Clinical Observation of AC/A ratio Affect after Aspheric Lenses and Multifocal Lenses for Myopia

Objective To investigate myopia AC/A ratio following the different designed glasses.Methods A prospective study.A total of 172 (344 eyes) myopia patients who underwent refraction examination from September 2010 to February 2011 were collected in our research,including 12 to 18 years old,average (15.37±2.01) years old,and-1.00 diopter to-6.00 diopters,mean (-3.50 ±1.42) D.All patients wore glasses for 1 year.All study subjects were divided into two groups:non-spherical lens group,104 patients (208 eyes),and 68 patients (126 eyes),AC/A ratio of non-spherical lens group and multifocal lens group was measured.And the results were analyzed.All data were mean ± standard deviation ((x)±s) said,using Independent-Samples T-test analysis.Results AC/A value of non-spherical lens group were 3.52±1.67.AC/A value of multifocal lens group were 2.88±1.23.Multifocal lens group was less than the non-spherical lens group.The differences between two groups were statistically significant (t =2.71,P ＜0.05).Conclusions The impact of myopia AC/A ratio who continue to wear multi-focal glasses is greater than that of non-spherical glasses,and makes the AC/A ratio decrease to some extent. Key words: AC/A ratio;  Myopia;  Non-spherical lenses;  Multi-focal lenses