Ocular biometry and refraction parameters for different birth parameters
| Early life variables | No | Axial length (mm) | Vitreous chamber depth (mm) | Lens thickness (mm) | |||
|---|---|---|---|---|---|---|---|
| Mean (SD) | Adjusted* mean (SD) | Mean (SD) | Adjusted* mean (SD) | Mean (SD) | Adjusted* mean (SD) | ||
| Birth weight (kg) | |||||||
| <2.5 | 80 | 23.17 (0.95) | 23.16 (2.16) | 16.13 (0.92) | 16.09 (2.09) | 3.49 (0.20) | 3.50 (0.45) |
| 2.5–2.9 | 343 | 23.13 (0.85) | 23.29 (1.26) | 16.05 (0.80) | 16.21 (1.21) | 3.50 (0.17) | 3.49 (0.26) |
| 3.0–3.4 | 657 | 23.44 (0.96) | 23.41 (0.84) | 16.35 (0.91) | 16.32 (0.81) | 3.48 (0.18) | 3.49 (0.18) |
| 3.5–3.9 | 288 | 23.67 (1.00) | 23.53 (1.44) | 16.56 (0.97) | 16.44 (1.40) | 3.46 (0.17) | 3.48 (0.30) |
| ⩾4.0 | 45 | 23.45 (0.84) | 23.65 (2.39) | 16.44 (0.86) | 16.56 (2.31) | 3.46 (0.17) | 3.47 (0.50) |
| p Value (trend) | <0.001 | <0.001 | <0.001 | <0.001 | 0.009 | 0.25 | |
| Reg† coefficient | 0.37 | 0.25 | 0.35 | 0.24 | −0.03 | −0.02 | |
| p Value (reg) | <0.001 | <0.001 | <0.001 | <0.001 | 0.004 | 0.18 | |
| Head circumference (cm) | |||||||
| <32 | 67 | 23.17 (0.93) | 23.22 (2.13) | 16.09 (0.89) | 16.13 (2.05) | 3.48 (0.18) | 3.51 (0.44) |
| 32–33.9 | 508 | 23.24 (0.90) | 23.33 (1.11) | 16.16 (0.84) | 16.25 (1.07) | 3.49 (0.18) | 3.50 (0.23) |
| 34–35.9 | 573 | 23.53 (0.97) | 23.44 (1.02) | 16.44 (0.95) | 16.36 (0.98) | 3.48 (0.17) | 3.48 (0.21) |
| 36–37.9 | 93 | 23.67 (1.02) | 23.55 (1.98) | 16.58 (1.00) | 16.48 (1.91) | 3.44 (0.17) | 3.47 (0.41) |
| ⩾38 | 8 | 23.58 (0.99) | 23.66 (3.14) | 16.57 (0.66) | 16.60 (3.03) | 3.44 (0.23) | 3.46 (0.65) |
| p Value (trend) | <0.001 | 0.002 | <0.001 | 0.001 | 0.07 | 0.11 | |
| Reg coefficient | 0.09 | 0.05 | 0.09 | 0.05 | −0.005 | −0.005 | |
| p Value (reg) | <0.001 | 0.004 | <0.001 | 0.002 | 0.10 | 0.18 | |
| Length at birth (cm) | |||||||
| <47.0 | 118 | 23.10 (0.94) | 23.28 (1.95) | 16.06 (0.92) | 16.22 (1.88) | 3.49 (0.19) | 3.49 (0.40) |
| 47.0–48.9 | 310 | 23.24 (0.95) | 23.35 (1.18) | 16.17 (0.91) | 16.27 (1.13) | 3.50 (0.18) | 3.49 (0.24) |
| 49.0–50.9 | 531 | 23.44 (0.92) | 23.41 (0.87) | 16.35 (0.89) | 16.33 (0.84) | 3.48 (0.17) | 3.49 (0.18) |
| 51.0–52.9 | 253 | 23.65 (1.01) | 23.47 (1.40) | 16.54 (0.96) | 16.38 (1.35) | 3.46 (0.17) | 3.48 (0.29) |
| ⩾53 | 67 | 23.53 (0.84) | 23.54 (2.23) | 16.44 (0.79) | 16.44 (2.15) | 3.50 (0.15) | 3.48 (0.46) |
| p Value (trend) | <0.001 | 0.022 | <0.001 | 0.04 | 0.14 | 0.66 | |
| Reg coefficient | 0.06 | 0.02 | 0.06 | 0.02 | −0.003 | −0.001 | |
| p Value (reg) | <0.001 | 0.044 | <0.001 | 0.05 | 0.14 | 0.66 | |
| Gestational age (weeks) | |||||||
| <37 | 85 | 23.31 (0.92 | 23.29 (2.05 | 16.21 (0.89 | 16.21 (1.98 | 3.52 (0.19 | 3.50 (0.42) |
| 37.0–38.9 | 454 | 23.33 (0.96 | 23.35 (1.07 | 16.25 (0.92 | 16.27 (1.03 | 3.48 (0.17 | 3.49 (0.22) |
| 39.0–40.9 | 649 | 23.44 (0.96 | 23.42 (1.00 | 16.35 (0.92 | 16.34 (0.97 | 3.48 (0.18 | 3.48 (0.21) |
| 41.0–42.9 | 58 | 23.46 (0.98 | 23.49 (1.95 | 16.34 (0.99 | 16.41 (1.88 | 3.47 (0.21 | 3.47 (0.58) |
| ⩾43 | 2 | 24.12 (1.17 | 23.56 (3.08 | 17.44 (0.94 | 16.48 (2.98 | 3.33 (0.18 | 3.46 (0.64) |
| p Value (trend) | 0.04 | 0.05 | 0.03 | 0.05 | 0.14 | 0.20 | |
| Reg coefficient | 0.04 | 0.04 | 0.05 | 0.04 | −0.008 | 0.008 | |
| p Value (reg) | 0.014 | 0.028 | 0.01 | 0.017 | 0.016 | 0.027 | |
| Early life variables | No | Anterior chamber depth (mm) | Radius of corneal curvature (mm) | Refractive error (D) | |||
|---|---|---|---|---|---|---|---|
| *Mean and regression coefficients adjusted for age, sex, school, parental myopia, height, and gestation (except in the analysis of gestational age data). All regression coefficients are derived from a single linear regression model with the ocular parameter as the dependent variable and birth variable as the independent variable, adjusted for age, sex, school, height, parental myopia, and gestation (except in the analysis of gestational age data). For example, in the multiple linear regression model with birth weight as the independent variable, for every 1 kg increase in birth weight, the axial length is 0.25 mm greater. | |||||||
| †Reg, regression. | |||||||
| Birth weight (kg) | |||||||
| <2.5 | 80 | 3.55 (0.28) | 3.57 (0.69) | 7.65 (0.20) | 7.66 (0.60) | −0.66 (1.80) | −0.52 (4.15) |
| 2.5–2.9 | 343 | 3.58 (0.29) | 3.58 (0.40) | 7.69 (0.24) | 7.71 (0.35) | −0.35 (1.51) | −0.52 (2.41) |
| 3.0–3.4 | 657 | 3.61 (0.26) | 3.60 (0.27) | 7.76 (0.25) | 7.76 (0.23) | −0.52 (1.74) | −0.52 (1.61) |
| 3.5–3.9 | 288 | 3.64 (0.27) | 3.61 (0.46) | 7.82 (0.23) | 7.81 (0.40) | −0.67 (1.80) | −0.52 (2.77) |
| ⩾4.0 | 45 | 3.55 (0.26) | 3.62 (0.76) | 7.83 (0.25) | 7.86 (0.66) | −0.24 (1.17) | −0.51 (4.58) |
| p Value (trend) | 0.008 | 0.26 | <0.001 | <0.001 | 0.36 | 0.98 | |
| Reg coefficient | 0.05 | 0.04 | 0.11 | 0.10 | −0.08 | 0.02 | |
| p Value (reg) | 0.002 | 0.08 | <0.001 | <0.001 | 0.41 | 0.84 | |
| Head circumference (cm) | |||||||
| <32 | 67 | 3.60 (0.27) | 3.58 (0.68) | 7.65 (0.22) | 7.69 (0.59) | −0.68 (1.74) | −0.52 (4.04) |
| 32–33.9 | 508 | 3.59 (0.29) | 3.59 (0.36) | 7.72 (0.24) | 7.73 (0.31) | −0.40 (1.60) | −0.52 (2.12) |
| 34–35.9 | 573 | 3.61 (0.26) | 3.60 (0.33) | 7.78 (0.24) | 7.77 (0.28) | −0.59 (1.74) | −0.52 (1.94) |
| 36–37.9 | 93 | 3.65 (0.30) | 3.60 (0.64) | 7.82 (0.28) | 7.81 (0.55) | −0.55 (1.74) | −0.52 (3.76) |
| ⩾38 | 8 | 3.58 (0.36) | 3.61 (1.01) | 7.89 (0.17) | 7.86 (0.88) | −0.55 (1.50) | −0.52 (5.98) |
| p Value (trend) | 0.09 | 0.59 | <0.001 | <0.001 | 0.39 | 0.98 | |
| Reg coefficient | 0.008 | 0.003 | 0.03 | 0.02 | −0.02 | 0.01 | |
| p Value (reg) | 0.11 | 0.56 | <0.001 | <0.001 | 0.54 | 0.76 | |
| Length at birth (cm) | |||||||
| <47.0 | 118 | 3.56 (0.29) | 3.57 (0.62) | 7.66 (0.24) | 7.69 (0.54) | −0.41 (1.56) | −0.62 (3.71) |
| 47.0–48.9 | 310 | 3.58 (0.28) | 3.58 (0.37) | 7.70 (0.23) | 7.72 (0.33) | −0.55 (1.73) | −0.57 (2.23) |
| 49.0–50.9 | 531 | 3.60 (0.27) | 3.59 (0.28) | 7.77 (0.24) | 7.76 (0.24) | −0.49 (1.71) | −0.51 (1.66) |
| 51.0–52.9 | 253 | 3.65 (0.27) | 3.61 (0.45) | 7.81 (0.24) | 7.80 (0.39) | −0.64 (1.70) | −0.46 (2.66) |
| ⩾53 | 67 | 3.59 (0.29) | 3.62 (0.71) | 7.83 (0.27) | 7.83 (0.62) | −0.46 (1.53) | −0.41 (4.24) |
| p Value (trend) | 0.004 | 0.24 | <0.001 | <0.001 | 0.50 | 0.31 | |
| Reg coefficient | 0.007 | 0.002 | 0.02 | 0.01 | −0.008 | 0.02 | |
| p Value (reg) | 0.03 | 0.53 | <0.001 | <0.001 | 0.68 | 0.30 | |
| Gestational age (weeks) | |||||||
| <37 | 85 | 3.57 (0.26) | 3.58 (0.65) | 7.74 (0.25) | 7.72 (0.57) | −0.29 (1.73) | −0.39 (3.90) |
| 37.0–38.9 | 454 | 3.59 (0.28) | 3.59 (0.34) | 7.73 (0.24) | 7.74 (0.30) | −0.48 (1.70) | −0.47 (2.03) |
| 39.0–40.9 | 649 | 3.60 (0.26) | 3.60 (0.32) | 7.76 (0.24) | 7.76 (0.28) | −0.58 (1.72) | −0.56 (1.91) |
| 41.0–42.9 | 58 | 3.65 (0.32) | 3.61 (0.62) | 7.80 (0.27) | 7.78 (0.54) | −0.38 (1.37) | −0.65 (3.70) |
| ⩾43 | 2 | 3.35 (0.04) | 3.62 (0.98) | 7.75 (0.23) | 7.81 (0.86) | −2.66 (4.83) | −0.72 (5.86) |
| p Value (trend) | 0.30 | 0.41 | 0.03 | 0.03 | 0.16 | 0.21 | |
| Reg coefficient | 0.0069 | 0.005 | 0.01 | 0.01 | −0.045 | −0.039 | |
| p Value (reg) | 0.18 | 0.31 | 0.03 | 0.032 | 0.16 | 0.22 | |