Abstract
Purpose :
A person’s ability to process and use temporal visual information may have an effect on emmetropization as this affects the spatial image content across the retina. We hypothesize that differences in retinal profile may affect temporal contrast sensitivity in individuals with myopia.
Methods :
We conducted a cross-sectional study to evaluate the temporal contrast sensitivity function (tCSF) at four spatial frequencies (1, 2, 4 and 8 cpd). Subjects performed a monocular quickCSF procedure (Lesmes et al., 2010) in each eye where they identified a flickering band-pass filtered letter in a 26AFC task. Subjects were 28 young adults (22-31yrs) with best-corrected VA 0.0 LogMAR (20/20) or better in each eye and no binocular or accommodative dysfunction measured by clinical tests. Refractive error was determined by objective and binocular subjective refraction. Subjects were classified as: myopes (SE -1.00 to -8.13D, n=15) or emmetropes (SE +0.63 to -0.25D, n=13).
Results :
Subjects with myopia showed higher critical flicker frequencies (CFF) than emmetropes (F=6.69, p=0.02), and larger refractive errors were associated with higher CFFs (Spearman’s r=0.42, p=0.03). In addition, we observed a spatial frequency dependent difference in the area under the log contrast sensitivity function (AULCSF) between the refractive groups (F=2.99, p=0.04). Subjects with myopia displayed a higher AULCSF at medium spatial frequencies than emmetropes (2cpd: t=-2.92, p<0.01, 4cpd: t=-1.74, p=0.04).
Conclusions :
The myopic subjects in our study had low to moderate amounts of myopia. They showed higher CFFs that was related to the amount of myopia. This contrasts with previous results showing lower CFFs in subjects with high myopia (>8.00D; Chen et al, 2000). Myopic subjects in our study also showed high contrast sensitivity at higher temporal frequencies and larger AULCSF for medium spatial frequencies. Overall, our findings suggest that subjects with myopia may have improved, rather than abnormal, temporal vision at higher temporal frequencies than emmetropes.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.