Characterization of Gaze Metrics and Visual Search Pattern Among Glaucoma Patients While Viewing Real-World Images.

Area of Science:

• Ophthalmology
• Neuroscience
• Human-Computer Interaction

Background:

• Visual search (VS) is crucial for daily activities like navigation and target identification.
• Glaucoma significantly impacts visual search capabilities, potentially altering gaze patterns.
• Individual differences in culture or coping mechanisms can influence VS strategies.

Purpose of the Study:

• To quantify and compare gaze metrics during visual search tasks between glaucoma patients and healthy controls.
• To label visual search patterns as predominantly global or focal using eye-tracking data.
• To investigate how glaucoma affects visual search behavior.

Main Methods:

• Eye movements of 27 glaucoma subjects and 30 healthy controls were recorded using an eye-tracker during a visual search task.
• Key gaze metrics including fixation count (FC), fixation duration (FD), saccade amplitude (SA), and visual search time (VST) were computed.
• A Z-score-based coefficient (K) was used to classify search patterns as global (short FD, long SA) or focal (long FD, short SA).

Main Results:

• Glaucoma subjects showed statistically significant increases in FC, FD, and VST compared to controls (P=0.01).
• Healthy controls displayed a balanced distribution of focal (47%) and global (42%) search patterns.
• Glaucoma subjects predominantly exhibited focal search patterns (56%) over global patterns (26%, P=0.008).

Conclusions:

• Glaucoma patients demonstrate a shift towards more focal search strategies during active gaze scanning.
• Altered viewing behavior in glaucoma likely represents compensatory mechanisms for visual deficits.
• Further research is needed to explore the influence of factors like saliency on these observed search patterns.