Progressive visual impairment often affects people as they age. Training is used to help people with low vision maintain travel independence, with new orientation and mobility skills to compensate for reduced visual information. Orientation is the ability to recognise one's position in relation to the environment, whereas mobility is the ability to move around safely and efficiently. Orientation and mobility (O&M) training teaches people to use their remaining vision and other senses to get around. Canes and optical aids may also be used.
We found two small studies with a total of 63 people comparing O&M training delivered by a trained volunteer to physical exercise. These studies did not show a difference between the two interventions, but they had little power to do so because of the small sample size and poor methodological quality. There were no adverse effects of O&M training in these studies.
There is little evidence from randomised controlled trials on which type of O&M training is better for people with low vision who have specific characteristics and needs.
Baca abstrak penuh
Orientation and mobility (O&M) training is provided to people who are visually impaired to help them maintain travel independence. It teaches them new orientation and mobility skills to compensate for reduced visual information.
Matlamat
The objective of this review was to assess the effects of O&M training, with or without associated devices, for adults with low vision.
Kaedah Pencarian
We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library, 2010, Issue 3), MEDLINE (January 1950 to March 2010), EMBASE (January 1980 to March 2010), Latin American and Caribbean Literature on Health Sciences (LILACS) (January 1982 to March 2010), System for Information on Grey Literature in Europe (OpenSIGLE) (March 2010), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com) (March 2010), ClinicalTrials.gov (http://clinicaltrials.gov) (March 2010), ZETOC (March 2010) and the reference lists of retrieved articles. There were no language or date restrictions in the search for trials. The electronic databases were last searched on 31 March 2010.
Kriteria Pemilihan
We planned to include randomised or quasi-randomised trials comparing O&M training with no training in adults with low vision.
Pengumpulan Data dan Analisis
Two authors independently assessed the search results for eligibility, evaluated study quality and extracted the data.
Keputusan Utama
Two small studies satisfied the inclusion criteria. They were consecutive phases of development of the same training curriculum and assessment tool. The intervention was administered by a volunteer on the basis of written and oral instruction. In both studies the randomisation technique was inadequate, being based on alternation, and masking was not achieved. Training had no effect in the first study but tended to be beneficial in the second but not to a statistically significant extent. Reasons for differences between studies may have been: the high scores obtained in the first study, suggestive of little need for training and small room for further improvement (a ceiling effect), and the refinement of the curriculum allowing better tailoring to patients' specific needs and characteristics, in the second study.
Kesimpulan Pengarang
The review found two small quasi-randomised trials with similar methods, comparing training to physical exercise and assessing O&M physical performance by means of a volunteer or a professional, which were unable to demonstrate a difference. Therefore, there is little evidence on which type of O&M training is better for people with low vision who have specific characteristics and needs. Orientation and mobility instructors and scientists should plan randomised controlled trials (RCTs) to compare the effectiveness of different types of O&M training. A consensus is needed on the adoption of standard measurement instruments of mobility performance which are proven to be reliable and sensitive to the diverse mobility needs of people with low vision. For this purpose, questionnaires and performance-based tests may represent different tools that explore people with low vision's subjective experience or their objective functioning, respectively. In fact, it has to be observed that low vision rehabilitation research is increasingly shifting towards the use of quality of life questionnaires as an outcome measure, sometimes with the aim to study complex and multidisciplinary interventions including different types of education and support, of which O&M can be a component. An example of this is an ongoing cluster RCT conducted by Zijlstra et al. in The Netherlands. This trial is designed to compare standardised O&M training with usual O&M care not only for its effectiveness, but also its applicability and acceptability. This study adopts validated questionnaires for patients' subjective assessment of performance during activities of daily living. As performance assessment does not need to be made by an O&M trainer, this allows for masking of assessors and a patient-centred outcome measure.
