T-MoCA VERSUS STANDARD MoCA IN ELDERLY PATIENTS WITH VISUAL FIELD DEFECTS: ELIMINATING SYSTEMATIC OVER-DIAGNOSIS OF MILD COGNITIVE IMPAIRMENT

Introduction. Standard cognitive screening tools, including the Montreal Cognitive Assessment (MoCA), include visuospatial subtests that fail in patients with visual field defects or central scotoma regardless of true cognitive status, causing systematic over-diagnosis of mild cognitive impairment (MCI) in geriatric ophthalmic practice. This study compared the diagnostic performance of the Telephone version of MoCA (T-MoCA) and standard MoCA in elderly patients with primary open-angle glaucoma (POAG) and age-related macular degeneration (AMD).

Methods. Prospective study (2024–2025; n=88): POAG (n=52) and AMD (n=36), age ≥60. Both instruments were administered at the same visit in counterbalanced order. T-MoCA (max 22 points, MCI threshold ≤17) omits visuospatial tasks; standard MoCA (max 30 points, threshold ≤25) retains them. Agreement was assessed by Cohen's kappa; sensitivity and specificity were calculated against clinician-verified MCI.

Results. Standard MoCA over-classified MCI by 13.5 percentage points in POAG (88.5% vs 75.0%; p=0.041) and 13.8 points in AMD (94.4% vs 80.6%; p=0.039). Mean visuospatial subtest scores were 2.1±1.3 (POAG) and 1.6±1.1 (AMD) out of 5, versus 4.2±0.9 in visually healthy controls (p<0.001), confirming sensory rather than cognitive failure. Cohen's kappa between instruments was 0.61 (moderate agreement). T-MoCA achieved 91.2% sensitivity and 83.6% specificity for clinician-verified MCI, versus 68.4% specificity for standard MoCA in the same population.

Conclusions. Standard MoCA systematically over-diagnoses MCI in elderly patients with visual field defects due to visuospatial subtest failure. T-MoCA provides superior specificity while preserving sensitivity and should be the instrument of choice for cognitive screening in geriatric ophthalmic practice, reducing unnecessary neurological referrals based on false-positive results.