Posters

An innovative vision chart optotype (Stripy Circle)

Poster Details

First Author: M.Pishnamazi IRAN

Co Author(s): H. Ostadi Moghadam                    

Abstract Details

Purpose:

The aim of this study was to design a new vision chart Stripy Circle (SC) for measurement of visual acuity (VA) and to compare the efficacy and reproducibility with standard chart Landolt C.

Setting:

Mashhad University of Medical Sciences, Optometry Clinic.

Methods:

Sixty healthy college students who had normal best corrected VA were enrolled in a double blind study. Each subject's VA measured monocularly after the best correction and after blurring of images induced by positive spherical or cylindrical lenses. The axis and power of lenses were recorded. A second examiner tested subject's VA with the new designed chart, the subjects was asked to answer all the optotypes of the chart as much as possible.

Results:

The average age of cases was 22.18 ± 3.29. There was a significant correlation between the two charts (r = 0.89) (p< 0.001). In most astigmatic cases we noticed that if the degree of astigmatism was 0.75 D or more, subjects could see the sings of chart that were perpendicular to astigmatism axis in a line higher than visual acuity level. The more astigmatic was the subject the more identification of lines. If the degree of astigmatism was 0.5D or less, the subject could see the sings of the chart perpendicular to astigmatism axis bolder than parallel ones.

Conclusions:

It seems that SC chart is very similar to Landolt rings and E chart from viewpoint of application. In other words; it can be used for different age groups with different refractive errors. Stripy circle chart may be used as a reliable chart for documentation of VA. Furthermore with SC chart we would be able to determine approximate astigmatism axis and power during determination VA, simultaneously.

Financial Disclosure:

None