Digital vision training may not be an effective treatment for amblyopia in children

In the “ThemenCheck Medizin” procedure offered by the German Institute for Quality and Efficiency in Health Care (IQWiG), interested members of the public can submit proposals for the assessment of medical procedures and technologies. On behalf of IQWiG, researchers from Germany and Austria, led by the Institute for Evidence in Medicine at the Medical Center – University of Freiburg, investigated the question of whether children and adolescents with developmental vision disorders can benefit from active vision training.

The research team identified 17 studies on digital vision training for weak-sightedness (amblyopia). However, there is no clear conclusion about the benefit of active vision training for children and adolescents with amblyopia. Although individual studies show that digital training can improve the visual acuity of the weaker eye in children with amblyopia, the demonstrated effect was so small that it showed no noticeable advantage. No study results are available for non-digital training.

An English translation of the report is now available.

A request from a member of the public was the starting point of the “ThemenCheck” report

Sharp and spatial vision develops in children up to the age of 9. However, many children and adolescents are affected by developmental vision disorders such as amblyopia, near-sightedness (myopia) or far-sightedness (hyperopia). In Europe, almost four per cent of the population suffers from amblyopia; in Germany, about eleven per cent of all children and adolescents between the ages of 0 and 17 are affected by myopia, which is corrected with visual aids. If amblyopia (e.g. caused by strabismus, i.e. squinting) is not treated properly, it can, for example, permanently affect spatial vision and therefore quality of life.

Currently, children with amblyopia are usually treated with occlusion therapy, which involves temporarily covering the better-seeing eye to improve vision in the weaker eye. Digital vision training (e.g. in the form of special video games designed to improve the interaction between the two eyes) is also available for children with amblyopia or other developmental vision disorders. In addition, non-digital vision training is available where children do regular vision exercises under professional guidance over a longer period of time, to train fixation or focusing, for example.

Against this background, a member of the public asked the ThemenCheck Medizin about the situations in which children and adolescents with vision problems can benefit from vision training.

The expert team commissioned by IQWiG investigated whether children and adolescents with developmental vision problems can be successfully treated with active vision training. In particular, this would be the case if active participation in such training led to a relevant improvement in visual acuity and binocular vision.

17 studies on digital vision training for amblyopia identified

The 17 studies identified by the external experts all investigated digital vision training for amblyopia.

For the criterion “best-corrected visual acuity of the amblyopic eye”, the studies showed a benefit of digital vision training compared to no training, sham training or occlusion therapy. However, the differences in visual acuity measured in these comparisons were so small that – according to the external experts – the children and adolescents affected did not experience any noticeable advantage. In addition, the interaction of both eyes did not improve with training: neither in comparison to no training, nor to sham training, nor to occlusion therapy.

Temporarily taping off one eye for amblyopia can be stressful for children and adolescents and their families, for example if it leads to stigmatization and subsequently to refusal of treatment. Replacing or at least shortening the period of occlusion therapy through digital training could therefore potentially reduce the burden of treatment. At present, however, the available digital vision training that has been investigated in studies does not represent an alternative or supplement to occlusion therapy.

There are no studies on non-digital vision training or on vision training for other developmental vision disorders such as myopia, hyperopia or severe strabismus. It would be desirable for these vision training programmes (which are usually paid for by the parents themselves) to be offered only if studies have shown that those affected actually benefit from them.

The “ThemenCheck Medizin” procedure

In a two-stage selection process, which also involves members of the public, up to five new topics are selected each year from all the proposals submitted. According to the legal mandate, these should be topics of particular importance for patient care.

The ThemenCheck reports are not written by IQWiG itself, but by external experts. Their assessment is published together with an easily understandable summary and a publisher’s comment by IQWiG.