Table 2

Unadjusted mean ocular biometry and refraction, by education, occupation, income, and housing type

NoAxial length (mm)Anterior chamber (mm)Lens thickness (mm)Vitreous chamber (mm)Nuclear opacity, LOCS IIICorneal curvature radius (mm)Refraction (dioptres)
Data are expressed as means (SD). Probabilities are based on test of trend, except for occupation, based on χ2 test. There were 29 people with missing data on occupation (unclassifiable occupation), 104 with missing data on income (including 95 who had retired) and 5 with missing data on housing type.
LOCS III: Lens Opacity Classification System III score (from 1 to 6).
*Refer to text for definition of occupation categories.
Education
    No education22922.72 (0.9)2.68 (0.4)4.93 (0.4)15.11 (0.9)3.6 (0.9)7.63 (0.3)0.38 (2.0)
    Primary (1–6 years)38223.07 (1.1)2.87 (0.4)4.79 (0.5)15.42 (1.0)3.2 (0.9)7.65 (0.3)−0.08 (2.2)
    Secondary (7–10 years)26623.67 (1.1)3.06 (0.4)4.62 (0.4)15.98 (1.1)2.9 (0.7)7.67 (0.3)−1.31 (2.8)
    Tertiary (11 or more years)7424.06 (1.5)3.06 (0.4)4.59 (0.4)16.42 (1.4)2.7 (0.7)7.69 (0.3)−2.35 (3.3)
p<0.001p<0.001p<0.001p<0.001p<0.001p=0.03p<0.001
Occupation*
    Others73123.06 (1.1)2.85 (0.4)4.79 (0.5)15.43 (1.0)3.2 (0.9)7.64 (0.3)−0.18 (2.4)
    Near work19123.86 (1.3)3.05 (0.4)4.64 (0.5)16.17 (1.3)2.9 (0.8)7.68 (0.2)−1.69 (3.0)
p<0.001p<0.001p<0.001p<0.001p<0.001p=0.05p<0.001
Income, per month
    $1000 or less56522.99 (1.1)2.81 (0.4)4.83 (0.5)15.37 (1.0)3.3 (0.9)7.63 (0.3)−0.16 (2.4)
    $1001–200017323.58 (1.2)3.07 (0.4)4.56 (0.5)15.95 (1.1)2.7 (0.7)7.68 (0.3)−1.05 (2.9)
    $2001–30006223.64 (1.0)3.13 (0.4)4.50 (0.5)16.01 (1.0)2.6 (0.5)7.70 (0.3)−1.50 (2.4)
    More than $30004724.37 (1.4)3.22 (0.4)4.50 (0.5)16.64 (1.3)2.5 (0.7)7.74 (0.3)−2.55 (3.3)
p<0.001p<0.001p<0.001p<0.001p<0.001p<0.001p<0.001
Housing type
    1–2 room flats16323.08 (1.1)2.85 (0.4)4.80 (0.5)15.43 (1.0)3.3 (0.9)7.64 (0.3)−0.34 (2.4)
    3 room flats51523.20 (1.1)2.87 (0.4)4.77 (0.5)15.57 (1.1)3.2 (0.9)7.66 (0.3)−0.43 (2.6)
    4–5 room/executive/private26823.38 (1.3)2.97 (0.5)4.70 (0.5)15.71 (1.2)3.1 (0.8)7.66 (0.2)−0.67 (2.7)
p=0.008p=0.003p=0.02p=0.01p=0.01p=0.72p=0.17