Table 1: Demographics of different group infants with birth weight ≤ 1000 g.

VariablesGroup A (no rop) Group B (light) Group C (severe) value

Gender, (%) male16 (16/21) (76.2%)11 (11/18) (61.1%)26 (26/38) (68.4%)
Birth weight (g), mean (SD)898.6 (102.6)936.7 (101.5)886.6 (115.3)
Gestational age (weeks), mean (SD)29.1 (2.0)28.0 (2.0)27.8 (1.4)
PMA of onset of ROP (weeks), mean (SD)36.5 (1.9)34.3 (1.7)

square test.
of variance.
SD: standard deviation.
PMA: postmenstrual age.