Visual and Oculomotor Alterations in Patients with Moderate Alzheimer’s Disease: A Preliminary Comparative Study

Background/Objectives: Alzheimer’s disease (AD) is a progressive neurodegenerative disorder that, in addition to its characteristic cognitive decline, may be associated with impairments in visual and oculomotor function. The aim of this study was to characterize and compare a battery of visual, binocular, and oculomotor skills in patients with moderate AD and age-comparable older adults without a known diagnosis of cognitive impairment or neurodegenerative disease. Methods: A cross-sectional comparative observational study was conducted in 16 patients with AD and 20 age-comparable controls. Monocular and binocular visual acuity at distance and near, near point of convergence (NPC), stereopsis using the Randot® test, ocular alignment, fixation, and clinical oculomotor function using the NSUCO test were assessed. In a subgroup of patients with AD, an objective assessment was also attempted using GazeLab® video-oculography. Results: No between-group differences in age were observed (p = 0.757). The AD group showed worse binocular distance visual acuity (0.16 ± 0.13 vs. 0.01 ± 0.05 logMAR, p = 0.003), a trend to more remote NPC (16.50 ± 5.35 vs. 10.80 ± 4.56 cm, p = 0.466), poorer stereopsis (188.5 ± 64.14 vs. 80.00 ± 24.48 arcseconds, p = 0.004), and lower NSUCO scores for saccadic and pursuit movements (p < 0.001). Video-oculography was feasible in a subgroup of patients with AD and yielded exploratory, descriptive observations; equivalent recordings were not obtained in control participants. Conclusions: The patients with moderate AD showed poorer performance across several visual, binocular, and oculomotor measures. These findings support the relevance of incorporating visual assessment into the functional characterization of AD.