Effects of low visual acuity on neuropsychological test scores: A simulation study

Objective: To systematically examine the effect of low visual acuity (LVA) on a number of commonly used neuropsychological tests.Method: In this study, the influence of LVA on a number of commonly used neuropsychological tests was examined in 238 healthy older adults (aged 50-80) without visual or neurological impairment. LVA was simulated using simulation glasses.Results: It was found that a simulated LVA of ∼0.2 (decimal acuity; Snellen 6/30 or 20/100, LogMAR 0.7) had a negative impact on test performance for the Trail Making Test, Complex Figure of Rey (copy score), and Visual Object and Space Perception battery subtest 3, but not for the Mini Mental State Examination and Balloons test. For some tests, the negative impact of LVA increased with age.Conclusions: These results have important implications for the use of neuropsychological tests in the visually impaired population. More specifically, when administering the Trail Making Test, Complex Figure of Rey (copy score), and Visual Object and Space Perception Battery subtest 3 to older people with LVA, low test scores should be interpreted with great caution. Low test scores on the Mini Mental State Examination and Balloons Test are not likely to be caused by LVA and are more likely to reflect actual cognitive impairment. The results contribute to the validity of neuropsychological assessment of older people with visual impairment, leading to more effective and more patient-based rehabilitation.