No description available.

Die Frühgeborenenretinopathie (Retinopathia praematurorum (RPM)) ist eine Erkrankung der Netzhaut, die vor allem sehr unreife Frühgeborene betrifft und in ihrem Endstadium zur Erblindung führen kann. Ein gesicherter Risikofaktor für die Entwicklung einer RPM ist die Gabe von hohen Konzentrationen an Sauerstoff nach der Geburt. Gegenstand dieser Arbeit war die Frage, ob nach der Einführung eines Sauerstoffprotokolls 2007 das Auftreten höherer Stadien der RPM reduziert werden konnte. Das Sauerstoffprotokoll hatte zum Ziel die Gabe von inspiratorischem Sauerstoff nach Möglichkeit zu senken und übermäßige Fluktuationen zu vermeiden. Hierfür wurden 268 Frühgeborene mit einem Gestationsalter < 32Wochen bei Geburt, welche in den Jahren von 2005 bis 2006 (pre-Gruppe) und 2008 bis 2009 (post-Gruppe) in der Universitätsklinik Leipzig geboren und einem RPM-Screening unterzogen wurden, verglichen. Es konnte gezeigt werden, dass die Inzidenz der RPM nach 2007 signifikant niedriger war. So erkrankten in der pre-Gruppe 12 von 102 Kinder an einer höhergradigen RPM (>Stadium 3), wohingegen diese Stadien in der post-Gruppe nicht mehr beobachtet wurden. Demzufolge reduzierte sich auch die Notwendigkeit einer Therapie von 7,4 % auf 0 % (jeweils p = 0.0005). In Hinblick auf die Kerndaten wie Gestationsalter, Geburtsgewicht, Körpergröße, sowie dem Auftreten schwerer Begleiterkrankungen wie u.a. der nekrotisierenden Enterokolitis oder der bronchopulmonalen Dysplasie fanden sich keine Unterschiede zwischen den Gruppen. Allerdings wies die post-Gruppe eine höheren Anteil an männlichen Frühgeborenen auf. Die Mortalität zeigte keine signifikante Veränderung nach der Intervention und lag bei 7.8 % in der pre- bzw. 6.6 % in der post-Gruppe (p = 0.81). Die Auswertung der pulsoximetrisch gemessenen Sauerstoffsättigung (SpO2) und der inspiratorischen Sauerstofffraktion (FiO2) zeigte, dass der SpO2 leicht und der FiO2 deutlich reduziert werden konnte. Ein signifikanter Unterschied ergab sich hier jedoch lediglich für den FiO2, insbesondere in den ersten 14 Lebenstagen. Die logistische Regressionsanalyse legt nahe, dass hohe SpO2- und FiO2-Werte sowie das Auftreten von intrakraniellen Blutungen mit schwerwiegenden ROP-Stadien korrelieren. Ein bedachter Umgang in der Sauerstofftherapie Frühgeborenen könnte in der Lage sein das Auftreten der Frühgeborenenretinopathie zu reduzieren ohne eine Erhöhung der Mortalitätsrate zu riskieren.

Maintaining adequate and stable blood oxygen level is important for preterm babies to avoid the risk of brain, lung and retinal injury such as retinopathy of prematurity (ROP). However, wide disparities in policies and practices of oxygenation in preterm babies exist among neonatal care providers as it is still unclear which best method of monitoring and what features of oxygen measurements are important to clinician’s interpretations for assessing preterm babies at risk of developing severe ROP or unstable health condition. This thesis consists of two projects: NZ-ROP that examines multiple factors of severe ROP including summary statistics (mean, standard deviation (SD), coefficient of variation (CV) and desaturation) for oxygen saturation (OS) features in very extreme preterm babies, and NZ-LP that investigates the efficacy of some of these statistics for health monitoring of late preterm babies. The OS data in NZ-ROP were recorded using modified oximeters that have offsets and inherent software artefact, both of which mask the actual saturation for certain OS ranges and may complicate the choice of methods in the analyses. Therefore, novel algorithms involving linear and quadratic interpolations are developed, implemented on the New Zealand data, and validated using the data of a UK preterm baby, as recorded from offsets and non-offsets oximeters. For all data sets, the algorithms produced saturation distributions that were very close to those obtained from the non-offset oximeter. The algorithms perform within the recommended standards of commercial oximeters currently used in the clinical practice. ROP is a multifactorial disease, with oxygenation fluctuations as one of the key contributors. The all-subsets logistic regression, robust and generalised additive statistical modelling, along with a model averaging approach, are applied in NZ-ROP to determine the relationship of variability and level of OS with severe ROP, and the extent of contribution of various clinical predictors to the severity of this eye disease. Desaturation, as a measure of OS variability, has the strongest association with severe ROP among all OS statistics, in particular, the risk of severe ROP is almost three times higher in babies that exhibit greater occurrences of desaturation episodes. Additionally, this study identifies longer periods of ventilation support, frequent desaturation events, extreme prematurity and low birth weight as the most important factors that substantially exacerbate the severity of ROP, and therefore signify babies’ underlying condition of being severely ill. Persistent cardiorespiratory instabilities prior to hospital discharge may expose preterm babies to a greater risk of neuro-developmental impairments. In NZ-LP, the statistical summaries of mean, SD and CV are computed from the OS measurements of healthy stable and unstable babies, and the performance of these statistics in detecting the unstable babies is evaluated using an extremeness index for outlying data and a hierarchical clustering technique. With SD and CV, the clinically unstable babies were very well separated from the group of stable babies, wherein, the separation was even more apparent with the use of CV. These suggest that measures of variability could be better than saturation level for highlighting babies’ underlying instability due to immature physiological systems, but the combination of variability and level through the CV are believed to be even better. Identification and summarisation of useful OS features quantitatively hold great promise for improved monitoring of oxygenation instability and diagnosis of severe ROP for preterm babies.

No description available.

Preterm birth may lead to complications during the neonatal period that can cause visual dysfunctions. Retinopathy of prematurity (ROP) and neurological complications are well known reasons for visual dysfunctions, but preterm children with no or only mild ROP and no evident neurological problems may also be affected visually when they grow up. Retinal development starts early after gestation and continues long after birth. Major processes are underway during the second half of pregnancy when preterm children are born, and a preterm birth could possibly have a negative effect on normal retinal development. The aims of the studies were to evaluate retinal morphology and function in former preterm children and compare the results with children born at term. Former preterm children aged 5 to 17 years and born in a gestational age (GA) of 32 weeks or less were included in the different study groups. Children of similar ages who were born at term and with normal visual acuity (VA) acted as controls. Best corrected VA and refraction in cycloplegia were assessed in all children. Macular thickness and retinal nerve fiber layer (RNFL) thickness were measured with optical coherent tomography (OCT). Total retinal function was assessed with fullfield electroretinography (ffERG) and central macular function was assessed with multifocal electroretinography (mfERG). Preterm children had thicker central maculae than controls. There was a positive correlation between central macular thickness and GA at birth. RNFL thickness was reduced in the preterm children with severe ROP and treated ROP, but children with mild or no ROP did not differ from the fullterm children. The photoreceptor function measured with ffERG and the macular function measured with mfERG were reduced in the preterm group compared to controls. Preterm birth affects the retina both morphologically and functionally, and ROP has been suggested to be a reason for retinal changes. However, the results of this thesis indicate that children with no ROP also have retinal changes, suggesting an effect of prematurity itself. There were no correlations between any retinal changes and VA, but it is possible that larger studies using improved techniques may elucidate this further.

Orientador: Eliane Chaves Jorge / Abstract: Background: The standard treatment of retinopathy of prematurity (ROP) is the ablation of the avascular retina with laser or cryotherapy. However, this therapy may leave permanent structural and visual sequelae and may not be effective in cases of posterior and aggressive ROP. Vascular endothelial growth factor (VEGF) is involved in the pathogenesis of ROP, and antiangiogenic therapy is an option in cases of failure of standard treatment. The potential adverse effects of the use of antiangiogenic drugs in preterm neonates and the lack of concrete evidence on the efficacy of these drugs justify a systematic review of the literature. Objective: To evaluate the efficacy and safety of antiangiogenic therapy, when compared with laser photocoagulation, cryotherapy or combination therapy, in the treatment of ROP. Method: A systematic review of the literature was conducted using the Cochrane collaboration methodology and electronic search platforms to identify studies using antiangiogenic drugs in the treatment of ROP. The quality of the evidence was evaluated by the GRADE system (Grading of Recommendations Assessment, Development, and Evaluation). Results: Twelve studies were included in this review (six randomized controlled trials - RCTs and six non-randomized observational studies), including 677 preterm infants. Through the meta-analyzes, there was a statistical difference benefiting anti-VEGF therapy in the occurrence of progression to retinal detachment (RR 0.14 [95% CI 0.05, ... (Complete abstract click electronic access below) / Resumo: Introdução: O tratamento padrão da retinopatia da prematuridade (ROP) é a ablação da retina avascular com laser ou crioterapia. No entanto, esta terapia pode deixar sequelas estruturais e visuais permanentes e não ser efetiva em casos de ROP posterior e agressiva. O fator de crescimento do endotélio vascular (VEGF) está envolvido na patogênese da ROP e a terapia antiangiogênica é opção nos casos de falha do tratamento padrão. Os potenciais efeitos adversos com o uso de antiangiogênicos em neonatos prematuros e a falta de evidências concretas sobre a eficácia destas drogas justifica uma revisão sistemática da literatura. Objetivo: Avaliar a eficácia e a segurança da terapia antiangiogênica, quando comparada com fotocoagulação a laser, crioterapia ou terapia combinada, no tratamento da ROP. Método: Uma revisão sistemática da literatura foi realizada, utilizando a metodologia da colaboração Cochrane e plataformas eletrônicas de busca para identificar estudos utilizando drogas antiangiogênicas no tratamento da ROP. A qualidade da evidência foi avaliada pelo sistema GRADE (Grading of Recommendations Assessment, Development and Evaluation). Resultados: Doze estudos foram incluídos nesta revisão (seis ensaios clínicos randomizados e seis estudos observacionais não randomizados), incluindo 677 recém-nascidos pré-termo (1288 olhos). Pelas metanálises, houve diferença estatística beneficiando a terapia anti-VEGF na ocorrência de progressão para descolamento de retina (RR 0.14 [IC 95% 0... (Resumo completo, clicar acesso eletrônico abaixo) / Mestre

Submitted by MATHEUS SENNA PEREIRA OGATA (mspogata@gmail.com) on 2018-09-18T00:16:15Z No. of bitstreams: 1 Dissertação (REFERENCIAS CORRGIIDAS) - Matheus Senna Pereira Ogata.pdf: 3338159 bytes, checksum: a4719346512d617a2a7beeb12f2c4a85 (MD5) / Approved for entry into archive by ROSANGELA APARECIDA LOBO null (rosangelalobo@btu.unesp.br) on 2018-09-18T17:16:07Z (GMT) No. of bitstreams: 1 ogata_msp_me_bot.pdf: 3338159 bytes, checksum: a4719346512d617a2a7beeb12f2c4a85 (MD5) / Made available in DSpace on 2018-09-18T17:16:07Z (GMT). No. of bitstreams: 1 ogata_msp_me_bot.pdf: 3338159 bytes, checksum: a4719346512d617a2a7beeb12f2c4a85 (MD5) Previous issue date: 2018-07-25 / Introdução: O tratamento padrão da retinopatia da prematuridade (ROP) é a ablação da retina avascular com laser ou crioterapia. No entanto, esta terapia pode deixar sequelas estruturais e visuais permanentes e não ser efetiva em casos de ROP posterior e agressiva. O fator de crescimento do endotélio vascular (VEGF) está envolvido na patogênese da ROP e a terapia antiangiogênica é opção nos casos de falha do tratamento padrão. Os potenciais efeitos adversos com o uso de antiangiogênicos em neonatos prematuros e a falta de evidências concretas sobre a eficácia destas drogas justifica uma revisão sistemática da literatura. Objetivo: Avaliar a eficácia e a segurança da terapia antiangiogênica, quando comparada com fotocoagulação a laser, crioterapia ou terapia combinada, no tratamento da ROP. Método: Uma revisão sistemática da literatura foi realizada, utilizando a metodologia da colaboração Cochrane e plataformas eletrônicas de busca para identificar estudos utilizando drogas antiangiogênicas no tratamento da ROP. A qualidade da evidência foi avaliada pelo sistema GRADE (Grading of Recommendations Assessment, Development and Evaluation). Resultados: Doze estudos foram incluídos nesta revisão (seis ensaios clínicos randomizados e seis estudos observacionais não randomizados), incluindo 677 recém-nascidos pré-termo (1288 olhos). Pelas metanálises, houve diferença estatística beneficiando a terapia anti-VEGF na ocorrência de progressão para descolamento de retina (RR 0.14 [IC 95% 0.05, 0.38] p=0.0001, I2 = 0%) e ocorrência de miopia ( Diferença de média ponderada 0.25 [IC 95% 0.14, 0.37] p<0.0001, I2 = 76%). No desfecho recorrência de ROP houve diferença estatística beneficiando o laser (RR 1.88 [IC 95% 1.34, 2.63] p=0.0003, I2 = 82%). Não houve porém, diferença entre a terapia anti-VEGF e o laser quanto à ocorrência de complicações oculares (RR 0.84 [IC 95% 0.34, 2.08] p=0.71, I2 = 0%). Na análise de sub grupo, na comparação entre as zonas de acometimento da ROP, o anti-VEGF apresentou menor risco de recorrência exigindo retratamento que o laser, em prematuros com ROP em zona I (RR 0.23 [IC 95% 0.11, 0.49] p=0.0001, I2 = 61%). A qualidade da evidência pelo GRADE variou de muito baixa a baixa. Conclusões: Há evidências de que a terapia anti-VEGF, usada como monoterapia, quando comparada ao laser, reduz o risco de progressão para descolamento de retina, a ocorrência de miopia e o risco de recorrência de ROP em prematuros com doença na zona I. No entanto, ainda faltam evidências de qualidade que permitam atestar a segurança da terapia, especialmente quanto aos potenciais efeitos sistêmicos em prematuros. Palavras-chave: Retinopatia da Prematuridade, antiangiogênicos, metanálise. / Background: The standard treatment of retinopathy of prematurity (ROP) is the ablation of the avascular retina with laser or cryotherapy. However, this therapy may leave permanent structural and visual sequelae and may not be effective in cases of posterior and aggressive ROP. Vascular endothelial growth factor (VEGF) is involved in the pathogenesis of ROP, and antiangiogenic therapy is an option in cases of failure of standard treatment. The potential adverse effects of the use of antiangiogenic drugs in preterm neonates and the lack of concrete evidence on the efficacy of these drugs justify a systematic review of the literature. Objective: To evaluate the efficacy and safety of antiangiogenic therapy, when compared with laser photocoagulation, cryotherapy or combination therapy, in the treatment of ROP. Method: A systematic review of the literature was conducted using the Cochrane collaboration methodology and electronic search platforms to identify studies using antiangiogenic drugs in the treatment of ROP. The quality of the evidence was evaluated by the GRADE system (Grading of Recommendations Assessment, Development, and Evaluation). Results: Twelve studies were included in this review (six randomized controlled trials - RCTs and six non-randomized observational studies), including 677 preterm infants. Through the meta-analyzes, there was a statistical difference benefiting anti-VEGF therapy in the occurrence of progression to retinal detachment (RR 0.14 [95% CI 0.05, 0.38] p = 0.0001, I2 = 0%) and myopia occurrence (Weighted mean difference 0.25 [95% CI 0.14, 0.37] p <0.0001, I2 = 76%). At the end of ROP recurrence, there was a statistical difference benefiting the laser (RR 1.88 [95% CI 1.34, 2.63], p = 0.0003, I2 = 82%). There was, however, no difference between the anti-VEGF therapy and the laser in the occurrence of ocular complications (RR 0.84 [95% CI 0.34, 2.08] p = 0.71, I2 = 0%). In the subgroup analysis, in the comparison between the ROP involvement zones, the anti-VEGF presented a lower risk of recurrence requiring retreatment than the laser in premature infants with zone I ROP (RR 0.23 [95% CI 0.11, 0.49] p = 0.0001, I2 = 61%).The quality of the GRADE evidence varied from very low to low. Conclusions: There is evidence that anti-VEGF therapy, used as monotherapy, when compared to laser, reduces the risk of progression to retinal detachment, the occurrence of myopia, and the risk of recurrence of ROP in preterm infants with the disease in zone I.However, there is still a lack of quality evidence to attest to the safety of therapy, especially regarding potential systemic effects in preterm infants.

The blind have generally been considered to be a homogeneous population whose deficits arise from an interaction of loss of vision, age of onset and socialization. Sequelae are posited to exist merely due to the limiting effects of blindness on experience. This is believed to affect all blind persons equally regardless of cause of blindness provided that independent secondary disabilities do not exist. This study investigated the possibility that different causes of blindness are related to specific neuropsychological deficits which cannot be explained by the mere presence of blindness. It was found that neuropsychological differences existed among specific sub-populations of blind persons. These results suggested that the cause of blindness may be a marker for specific Central Nervous System involvement.

A retinopatia da prematuridade é uma doença ocular do desenvolvimento associada a um crescimento vascular retiniano anormal e ocorre somente em recém-nascidos com menos de 32 semanas de gestação e submetidos a longos períodos em incubadoras, tipicamente ricas em oxigênio. A doença possui duas fases: (1) a inibição do desenvolvimento normal de vasos na retina, decorrente da hiperóxia induzida pelo ambiente da incubadora; (2) neovascularização retiniana devido ao aumento de fatores de crescimento desencadeados pela pouca disponibilidade de oxigênio fora da incubadora. O objetivo deste trabalho é avaliar a função visual em um modelo animal de retinopatia da prematuridade, comparando-o a animais sadios. Eletrorretinogramas (ERGs) de campo total foram realizados em camundongos (Mus musculus) controle e camundongos submetidos hiperoxigenação em câmara hiperbárica (75% de oxigênio) durante o desenvolvimento retiniano pós-natal para entender as perdas visuais que ocorrem na retinopatia da prematuridade. Foram utilizados 122 animais, divididos em dois grupos: no grupo controle¸ ERGs foram realizados em P17 (n = 32), P30 (n = 26) e P60 (n = 44) com estimulação em comprimentos de onda distintos (LEDs com pico de emissão em 365 nm, 459 nm, 525 nm e 635 nm) para avaliação da atividade funcional da retina ao longo do desenvolvimento, não passando por nenhuma manipulação experimental adicional; no grupo experimental, os animais foram submetidos à hiperoxigenação de P7 a P12 para indução da angiogênese e avaliados com ERGs com estimulação em 459 nm em P17 (n = 7), P30 (n = 6) e P60 (n = 7), para acompanhar o desenvolvimento retiniano. Todos os animais foram adaptados ao escuro por pelo menos duas horas antes da realização dos experimentos. Em sessão de 40 a 60 minutos de duração, os animais foram submetidos a flashes de luz em intensidades crescentes. Amplitudes e latências das ondas a, b e potenciais oscilatórios foram medidas, e relações intensidade-resposta ajustadas com modelos matemáticos diferentes para comparação entre indivíduos e entre grupos. Os parâmetros obtidos com os ajustes foram comparados através de ANOVA e testes T de Student com as devidas correções de Bonferroni. Nos níveis luminosos testados, a onda b do ERG murino é majoritariamente dominada pela atividade dos bastonetes e a onda a majoritariamente dominada pelos cones. Os registros em animais em P17 e P30 do grupo controle foram similares aos realizados em P60 quanto à latência e amplitude de resposta, bem como quanto à sensibilidade e grau de cooperação entre os distintos elementos do ERG. Entretanto, as amplitudes máximas de resposta foram ligeiramente maiores em P30 para todos os comprimentos de onda e houve ligeira redução da sensibilidade absoluta ao longo do desenvolvimento. Para o grupo experimental, os animais em P17 sofreram as maiores perdas, com diminuições nas amplitudes de todos os componentes do ERG, sem prejuízo das latências ou sensibilidade. Também houve uma sucessiva recuperação das respostas ao longo do desenvolvimento animal. Esses achados indicam que o modelo de ROP em camundongos reproduz aspectos essenciais ao quadro patológico severo humano / The retinopathy of prematurity is an ocular developmental disorder associated with abnormal retinal vascular growth and occurs only in neonates younger than 32 weeks of gestation and undergoing long periods in incubators, typically rich in oxygen. The disease has two phases: (1) the inhibition of the normal development of vessels in the retina, due to the hyperoxia induced by the incubator environment; (2) retinal neovascularization due to the increase in growth factors triggered by the low availability of oxygen outside the incubator. The objective of this study is to evaluate the visual function in an animal model of retinopathy of prematurity, comparing it to healthy animals. Full-field electroretinogram (ERGs) were performed on control mice (Mus musculus) and that were exposed to a hyperbaric chamber (75% oxygen) during post-natal retinal development to understand the visual losses that occur in retinopathy of prematurity. We used 122 animals, divided into two groups: in the control group, ERGs were performed at P17 (n = 32), P30 (n = 26) and P60 (n = 44) with stimulation at different wavelengths (LEDs with peak of emission at 365 nm, 459 nm, 525 nm and 635 nm) for evaluation of the functional activity of the retina throughout the development, without any additional experimental manipulation; in the experimental group, animals were submitted to hyperoxogenation of P7 to P12 for induction of angiogenesis and evaluated with ERGs with stimulation at 459 nm in P17 (n = 7), P30 (n = 6) and P60 (n = 7) to follow up retinal development. All animals were dark adapted for at least two hours prior to the experiments. In sessions with 40 to 60 minutes, the animals were subjected to flashes of light at increasing intensities. Amplitudes and latencies of a-waves, b-waves and oscillatory potentials were measured, and intensity-response relationships adjusted with different mathematical models for comparison between individuals and between groups. The parameters obtained with the adjustments were compared through ANOVA and Student\'s T tests with the appropriate Bonferroni correction. In the light levels tested, the murine ERG b-wave is dominated by rod activity and the a-wave is dominated by the cones. The records in animals at P17 and P30 of the control group were similar to those performed at P60 regarding the latency and amplitude of response, as well as the sensitivity and degree of cooperation between the different ERG elements. However, the maximum response amplitudes were slightly higher at P30 at all wavelengths and there was slight reduction of absolute sensitivity throughout development. For the experimental group, the animals at P17 suffered the greatest losses, with decreases in the amplitudes of all the components of the ERG, without prejudice to the latencies or sensitivity. There was also a successive recovery of responses throughout animal development. These findings indicate that the ROP model in mice reproduces aspects essential to the severe human pathology

Introdução: A retinopatia da prematuridade (ROP) é uma das principais causas de cegueira e morbidade visual na infância. É uma doença ocular vasoproliferativa secundária à vascularização inadequada da retina dos recém-nascidos (RNs) prematuros (PMTs), cuja etiologia é multifatorial e não está completamente elucidada. Dentre os fatores implicados na sua patogênese estão a exposição da retina em desenvolvimento a níveis anormais de oxigênio e a deficiência do fator de crescimento insulínico-1 (insulin-like growth factor-1, IGF-1). O leite materno (LM) contém IGF-1 e pode ter um efeito protetor contra o desenvolvimento da ROP. Objetivos: Avaliar o possível efeito protetor do LM contra a ROP, através da comparação da quantidade de LM recebida entre os pacientes que desenvolveram ROP e aqueles livres da doença. Tentar determinar a quantidade mínima necessária e o momento em que o RN precisa receber o LM para que esse efeito seja significativo. Pacientes e métodos: Estudo de coorte observacional incluindo RNs com peso de nascimento (PN) inferior a 1500 gramas e / ou com idade gestacional (IG) inferior a 32 semanas, nascidos no período de janeiro de 2011 a outubro de 2014 e internados nas primeiras 24 horas de vida na UTI Neonatal do Hospital da Criança Conceição (HCC) em Porto Alegre. Resultados: A prevalência da ROP em qualquer grau foi de 31% (100 casos em 323 pacientes) e a de ROP grave foi de 9% (29 casos em 323 pacientes). A mediana da quantidade de LM recebida pelos pacientes foi de 10,2mL/kg/dia entre os pacientes sem ROP (amplitude interquartil 1,5-25,5) e de 4,9 mL/kg/dia entre os pacientes com ROP (0,3-15,4). A quantidade de LM recebida nas primeiras seis semanas de vida foi inversamente associada à incidência de ROP em qualquer grau e de ROP grave nas análises univariadas, mas a significância estatística não se manteve após análise multivariada para controle de fatores confundidores na maioria dos períodos avaliados, exceto na sexta semana de vida. Conclusão: Pequenas quantidades de LM não são suficientes para prevenção de ROP em PMTs de risco para a doença. / Introduction: Retinopathy of prematurity (ROP) is one of the major causes of blindness and visual morbidity in childhood. It is a vasoproliferative eye disease secondary to inad-equate vascularization of the retina in premature neonates. Its etiology is multifactorial and it is not completely elucidated. The exposure of the developing retina to abnormal oxygen levels and the deficiency of insulin-like growth factor-1 (IGF-1) are among the factors involved in its pathogenesis. Breast milk (BM) contains IGF-1 and may have a protective effect against the development of ROP. Objectives: To evaluate the possible protective effect of BM against ROP by comparing the amount of breast milk received among patients who developed ROP and those who were disease-free. To attempt to determine both the required minimum amount and the time in which a neonate needs to receive BM for this effect to be significant. Patients and methods: Observational cohort study of newborns with a birth weight be-low 1500 grams and/or gestational age less than 32 weeks, born from January 2011 to October 2014 and hospitalized within their first 24 hours of life in the Neonatal Intensive Care Unit (NICU) at the Hospital da Criança Conceição (HCC), in Porto Alegre- RS- Brazil. Results: The prevalence of ROP at any degree was of 31% (100 cases in 323 patients) and of severe ROP was of 9% (29 cases in 323 patients). The median amount of BM received by patients was 10.2 mL/kg/day among patients without ROP (interquartile range 1.5-25.5) and 4.9 mL/kg/day among patients with ROP (0.3-15.4). The amount of breast milk received in the first six weeks of life was inversely associated with the inci-dence of ROP in any degree and of severe ROP in the univariate analyses. The statistical significance was not maintained after a multivariate analysis to control for confounding factors in the majority of the periods evaluated, except in the sixth week of life. Conclusion: Small amounts of BM are not enough to prevent ROP in premature new-borns at risk of the disease.