Table 1

 Correlation (r2) between image grade and edge detection or relative colouration image analysis for the Annunziato, Efron, CCLRU, and Vistakon-Synoptik grading scales

Linear correlationQuadratic correlation
Edge detectionColourationEdges detectionColouration
Bulbar hyperaemiaAnnunziato0.870.690.890.88
Efron0.970.890.990.99
CCLRU0.830.970.890.98
Vistakon0.140.850.350.97
Palpebral hyperaemiaAnnunziato0.320.990.710.99
Efron0.950.970.960.98
CCLRU0.390.620.840.99
Vistakon0.020.750.840.81
Palpebral roughnessCCLRU white light0.320.530.940.92
CCLRU Nafl0.010.040.300.39
Vistakon0.730.770.840.89
Corneal stainingAnnunziato0.880.830.880.95
Efron0.490.550.990.95
CCLRU0.510.860.650.99
Vistakon0.950.040.960.57