Table 4.

Amplitude of Diurnal Variation (Mean ± Standard Error) and Acrophase for Each Measured Parameter for All Subjects (n = 42)

Parameter	Amplitude	Acrophase, Peak, h	Time of Day	Refractive Error	Time by Refractive Error
Axial length, μm	35.71 ± 2.99	12.96	<0.001*	1.00	0.501
Choroidal thickness, central 1 mm, μm	25.80 ± 2.08	2.42	<0.001*	0.32	0.37
Intraocular pressure, mm Hg	4.92 ± 0.25	11.42	<0.001*	0.96	0.42
Body temperature, °C	0.52 ± 0.04	15.9	<0.001*	<0.001*	0.16
Heart rate, bpm	14.71 ± 0.77	21.66	0.034*	0.11	0.73
Systolic blood pressure, mm Hg	16.38 ± 0.88	17.97	<0.001*	0.14	0.71
Diastolic blood pressure, mm Hg	11.43 ± 0.7	20.85	0.015*	0.94	0.70
Mean arterial pressure, mm Hg	11.89 ± 0.67	19.14	<0.001*	0.36	0.88
Mean ocular perfusion pressure, mm Hg	9.70 ± 0.49	22.02	<0.001*	0.88	0.55
Melatonin, pg/mL	26.95 ± 1.88	3.19	<0.001*	0.69	0.19
Cortisol, dg/mL	0.50 ± 0.05	8.86	<0.001*	0.16	0.87

^Pvalues are from two-factor repeated measures ANOVA for time of day, refractive error, and time of day by refractive error.

^*Significance at P < 0.05.