The Improvment Of Near Contrast Visual Acuity Chart And It’s Clinical Applicationsln In Myopia

Objetive:Improve the function of the near-contrast visual acuity chart, make a new type of near-contrast visual acuity chart and use that to test the eyesight of short-sighted patients in order to find out the relation between the characteristic of short-sighted patient’s contrast visual acuity and its relationship with myopia.Methods:Based on the new vision of standard near visual chart, we have improved the function of near-contrast visual acuity chart, and made a new type of near-contrast visual acuity chart. The design of the vision statement includes not only100%contrast,but10%contrast and low brightness.We’11use this to test the Contrast visual acuity of the patients and compare it with the equipment of far contrast visual acuity。Collect2013.08-2014.02students’information (112cases,240eyes) of Guangzhou University of Traditional Chinese Medicine. Given the anterior segment, fundus, visual acuity, refraction, intraocular pressure, axial length, corneal thickness, anterior chamber depth, lens thickness inspection, The myopic patients were divided into diopter low myopia group (-0.25DS～-3. OODS), moderate myopia group (-3.25DS～-6. OODS), and high myopia (≥-6.25DS). Myopic patients were examined three groups of nearly10%contrast visual acuity, low contrast, brightness near vision, far from standard low contrast visual acuity. After data collecting, established an Excel table and use SPSS19.0statistical software for statistical analysis, measured data by using independent sample t test and ANOVA.Results:Use the new kind of near-contrast visual acuity chart. We can study:①low to moderate myopia and myopic group, low to moderate myopia and high myopia group, moderate myopia and high myopia group contrast of nearly10%comparing visual, P>0.05, the differences were all not statistically significant;Group of patients with normal fundus leopard-like eyes set relatively myopic vision contrast nearly10%contrast near vision,P<0.05, the differences were statistically significant;Leopard-like eyes with high myopia group and the high myopia group10%contrast near vision P>0.05, the differences were all not statistically significant;Low myopia leopard-like eyes with low myopia group of normal retinal contrast comparison group of nearly10%contrast near vision P<0.05, the differences were all statistically significant;Non-myopic astigmatism myopia and astigmatism10%contrast near vision,P<0.05,the differences were all statistically significant.②Low to moderate myopia and myopic group of low luminance contrast visual acuity relatively recent, P>0.05, the difference was not statistically significant;Low to moderate myopia and high myopia group、moderate myopia and high myopia group relatively low luminance contrast near vision, P<0.05, the differences were all statistically significant;Group of patients with normal fundus leopard-like eyes set relatively myopic vision contrast nearly low luminance contrast near vision, P <0.05, the differences were statistically significant;Leopard-like eyes with high myopia group and the high myopia group contrast relatively low brightness near vision P>0.05, the differences were all not statistically significant;Low myopia leopard-like eyes with low myopia group of normal retinal contrast comparison group of relatively low brightness near vision, P<0.05, the differences were all statistically significant;Non-myopic astigmatism myopia and astigmatism relatively low brightness contrast near vision P<0.05, the differences were all statistically significant.③Low to moderate myopia and myopic group、moderate myopia and high myopia group scale contrast relatively distant vision, P>0.05, the differences were all not statistically significant;Low to moderate myopia and high myopia group marked contrast relatively low distant vision, P<0.05, the difference was statistically significant;Group of patients with normal fundus leopard-like eyes low contrast distant vision contrast relatively near vision, P>0.05, the difference was not statistically significant;Leopard-like eyes with high myopia group and the high myopia group low contrast distant vision contrast relatively near vision, P>0.05, the differences were all not statistically significant; Low myopia leopard-like eyes set with low myopia group labeled normal fundus relatively low contrast distant vision, P>0.05, the difference was statistically significant;Non-myopic astigmatism myopia and astigmatism low contrast distant vision contrast relatively near vision P<0.05,the differences was statistically significant.Conelusion:(1)This study has improved the near-contrast visual acuity chart, it can be successfully used in clinical testing of visual function in patients with myopia, provide more parameters for visual assessment.(2)Compared with the traditional far contrast visual acuity, we have the following results:①Both far contrast visual acuity chart and near-contrast visual acuity chart, can detect the visual descent of low myopia and high myopia. But the improved near-contrast visual acuity chart can detect the visual descent of moderate myopia sensitively.②Both the far contrast visual acuity chart and the near-contrast visual acuity chart, can detect the visual descent of astigmatism myopia.,③the improved of the near-contrast visual acuity chart can detect the visual descent of leopard-like eyes myopia sensitively.(3)The improved of near-contrast visual acuity chart is easy to carry and it cost less time to examine the patients so it is more convenient for clinical use.