Ownagh Vahid
Golestan University of medical sciences, Iran
Posters & Accepted Abstracts: Clin Exp Ophthalmol
Purpose: To evaluate the magnitude and axis orientation of the anterior, posterior, and total corneal astigmatism in
normal healthy eyes of an Iranian population.
Methods: In a prospective cross-sectional study, ophthalmic and anterior segment parameters of 153 healthy eyes of
153 subjects were evaluated by Galilei dual Scheimpflug analyzer. The magnitude and axis orientation [with-the-rule
(WTR), against-the-rule (ATR), and oblique] of the anterior, posterior, and total corneal astigmatism measurements
(ACA, PCA, and TCA) were compared according to the age, sex, and other ophthalmic parameters.
Results: The mean ± SD age of the study population was 30 ± 5.9 years. The mean magnitude was 1.09 ± 0.76 diopters
(D) for ACA, 0.30 ± 0.13 D for PCA, and 1.08 ± 0.77 D for TCA. Males had a significantly higher magnitude of PCA
than females (p = 0.041). Most eyes had a WTR anterior astigmatism and an ATR posterior astigmatism. The WTR
astigmatism had a higher mean magnitude compared to the ATR and oblique astigmatism in all the astigmatism
groups, with a significant difference in the ACA and TCA groups (p < 0.05). PCA magnitude exceeded 0.50 D in only
7.8% of the subjects. ACA, PCA, and TCA were significantly correlated with each other and also had a significant
correlation with the anterior and posterior maximum corneal elevation measurements (p < 0.001).
Conclusion: The results of this study although are limited due to the small number of participants and confined to
our demographics, provided information regarding a population that was not described before and may be helpful
in obtaining optimum results in astigmatism correction in refractive surgery or designing new intraocular lenses.
