Community-based trial of a peripheral prism visual field expansion device for hemianopia

Arch Ophthalmol. 2008 May;126(5):657-64. doi: 10.1001/archopht.126.5.657.


Objective: To determine the functional utility for general mobility of peripheral prism glasses, a novel visual field expansion device for hemianopia, in a large-scale, community-based, multicenter study with long-term follow-up.

Methods: Forty-three participants with homonymous hemianopia were fitted with temporary press-on Fresnel peripheral prism segments of 40 prism diopters. Follow-up questionnaires evaluating functional benefits for mobility were administered in the office at week 6. Participants who continued wearing the prisms were interviewed again by telephone after a median of 12 months. Primary outcome measures included clinical success (a clinical decision to continue wear) and 5-point ratings of prism helpfulness for obstacle avoidance when walking.

Results: Thirty-two participants (74%) continued prism wear at week 6, and 20 (47%) were still wearing the prisms after 12 months (median time, 8 hours per day). These participants rated the prism glasses as very helpful for obstacle avoidance and reported significant benefits for obstacle avoidance in a variety of mobility situations. Success rates varied among clinic groups (27%-81%), with higher rates at the clinics that fitted more patients.

Conclusion: Our results demonstrate the functional utility of peripheral prism glasses as a general mobility aid for patients with hemianopia.

Publication types

  • Clinical Trial
  • Multicenter Study
  • Research Support, N.I.H., Extramural

MeSH terms

  • Activities of Daily Living
  • Eyeglasses*
  • Follow-Up Studies
  • Hemianopsia / physiopathology
  • Hemianopsia / therapy*
  • Humans
  • Patient Satisfaction
  • Prosthesis Fitting
  • Surveys and Questionnaires
  • Visual Fields / physiology*