Table 1

Baseline characteristics of the patients

EMONO group (n=22)Control group (n=18)
Gestational age at birth (weeks)27.8±1.628.1±1.7
Corrected gestational age at examination (weeks)35.0±1.835.4±1.5
Birth weight (g)1003.4±199.01052.2±297.9
Weight at examination (g)2174.5±426.52174.4±373.1
Male/female13/99/9
Clinical Risk Index for Babies II Score309.0±2.68.3±2.6
Completed antenatal steroids* (%)16 (72.7)15 (83.3)
Prior intubation (%)12 (54.5)11 (61.1)
On supplemental oxygen by nasal cannula at the time of examination (%)12 (54.5)7 (38.9)
On caffeine at the time of examination (%)12 (54.5)10 (55.6)
Prior IVH grade II or IV, PVL (%)311 (4.5)1 (5.6)
Prior ligation of patent ductus arteriosus6 (27.2)5 (27.8)
Number of previous eye examinations1.4±1.91.4±1.3
Previous surgery for retinopathy of prematurity (%)1 (4.5)1 (5.6)
Number of painful procedures in the 24 h preceding the eye examination0.23±0.430.11±0.32
  • * Received two doses of 12 mg intramuscular betamethasone 24 h apart or four doses of intramuscular dexamethasone at 12-h intervals.

  • EMONO, equimolar mixture of nitrous oxide and oxygen; IVH, intraventricular haemorrhage; PVL, periventricular leukomalacia.