Catalogue Number: 1664
Friedmann visual field analyser Mark II
Sub-Category: Perimeter, visual field analyser
Designer/inventor: FRIEDMANN A I
Year Of Publication/Manufacture: c 1980
Time Period: 1940 to 1999
Place Of Publication/Manufacture: England
Publisher/Manufacturer: Clement Clarke International Ltd
Description Of Item: An instrument for testing central visual fields using static perimetry. Grey metal and plastic casing. Patient chin and head rest,which includes a source of illumination for the patient side of a stimulus screen. Circular black stimulus screen the apertures in which are illuminated by an internal electronic flash tube. The stimulus pattern is varied by a rotating mask behind the stimulus screen operated manually by a lever on the side of the screen. Internally illuminated recording screen over which a record sheet is placed. Control panel, Firing button on the end of a coiled electrical lead. Marked as made by Clement Clarke Great Britain, Model 5304001 Serial Number 1032. 30 page instruction book, record pads, plastic stimulus pattern template. Grey plastic dust cover.
Historical Significance: Perimetry has a long history but was revolutionised by the introduction of automated static perimetry in the 1980s. The Friedmann visual field analyser is a precursor to automated static perimetry. Von Graefe is credited with introducing perimetry in 1855 when he published "Examination of the Visual Functions in Amblyopic Affections." He used a crude tangent screen for his investigations. It was not until 1869 that the arc perimeter was devised by Aubert and Forster. Danish ophthalmologist, Jannik Bjerrum (1851-1920), advanced the idea of testing central fields using a tangent screen in the closing years of the 19th C. Goldmann and Traquair (1875-1954) standarised measurement of visual fields by better instruments (the Goldmann Perimeter) and standardised targets (in the Goldmann perimeter in 1945 and Traquair targets for central field testing). Automated static perimetry began with the automation of the Goldmann bowl in 1980 followed by the development of instruments such as the Octopus and Humphrey visual field analysers that used projection stimuli in the bowl. Friedman devised this instrument in 1966. Reference: Friedmann AI. Serial analysis of changes in visual field defects employing a new instrument to determine the activity of diseases involving the visual pathway Ophthalmologica 1966; 152: 1-12]. Mark II was produced in 1979 and it had 99 stimuli and was more automated. Friedmann is a British ophthalmologist. His 1966 paper on this instrument gives his address as the Royal College of Surgeons and the Royal Eye Hospital London. He was research active between 1955 and 1989.
How Acquired: Donated by VCO Optometry Clinic
Date Acquired: Nov 2010
Condition: Very good
Location: Archive office. East wall shelves unit 1