Research Day
PRISM CORRECTION OF HOMONYMOUS HEMIANOPSIA BY DISPLACEMENT FIELD TECHNOLOGY
Document Type
Abstract
Date
2021
Abstract
Introduction: Homonymous Hemianopia (HH) is characterized by loss of vision in half of the visual field. These visual field deficits adversely affect patients' quality of life, especially due to its impact on driving. Patients utilize prism glasses to displace images from affected areas of their vision to "expand" their existing visual field. The efficacy of prisms in improving daily function in patients with HH remains an area of active research.
Case History: The patient is a 60-year-old man diagnosed with melanoma in 2011. Metastasis to the brain was treated with craniotomy and stereotactic radiation, leading to loss of vision in his right visual field. The patient had difficulty with reading, using a computer, playing tennis, biking, and he was forced to discontinue driving. After multiple interventions from low-vision specialists, the patient utilized an oblique Peli prism, which displaced the right field defect into the left superior field. Humphrey Visual Field (HVF) testing demonstrated that the right-side scotoma was displaced, allowing near full visual field. The patient passed a Michigan Secretary of State Driving Skills Test and has resumed tennis and reading.
Conclusions: This case describes success by returning to driving with the use of an oblique Peli prism. Consistent with past studies, prism use did not actually decrease the field defect over time. Rather, the prism may help in certain situations to increase awareness, such as aiding in accident avoidance and improving quality of life.