[A multivariate analysis of prevalence and risk factors of retinopathy of prematurity].

OBJECTIVE

To investigate the prevalence and risk factors of retinopathy of prematurity (ROP).

METHODS

This investigation involved 125 premature infants admitted in the neonate intensive unit between July 1st, 2006 and Feb 1st, 2007, who were less than 37 weeks of postconceptional age, or more than 37 weeks but with birth weight <2500 g. At the fourth postnatal week or the corrected gestational age of 32 to 34 weeks, the infants underwent ROP examination of both eyes using RetCam digital retinal camera. Diagnosis and staging of ROP were established according to the international guidelines, with another 20 full-term infants as the control group.

RESULTS

All the 125 infants completed the follow up. The prevalence of ROP in the premature group was 6.4%, while no ROP was found in the control group. Of the premature infants, the prevalence of ROP in infants with birth weight </=2000 g (12.7%) was significantly higher than that in those with birth weight more than 2 000 g (0 , %KHgr;(2) =6. 42, P=0.01). In premature infants with postconceptional age </=32 weeks, the prevalence of ROP reached 17.5%, significantly higher than that in infants with postconceptional age over 32 weeks (1.1% , Chi(2)=9.52, P=0.002). The postconceptional age (OR=0.865, P=0.038) and birth weight (OR=0.768, P=0.042) were identified as the most important risk factors for ROP, and correlation was not found between ROP and oxygen inhalation mode, mechanical ventilation, use of indomethacin, or maternal conditions.

CONCLUSIONS

The prevalence of ROP is significantly higher in premature infants than in full-term infants, and shorter postconceptional age and lower body weight at birth are associated with increased risk of ROP. Routine examination of the ocular fundus of premature infants on a regular basis can be helpful for early detection of ROP.