Pentacam HR Indices Variation in Normal Corneas with Different Corneal Thickness

Table 2

The mean, standard deviation (SD), and the suggested cutoff values (2 and 3 SD from the mean) of different parameters in the three groups.

Index	Group 1				Group 2				Group 3
	Mean	SD	2 SD limit	3 SD limit	Mean	SD	2 SD limit	3 SD limit	Mean	SD	2 SD limit	3 SD limit
PPI avg	0.980	0.117	1.214	1.332	0.926	0.102	1.130	1.233	0.930	0.142	1.214	1.355
PPI max	1.244	0.168	1.580	1.748	1.132	0.143	1.418	1.561	1.120	0.187	1.494	1.681
ART avg	522.3	66.4	389.5	323.1	591.6	68.1	455.4	387.3	642.8	91.3	460.3	369.1
ART max	413.4	61.9	289.6	227.7	485.8	64.2	357.3	293.1	536.7	89.8	357.1	267.3
FE from BFS	3.4	1.3	6.0	7.3	3.1	1.5	6.0	7.4	3.2	1.8	6.7	8.5
BE from BFS	4.7	3.6	11.9	15.5	4.6	4.0	12.7	16.7	6.9	4.4	15.6	20.0
FE from BFTE	0.2	1.0	2.1	3.1	0.1	1.0	2.0	3.0	0.1	0.9	2.0	2.9
BE from BFTE	0.3	2.6	5.5	8.1	0.4	2.4	5.3	7.7	1.7	2.8	7.3	10.2

ART avg = average Ambrosio’s relational thickness index, ART max = maximum Ambrosio’s relational thickness index, PPI avg = average pachymetry progression index, PPI max = maximum pachymetry progression index, FE = front elevation of the thinnest point, BFS = best fit sphere, BE = back elevation of the thinnest point, BFTE = best fit toric ellipsoid, and SD= standard deviation.