Randomised controlled trial of efficacy of Optometric Interventions
Ms Claire O’Leary
Optometrists usually prescribe interventions (spectacles, contact lenses or orthoptics) if the intervention improves visual acuity, or if it is believed that it will resolve symptoms. For optometric interventions that are prescribed for symptomatic relief, clinical tests of visual acuity (VA) often do not indicate significant improvement with the intervention.
Visual problems which cause symptoms but do not impair static VA might affect performance on dynamic tasks. Refractive errors and heterophoria are best described as continuous variables and the decision as to when to prescribe an intervention is based on clinical signs whose sensitivity and specificity for detecting symptoms is often, at best, under researched.
The objectively validated Wilkins Rate Of Reading Test will be used to assess the benefit of interventions. This test uses simple words and is relatively independent of reading skill and does not assess linguistic or semantic factors. The results are very dependent on dynamic visual skills and require sustained binocular single vision and clear vision.
The aims of the research
- In conditions where optical corrections may be prescribed but not improve VA (e.g. decompensated heterophoria): to investigate whether optical corrections influence performance at the Wilkins Rate of Reading test.
- In conditions where optical corrections may be prescribed and improve VA (e.g. astigmatism): to investigate whether optical corrections influence performance at the Wilkins Rate of Reading test.
- In both (1) and (2), to investigate the relationship between the severity of the optometric anomalies and the magnitude of any improvement in the Rate of Reading.
- If the Wilkins Rate of Reading Test does prove to be a useful tool for exploring any benefit from the “borderline” optometric interventions, to investigate the inter-relationships between the Wilkins Rate of Reading Test result, symptoms and conventional clinical test results.