Visual performance fall-off with eccentricity in myopes versus emmetropes

Purpose: To compare the central and peripheral visual performance of myopic and emmetropic eyes. Methods: Thirty emmetropic (−0.50 to +0.50 D) and 60 myopic (−2.00 to −9.62 D) subjects were recruited. Resolution acuity was assessed at central and 12 peripheral retinal locations (±10 ◦ , ±20 ◦ , ±30 ◦ along the horizontal meridian, and ±10 ◦ , ±20 ◦ , ±25 ◦ along the vertical meridian) using a modified version of the Contrast Acuity Assessment test at low (l/l = 14%) and high (l/l = 100%) contrast levels. The central and peripheral data were analysed using univariate and repeated-measures analysis of variance respectively. In addition, asymmetries in visual function, along both the horizontal (temporal versus nasal) and vertical (superior versus inferior) meridians, were investigated. Results: When analysed in terms of acuity fall-off with eccentricity, repeated measures ANOVA exhibited a statistically significant difference in peripheral visual performance between refractive groups for high contrast stimuli (p = 0.025), with a more rapid fall-off in myopes compared to emmetropes. Nasal and superior retinal regions performed better than temporal (high contrast: p < 0.001, low contrast: p < 0.001) and inferior (high contrast: p < 0.001, low contrast: p = 0.003) regions for both refractive groups, consistent with differences between quadrants in neural cell density reported by histological studies. Conclusion: The myopic patients evaluated in this study exhibited reduced peripheral visual performance compared to their emmetropic counterparts when assessed using the Contrast Acuity Assessment test at high contrast level. © 2012 Spanish General Council of Optometry. Published by Elsevier Espana, S.L. All rights reserved.