title: Ultra wide field fundus biomicroscopy with the Volk Quadraspheric lens.
abstract: Fundus biomicroscopy as a clinical technique has been enhanced significantly by the addition of indirect view condensing lenses. The combination of this type of lens with a corneal contact element allows higher power and better stability so that a wider field can be obtained. The Panfunduscope of Schlegel and the Mainster retinal lens are examples of this design that have been successfully applied to both examination and to pan-retinal photocoagulation. Volk has recently introduced a new aspheric design indirect contact lens system which is higher in power and provides a wider field of view (125 degrees) than previously obtainable. This article describes the optical properties and use of the Quadraspheric lens.
authors.affiliation: Pennsylvania College of Optometry, Philadelphia 19141.
authors.forename: F M
authors.initials: FM
authors.lastname: Barker
authors.forename: J T
authors.initials: JT
authors.lastname: Wing
mesh_terms: D005069:Evaluation Studies as Topic; D005654:Fundus Oculi; D006801:Humans; D007909:Lenses; D008853:Microscopy / Q000295:instrumentation* / Q000379:methods; D012164:Retinal Diseases / Q000175:diagnosis