title: Bitemporal hemianopia; its unique binocular complexities and a novel remedy.
abstract: Bitemporal hemianopic visual field impairment frequently leads to binocular vision difficulties. Patients with bitemporal hemianopia with pre-existing exophoria complain of horizontal diplopia, sometimes combined with vertical deviation (with pre-existing hyperphoria). The symptoms are a result of the phoria decompensating into a tropia (hemi-slide) due to the lack of retinal correspondence between the remaining nasal fields of both eyes. We measured these effects using a dichoptic perimeter. We showed that aligning the eyes with prisms could prevent diplopia if the bitemporal hemianopia is incomplete. We also describe the successful use of a novel fusion aid - the 'stereo-typoscope' - that utilizes midline stereopsis to prevent diplopia resulting from hemi-sliding in patients with complete bitemporal hemianopia.
authors.affiliation: Schepens Eye Research Institute, Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, USA.
authors.forename: Eli
authors.initials: E
authors.lastname: Peli
authors.forename: PremNandhini
authors.initials: P
authors.lastname: Satgunam
mesh_terms: D000328:Adult; D006423:Hemianopsia / Q000175:diagnosis / Q000503:physiopathology / Q000534:rehabilitation*; D006801:Humans; D008297:Male; D015348:Vision, Binocular / Q000502:physiology*; D058609:Visual Field Tests / Q000379:methods; D014794:Visual Fields / Q000502:physiology*
keywords: field defects; hemianopsia; heteronymous hemianopia; optic chiasm lesions; tropia