS, which can be used to assess patients with severe visual deficits. We studied patients aged 60 and above, referred to the LVR Hospital in Paris. Neurological and cognitive evaluations were performed in an expert memory center. Thirty-eight individuals, 17 women and 21 men with a mean age of 70.3 ± 1.3 years and a mean visual acuity of 0.12 ± 0.02, were recruited over a one-year period. Sixty-three percent of participants had normal cognitive status. Cognitive impairment was diagnosed in 37.5% of participants. The COGEVIS score cutoff point to screen for cognitive impairment was 24 (maximum score of 30) with a sensitivity of 66.7% and a specificity of 95%. Evaluation following 4 months of visual rehabilitation showed an improvement of Instrumental Activities of Daily Living (p = 0.004), National Eye Institute Visual Functioning Questionnaire (p = 0.035), and Montgomery-Åsberg Depression Rating Scale (p = 0.037). This study introduces a new short test to screen for cognitive impairment in visually impaired patients.

Figure 1

Distribution of the participants according to cognitive status (a) or visual status (b). AD: Alzheimer's disease; LBD: Lewy body dementia; MCI: mild cognitive impairment; NC: normal cognition.

Figure 2

Receiver operating characteristic (ROC) curve of the COGEVIS to diagnose cognitive impairment. AUC: area under the curve. A yellow line is drawn at a 45-degree angle tangent to the ROC curve. This marks a good cutoff point under the assumption that false negatives and false positives have similar costs. In this case, a COGEVIS below 24 yielded a sensitivity of 66.7% and a specificity of 94.7%.