Table 5.

 Association (R²) between sources of variability and intraobserver/intravisit rim area differences (mm²)

Source of variability	HRT Classic		HRT Explorer		HRT-II Explorer
	R2	p Value	R2	p Value	R2	p Value
Reference height difference	0.7	<0.0001	0.7	<0.0001	0.5	<0.0001
Mean MPHSD	0.5	<0.0001	0.4	<0.0001	0.5	<0.0001
Central nuclear dip	0.1	0.005	0.3	<0.0001	0.2	<0.0001
LOCS III nuclear opalescence	0.1	0.001	0.2	0.0006	0.2	<0.0001
LOCS III nuclear colour	0.03	0.1	0.1	0.001	0.2	<0.0001
Cylindrical power	0.2	<0.0001	0.03	0.4	0.1	0.005
Spherical power	0.07	0.02	0.02	0.2	0.04	0.1
Spherical equivalent	0.04	0.08	0.01	0.3	0.02	0.2
Age	0.05	0.05	0.04	0.1	0.07	0.02
Baseline rim area	0.05	0.05	0.02	0.2	0.0003	0.9
Disc area	0.001	0.8	0.01	0.5	0.001	0.8
Intraocular pressure	0.05	0.05	0.05	0.07	0.01	0.4
LOCS III posterior subcapsular	0.01	0.4	0.001	0.8	0.005	0.6
LOCS III cortical	0.0001	0.9	0.005	0.6	0.01	0.5

MPHSD = mean pixel height standard deviation, LOCS III = Lens Opacity Classification System III.