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)
Objectives To observe the characteristics of occurrence a nd progres s of retinopathy of prematurity (ROP) in premature infants and search the reason able ROP screening time and therapeutic methods.〓〖WTHZ〗Methods〓〖WTBZ〗ROP s creening was perf ormed on 829 infants, with the gestational agele;35 weeks and the birth weightle; 2000 g, by indirect ophthalmoscopy combined with scleral pressurizing implement. Thirtytwo infants with prethreshold type I and threshold ROP underwent cryot he rapy. The followup duration after the operation was 316 months, and the crit er ia of the control of the diseases included: alleviation of the plus disease, all eviation of the vascular ridge, formation of the cryospots, absorption of vitr e oretinal hemorrhage, and non bad retinal structure. If the disease was not contr olled, recryotherapy or vitrectomy would be carried out.〓〖WTHZ〗Results〓〖W TBZ〗ROP was fou nd in 86 infants (172 eyes). The difference of oxygen duration time among ROP g roups and nonROP group was significant; the occurrence rate of ROP in the infa n ts with the birth weightle;1000 g, 10011500 g and 15012000 g was 6956%, 16 38% , and 414%, respectively; the occurrence rate of ROP in the infants with the g estat ional agele;30 weeks, 3132 weeks, and 3335 weeks was 37.14%, 10.43%, and 2.91 %, respectively; the occurrence rate of ROP in singleembryo infants group and mul t iple embryo infants group was 7.52% and 20.22%, respectively. Favorable outcom e was observed in 30 out of 32 infants who had undergone cryotherapy; 2 infants d eveloped retinal detachment with plus disease and peripheral retinal hemorrhage. The sccess rate of cryotherapy is high in the infants with the gestational age lt;32 weeks.〓〖WTHZ〗Conclusions〓〖WTBZ〗The ROP incidence rate is higher in the infants with lo ng oxygenbreathing duration, birth weighle;1000 g, and gestational age le; 32 we ek infants, which should be screened carefully. The infants having ROP onset within 32 weeks, with plus disease, and peripheral retinal hemorrhage should be follow ed up closely. The prognosis of cryotherapy for type I prethreshold and thresh old ROP is good and the operation is safe.
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.
Objective To observe the characteristics of morphological development of premature retina at 33-46 weeks of gestational corrected age (GCA). Methods A total of 268 premature infants were divided into 7 groups according to the GCA (33-34，35-36，37-38，39-40，41-42，43-44 and 45-46 weeks). The ocular fundus of those infants were recorded and analyzed by an indirect ophthalmoscopelinked imaging system. Results As GCA increases, noticeable macular morphological changes occurred and recorded in 96% of infant at 45-46 weeks of GCA. Retinas were gradually vascularized at 41-42 weeks (nasal retina) or 43-44 weeks (area Ⅲ,temporal retina), and pigmented in 84% of infant at 45-46 weeks of GCA. Conclusion Macular morphological patterns, retinal blood vessels and pigments continue to develop in postnatal premature infants.
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.