Objective To explore the effect of oxygen inhalation on the retinae of newborn rats and its mechanism.Methods We mimicked the retinopathy of prematurity(ROP) by putting the newborn rats in high concentrated oxygen. One-day old rats were put into the oxygen box with the oxygen concentration of 80% for continuous 7 days; then in air condition for 7 days. The arterial blood oxygen pressure, retinal superoxide dismutase (SOD), and malondialdehyde (MDA) of the rats (1,2,4,7,8,9,11,14 days old) were examined. The diameter of retinal vessels′main branch and the coverage rate of peripheral vessels were measured in 7- and 14-day-old rats by ink perfusion. The retinal neovascularization of rats (8,9,11, 14 days old) were observed by HE staining. The rats of the same age fed in air condition were in the control group.Results The differential pressures of blood oxygen of rats (1,2,4,7 days old) in study group were significantly higher than those in the control group (P＜0.01), while the differential pressures of blood oxygen of rats (8,9,11,14 days old) in study group were lower than those in the control group (P＞0.05). The contents of SOD of the retinae in the rats ( 1,2,4,7,8 days old) were significantly lower than those in the control group(P＜0.01, P＜0.05 ), while the contents of MDA were significantly higher than those in the control group (P＜0.01,P＜0.05). The diameter of retinal vessels′main branch in 7-day rats was 75% of the control group, and the coverage rate of peripheral vessels was 22% of the control group; and was 61% and 73% respectively in 14-day-old rats. The neovascularization could be seen in 16.7% of the rats in the study group and nought in the control group.Conclusion The damage of free radical of the retina in high concentrated oxygen and hypoxia situation after oxygen supply may be one of the most important mechanism of ROP. (Chin J Ocul Fundus Dis，2003，19：269-332)
ObjectiveTo observe the therapeutic effect of segmental scleral buckling and vitrectomy with/without lensectomy on the retinopathy of prematurity (ROP) stage 4a, 4b and 5. MethodsOne hundred and thirty-four ROP infants (181 eyes) diagnosed as stage 4a, 4b and 5, and performed with segmental scleral buckling or vitreous with/without lensectomy were retrospectively analyzed. The operated 4a-, 4b- and 5- stage eyes were 40, 51 and 90 eyes. The operational method depended on the location and severity of fibrovascular membrane. Of 181 eyes, segmental scleral buckling was referred for 37 eyes which include 23 eyes with 4a stage and 14 eyes with 4b stage; vitrectomy was referred for 50 eyes which include 14 eyes with 4a stage, 29 eyes with 4b stage and 7 eyes with 5 stage; vitrectomy with lensectomy was referred for 94 eyes which include 3 eyes with 4a stage, 8 eyes with 4b stage and 83 eyes with 5 stage. The effect was classified as success, improved and failure. Failure includes lost eye. Follow-up for 4a, 4b and 5 stage patients are 34, 31 and 29 months respectively. ResultsSegmental scleral buckling was referred for 37 eyes, success in 23 eyes (62.16%), improved in 11 eyes (29.73%), failure in 3 eyes (8.11%). Vitrectomy was referred for 50 eyes, and success in 20 eyes (40.00%), improved in 22 eyes (44.00%), and failure in 8 eyes (16.00%). In the total of 94 eyes underwent vitrectomy with lensectomy, 20 eyes was success (21.28%), improved in 17 eyes (18.08%), failure in 57 eyes (60.64%). In 40 stage 4a eyes, 33 successes (82.50%), 6 improved (15.00%) and 1 failure (2.50%). In 51 stage 4b eyes, 11 successes (21.57%), 30 improved (58.82%) and 10 failures (19.61%). For 90 stage 5 eyes, 14 successes (17.50%), 19 improved (23.75%) and 57 failures (71.25%). The therapeutic effect of segmental scleral buckling for stage 4a was better than that for stage 5 (χ2=6.707,P=0.035). The difference of therapeutic effect of vitrectomy for different stage was significant (χ2=21.010,P=0.000); stage 4a was the best; stage 4b was the second, stage 5 was the worst. The therapeutic effect of vitrectomy with lensectomy for stage 5 was worse than that for stage 4a and 4b (χ2=16.066,P=0.003). ConclusionThe surgery patterns of ROP was determined based on the disease severity, the surgery effects of stage 4a and 4b were better than stage 5, which had nothing to do with the surgical procedures.
ObjectiveTo observe the effect of retinal hemorrhage on the treatment of retinopathy of prematurity (ROP) by laser photocoagulation.MethodsRetrospective case analysis. Screening and diagnosis of 134 eyes in 67 patients with ROP in Zone Ⅱ Stage 3+ were included in the study. Among them, 32 patients were male and 35 patients were female. The average birth gestational age was 27.80±2.55 weeks. The average birth weight was 1060±320 g. All children underwent binocular indirect ophthalmoscopy and RetCam Ⅲ. Of the 134 eyes, 38 eyes (28%) with anterior, ridge or vitreous hemorrhage (group A); 96 eyes (72%) without hemorrhage. Retinal avascular photocoagulation was performed within 72 hours after diagnosis by intravenous sedative combined with ocular surface anesthesia with 810 nm laser. Follow-up was performed at 1, 4, 8 and 12 weeks after treatment, and then every 6 months thereafter. The same equipment and methods before treatment were used to examine and document the regression and progression of ROP. The number of eyes with lesions after photocoagulation in the two groups was compared by χ2 test. The t-test was used to compare the gestational age and birth weight.ResultsAmong 134 eyes, lesions completely resolved in 125 eyes (93.3%), progressed in 9 eyes (6.7%). In group A, 7 eyes were progressive (18.4%). In group B, 2 eyes were progressive (2.1%). There was a statistically significant difference in the number of eyes with lesions after laser treatment in group A and B (χ2=9.14, P=0.003). There was no significant difference in birth gestational age and birth weight (t=0.85, 0.25; P=0.40, 0.80).ConclusionThe laser photocoagulation is safe and effective in the treatment of ROP. The preretinal, ridge or vitreous hemorrhage is related to the progression of the lesion after laser photocoagulation.
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.
ObjectiveTo analyze the regulative rule of mRNA of vascular endothelial growth factor (VEGF) in mice with oxygen-induced retinopathy, and to elucidate the possible mechanism of occurrence of neovascularization in retinopathy of prematurity (ROP).MethodsSixty 7-day-old C57BL/6J mice were divided into oxygen-induced retinopathy group and control group. In oxygen-induced retinopathy group, 36 mice were exposed to 75% oxygen for 5 days and then to room air for 5 days; in control group, 24 mice were raised in room air. Vascular perfusion of fluorescein and retinal stretched preparation were used to observe the morphologic changes of retinal vessels. Reversal transcriptionpolymerase chain reaction (RT-PCR) was used to observe changes of VEGF mRNA in each group. ResultsIn oxygen-induced retinopathy group, the morphologic characteristics of retinal vessels were the unperfused area at the center of superficial and deepseated vessels, and the neovascularization appeared at mid-peripheral retina after 2 days in relative hypoxia condition. The results of RT-PCR showed space-time corresponding relation between expression of VEGF and neovascularization, which meant that the transcription of VEGF mRNA decreased in hyperxia conditionand increased in relative hypoxia condition. ConclusionHypoxia is the main reason of occurrence of retinal neovascularization; increased expression of VEGF caused by relative hypoxia after hyperxia might be effective in reducing the occurrence of neovascularization in ROP.(Chin J Ocul Fundus Dis, 2005,21:292-295)
ObjectiveTo detect the effect of adeno-associated-virus induced Kringles5 gene on retinal neovascularization in rats with retinopathy of prematurity (ROP), and to explore the new ways of treatment for ROP.MethodspSNAV-Kringle5-gfp carrier was constructed by subclone and adeno-associated-virus was packed to form rAAV-Kringle5-gfp. ROP model was set up under circumstances of high oxygen in 21 SD rats which were divided into experimental (21 eyes) and control group (21 eyes). Eighteen eyes from each group was used to making the histologic section of retina, and the other 3 eyes in each group was detected by polymerase chain reaction (PCR) and Western blotting. There were 5 rats in the normal control group. AAV-Kringle5-gfp with the dosage of 10 μl and titer of 2.5×1012vg/ml was injected into the eyes in experimental group, while rAAVlacZ with the same dosage and titer of 2.5×1011vg/ml was injected in to the eyes in control group. The expression of target gene in ocular tissues was observed under the fluoroscope. Twelve weeks later, the rats were executed, and the staining of Ⅷ factor related antigens in retinal vascular endothelial cells was performed and number of nucleolus of vascular endothelial cells were counted. ResultsThe plasmid of pSNAV-Kringle5-gfp was correct according to the sequence measurement; the expression of rAAV-Kringle5-gfp was found in vitreous cavity and on retina; the expression of target gene was found on the level of mRNA and protein; the number of nucleolus of vascular endothelial cells on the surface of retina was (19.954 2±3.825 7) in experimental group and (7.335 2±2.731 3) in the control group, which had significant difference between the two groups (P＜0.01）.ConclusionsAdeno-associated-virus induced Kringles5 gene can inhibit the occurrence of retinal neovascularization in patients with ROP.(Chin J Ocul Fundus Dis, 2005,21:288-291)
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.
ObjectiveTo observe the effect of breastfeeding on the incidence of retinopathy of prematurity (ROP).MethodsA retrospective clinical study. From June 2017 to December 2019, 1256 eyes of 628 premature infants who were born in Ningbo Women and Children's Hospital and were screened for ROP were included in the study. Among them, there were in 325 males (650 eyes) and 303 females (606 eyes). According to the feeding situation, premature infants were divided into breastfeeding (research) group and formula feeding (control) group, with 390 cases of 780 eyes and 238 cases of 476 eyes, respectively. The changes in the retina of the fundus of the two groups of premature infants during the observation period were compared. The qualitative data comparison between groups was performed by the χ2 test; the quantitative data comparison was performed by the two independent sample t test.ResultsThe sex ratio of premature infants in the study group and control group (χ2=0.217), birth weight (t=0.728), gestational age at birth (t=0.351), Apgar score at birth (t=0.816), oxygen inhalation time (t=0.427), were compared with the length of stay in the neonatal intensive care unit (t=1.580), the difference was not statistically significant (P＞0.05). Among the 390 cases in the study group, 108 cases (27.7%, 108/390) and 282 cases (72.3%, 282/390) were with or without ROP, respectively; in the 238 cases in the control group, 86 (36.1%, 86/238) were with ROP, 152 (63.9%, 152/238) cases were without ROP. There was a statistically significant difference in the incidence of ROP between the two groups (χ2=4.934, P=0.026). Among the 108 cases of ROP in the study group, 50 (12.8%, 50/108), 35 (9.0%, 35/108), 23 (5.9%, 23/108) cases were in stage 1, 2 and 3, respectively. Among the 86 ROP cases in the control group, stages 1, 2 and 3 were 25 (10.5%, 25/86), 40 (16.8%, 40/86), and 21 (8.8%, 21/86), respectively. In the comparison of ROP staging between the two groups, the difference in stage 1 was not statistically significant (χ2=0.754, P＞0.05), and the difference in stage 2 and above was statistically significant (χ2=11.400, P＜0.05).ConclusionBreastfeeding may reduce the incidence and severity of ROP.
ObjectiveTo investigate the efficacy of laser photocoagulation and intravitreal ranibizumab treatment of retinopathy of premature(ROP). MethodsThis study included 49 ROP infants (96 eyes), including type 1 pre-threshold ROP (7 infants, 14 eyes), threshold ROP (38 infants, 44 eyes) and aggressive posterior ROP (AP-ROP, 4 infants, 8 eyes). According to the treatments received, all patients were divided into laser photocoagulation (LP) group (40 infants, 78 eyes) and intravitreal ranibizumab (IVR) treatment group (9 infants, 18 eyes). Generally, zoneⅡand stage 3 ROP with clear refractive media received laser photocoagulation, zoneⅠROP and AP-ROP, or eyes with unclear refractive media or infants with poor general condition received IVR. The infant gestational age, birth weight, corrected gestational age at first treatment and the cure rate of the first treatment were analyzed between the two groups, and between three disease types (type 1 pre-threshold, threshold and AP-ROP). ResultsThe gestational age and birth weight was no difference between the LP group and IVR group (t=0.827, 1.911; P > 0.05). The corrected gestational age at first treatment of LP group was significantly smaller than that in the IVR group (t=3.041, P < 0.05). In the LP group, 75 of 78 eyes (96.15%) was cured by the first treatment, 3 of 78 eyes (3.85%) progressed to stage 4A after the first treatment and was controlled by vitrectomy. In the IVR group, 8 of 18 eyes (44.44%) was cured by the first treatment, 10 of 18 eyes (55.56%) progressed to next stage after the first treatment and was controlled by additional laser photocoagulation or repeated IVR. The gestational age and birth weight was no difference between type 1 pre-threshold, threshold and AP-ROP infants (t=2.071, 0.664; P > 0.05). The corrected gestational age at first treatment of type 1 pre-threshold infants was the same of the threshold lesion infants (t=2.054, P > 0.05). The corrected gestational age at first treatment of AP-ROP infants was significantly smaller than that of type 1 pre-threshold and threshold lesion infants (t=3.250, P < 0.05). The cure rate was statistically significant (χ2=24.787, P < 0.05) between there three ROP lesions. ConclusionIVR treatment is suitable for zoneⅠlesions, AP-ROP and Plus lesions, while laser photocoagulation is appropriate for zoneⅡlesions with fibrosis and less vascular proliferation.