Abstract
Purpose :
The peripheral retinal structure is very important in the pathogenesis and management of myopia. However, the quantitative relationship between peripheral visual function and myopia remains unknown. This study evaluated contrast sensitivity function in peripheral vision in myopia and emmetropia with the qCSF method.
Methods :
The study recruited 19 myopia subjects (23.42±4.0 years) and 12 normal subjects (22.92±2.9 years). The average spherical and cylinder corrections were -2.95±3.26D and -0.03±0.74D in myopia group, and -0.34±0.52D and -0.30±0.42D in normal group. The BCVA was 0.00±0.00 logMAR in both groups. All subjects performed the qCSF test in foveal vision and fifteen peripheral locations (superior, inferior, temporal and nasal quadrants at 60, 120, 180 and 240 eccentricities, excluding the physiological scotoma at 180) and optical quality assessment with the double-pass Optical Quality Analysis System II, OQAS. The myopes wore soft contact lens with best corrected visual acuity (BCVA). To summary metrics, the cutoff spatial frequency (cut-off SF) and the area under log CSF (AULCSF), and contrast thresholds at 19 spatial frequencies (equally spaced in log units) at each of the 16 test locations were derived from qCSF test results.
Results :
Results from the OQAS assessment found that there was no significant optical quality difference between two groups, including MTF cutoff, OV100%, OV20%, and OV9% and OSI (p>0.10). There was also no significant difference between two groups in any of the CSF metrics in foveal vision (p>0.10). Further analysis showed that myopes had significantly increased AULCSF in the superior (p=0.026), inferior (p=0.024) and nasal (p=0.022) quadrants at 120. Across the fifteen peripheral locations, there was no significant cut-off SF difference between two groups (p>0.10). In addition, contrast sensitivity in the myopia group was greater than that of normal group in the inferior quadrant at 60 (p<0.05), and the superior, inferior and nasal quadrants at 120 (p<0.05), but not at any of the other test locations.
Conclusions :
Our findings showed that, with best optical correction, the myopic visual system exhibited normal CSF in foveal vision but enhanced CSF in certain peripheral locations. We speculate that these results may be attributed to compensatory improvements of peripheral vision from its extensive use during near visual activities in the emmetropization process of myopic visual system.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.