Randomised Controlled Trial of Efficacy of Optometric Interventions

ISRCTN ISRCTN77268814
DOI https://doi.org/10.1186/ISRCTN77268814
Secondary identifying numbers M0003074909
Submission date
30/09/2005
Registration date
30/09/2005
Last edited
10/09/2008
Recruitment status
No longer recruiting
Overall study status
Completed
Condition category
Eye Diseases
Prospectively registered
Protocol
Statistical analysis plan
Results
Individual participant data

Plain English Summary

Not provided at time of registration

Contact information

Prof Bruce Evans
Scientific

23 Shenfield Rd
Brentwood
CM15 8AG
United Kingdom

Phone +44 (0)1277 211164
Email bruce.evans@virgin.net

Study information

Study designRandomised controlled trial
Primary study designInterventional
Secondary study designRandomised controlled trial
Study setting(s)Not specified
Study typeNot Specified
Scientific title
Study hypothesisOptometrists 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
1. 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.

2. 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.

3. 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.

4. 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.
Ethics approval(s)Not provided at time of registration
ConditionEye Diseases: Vision disorders
InterventionSubjects will be invited to return on the research day. They will then be tested four times with the rate of reading test, twice with the appropriate intervention A and twice with the control lens (B). The order of testing will be ABBA or BAAB (randomly) to control for practice effects. The interventions and controls for the five groups identified are summarised.

Hypermetropes will be tested with subjective refractive correction (A) and size lenses to give similar magnification (B)

Astigmats will be tested with subjective cylindrical correction (A) and best vision sphere (B)

Horizontal heterophorias will be tested with aligning prism from Mallett unit (A) and size lenses for exophoria or plano for esophoria as appropriate (B)

Vertical heterophorias will be tested with larger of aligning prism/dissociated heterophoria (A) and plano trial lenses (B)

Early presbyopes will be tested with near refractive correction (A) and size lenses (B).

Clinical data will be obtained using standard testing protocols on all subjects, and a selection from VA, cover test, foveal suppression, dissociated heterophoria, fusional reserves, Randot circles, fixation disparity. Detailed symptom questionnaires designed for each group will be used.
Subjects will be assessed from patients routinely attending the practice for eye examinations.
Intervention typeOther
Primary outcome measureProcess measure: does prescribing optometric correction for marginal refractive and orthoptic anomalies benefit patients in terms of improved performance on the Wilkins Rate of Reading test?
Secondary outcome measuresNot provided at time of registration
Overall study start date01/07/1998
Overall study end date31/03/2008

Eligibility

Participant type(s)Patient
Age groupAdult
SexNot Specified
Target number of participantsNot provided at time of registration
Participant inclusion criteriaSubjects meeting the following criteria will be selected, regardless of whether they have any existing refractive correction. All subjects meeting the criteria will be invited to participate.
1. Hypermetropes of age <40years with either retinoscopy or subjective refraction in the better eye in the range +0.75 to +1.50D
2. Patients aged 40-45 years with a subjective near correction in the range +0.50 to +1.50D
3. Astigmats of any age with astigmatism (subjectively) in the better eye in the range 0.50 to 1.50DC
4. Patients of any age with horizontal heterophoria that may be decompensated
5. Patients of any age with a vertical heterophoria either on the Mallett unit or dissociation test of >0.5^
Participant exclusion criteriaNo specific patient exclusion criteria
Recruitment start date01/07/1998
Recruitment end date31/03/2008

Locations

Countries of recruitment

  • England
  • United Kingdom

Study participating centre

23 Shenfield Rd
Brentwood
CM15 8AG
United Kingdom

Sponsor information

Department of Health
Government

Richmond House
79 Whitehall
London
SW1A 2NL
United Kingdom

Phone +44 (0)20 7307 2622
Email dhmail@doh.gsi.org.uk
Website http://www.dh.gov.uk/Home/fs/en

Funders

Funder type

Government

City Eye Clinic (EYENET) (UK), NHS R&D Support Funding

No information available

Results and Publications

Intention to publish date
Individual participant data (IPD) Intention to shareNo
IPD sharing plan summaryNot provided at time of registration
Publication and dissemination planNot provided at time of registration
IPD sharing plan

Study outputs

Output type Details Date created Date added Peer reviewed? Patient-facing?
Results article results 01/11/2006 Yes No