Abstract
Purpose :
Standard assessments of central visual functions such as visual acuity (VA) and central visual field (VF) tests using microperimetry may be used to gauge disease activities in age-related macular degeneration (AMD). However, these are subject to certain limitations such as being subjective, inability to pick up the disease at an early stage and require visits to the hospital. Eye gaze tracking using infrared imaging system to detect and document eye movement performance (EMP) can yield additional information about central visual function. This study aims to explore the relationship between EMP and VA, central VF, as well as AMD features.
Methods :
In this cross-sectional observational study, subjects (n = 187) monocularly pursued a computer generated target moving in a sinusoidal waveform while tracked with an infrared eye gaze tracker (Tobii TX300). We recorded gaze points from 343 eyes in total and analysed their excursion pathways relative to the sinusoidal waveform and computed the goodness-of-fit assessment [range: 0.0 (poor fit) to 1.0 (perfect fit)]. Central VF integrity was measured using microperimetry (Nidek MP1) and expressed as Proportion of Unseen Lighted Stimulus Points (PULSP). Linear regression analysis was conducted to assess the effect of VA, PULSP, as well as AMD features on EMP, after adjusting for age. Student's t-test was used for comparing the mean EMP difference between eyes with AMD features and those without AMD features. Two sided signicance level of 0.05 was used for all the tests.
Results :
After adjusting for age, we found a negative correlation between EMP and VA values (correlation coefficient β= -0.15; 95% confidence interval CI:-0.20 to -0.09; p<0.001), PULSP (β= -0.44; 95% CI:-0.53 to -0.35; p<0.001) and eyes with AMD features compared to those without (β= -0.09; 95% CI:-0.13 to -0.06; p<0.001). Also, the mean difference in EMP for eyes with AMD features (n=177) and those without AMD features (n=166) was 0.10 (95% CI:0.06 to 0.14; p<0.001).
Conclusions :
Independent of age, poorer VA and impaired central VF correlated with poorer EMP, and vice versa. Eyes without AMD features had better EMP than eyes with AMD features. Tracking eye gaze can assist visual function assessment in AMD.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.