We determined the capacity for binocular visual measures of low-contrast letter acuity (LCLA), Mobile Universal Lexicon Evaluation System (MULES, rapid picture naming) and the Staggered Uneven Number (SUN, rapid number naming) to distinguish patients with mild cognitive impairment (MCI) due to Alzheimer’s disease and Alzheimer’s dementia (AD) vs. cognitively normal controls.

Participants were invited at a single-institution ADRC; all had diagnoses of MCI or AD by NIA-AA criteria or were cognitively normal controls.  LCLA was tested at 2.5% and 1.25%. MULES and SUN were administered using paper/pencil and computerized tablet (Mobile Integrated Cognitive Kit [MICK] app).

There were 75 participants (31 MCI, 10 AD, 34 controls; aged 74±6 years). LCLA scores at 2.5% were significantly lower (worse) in MCI vs. controls (28 vs. 36 letters, p=0.02, two-sample t-test); this was similar for 1.25% (5 letters for MCI vs. 12 for controls, p=0.004). MULES times were slower (worse) in MCI compared with controls using the tablet (75 sec for MCI vs. 60 for controls, p=0.03), and for AD vs. controls for both paper/pencil (152 vs. 59 sec, p=0.0001) and tablet (100 vs. 60 sec, p=0.003). SUN test scores, however, did not differ between MCI and controls, but better distinguished AD vs. controls for both paper/pencil (84 vs. 56 sec, p=0.0001) and tablet (85 vs. 60 sec, p=0.003).

Binocular low-contrast acuity, MULES and SUN have potential roles in MCI and AD in a manner similar to multiple sclerosis and are analogous to patient-specific measures such as cognition. MULES, SUN and LCLA complement eye-specific measures and may promote identification of MCI for early clinical trial participation and for disease-modifying therapies.