Purchase this article with an account.
A. R. Bowers, K. Keeney, D. Apfelbaum, E. Peli; Randomised Controlled Multi-Center Trial of High-Power Peripheral Prism Glasses for Hemianopia - Interim Results. Invest. Ophthalmol. Vis. Sci. 2009;50(13):3210.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
We are conducting a community-based, multi-center trial to evaluate the functional utility for general mobility (walking) of new high power (57Δ, ~30°) peripheral prism (PP) glasses, which provide visual field expansion for patients with homonymous hemianopia. Here we report interim results.
Patients (with homonymous hemianopia with neither visual neglect nor significant cognitive decline) are randomly allocated to receive either real horizontal and sham oblique PP glasses, or real oblique and sham horizontal PP glasses. Order of sham and real glasses are counterbalanced. PP segments are fitted unilaterally on the side of the field loss at a standard 12mm inter-prism separation. With the exception of the allocator (DA) and optical lab (Chadwick), patients and personnel are masked (as far as possible) to the treatment allocation. Following protocols set up by the coordinating center (Schepens), practitioners at each of the sites recruit and screen patients, fit prism glasses, train patients in their use, and conduct an in-office questionnaire evaluating functional benefits for mobility after each pair of glasses has been worn for 4 weeks. Patients with a clinical decision to continue wear at the end of the crossover period are interviewed by telephone 6 months later. The primary outcome measure is the proportion of patients who prefer real to sham PP glasses in each group. Secondary measures include ratings of mobility difficulties with and without the glasses.
To date, 83 patients have been screened at 14 vision rehabilitation clinics; 61 met the criteria and were enrolled; 6 subsequently withdrew before collecting the first pair of glasses; 31 have now completed the crossover, with 21 (68%) continuing to wear real PP glasses; 12 have completed 6 months, with 9 continuing wear. The code on the treatment allocations has not yet been broken.
Interim results are promising with overall clinical success rates after the crossover (68%) similar to those reported in our open-label multi-center trial of 40Δ PP glasses (Arch Ophthalmol, 2008, 126: 657-664).
Clinical Trial: :
This PDF is available to Subscribers Only