Table 1.

Mean scores of dry eye redness graded in 99 photographs using the clinical investigator-grading system (Ora Calibra™ Dry Eye Redness Scale [OCDER]) and the computer grading system (COM)

Computer score	OCDER mean	Computer mean	Standard deviation OCDER	Standard deviation computer	Pearson’s correlation coefficient	Accuracy	Concordance correlation coefficient (CCC)	Lower 90% confidence interval CCC	Upper 90% confidence interval CCC
Raw scores (0–255)
COM-Hor	1.98	33.47	0.78	4.51	0.67	0.01	0.00	0.00	0.01
COM-Red	1.98	14.78	0.78	6.36	0.67	0.05	0.03	0.02	0.04
Log base2 scores (0–8)
COM-Hor	1.98	5.09	0.78	0.19	0.66	0.03	0.02	0.01	0.02
COM-Red	1.98	3.88	0.78	0.54	0.69	0.19	0.13	0.09	0.16
Regression scores (0–4 scale)
COM-PredHor	1.98	1.98	0.78	0.52	0.66	0.92	0.61	0.51	0.69
COM-PredRed	1.98	1.98	0.78	0.54	0.69	0.94	0.65	0.55	0.72
COM-PredHR	1.98	1.98	0.78	0.59	0.76	0.96	0.73	0.65	0.79
Standardized regression scores (0–4 scale)
COM-PredHor	1.98	1.98	0.78	0.78	0.66	1.00	0.66	0.56	0.74
COM-PredRed	1.98	1.98	0.78	0.78	0.69	1.00	0.69	0.59	0.77
COM-PredHR	1.98	1.98	0.78	0.78	0.76	1.00	0.76	0.68	0.82

Notes: Computer grades were transformed from the raw scale to a log scale for improved normal distribution and linearity, after which regressions and standardized regressions were calculated on predicted scores to obtain agreement, accuracy and concordance. Note that the OCDER mean is one score, whose mean and standard deviation are repeated in the table for ease of use.

Abbreviations: COM-Hor, computer-graded horizontality; COM-Red, computer-graded redness; COM-PredHor, regression predicted computer grade for horizontality; COM-PredRed, regression predicted computer grade for redness; COM-PredHR, regression predicted computer grade for horizontality and redness combined; OCDER, Ora Calibra™ Dry Eye Redness Scale.