[Differentiation between dyslexia and ocular causes of reading disorders].

BACKGROUND Dyslexia is defined as a reading and/or writing disability persisting after exclusion of organic causes. Studies show that ocular disorders, especially small refraction errors, hypoaccommodation and symptomatic heterophoria, are often not detected or treated in cases of reading and/or writing problems which were otherwise diagnosed as dyslexia. METHODS We evaluated the data of patients referred to our department from December 1997 to March 2000 with the diagnosis of dyslexia. RESULTS We found ocular disturbances in 28 (84.8%) out of 33 children, 26 (78.8%) showed improved reading after therapy. They had mostly accommodative problems: uncorrected hyperopia, hypoaccommodation and/or exophoria compensated by accommodative convergence (pathophoria). CONCLUSIONS Our results underline the importance of the correction of even small refraction and/or motility errors in the presence of reading and writing difficulties.