Issue Topic: Epidemiologlcal Researches on Padiatric Ophthalmology
A Study of the Astigmatism in Adolescent Myopia
Binxian Yan, chao Zhou
Published 2017-12-10
Cite as Chin J Pract Ophthalmol, 2017, 35(12): 1144-1149. DOI: 10.3760/cma.j.issn.1006-4443.2017.12.006
Abstract
ObjectiveTo study the prevalence, the type, the relationship and proportion between total astigmatism, internal astigmatism and corneal astigmatism in patients aged 8 to 18 years old with myopia.
MethodsA total of 2330 myopic astigmatism patients (aged 8 to 18 years old), who were treated in the WuHan Aier Eye Hospital during September 2011 to August 2014 were required. Three refractive error measurements were taken under cycloplegia using cyclopentolate-hydrochloride, the average of the three sets as the refractive astigmatism (RA), corneal topography (OCULUS, Germany) was used to measure the corneal astigmatism (CA), the internal astigmatism (IA) was calculated. Then the proportion of IA in RA, and the proportion of IA under different RA range were obtained. Statistical method was used to research the correlation between RA and CA; as well as the proportion of the astigmatism with the rule, against the rule, and the oblique astigmatism in the eye.
ResultsMild to moderate patients aged 8 to 18 years old accounted for 75.22% of compound myopic astigmatism. The prevalence of astigmatism was 29.74% exclude the physiological astigmatism patients. IA accounted for 37.37%, CA accounted for 62.63%; and the IA decreased with the increase of RA. Differences between groups was statistically significant (P<0.01). The axis opposite between RA and CA accounted for 96.50%; In vector analysis, After the vector analysis, the linear regression equation were RJ0=0.65 CJ0-0.11 RJ45=0.43 CJ45-0.02, RJ45=0.57 CJ45-0.04 when CA in 180°axis, 135°axis, 45°axis. The linear regression equation of CA in the 90°axis was not established. For compound myopic astigmatism patients' RA, the astigmatism with the rule, the astigmatism against the rule, the oblique astigmatism accounted for 88.1%, 6.8% and 5.1%.
ConclusionsClinical patients aged 8 to 18 years old myopia are mainly with the rule astigmatism. CA account for the main component of RA. But IA is an important auxiliary function which could not be ignored. And the proportion of IA decreases when the RA increase, after the vector analysis, CA and RA has linear correlation except CA in 90° axis.
Key words:
Corneal astigmatism; Intraocular astigmatism; Astigmatism with the rule; Astigmatism against the rule; Oblique astigmatism
Contributor Information
Binxian Yan
Wuhan Aier Eye Hospital, 430000 Wuhan, China
chao Zhou
