Table 1
Values represent adjusted mean ± standard error of ophthalmic measures. Data obtained for visual acuity were converted into logMAR units. Intraocular pressure and horizontal and vertical cup-to-disk ratios were log-transformed. For visual field mean deviation and nerve-fiber-layer thickness, a z-transformation procedure was used. Values were adjusted for effects of age and gender.
| MANCOVA: Race Effects on Ophthalmic Measures | ||||
| Variable | Black (mean ± SE) | White (mean ± SE) | F | p |
| Visual Acuity (logMAR) | -0.27 ± 0.07 | -0.18 ± 0.06 | 0.872 | 0.359 |
| Intraocular Pressure (mmHg) | 1.25 ± 0.02 | 1.18 ± 0.02 | 4.991 | 0.034 |
| Vertical Cup/Disk Ratio (mm2) | -0.39 ± 0.06 | -0.56 ± 0.05 | 6.090 | 0.020 |
| Horizontal Cup/Disk Ratio (mm2) | -0.44 ± 0.05 | -0.60 ± 0.04 | 5.060 | 0.033 |
| Visual Field Mean Deviation (dB) | -0.52 ± 0.33 | 0.13 ± 0.27 | 2.064 | 0.163 |
| Nerve-Fiber-Layer Thickness (μm) | -0.36 ± 0.32 | 0.53 ± 0.28 | 4.011 | 0.056 |
Table 2
Adjusted mean values ± standard error for illumination (lux), melatonin (aMT6s), and sleep measures. Values were adjusted for effects of age and gender.
| MANCOVA: Race Effects on Illumination, Melatonin, and Sleep | ||||
| Variable | Black (mean ± SE) | White (mean ± SE) | F | p |
| Light Mesor [log] | 1.03 ± 0.10 | 1.38 ± 0.08 | 6.033 | 0.022 |
| Light Phase [hr] | 13.57 ± 0.34 | 14.54 ± 0.27 | 4.306 | 0.049 |
| aMT6s Mesor [log] | 2.67 ± 0.14 | 2.31 ± 0.11 | 3.311 | 0.082 |
| aMT6s Phase [hr, after midnight] | 2.35 ± 0.37 | 3.45 ± 0.29 | 4.745 | 0.040 |
| Phase Angle Between aMT6s and Sleep Timing [hr] | 2.55 ± 0.43 | 2.25 ± 0.29 | 0.305 | 0.586 |
| Mid-Sleep [hr] | 4.76 ± 0.34 | 5.51 ± 0.27 | 2.580 | 0.122 |
| Sleep Duration [hr] | 5.75 ± 0.28 | 6.57 ± 0.21 | 4.800 | 0.039 |
Table 3
Values represent correlation coefficients (Coef.) for associations of ambient illumination with melatonin measures from three separate analyses. First, Pearson correlations were run with no control for the covariates. Second, partial correlations were run with control for sleep duration and race. Third, partial correlations were run with control for intraocular pressure (IOP) and cup-to-disk ratio (CDR).
| Relationships Between Illumination and Melatonin | |||||
| aMT6s Mesor | aMT6s Phase | ||||
| Variable | Coef. | p | Coef. | p | |
| No control [r] | Light Mesor | 0.07 | 0.73 | 0.31 | 0.09 |
| Light Phase | -0.50 | 0.01 | 0.18 | 0.35 | |
| Control for sleep and race [rp] | Light Mesor | 0.19 | 0.35 | 0.28 | 0.16 |
| Light Phase | -0.43 | 0.03 | 0.03 | 0.88 | |
| Control for IOP and CDR [rp] | Light Mesor | 0.07 | 0.71 | 0.22 | 0.25 |
| Light Phase | -0.49 | 0.01 | 0.08 | 0.61 | |