title: Use of a blue filter in visual field analysis.
abstract: One hundred and twenty seven eyes of 127 patients were studied by means of a Kodak 47B Wratten blue gelatin filter in conjunction with the Friedmann Mark 1 visual field analyser. There were 49 patients in the normal group, 50 patients in the ocular hypertension group, and 28 patients in a group with early glaucoma. A simple scoring system did not show a useful difference between these three groups. However, use of a derived threshold value for each target group designated by the letters B to P (giving selective blue field scores) differentiated between normal subjects and those with early glaucomatous field loss. When used with a calculated upper limit of normal to give a specificity of 96%, this test had a sensitivity of 64%. Of the ocular hypertension group 22% gave abnormal results in comparison with normal persons. This simple adaptation to the Friedmann protocol may aid the ophthalmologist in the detection and confirmation of early glaucoma.
authors.affiliation: Department of Ophthalmology, King's Mill Hospital, Sutton-in-Ashfield, Nottinghamshire.
authors.forename: C E
authors.initials: CE
authors.lastname: Hugkulstone
authors.forename: S A
authors.initials: SA
authors.lastname: Vernon
mesh_terms: D005069:Evaluation Studies as Topic; D005374:Filtration / Q000295:instrumentation; D005902:Glaucoma, Open-Angle / Q000175:diagnosis / Q000503:physiopathology; D006801:Humans; D008875:Middle Aged; D009798:Ocular Hypertension / Q000503:physiopathology; D012684:Sensory Thresholds / Q000502:physiology; D058609:Visual Field Tests / Q000295:instrumentation*; D014794:Visual Fields / Q000502:physiology*