TY - JOUR
T1 - Computerised densitometry of red-free retinal photographs correlated with automatic perimetry
AU - Cooper, Richard L.
AU - Eikelboom, Robert H.
AU - Barry, C.
PY - 1988
Y1 - 1988
N2 - An image analyser installed in a 16 bit personal computer was used to measure grey levels in red free photographs of normal and glaucomatous eyes. Regional photographic image intensity and density were correlated with Humphrey Field Analyser results for corresponding areas of visual field. Two methods for standardising photographic exposure by histogram equalisation and slide were compared in two groups of eyes from 13 subjects. For histogram equalisation, r2 varied from 0.16 to 0.29 for linear fits in temporal retinal quadrants. For the histogram slide, r2 varied between 0.19 to 0.45 for linear fits. Similar results were found for mean histogram equalised image intensity versus Humphrey Field Analyser global indices: Mean Deviation, (r2 = 0.27) and Pattern Standard Deviation, (r2 = 0.37). For histogram equalised image data, resistant line analysis showed a linear goodness of fit of 0.92 and for histogram slide goodness of fit was 0.97 for upper and 0.87 for lower temporal quadrants.
AB - An image analyser installed in a 16 bit personal computer was used to measure grey levels in red free photographs of normal and glaucomatous eyes. Regional photographic image intensity and density were correlated with Humphrey Field Analyser results for corresponding areas of visual field. Two methods for standardising photographic exposure by histogram equalisation and slide were compared in two groups of eyes from 13 subjects. For histogram equalisation, r2 varied from 0.16 to 0.29 for linear fits in temporal retinal quadrants. For the histogram slide, r2 varied between 0.19 to 0.45 for linear fits. Similar results were found for mean histogram equalised image intensity versus Humphrey Field Analyser global indices: Mean Deviation, (r2 = 0.27) and Pattern Standard Deviation, (r2 = 0.37). For histogram equalised image data, resistant line analysis showed a linear goodness of fit of 0.92 and for histogram slide goodness of fit was 0.97 for upper and 0.87 for lower temporal quadrants.
UR - http://www.scopus.com/inward/record.url?scp=0023751901&partnerID=8YFLogxK
U2 - 10.3109/02713688809033210
DO - 10.3109/02713688809033210
M3 - Article
C2 - 3180830
AN - SCOPUS:0023751901
SN - 0271-3683
VL - 7
SP - 789
EP - 798
JO - Current Eye Research
JF - Current Eye Research
IS - 8
ER -