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 analysis the fundus characteristics of fundus fluorescein angiography (FFA) of retinopathy of prematurity (ROP). MethodsEighty-four cases (168 eyes) who were diagnosed with ROP by a binocular indirect ophthalmoscope were included in the study. Among the 84 cases, there were 2 cases (4 eyes) of stage 1 ROP, 26 cases (52 eyes) of stage 2 ROP, 40 cases (80 eyes) of stage 3 ROP, 4 cases (8 eyes) of stage 4 ROP, and 4 cases (8 eyes) of stage 5 ROP, 9 cases (18 eyes) of plus disease, 8 cases (16 eyes) of aggressive posterior ROP (APROP). All infants received FFA with RetCam Ⅱ under general anesthesia and mydriasis. The retinal vein morphology, capillary filling state, neovascularization morphology and fluorescein leakage were observed. ResultsFFA revealed increased branching, expansion and tortuous peripheral retinal capillaries, increased capillary permeability with a small amount of fluorescein leakage in stage 1 ROP. There was a clear dividing line between the vascular area and the remote avascular area. In stage 2, the peripheral branches of temporal retinal blood vessels increased, and parallel distributed like a broom. The capillary end anastomosed with each other to form a loop. The fibrous tissues at the lesion edge proliferated as a ridge, with popcorn phenomenon. In stage 3, the ridge continued broadening, and the neovascular fibrous membrane formed breakthrough internal limiting membrane, stretched into the vitreous with a lot of fluorescein leakage. The ridge and remote avascular zone demarcated clearly. In stage 4 and 5, the vessel changes had similar phenomenon with the stage 2 and 3 in undetached retina, but the vessels in the detached retina expanded with fluorescein leakage. As for plus disease, the retinal arterioles in the posterior pole were tortuous, there were a large number of non-perfusion area in the peripheral retina with hemorrhage and obscured fluorescence. The retinal vessels in posterior pole in AP-ROP were also tortuous, and the capillaries were extreme expanded, while there were very few tortuous vessels and no capillary formation in the other part of retina.At the avascular zone boundaries, there were a large group of neovascularization with fluorescein leakage. ConclusionsThe demarcation line separating the avascular from the vascularized retinal regions is formed in stage 1, 2 and 3, and the amount of fluorescein leakage gradually increase from stage 1 to stage 3 ROP. The detached retina of stage 4 and stage 5 has an unclear focal length in the FFA. The plus disease mainly has arteriolar tortuosity in the posterior pole retina. In the AP-ROP cases, both of the arterioles and venules in posterior pole of retina are tortuous and expanding with neovascularization leakage of fluorescein.
Objective To determine the effect of methimazole (MMI) on retinal vascular development in neonatal rats, and to investigate the relationship between the concentration of insulin-like growth factor-I (IGF-I) in serum and the development of normal blood vessels and between the concentration of IGF-I and the formation of abnormal blood vessels. Methods There were 75 neonatal SpragueDawley rats in experimental group whose mothers were raised with water with 0.1% MMI at the first day of parturition. Another 50 neonatal rats were in the control group whose mothers were raised with normal water. The rats in the two groups were sub-divided into 4day and 10day subgroup, respectively. The retinal flatmount of the right eyes were stained with adenosine diphosphatase (ADPase); with the paraffin section of the left eyes, the number of nucleolus breaking through retinal inner limiting membrane was counted and the retinal blood vessels were evaluated. Serum IGF-I levels were detected by radioimmunoassay, and the weight of the neonatal rats in each group were observed and recorded. Results The incidence of retinal neovascularization in 10 day MMI group was 27%, and 0% in 4-day MMI group and control group. The serum IGF-I level in 4-day and 10-day MMI group (73.07 ng/ml, 175.13 ng/ml) was obviously lower than which in the 4-day and 10-day control group (168.73 ng/ml,306.38 ng/ml) （P=0.00）. Obvious slow growth of the neonatal rats was found in MMI group compared with which in the control group. Conculsions MMI may inhibit the normal growth of retinal blood vessels and lead neovascularization, which may relate to the initial decrease of the serum IGF-I level. (Chin J Ocul Fundus Dis, 2007, 23: 198-201)
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.
ObjectiveTo evaluate the efficacy and safety of intravitreal ranibizumab (IVR) for the treatment of retinopathy of prematurity(ROP). MethodsA total of 57 eyes of 29 premature infants with diagnosis of high-risk pre-threshold, threshold ROP, or aggressive posterior ROP were reviewed and analyzed in the study. The lesions of 18 eyes were located in zoneⅠ, 39 eyes were located in zoneⅡ. All infants in the study received IVR (10 mg/ml, 0.025 ml) as the initial treatment within 24 hours after diagnosis. Follow-up examinations were performed after treatment, every week at the first month, every 2 weeks at the second and third month, every month afterward, until vascularization of zoneⅢwas observed. Follow-up ranged from 16 weeks to 52 weeks, and the average follow-up time was (28.1±11.7) weeks. If the infants didn't respond positively to the treatment or the disease recurred, the additional treatments were applied. 36 eyes (63.2%) received a single injection, whereas 21 eyes (36.8%) received additional treatments. The follow-up examinations included the development of retinal vessels, the ocular or systemic adverse events. ResultsAmong the eyes, the development of peripheral retinal vessels could be observed in 36 eyes (63.2%) which received a single injection; clinical improvement in 11 eye (19.3%) which received repeat injection; stable disease in 10 eyes (17.5%) which received laser therapy. Among the eyes, 18 eyes (31.6%) recurred, including ggressive posterior ROP (14 eyes), threshold ROP (2 eyes) and high-risk pre-threshold ROP (2 eyes). The mean time of recurrence was (5.7±2.1) weeks (range 2.0-8.0 weeks). Three eyes (5.3%) of high-risk pre-threshold, threshold ROP lacked a positive response to the treatment. The lesions were controlled after additional laser given in these eyes. No serious ocular or systemic adverse events associated with the drug or the injection was observed during the follow-up period. ConclusionIVR is safe and effective for most ROP infants. In cases of recurrence or no response, conventional laser treatment or an additional IVR injection were needed.