The advanced way to quantitiate metamorphopsia

In patients with metamorphopsia, a straight line projected onto the retina is recognized as an irregular or curved line. When a dotted line is used and the dot interval changes from fine to coarse, metamorphopsia decreases and finally disappears. Based on this phenomenon, M-CHARTS® are developed to quantitatively assess metamorphopsia easily and quickly.
M-CHARTS® include a straight line and 19 kinds of dotted lines with dot intervals range from 0.2° to 2.0° of visual angle. The length of the lines, the dot size of the dotted lines, and the size of the fixation point are 20° , 0.1 ° , and 0.3° of visual angle, respectively. Type I has one line that passes through the fixation point and Type II has two lines which are 1 ° apart from the fixation point on each side. Type II is designed for patients with central scotoma.
For patients with low vision, M-CHARTS® with a dot size of 0.5°visual angle are available.