Peripheral spatial contrast sensitivity of the eyes

AIM: To develop a method for evaluating peripheral spatial contrast sensitivity and to use it in comparative studies of peripheral spatial contrast sensitivity in children with myopia under correction conditions with glasses with a highly aspherical lenslet (HAL) and single vision lenses (SVL).

MATERIAL AND METHODS: A method for evaluating peripheral spatial contrast sensitivity was developed, in which visual control was carried out with the patient’s gaze fixed in the forward direction using a remote binocular autorefractometer, and the test image was sent to the selected area of the retina periphery. The SVL values were evaluated in three ranges of spatial frequencies, namely, low (0.5–2.0 cycle/deg), medium (4.0 to 8.0 cycle/deg), and high (11.31–16.0 cycle/deg). Peripheral spatial contrast sensitivity was examined descriptively in 20 patients with low and moderate myopia. The age of the patients ranged from 8 to 13 (average, 11.4±1.5) years, and the degree of myopia ranged from −1.0 to −3.75 (average, −2.66±1.5 D). The patients were examined in glasses with HAL and in a trial frame with SVL correction.

RESULTS. In HAL, which induces volumetric myopic defocus on the periphery of the retina, the peripheral spatial contrast sensitivity was lower than that in the SVL. This decrease was most pronounced at medium and high spatial frequencies, where it reached 30–50%. The revealed differences in the peripheral spatial contrast sensitivity at high frequencies (8; 11.31 and 16 cycles/deg) were statistically significant: 7.5 and 10.8 at the frequency of 8 cycles/deg, 5.8 and 9.05 at the frequency of 11.31 cycles/deg, and 4.4 and 9.2 at the frequency of 16 cycles/deg, respectively.

CONCLUSION: The peripheral spatial contrast sensitivity in glasses with rings of HAL, compared with the peripheral spatial contrast sensitivity in SVL, is significantly reduced at high spatial frequencies.