Table 1

Study population characteristics

Screened for ROPNo ROPOverall ROPMild ROPSevere ROP
Patients (n)1688136432429430
GA30.1 (28.6–31.4)30.7 (29.3–31.7)28.0 (26.4–29.4)28.1 (26.6–29.6)26.3 (25.4–27.0)
BW1320 (1050–1560)1400 (1150–1620)950 (780–1212)960 (790–1225)890 (730–1060)
Examinations (n)3891240214891250239
Median2 (1–3)1 (1–2)4 (3–6)4 (3–6)6 (5–10)
1st exam PMA35.4 (33.7–37.0)35.9 (34.4–37.1)33.1 (31.4–34.9)33.4 (31.6–34.9)31.7 (31.0–34.1)
1st exam PNA5.6 (5.0–6.4)5.6 (5.0–6.4)5.4 (5.0–6.1)5.4 (5.0–6.1)5.7 (5.1–6.7)
1st exam >42 days (N)59251379745
1st detection ROP PMANANA34.1 (32.4–36.0)34.3 (32.4–36.0)34.0 (32.3–35.6)
1st detection ROP PNANANA6.3 (5.3–7.7)6.3 (5.3–7.6)7.3 (6.0–8.0)
  • Number (n) of infants, screening examinations and initial examinations >42 days after birth.

  • Median values with 25–75 IQR for gestational age (GA), birth weight (BW), number of examinations, 1st screening examination and first detection of ROP.

  • exam, examination; NA, not applicable; PMA, postmenstrual age; PNA, post natal age; ROP, Retinopathy of Prematurity.