Table 1.
Results and Intraobserver Repeatability of Peak Cone Density Measurements
| CNGA3 | CNGB3 | |||
|---|---|---|---|---|
| Metric | Observer 1 | Observer 2 | Observer 1 | Observer 2 |
| Median; IQR (cones/mm2) | 14,380; 9358 | 11,878; 12,778 | 21,917; 17,447 | 18,951; 16,799 |
| Coefficient of variation (%) | 9.33a | 11.08a | 5.47 | 10.97 |
| ICC (95% CI) | 0.983 (0.966 to 1.0) | 0.979 (0.957 to 1.0) | 0.991 (0.981 to 1.0) | 0.963 (0.926 to 1.0) |
| Bland-Altman analysisb | ||||
| Bias (95% CI) | −4.48% (+1.58% to −10.54%) | +5.18% (−3.69% to +14.05%) | −508 cones/mm2 (−1589 to +574) | −605 cones/mm2 (−2514 to +1304) |
| Upper LOA (95% CI) | +16.95% (+6.60% to +27.31%) | +36.56% (+21.40% to +51.72%) | +3320 cones/mm2 (+1470 to +5169) | +6152 cones/mm2 (+2887 to +9417) |
| Lower LOA (95% CI) | −25.92% (−15.56% to −36.28%) | −26.20% (−11.04% to −41.36%) | −4335 cones/mm2 (−2485 to −6184) | −7362 cones/mm2 (−4097 to −10,627) |
IQR, interquartile range.
a
Logarithmic transformation was applied and coefficient of variation is computed using the antilog of the within-subject standard deviation.
b
CNGA3 measurements were nonnormally distributed; therefore, we report percentages and Bland-Altman analysis after logarithmic transformation.