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Query: UMLS:C0728731 (prematurity)
 7,134 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We compiled the results of pars plana vitrectomy in rare proliferative and hemorrhagic diseases. In retinal vasculitis of unknown origin (perhaps Eales' disease), six out of seven eyes had visual improvement; in sickle cell disease, two out of three eyes improved. Three eyes with presumed toxocariasis were successfully treated. In retrolental fibroplasia (RLF), only lighter degrees of the cicatricial stage with traction detachments can be treated. Some cases may simulate Coats' disease. There are also cases which simulate the typical picture of RLF, where there is no history of prematurity or oxygen usage. Five patients with RLF were treated, three of these successfully. Cryoglobulinemia (one case) and hereditary hemorrhagic telangiectasia (one case) were successfully treated. Senile macular degeneration can also be an indication for vitrectomy (two out of three eyes were successfully treated).
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PMID:Results of vitrectomy for rare proliferative and hemorrhagic diseases. 57 91

A premature infant who was developing cicatricial retrolental fibroplasia, was given cryotherapy to both eyes. This stopped the progress of the disease in almost all areas of the retina. The infant died three months later of complications related to prematurity. A comparison between the inadequately treated areas and those adequately treated during the clinical follow-up prior to death and in the pathology of the eyes confirms the value of cryotherapy in preventing cicatricial retrolental fibroplasia and indicates where it should be applied.
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PMID:Prevention of cicatricial retrolental fibroplasia by cryotherapy. 58 47

A refined classification of the stages of the retinopathy of prematurity (RLF) based on the experience of over 7500 examinations during the past decade is presented. We have been using the basic elements of this classification since 1972 in order to evaluate the influence of vitamin E on retrolental fibroplasia (RLF). It is our impression that it provides a more accurate clinical method of following the course of the retinopathy and a tool for assessing the factors other than prematurity and hyperoxia that may play a subtle role in the development of RLF.
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PMID:A classification of retrolental fibroplasia to evaluate vitamin E therapy. 58 96

A group of 39 patients with retinopathy of prematurity or retrolental fibroplasia have been evaluated. Nine of these were prematures at the time of their examination and showed severe bilateral disease. One eye in each patient was treated with the other eye serving as a control using either Xenon photocoagulation or cryocoagulation. It will take many years to observe the effect of this form of therapy but initial changes suggest alterations in the amount of retinal traction and in the appearance of blood vessels at the posterior pole in some of the treated patients. Thirty older patients have been assessed and of these, 18 eyes developed retinal detachments. Of the 16 operated upon, 87% had successful scleral buckling surgery. Three additional patients had similar retinal findings to retrolental fibroplasia but no history of prematurity or oxygen therapy. These patients were not included in this study. Retinopathy of prematurity is much less common now that it was 2 decades ago, but still represents a significant cause of ocular morbidity and blindness.
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PMID:Retinopathy of prematurity and retinal detachment. 94 63

In cases with persistent primary vitreous in full-term infants there were vitreoretinal reactions including vitreoretinal anastomoses of blood vessels, vitreoretinal strands, traction folds of the retina, avascular retinal areas, hypoplasia of retinal blood vessels, rarefaction of retinal ganglion cells, and ischaemic structural changes of the retina. New vessel formation on the surface of avascular retinal areas was supplied from persistent hyaloid blood vessels. This finding may be of some importance in explaining those cases histologically resembling classical retrolental fibroplasia with no history of prematurity or oxygen treatment.
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PMID:Vitreoretinal reactions and persistent hyaloid vessels. 103 66

The effects of oxygen in the immature or incompletely vascularized retina are conveniently divided into an initial vasoconstrictive and obliterative stage and a secondary vasoproliferative response that occurs after removal of the subject from an enriched oxygen environment. Vasoproliferation starts at the zone of perfused and nonperfused retina. The incompletely vascularized retina is uniquely responsive to these oxygen-induced changes. After vascularization is complete and the retinal vessels reach the ora, the susceptibility to hyperoxia disappears. The vessels in the temporal periphery of the retina have a peculiar susceptibility to the primary and secondary effects of hyperoxia on the immature retina. Ophthalmoscopic examination of the temporal periphery therefore should always be done carefully in the premature infant or in older individuals giving a history of prematurity. The indirect ophthalmoscope provides the most satisfactory instrument for examination. The incidence of retrolental fibroplasia has been greatly reduced following the incrimination of oxygen as its principal cause. Further studies are still required to determine precise blood oxygen levels that are safe for the premature retina and to discover other factors that may play a role in the pathogenesis or RLF.
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PMID:The role of oxygen in retrolental fibroplasia. 107 6

The toxic consequences of oxygen therapy may be development some neonatal diseases, for example: retrolental fibroplasia and bronchopulmonary dysplasia. It's now generally believed that oxygen induced cell toxicity is the result of formation of highly reactive free radicals. The greater incidence of these disorders in preterm infants suggest that some aspect of prematurity increases susceptibility of effects of toxic oxygen species. It's proposed the term for these disorders: "oxygen radical diseases of prematurity". Verification of the hypothesis about role of the antioxidant defense mechanisms of neonate may have important implications in the pursuit of the etiology these diseases and in identification of agents that may minimize toxicity associated with oxygen therapy.
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PMID:[Antioxidant agents--importance in neonatology]. 130 29

Refraction and axial eye dimensions, evaluated by ultrasound measurements, were investigated in 101 pre-term infants and 25 full-term controls. Gestational ages in the pre-term group ranged from 25 to 34 weeks, birth weights from 728 to 2480 g. All were seen in the eye clinic due to risk of developing retinopathy of prematurity. Age at examination was 36-54 weeks (gestational/conceptional) in the pre-terms and 37.3-50 weeks in the term infants. Adjusted to a 40 weeks axial length value (based on an assumed average eye elongation of 0.14 mm per week) the term-values were similar, 17.02 and 17.03 mm in the two groups. Within the premature group, however, the 40-week adjusted axial lengths were shorter, the shorter the gestational age. The study demonstrated more foetal anterior segment proportions, with flatter anterior chambers and thicker, more spheroid lenses in the preterm infants. Probably this explains the early preponderance of myopia in that group, at feature eventually to disappear, and not to be confused with myopia of prematurity. As compared to the full-terms a correlational disturbance by pre-term delivery was further indicated by the absence of the usual correlation between axial length and refractive value.
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PMID:Pre-term delivery and the growth of the eye. An oculometric study of eye size around term-time. 133 82

Previous data have suggested that neonatal complications amongst preterm ventilated infants increase with decreasing gestational age and thus are likely to be greatest among ventilated infants of less than 28 weeks gestational age. The aim of this study was to test that hypothesis, thus we report the neonatal complications of 175 extremely preterm mechanically ventilated infants (gestational age less than or equal to 28 weeks). Of the infants 152 were ventilated because of respiratory distress syndrome (RDS) or respiratory distress of severe prematurity, 41% of these infants died. Amongst infants with RDS or respiratory distress of extreme prematurity, mortality was significantly increased in infants of gestational age less than or equal to 24 weeks and birth weight less than or equal to 1000 g. In this group 20% developed a pneumothorax, and mortality was inversely related to gestational age. In infants with RDS, 43% developed a periventricular haemorrhage and 37% were still oxygen-dependent at 28 days of age; neither of these complications was significantly related to birth weight or gestational age. Of infants with RDS 38% developed a patent ductus arteriosus and 16% developed retinopathy of prematurity. These data suggest that even amongst very immature infants there has been an impressive reduction in the neonatal complications of mechanical ventilation.
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PMID:Neonatal complications of extreme prematurity in mechanically ventilated infants. 139 33

Several intellectual "autopsies" have recently reviewed errors in clinical epidemiologic studies of causation, such as the original claim that amyl nitrite "poppers" caused AIDS. The current autopsy was done to determine why it took more than a decade--1942 to 1954--to end an iatrogenic epidemic in which high-dose oxygen therapy led to retrolental fibroplasia (RLF) in premature infants, blinding about 10,000 of them. The autopsy revealed a museum of diverse intellectual pathology. When first noted, RLF was regarded as neither a new disease nor a postnatal effect. In early investigations, the ophthalmologists did not establish explicit criteria for diagnosis and confused RLF with malformations previously seen in full-term infants. Because the patients were not referred until months after birth, the ophthalmologists assumed that the lesion, which resembled an embryologic structure, must have occurred prenatally. Other events suggesting a prenatal cause for RLF were its strong statistical associations with fetal anomalies, multiple gestations, and maternal infections. Although these events were also associated with prematurity, it was ignored when the RLF cases were compared with controls who were mainly full-term infants. The postnatal timing of RLF was eventually recognized when investigators did cohort studies in premature infants and found that RLF could develop in eyes that were normal at birth. As the search for a cause turned to events occurring after birth, statistical associations were produced for agents such as light, vitamins, iron, vitamin E deficiency, and hypoadrenalism. Each study had its own methodologic flaws: controls were missing for light; co-maneuvers were ignored for vitamins and iron; objective diagnosis was not used for vitamin E deficiency; and the research on hypoadrenalism contained biases in susceptibility and detection as well as problems of a competing outcome event. When the role of oxygen administration was first considered, the statistical association with RLF was stronger for vitamin- and iron-therapy than for oxygen. In addition, many investigators were dissuaded by contradictory evidence from institutions in which RLF was either absent despite high-dose oxygen or persistent despite reduced dosage. The contradictory evidence was later regarded as erroneous because of unsatisfactory delivery systems for the oxygen or failure to check the actual oxygen concentrations. An alternative explanatory hypothesis, rejecting the role of high-dose and long-duration oxygen, was the idea that RLF was due to "relative hypoxia", produced by overly rapid weaning from oxygen therapy rather than the duration of oxygen treatment itself.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Oxygen as a cause of blindness in premature infants: "autopsy" of a decade of errors in clinical epidemiologic research. 143 8


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