Evaluating Cognitive Function in Primary Open Angle Glaucoma Using Functional Near-Infrared Spectroscopy (fNIRS): A Case Control Study.

PRECIS: This study used fNIRS during a Go/No-Go task to reveal altered prefrontal activation in POAG patients, indicating compensatory cortical recruitment and subtle cognitive dysfunction, highlighting glaucoma's broader neurodegenerative and cognitive impact.

PURPOSE: To evaluate cognitive function in individuals with primary open-angle glaucoma (POAG) by assessing prefrontal cortical activity during a behavioral inhibition test (Go/No-Go task) using functional near infrared spectroscopy (fNIRS).

PATIENTS: Fifteen patients with mild to moderate POAG and fifteen age and gender matched healthy controls.

METHODS

In this pilot case-control study, all participants underwent cognitive assessment using Addenbrooke's Cognitive Examination III (ACE-III), and quality-of-life assessment using EuroQol 5-Dimension 5-Level (EQ-5D-5L) questionnaire. Prefrontal cortical activation patterns were assessed in the prefrontal cortex using a 17-channel fNIRS system during a block-design Go/No-Go task assessing sustained attention and response inhibition. Using statistical parametric mapping (SPM) with general linear model (GLM) analysis, the study observed activation/deactivation in prefrontal cortical regions.

RESULTS

Mean age and gender ratio were comparable between the two groups. POAG patients demonstrated significantly lower cognitive scores on ACE-III and reduced health-related quality of life compared to healthy controls (P<0.001). fNIRS demonstrated abnormal prefrontal activation in POAG, with significant hyperactivation during Go versus Rest at channels 8, 13, and 14 (P<0.05), not observed in healthy controls. Conversely, in No-Go vs Rest, healthy controls exhibited significant activation at channels 8, 10, and 15 (P<0.05), absent in POAG. Finally, the Go vs No-Go contrast revealed heightened deactivation in POAG at channel 17 (P<0.05), not observed in healthy controls.

CONCLUSIONS

Patients with POAG demonstrated altered and less efficient prefrontal cortical activation patterns during tasks requiring attention and inhibition. These fNIRS based findings suggest early cortical dysfunction in glaucoma.