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Retinopathy of prematurity: screening, incidence and risk factors analysis.

BACKGROUND
The sequela of retinopathy of prematurity (ROP) is an important cause of infant blindness. This study was designed to screen the high-risk premature infants and investigate the incidence and risk factors associated with the development of ROP.


METHODS
From October 1997 to October 1998, all premature infants with birth body weight (BBW) less than 2000 gm or gestational age (GA) less than 36 weeks were enrolled and underwent ophthalmologic examination at 4 to 6 weeks of age at Taipei Veterans General Hospital. The perinatal variables were analyzed to evaluate their correlation with the development of ROP.


RESULTS
In totally 108 premature infants, the incidence for development of ROP was 25% (27 in 108 patients). The threshold ROP occurred in 15 eyes (7%). The average BBW and GA (1267+/-341 gm and 29.7+/-2.7 weeks) were significantly lower in ROP group than in the non-ROP group (1703+/-368 gm and 32.3+/-2.2 weeks). The artificial ventilation for more than 5 days, chronic lung disease and periventricular leukomalacia were significant risk factors associated with highest rate of ROP. The respiratory distress syndrome, intraventricular hemorrhage, congenital heart disease and sepsis were significant risk factors accompanied by moderate rate of ROP.


CONCLUSION
Low birth body weight and young gestational age are the most important risk factors in the development of ROP. The analysis of risk factors will be helpful in understanding and prediction of ROP formation in high-risk neonates. The timely clinical screening retina examination of high-risk premature infants is important to prevent the development of advanced ROP.