Objective To explore the effect of polycythemia on retinopathy of prematurity (ROP). Methods The clinical data of 262 premature cases was analyzed retrospectively in Xi'an Children Hospital from January 2005 to January 2009. Polycythemia was found in 46 cases (17.56%), including 27 males and 19 females. In 216 infants without polycythemia (82.46%), 155 were male and 61 were female. The difference of the birth weight (t=0.730, P=0.466), gestational age (t=1.603,P=0.110), oxygen inhalation numbers (chi;2=0.04,P＞0.90) and times (t=1.225,P=0.223), and concentration (t=1.823,P=0.071) between polycythemia group and no polycythemia group were not significant. In order to diagnose ROP, the ocular fundus of all premature infants was examined with binocular indirect ophthalmoscope,and the stage of ROP was assessed.Results In all the premature infants,ROP was found in 120 cases (45.80%). In 46 cases of polycythemia, ROP was found in 25 cases (54.34%); in 216 infants without polycythemia, ROP was found in 95 cases (43.98%); the difference of ROP incidence between the two groups was not significant (chi;2=1.64, Pgt;0.1).In 120 ROP patients, 104 cases (86.67%) with ROP＜3 stage and 16 cases (13.33%) with ROP ge;3 stage were found. In 25 ROP patients with polycythemia, 18 cases (72.00%) with ROP ＜3 stage and 7 cases (28.00%) with ROP ge;3 stage were found. In 95 ROP patients without polycythemia, 86 cases (90.53%) with ROP ＜3 stage and 9 cases (9.47%) with ROP ge;3 stage were found. The difference of the incidence of ROP ＜and ge;3 stage between the two group was significant (chi;2=4.38, Plt;0.05). In 120 cases of ROP, prethreshold retinopathy was found in 106 cases (88.33%), while threshold and post-threshold retinopathy was in 14 cases (11.67%). In 25 ROP patients with polycythemia, prethreshold retinopathy was found in 19 cases (76.00%), and threshold and post-threshold retinopathy was in 6 cases (24.00%).In 95 ROP infants without polycythemia, pre-threshold retinopathy was found in 87 cases (91.58%),while threshold and post threshold retinopathy was in 8 cases (8.42%).The difference of the incidence of ROP with prethreshold, and threshold and post-threshold retinopathy between the two groups was not significant (chi;2=3.27,P＞0.05).Conclusion Polycythemia may not affect the incidence of ROP,but impact on the severity of ROP.
Objective To determine the incidence of and risk fact ors for retino pathy of prematurity (ROP) among preterm infants in Beijing after implementation of the ROP guidelines. Methods The preterm infants with birth weight le; 2000 g or gestational age le; 3 4 weeks who were admitted to the neonatal intensive care units in 6 hospitals in Beijing from Jan. 1, 2005 to Dec. 31, 2005 were screened. Ophthalmologic examin ations started 3-4 weeks after birth and ROP was classified by the revised Inte r national Classification. Maternal and perinatal risk factors of occurrence of R OP were analyzed. Results In the 639 infants who had been scre ened in the 6 ho spitals, ROP was detected in 69 (10.8%), in whom 23 infants (39 eyes) (3.6%) had type 1 ROP and underwent photocoagulation. The lower the birth weight and small er the gestational age was, the higher the incidence of ROP was. Logistic regres sion analysis indicated that low birth weight, apnea gt;20 seconds, anemia, hypoxic-ischemic encephalopathy and placenta abruption were the high risk factor of R O P.Conclusion In Beijing the incidence of ROP is 10.8% after i mplementation of the ROP guidelines. Low birth weight, apnea gt;20 seconds, anemia, hypoxicischem ic encephalopathy and placenta abruption were the high risk factor of ROP.
Objective To determine the association between the geneti c polymorp hisms of vascular endothelial growth factor (VEGF) gene and the prognosis for retinopathy of prematurity (ROP) in Chinese. Methods Twenty infants with threshold ROP who had undergone retinal photocoagulation were in the treated group and 20 infants with self-regressed ROP without any treatment were in the control grou p . In the two groups, all the infants had oxygen-breathing history and the sex a n d gestational age were all suitable to be compared, except birth weight. Polymer ase chains reaction-restriction fragment length polymorphism was used to determine the frequencies of VEGF genes in the two groups. Results The frequencies of +405C allele were higher in the treated group than those in the control group (P＜0.05). The frequencies of the VEGF-460T/C and +936C/T ploymorphisms were similar in both groups (P＞0.05). Conclusions The +4 05C/G ge netic polymorphisms of VEGF may correlate to the prognosis of ROP. The carriers of +405CC allele are more susceptible to ROP.
Objective To investigate the incidence of retinopathy of prematuri ty (ROP) in the area of Shanghai, and to provide the preliminary data for the ev aluation of present criteria for ROP screening. Methods Record s of 289 prematur e infants who had undergone ROP screening from the four NICU in Shanghai between February 2004 and January 2005 were analyzed. Screening criteria included prete rm infants or low birth weight (LBW) infants with BW of 2000g or less. The first examination starts at 4 to 6 weeks chronologic age or 32 weeks post conceptual age. Results In the 289 screened infants, 19 had developed acu te ROP. There we re 3 threshold ROP, 7 prethreshold ROP and 9 developed ROP less than prethreshol d. The incidence of ROP was 6.6%. According to the British recommended guideline s（BWle;1500 g or GAle;31 weeks）, only 119 out of 289 needed screening and one ca se of stage 1 ROP was missed; the incidence of ROP was 15.1% (18/119). When lowered sc reening criteria to the American guidelines（BWle;1500g or GAle;28 weeks）, t here were only 83 infants needed screening, and we missed 2 stage 1 and 1 prethreshold ROP and the incidence of ROP was 19.3% (16/83). Conclusions The i ncidence of ROP i s 6.6% according to our study. It is lower than other reports and it has somethi ng to do with our present screening guideline. Further epidemiological data are needed to modify the guideline accordingly.
Objective To learn the screening results of retinopathy o f prematur ity (ROP) of the preterm infants in three hospitals in Shenzhen. Metho ds From Jan. 2004 to Jan. 2007, 1372 preterm infants (2744 eyes) with birth weight lt;200 0 g or but the ones having severe systemic disease in Shenzhen People's Hospita l, Shenzhen Maternity and Child Healthcare Hospital and Shenzhen Eye Hospital we re screened for ROP with binocular indirect ophthalmoscope and (or) widefield digital pediatric retinal imaging system (RetCamII). Cryotherapy or laser photoco agulation was performed if threshold or pre-threshold type I ROP was found. All preterm infants were followed up until retina is completely vascularized or the disease regressed. Results In all the infants, 218 cases (436 eyes) (15.9％) developed ROP, including 190 eyes (6.9％) suffering from threshold or pre-threshold type 1 ROP, 16 eyes (0.6％) from stage 4 or stage 5, and 230 eyes (8.4％) from stages below threshold or pre-threshold type 1 ROP. There were 435 infants ( 870 eyes) (31.7%) with BW of 1500g or less, in which 236 eyes (27.1％) developed ROP, including 126 eyes (14.5％) suffering from threshold or pre-threshold type 1 ROP, 10 eyes (1.1％) from stage 4 or stage 5, and 100 eyes (11.5％) from stages below threshold or pre-threshold type 1 ROP. There were 137 infants 274 eyes (10%) with BW of 1250g or less, in which 108 eyes (39.4％) developed ROP, including 60 eyes (21.9％) suffering from th reshold or pre-threshold type 1 ROP, 4 eyes (1.4％) from stage 4 or stage 5, and 44 eyes (16％) from stages below threshold or pre-threshold type 1 ROP. Th eincidence of ROP（chi;2=60.43，Plt;0.001）, the incidence of threshold or pre-threshold type 1 ROP（chi;2=46.82，Plt;0.001）and the incidence of below threshold or pre-threshold type 1 ROP （chi;2=10.71，P=0.005）among the total group, BWle;1500g group and BWle;1250g group had statistical differences. Conclusions The incidence of ROP in the three hospitals in Shenzhen was lower. However, the incidence of severe ROP (threshold or pre-threshold type 1 ROP) was higher. Birth weight is an important factor to affect ROP incidence.
Objective To investigate the effect of inducible nitric oxide synth ase (iNOS) or cyclooxygenase－2 (COX－2) on retinal neovascularization and its possible mechanism in oxygen－induced retinopathy （OIR） mouse model. Methods Retinal neovascularization was induced by oxygen with different concentration. The expression of iNOS, COX－2, matrix metalloproteinases 2 (MMP－2) and vascular end othelial growth factor (VEGF) in the retinae of experimental animals were analyzed by immunohistochemistry, realtime polymerase chain reaction and western blotting technologies. Results The inhibition of COX－2 or iNOS obviously attenuated retinal neovascularization and decreased the expression of VEGF and MMP－2. The iNOS inhibition decreased COX－2 expression, and vice versa. Conclusions COX－2 and iNOS may play a role in retinal neovascularization in OIR mouse model, which may act by regulating the expression of VEGF and MMP－2.
Objective To observe the expression of erythropoietin (EPO) and its receptor (EPOR) mRNA and protein levels in retinae of mice with oxygen-induced retinopathy, and to evaluate the effect of EPO and EPOR in retinal vascular develo pment and in the occurrence and development of oxygen-induced retinopathy. Methods One hundred and thirty-two 7-day-old C57BL/6J mice were divided into two g rou ps: normal control group (control group) and oxygen-induced retinopathy group (experimental group). The proliferative neovascular response was estimated by obse rving the vascular pattern in adenosine diphosphatease (ADPase) stained retina flat-mounts by executing 6 mice in each group at the 12th, 15th, and 17th day, respectively. The expression of EPO, EPOR mRNA was determined by reverse transcription-polym erase chain reaction (RT-PCR), and the protein levels of EPO and E PO R were determined by immunohistochemistry. RT-PCR and immunohistochemistry were done every other day from the 7th to the 21st day. Results In the control group, retinal vascularization was found. In the experimental group, the large vesse ls were constricted straight, the branches decreased, and alarge nonperfusion area was observed at the 12th day; the large vessels were dilated and tortuous and neovascularization occurred at the 15th day; a mass of neovascularization was found and the vascular net structure of the deep and shallow layer was destroye d at the 17th day. The expression of EPO mRNA decreased from the 7th day and kee p decreasing in the whole oxygen-breathing duration in the experimental group. A fter the mice were returned to room air, the expression increased obviously from the 15th day and kept the high level until the 21st day. The expression of EPO mRNA increased at the 7th day and reached the peak at the 11th day, and kept the high level until the 21st day. The changes of protein levels of these three fac tors were later than that of their mRNA, but had the same trend. The difference of the expression between the two groups at the different time point was signifi cant except for the 7thday point (Plt;0.05). Conclusion It 's suggested that EPO and EPOR played important roles on the development of normal retina vascularizati on and the pathogenesis of ROP, which may provide new conception and method for the prevention and treatment of the oxygen-induced retinopathy.