Clinical Analyses On The Risk Factors Of 136 Cases And Approachs For Screening Of 112 Cases Of Retinopathy Of Prematurity

Retinopathy of prematurity(ROP) is a disease of developing retinal blood vessels that occurs most frequently in very low birth weight(BW) and short gestation age(GA). Along with development of neonatal intensive care unit(NICU) and treatment for premature infant and low birth weight infants especially extremely low birth weight infants, the incidence of ROP is also increasing. We should know the high risk factors of ROP to prevent ROP in the preterm infants. The pathogenesis of ROP is still poor understood. Now BW and GA are considered significant as risk factors for ROP. There are, however, many other risk factors for ROP. Multiple risk factors associated with the development of ROP have been studied. Various definitions of variables were used, but those risk factors including sex, oxygen therapy, anemia, transfusion, metabolic acidosis, infection, apnea and some drugs considered significant were different in each study. It is important to diagnose early before the treatment of ROP, but the screening for ROP isn't prevalence in our country. Except indirect ophthalmoscope, digital retinal camera (RetCam) and B-ultrasound are raised to screening the ROP at home and abroad. We should enhance the screening for ROP in every neonatal unit to reduce the impairment of eyesight induced by ROP.The purpose of this study is to obtain the epidemiology data of the incidence of ROP and analyze the high risk factors on the development of ROP. And we compared the method of B-ultrasound and RetCam in screening ROP to the standard method of screening for ROP by ophthalmologic examination.First, 136 cases who were preterm infants and accepted treatment in our department from Mar. 8th 2007 to Mar. 8th 2008 were followed up and analyzed retrospectively in the study. Their clinical data were integrated. They were divided into observation group and control group according to whether they were diagnosed ROP by indirect ophthalmoscope. Data were compared between two groups in 14 potential factors, including BW, GA, sex, time of oxygen therapy, the maximal concentration, the maximal pressure of artery, metabolic acidosis, pneumonia, sepsis, anemia, transfusion, using dopamine, using pulmonary surfactant (PS) and apnea. Chi-square test was used to analyze all potential factors with the method of single-factors analysis. In order to remove interfere factor, multivariate analysis by multiple logistic regression was performed to determine which factors had an independent significant association with developing ROP. Differences with a P value of <0.05 were considered significant. Second, 112 cases who were preterm infants and accepted treatment in our department from Jun.1st 2007 to Mar. 8th 2008 were followed up and analyzed retrospectively in the study. Now indirect ophthalmoscope is the gold standard for ROP screening. B-ultrasound, RetCam and indirect ophthalmoscope were performed on infants in one day to evaluate the effectiveness and practicality of RetCam and B-ultrasound.In the first segment of this study, the incidence of ROP( including single eye or double eyes) was 23.7% in this research. The rate of different BW was 67.7% in BW<1000g group, 43.2% in 1000g≤BW<1500g group, 16.4% in 1500g≤BW<2000g group and 2.9% in BW≥2000g group. The rate of different GA was 43.5% in GA<30 weeks group, 37.9% in 30 weeks≤GA<32 weeks group, 15.8% in 32 weeks≤GA<34 weeks group and 3.7% in GA≥34 weeks group. According to the result of single-factors analysis, there were significantly difference between with and without ROP group in BW, GA, time of oxygen therapy, the maximal concentration of oxygen therapy, anemia, transfusion, using dopamine, using PS(p<0.05). Multi-factors Logistic regression analysis showed BW(p=0.07), GA(p=0.06), the maximal concentration of oxygen (p=0.028) as independent significant risk factors for the development of ROP, and using PS(p=0.039) as a protective factors for ROP. In the second segment, ROP were detected in 44 eyes by indirect ophthalmoscope and no ROP were detected in 180 eyes. By RetCam, ROP were detected in 46 eyes, in which 43 eyes were identified by indirect ophthalmoscope and 3 eyes were no ROP by indirect ophthalmoscope. A stageⅠROP in zone 3 was underdiagnosed. Sensitivity of RetCam was 97.7% (43/44) and specificity was 98.3% (177/180). The positive and negative predictive values were 93.5% and 99.4% respectively. In this study, stageⅢwere detected in 13 eyes by B-ultrasound. 11 eyes were identified by indirect ophthalmoscope and 2 eyes were no ROP. Sensitivity of B-ultrasound was 25% (11/44) and specificity was 98.9% (178/180). The positive and negative predictive values were 84.6% and 84.4% respectively. We didn't find stageⅠand stageⅡROP by B-ultrasound. 9 eyes were identified as stageⅢROP, 2 eyes were identified as stageⅡROP and 2 eyes were identified no ROP in eyes that were detected as stageⅢROP by B-ultrasound.In this study, we could summarize 6 conclusions.First, the incidence of ROP( including single eye or double eyes) was 23.7% in this research. The rate of different BW was 67.7% in BW<1000g group, 43.2% in 1000g≤BW<1500g group, 16.4% in 1500g≤BW<2000g group and 2.9% in BW≥2000g group. The rate of different GA was 43.5% in GA<30 weeks group, 37.9% in 30 weeks≤GA<32 weeks group, 15.8% in 32 weeks≤GA<34 weeks group and 3.7% in GA≥34 weeks group.Second, the independent siginificant risk factors of ROP were BW, GA and the maximal concentration of oxygen.Third, using PS was a protective factor for the development of ROP. Forth, time of oxygen therapy, anemia, transfusion and using dopamine were probably risk factors of ROP.Fifth, the sensitivity and the specificity were all satisfactory in screening for ROP by RetCam and it also has many advantages compared with the indirect ophthalmoscope. We should extend the use of RetCam in screening for ROP.Sixth, B-ultrasound was not an effective method in screening for ROP, but because of its sinple and safe operation, we should advace its technique to enhance the rate of ROP diagnosis.