Abstract
Purpose :
Studies have shown that both temporal and spatial visual performances decrease in amblyopia, but there is lack of information regarding the correlation between these visual functions in such patients. Similarly, there is lack of information regarding binocular summation in visual temporal functions. In this study, we investigated both the correlation between temporal and spatial visual function and binocular summation in normal and amblyopic subjects
Methods :
We investigated the temporal visual function performance by measuring the Critical Flicker Frequency (CFF) using a customized setup, based on a software controlled led. To measure the spatial visual function we used monitor projected stimuli generated by a customized computer software. We studied the contrast sensitivity (CS) at different spatial frequencies, presentation times and backward masking (BM) technique using Gabor patches as the stimuli. The experiments were performed using the staircase method in a 3/1 paradigm.
Results :
A significant temporal binocular summation(~12%) was observed in normal subjects under mesopic luminance conditions. Binocular CS summation was observed in normal subjects with larger effect found for low spatial frequencies, longer stimuli presentation and long BM. Similar summation characteristics were found in amblyopes excluding temporal summation. In both normal and amblyopic subjects there is significant correlation between spatial and temporal performance. The highest correlations were observed between CFF and CS of 6 cycle per degree, in normal subjects (r=0.63, p<0.005) and amblyopes (r=0.75, p<0.001).
Conclusions :
The superiority of binocular vision has distinct and different characteristics for spatial and temporal functions. Correlation between these two visual functions are dependent on stimuli charactaristics and are different in amblyopes as compared to normal subjects. This study furthers our understanding of temporal and spatial visual functions in amblyopic subjects.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.