Effect of astigmatism and spherical equivalent correction on contrast sensitivity

Autor: Maryam Saffarizadeh, Saeed Rahmani, Alireza Akbarzadeh Baghban, Mohammad Ghassemi-Broumand
Jazyk: angličtina
Rok vydání: 2024
Předmět:
Zdroj: International Journal of Ophthalmology, Vol 17, Iss 12, Pp 2243-2247 (2024)
Druh dokumentu: article
ISSN: 2222-3959
2227-4898
DOI: 10.18240/ijo.2024.12.12
Popis: AIM: To investigate the effect of astigmatism and spherical equivalent (SE) correction on contrast sensitivity (CS). METHODS: In this cross-sectional study, 103 visually normal subjects aged 18 to 36y with bilateral regular astigmatism in range of 1.00 diopter cylinder (DC) to 4.00 DC and normal best-corrected visual acuity (20/20) were recruited. Binocular CS was assessed by linear sine-wave gratings at 1.5, 3, 6, 12, and 18 cycles per degree (cpd), before correction of astigmatism, after full correction of astigmatism by cylindrical spectacle lenses, and after SE of refractive error. The repeated measures ANOVA and Bonferroni test were used to compare the effects of astigmatism correction on logCS. RESULTS: Totally 39 patients were male and 64 patients were female with the mean age of 28.25±5.38y. The average degree of astigmatism in right and left eye was 2.03±0.83 and 2.10±0.78, respectively. Increases in uncorrected astigmatic power correlated with decreases in the logCS, especially at high spatial frequencies. A statistically significant difference in logCS was found between these three cases: before correction of astigmatism, after SE of refractive error, and after full correction of astigmatism by cylindrical spectacle lenses at all frequencies (P
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