Gaze and pupil changes during navigation in age-related macular degeneration

Area of Science:

• Ophthalmology
• Neuroscience
• Human Factors Engineering

Background:

• Age-related macular degeneration (AMD) significantly impacts central vision, affecting daily activities like navigation.
• Assessing navigational function in AMD patients under standardized conditions presents a challenge.
• Understanding gaze behavior and pupil responses during navigation is crucial for AMD patient care.

Purpose of the Study:

• To investigate gaze function and pupil diameter during simulated navigation in individuals with AMD.
• To establish objective clinical measures for assessing navigational challenges in AMD.
• To explore the relationship between visual acuity and navigational performance in AMD.

Main Methods:

• An observational case-control study involving 34 AMD patients and 23 controls.
• Simulated a walking journey using video projection with automated eye-tracking.
• Recorded visual acuity, fixation count, fixation duration, pupil diameter, and subjective voice comments.

Main Results:

• AMD patients exhibited significantly larger pupil diameters in both easy and difficult navigation segments (p=0.002).
• Fixation counts were significantly higher in AMD patients during difficult navigation segments (p=0.001).
• Both pupil diameter and fixation count differences correlated with visual acuity.

Conclusions:

• Fixation count serves as a reliable indicator of challenging navigational environments for AMD patients.
• Video projection combined with eye tracking provides a valuable clinical tool for assessing visual navigation.
• This methodology offers objective, standardized measures for AMD intervention research.