Table 2.
Outcomes at 3 years for Bifocal + Atropine, Bifocal, and Single Vision (SV) groups.
| Outcome | Bifocal + Atropine | Bifocal | Single Vision (SV) | Mean difference | P-value |
|---|---|---|---|---|---|
| Primary outcome | |||||
| Refractive error, D | |||||
| Baseline mean (SD) | −2.28 (0.98) | −2.26 (0.80) | −2.30 (0.90) | ||
| Year 3, mean (SD) | −2.75 (1.14) | −2.82 (1.09) | −3.37 (1.26) | ||
| 3-y absolute change (95% CI) | −0.47 (−0.60 to −0.35) | −0.56 (−0.68 to −0.44) | −1.08 (−1.23 to −0.92) | ||
| Bifocal + Atropine vs. Bifocal | 0.09 (−0.10 to 0.28) | .36 | |||
| Bifocal + Atropine vs. SV | 0.60 (0.41 to 0.79) | < .01 | |||
| 3-y Adjusted Change (95% CI) | −0.52 (−0.65 to −0.39) | −0.55 (−0.66 to −0.44) | −1.09 (−1.24 to −0.95) | ||
| Bifocal + Atropine vs. Bifocal | 0.03 (−0.14 to 0.21) | .70 | |||
| Bifocal + Atropine vs. SV | 0.57 (0.38 to 0.77) | < .01 | |||
| Secondary Outcomes | |||||
| Axial Length, Mm | |||||
| Baseline Mean (SD) | 24.37 (0.63) | 24.31 (0.75) | 24.50 (0.91) | ||
| Year 3, Mean (SD) | 24.67 (0.70) | 24.70 (0.84) | 25.16 (0.93) | ||
| 3-y Absolute Change (95% CI) | 0.30 (0.23 to 0.36) | 0.38 (0.33 to 0.44) | 0.67 (0.60 to 0.73) | ||
| Bifocal + Atropine vs. Bifocal | −0.09 (−0.18 to −0.0002) | .049 | |||
| Bifocal + Atropine vs. SV | −0.37 (−0.46 to −0.28) | < .01 | |||
| 3-y Adjusted Change (95% CI) | 0.31 (0.25 to 0.37) | 0.39 (0.34 to 0.44) | 0.68 (0.61 to 0.74) | ||
| Bifocal + Atropine vs. Bifocal | −0.08 (−0.16 to 0.002) | .054 | |||
| Bifocal + Atropine vs. SV | −0.37 (−0.46 to −0.28) | < .01 | |||
| VA, Mean (95% CI), logMAR | |||||
| High Contrast Distance | −0.06 (−0.07 to −0.04) | −0.03 (−0.05 to −0.02) | −0.06 (−0.07 to −0.04) | ||
| Bifocal + Atropine vs. Bifocal | −0.02 (−0.05 to −0.004) | .017 | |||
| Bifocal + Atropine vs. SV | 0.00 (−0.02 to 0.02) | > .99 | |||
| High Contrast Near | −0.13 (−0.14 to −0.11) | −0.07 (−0.09 to −0.05) | −0.11 (−0.13 to −0.09) | ||
| Bifocal + Atropine vs. Bifocal | −0.06 (−0.08 to −0.04) | < .01 | |||
| Bifocal + Atropine vs. SV | −0.02 (−0.04 to 0.003) | .10 | |||
| Low Contrast Distance | 0.12 (0.10 to 0.14) | 0.11 (0.09 to 0.13) | 0.07 (0.05 to 0.09) | ||
| Bifocal + Atropine vs. Bifocal | 0.01 (−0.01 to 0.04) | .40 | |||
| Bifocal + Atropine vs. SV | 0.05 (0.03 to 0.08) | < .01 | |||
| Pupil Size, Mean (95% CI), mm | |||||
| Photopic | 5.10 (4.94 to 5.26) | 4.75 (4.59 to 4.90) | 4.87 (4.71 to 5.02) | ||
| Bifocal + Atropine vs. Bifocal | 0.36 (0.13 to 0.58) | < .01 | |||
| Bifocal + Atropine vs. SV | 0.24 (0.01 to 0.46) | .04 | |||
| Mesopic | 6.41 (6.26 to 6.57) | 6.30 (6.15 to 6.45) | 6.23 (6.07 to 6.38) | .25 | |
| Acc. Lag, Mean (95% CI), D | −0.86 (−1.03 to −0.70) | −1.32 (−1.56 to −1.08) | −1.09 (−1.21 to −0.97) | ||
| Bifocal + Atropine vs. Bifocal | 0.46 (0.21 to 0.71) | < .01 | |||
| Bifocal + Atropine vs. SV | 0.23 (−0.02 to 0.48) | .07 | |||
| Post Hoc Outcomes, No. (%) [95% CI] | (n = 46) | (n = 46) | (n = 46) | ||
| Progress >1.00 D | 8 (17.4) | 7 (15.2) | 22 (47.8) | ||
| Bifocal + Atropine vs. Bifocal | 3.3 (−11.6 to 18.1) | .67 | |||
| Bifocal + Atropine vs. SV | −30.4 (−48.6 to −12.3) | .002 | |||
| Eye Growth >0.36 mm | 18 (39.1) | 23 (50.0) | 39 (84.8) | ||
| Bifocal + Atropine vs. Bifocal | −9.8 (−30.0 to 10.4) | .35 | |||
| Bifocal + Atropine vs. SV | −44.6 (−62.3 to −26.9) | < .01 |
SV = single vision; VA = visual acuity; Acc. Lag = accommodative lag; CI = confidence interval; SD = standard deviation; D = diopters