The Orthoptic Treatment of Dyslexia

Abstract

This chapter explains the orthoptic treatment of dyslexia. In this method, interference between accommodation and convergence, or refractive asymmetry between the eyes, is first prevented by meticulous objective and subjective refraction testing at long and short range, with visual aid correction even of slight ametropia and anisometropia. Latent strabismus (heterophoria) is then compensated with adhesive prismatic foils to the extent of sensoric orthophoria. The low initial prismatic values are increased with the gradually increasing heterophoria angle normally encountered, to the point of complete relaxation. With prismatic values below 15 cm/m, the prisms are ground into the visual aid lenses, while in case of higher values a squint operation is undertaken. During prism fitting, measures are taken to eliminate central scotoma by exercises designed to stimulate the foveolae on the Synoptophore, or by accommodation and convergence exercises at home with the accommodation-convergence bar specially designed for this purpose. To determine the angle of heterophoria, the cover test is done as along with the Synoptophore, Polatest, and Bagolini Test. Particularly suitable for diagnosing central scotoma are the Pola and Bagolini tests. The reading ability is assessed based on reading speed and number of errors.