Alterations in the shape of the automated perimetric profile arising from cataract.
The attenuation of the perimetric response arising from cataract was investigated and related to the degree of cataract quantified by glare sensitivity. Visual fields were measured with the Octopus and Dicon automated perimeters out to an eccentricity of 30 degrees. Nuclear and non-nuclear cataracts differed in their effect on the perimetric profile. Non-nuclear cataracts exhibited the same qualitative characteristics as a model developed in previous studies, whereby the overall pattern of perimetric attenuation was dependent upon target configuration. For these subjects, perimetric sensitivity was depressed to a greater extent at an eccentricity of 30 degrees compared with fixation when measured with the large projected stimuli, whereas the reverse was true when sensitivity was measured with the small LED stimuli. Conversely, nuclear cataracts depressed perimetric sensitivity to a greater extent at the fovea compared with more peripheral regions for both the large projected and small LED stimuli.
Wood
J M
JM
Department of Vision Sciences, Aston University, Birmingham, United Kingdom.
Wild
J M
JM
Smerdon
D L
DL
Crews
S J
SJ
D000368:Aged; D002386:Cataract / Q000473:pathology / Q000503:physiopathology*; D006801:Humans; D008027:Light; D012542:Scattering, Radiation; D058609:Visual Field Tests; D014794:Visual Fields