An Evaluation of Clinical Treatment of Convergence Insufficiency For Children With Reading Difficulties

Wolfgang A Dusek; Barbara K Pierscionek; Julie F McClelland


BMC Ophthalmol. 2011;11(21) 

In This Article


It is well documented that children with reading difficulties are at a greater risk for anomalies of visual function and asthenopic symptoms than their peers without reading difficulties.[1–3] Reading difficulties are significantly related to various aspects of visual function including refractive error and binocular vision status.[4–9] Dusek et al[10] demonstrated differences in visual status between a large group of children with reading difficulties (n = 825) and a clinical control group (n = 328) in terms of visual acuity, ocular posture, accommodation, reading speed and convergence. One of the most significant findings was the high proportion of children with reading difficulties who demonstrated convergence insufficiency (CI) (18.2%).[10] This is a common binocular vision disorder that frequently underpins a wide range of asthenopic symptoms in both adults and children.[11–13]

Although a substantial volume of literature that describes various different treatments options for CI exists, progress is hampered by inconsistencies regarding the most appropriate treatment and a paucity of suitable treatment options for children with reading difficulties.[14–17] Evaluation of the use of base-in prism spectacles for CI is also limited.[18,19] To the best of the authors' knowledge, no controlled studies linking CI and reading difficulties have been undertaken on large European populations and certainly no previous studies have been conducted on Austrian school children.

The Austrian approach to detecting, evaluating and treating reading, writing and other learning difficulties is holistic. Children in Austria undergo regular health examinations and those who have difficulties with reading and writing are referred routinely by their teacher or parent to educational institutions for an assessment of their academic status. A range of standardised tests are conducted by educational psychologists to determine the cause(s) that may impede learning. The tests include intelligence assessments to investigate whether the difficulties arise from a reduced level of intelligence (low IQ) or whether there are any other underlying factors. In Vienna, these assessments are carried out in one of three educational institutes (Holistic Institut, Förderpädagogisches Zentrum and Gesundheits Zentrum). A significant proportion of these children are found to have a normal or above normal level of intellectual ability despite their reading and writing difficulties. These particular children are all referred to a single specialist clinician (WD) for a full assessment of visual status. Given that over a quarter of the Austrian population resides in Vienna and that this specialist clinic also accepts referrals from other regions of Austria, the database of children examined in this clinic is representative of the country as a whole and is characteristic of a European population of school children.

The present study is the first controlled study on a large homogenous European population examined by a single specialist. It investigates two different treatment options for CI for a group of children with reading difficulties referred by the aforementioned educational institutes to the specialist eye clinic in Vienna.