Analysis of the horizontal corneal diameter, central corneal thickness, and axial length in premature infants / Diâmetro horizontal corneano, espessura corneana central e o comprimento axial em prematuros

Purpose: To determine the horizontal corneal diameter, central corneal thickness, and axial length in premature infants. Methods: Infants with a birth weight of less than 2,500 g or with a gestation period of less than 36 weeks were included in the study. Infants with retinopathy of prematurity (ROP) were allocated to Group 1 (n=138), while those without ROP were allocated to Group 2 (n=236). All infants underwent a complete ophthalmologic examination, including corneal diameter measurements, pachymetry, biometry, and fundoscopy. Between-group comparisons of horizontal corneal diameter, central corneal thickness, and axial lengths were performed. Independent sample t-tests were used for statistical analysis. Results: Data was obtained from 374 eyes of 187 infants (102 female, 85 male). The mean gestational age at birth was 30.7 ± 2.7 weeks (range 25-36 weeks), the mean birth weight was 1,514 ± 533.3 g (range 750-1,970 g), and the mean postmenstrual age at examination was 40.0 ± 4.8 weeks. The mean gestational age and the mean birth weight of Group 1 were statistically lower than Group 2 (p<0.05). There were no significant differences in horizontal corneal diameter, central corneal thickness, and axial length between the two groups (p>0.05). Conclusions: The presence of ROP in premature infants does not alter the horizontal corneal diameter, central corneal thickness, or axial length. .

Objetivo: Determinar o diâmetro horizontal corneano, a espessura corneana central e o comprimento axial de prematuros. Métodos: Crianças com peso de nascimento menor que 2.500 g ou idade gestacional menor que 36 semanas foram incluídas no estudo. Recém-nascidos com retinopatia da prematuridade (ROP) foram alocados no Grupo 1 (n=138), sem ROP foram alocados no Grupo 2 (n=236). Todos os bebês foram submetidos a exame oftalmológico completo, incluindo medida do diâmetro corneano, paquimetria, biometria e fundoscopia. O diâmetro horizontal corneano, a espessura corneana central e o comprimento axial dos grupos foram comparados. Teste de "Student" para amostras independentes foi utilizado na análise estatística. Resultados: Os dados foram obtidos a partir de 374 olhos de 187 crianças (102 meninas, 85 meninos). A idade gestacional média ao nascer foi de 30,7 ± 2,7 semanas (variação de 25 a 36 semanas). O peso médio ao nascer foi de 1.514 ± 533,3 g (variação de 750 a 1.970 g). A idade pós-menstrual média de exame foi de 40,0 ± 4,8 semanas. A idade gestacional e o peso médio do Grupo 1 eram estatisticamente inferiores aos do Grupo 2 (p<0,05). Não houve diferenças significativas no diâmetro horizontal da córnea, espessura corneana central e medidas de comprimento axial entre dois grupos (p>0,05). Conclusões: A presença de ROP em prematuros não altera o diâmetro da córnea horizontal, espessura corneana central e o comprimento axial. .

Características estruturais maculares de olhos de pré-escolares nascidos prematuros: análise por tomografia de coerência óptica e oftalmoscopia binocular indireta / Structural features of macular eyes of preschoolers born preterm: analysis by optical coherence tomography, and indirect ophthalmoscopy

OBJETIVO: Comparar a estrutura retiniana da mácula e fóvea entre prematuros com retinopatia da prematuridade (ROP) estágios II e III pós-tratamento, com ROP estágios II e III regredida espontaneamente e sem ROP, através de exames de tomografia de coerência óptica (OCT) e da oftalmoscopia binocular indireta (OBI). MÉTODOS: Estudo do tipo transversal, observacional e não cego. Foram incluídas crianças prematuras nascidas entre 06/1992 e 06/2006 e examinadas entre 06/2009 e 12/2010; idade gestacional menor ou igual a 32 semanas e peso ao nascer menor ou igual a 1.599 g; com mínimo de três consultas durante o período de seleção; sem retinopatia da prematuridade ou com diagnóstico de ROP estágios II ou III em pelo menos um dos olhos com regressão espontânea ou após tratamento; máximo de seis meses de idade cronológica para o primeiro exame no serviço; idade cronológica mínima de quatro anos no período da reavaliação. Foram excluídas crianças prematuras que não compareceram ou que não tinham condições clínicas para a realização dos exames de reavaliação. Os prematuros foram divididos em três grupos: G1- com ROP pós-tratamento; G2- com ROP pós-regressão espontânea; e G3- sem ROP. Os exames realizados foram OBI e OCT. RESULTADOS: Vinte e quatro prematuros (48 olhos) apresentaram os critérios exigidos para a pesquisa, com idade média cronológica entre 5 e 6 anos. À OBI, houve diferença estatística significativa para a presença de alterações na retina dos prematuros do grupo G1. No entanto estas alterações corresponderam às lesões cicatriciais deixadas pelo tratamento da ROP, sem comprometimento visível da região macular. À OCT houve diferença estatística significativa para a maior espessura foveal para os prematuros do grupo G1. Considerando-se o olho esquerdo, não houve diferença estatística significativa relacionada à espessura da fóvea entre G1 e G3. Não houve diferença entre os três grupos estudados quanto às alterações encontradas nas camadas da retina ao OCT. CONCLUSÃO: Os prematuros com ROP pós-tratamento apresentaram espessura foveal maior que os prematuros com ROP pós-regressão espontânea e espessura foveal semelhante aos prematuros sem ROP em relação à avaliação do olho esquerdo. Em relação às alterações das camadas da retina detectadas ao OCT, os três grupos foram semelhantes, sem expressão de diferença para o grupo tratado neste estudo.

PURPOSE: Compare the retinal structure of the macula and fovea among premature infants with retinopathy of prematurity (ROP) stages II and III post treatment, premature infants with ROP stages II and III with spontaneous regression and premature infants without ROP, through optical coherence tomography (OCT) and binocular indirect ophthalmoscopy (BIO) examinations. METHODS: Cross-sectional observational and not-blinded study. There were included premature infants born between 06/1992 and 06/2006 and examined between 06/2009 and 12/2010; gestational age less than or equal to 32 weeks and birth weight less than or equal to 1,599 g; with a minimum of three visits during the selection period; without retinopathy of prematurity, or with the diagnosis of ROP stages II or III in at least one eye with spontaneous regression or after ROP treatment; maximum of six months of chronological age for the first examination at the service; minimal chronological age of four years old in the reassessment period. There were excluded premature infants who did not attend or did not have clinical conditions for the reassessment examination. The premature infants were divided into three groups: G1 - with ROP post-treatment; G2 - with ROP post-spontaneous regression; and G3 - without ROP. The exams performed were BIO and OCT. RESULTS: Twenty-four premature infants (48 eyes) presented the criteria required for the research, chronological age ranging from 5 to 6 years. At BIO, there was a statistically significant difference for the presence of alterations in the retina of premature infants from group G1. However these changes corresponded to the cicatricial lesions left by the ROP treatment, without visible impairment to the macular region. At OCT there were statistically significant differences for the greatest foveal thickness between premature infants from groups G1 and G2. Considering the left eye, there was no statistically significant difference related to the thickness of the fovea between G1 and G3. There was no difference among the three groups studied in relation to the changes of the retinal layers at OCT. CONCLUSION: Premature infants with ROP post-treatment showed foveal thickness greater than premature infants with ROP post-spontaneous regression; and foveal thickness similar to premature infants without ROP in relation to assessment of the left eye. Regarding the changes of the retinal layers detected at OCT, the three groups were similar, without expression of difference for the treated group in this study.

Capillary-free Vascularized Retina in Patients with Aggressive Posterior Retinopathy of Prematurity and Late Retinal Capillary Formation

PURPOSE: To report the clinical features, clinical course, and treatment outcomes after laser photocoagulation in infants with aggressive posterior retinopathy of prematurity (APROP) and capillary-free zones in vascularized retina. METHODS: Six patients (12 eyes) with APROP and capillary-free zones in vascularized retina were retrospectively reviewed. Twelve eyes of six infants were included and were treated with laser photocoagulation for avascular retina and for capillary-free zones in vascularized retina, except for the posterior pole, and fundus findings were photographically-documented in sequence. In addition, anatomic and visual outcomes were evaluated with complications of APROP. RESULTS: Among all of the consecutive infants with APROP, capillary-free zones in vascularized retina were demonstrated in 24% of the infants. All of the infants were >27 weeks of gestation age and had birth weights >1,000 g. After laser treatment, 7 eyes (58.3%) had favorable outcomes, and late capillary filling in capillary-free zones of vascularized retina were noted, however 4 eyes (33.3%) progressed to retinal detachment and 1 eye (8.3%) was complicated by a retinal fold-distorting posterior pole. The visual outcomes were associated with anatomic outcomes. CONCLUSIONS: The anatomic outcomes in infants with APROP who had capillary-free zones were comparable to previously reported infants with APROP. The late capillary filling of capillary-free zones in vascularized retina was noted, and angiogenesis was considered to be involved. This process toward normal capillary formation or neovascularization in APROP, might determine its outcome.

Capillary-free Vascularized Retina in Patients with Aggressive Posterior Retinopathy of Prematurity and Late Retinal Capillary Formation

PURPOSE: To report the clinical features, clinical course, and treatment outcomes after laser photocoagulation in infants with aggressive posterior retinopathy of prematurity (APROP) and capillary-free zones in vascularized retina. METHODS: Six patients (12 eyes) with APROP and capillary-free zones in vascularized retina were retrospectively reviewed. Twelve eyes of six infants were included and were treated with laser photocoagulation for avascular retina and for capillary-free zones in vascularized retina, except for the posterior pole, and fundus findings were photographically-documented in sequence. In addition, anatomic and visual outcomes were evaluated with complications of APROP. RESULTS: Among all of the consecutive infants with APROP, capillary-free zones in vascularized retina were demonstrated in 24% of the infants. All of the infants were >27 weeks of gestation age and had birth weights >1,000 g. After laser treatment, 7 eyes (58.3%) had favorable outcomes, and late capillary filling in capillary-free zones of vascularized retina were noted, however 4 eyes (33.3%) progressed to retinal detachment and 1 eye (8.3%) was complicated by a retinal fold-distorting posterior pole. The visual outcomes were associated with anatomic outcomes. CONCLUSIONS: The anatomic outcomes in infants with APROP who had capillary-free zones were comparable to previously reported infants with APROP. The late capillary filling of capillary-free zones in vascularized retina was noted, and angiogenesis was considered to be involved. This process toward normal capillary formation or neovascularization in APROP, might determine its outcome.

Retinopatía del prematuro en la unidad de cuidados intermedios: servicio de neonatología hospital central de maracay / Retinopathy of prematurity in the intermediate care unit: neonatology service Maracay Central Hospital

La incidencia de la Retinopatía del Prematuro (ROP) se asocia con las tasas de supervivencia y con la gravedad del proceso sistémico en elrecién nacido pretérmino y está influenciada por diversos factores. 1- Conocer la incidencia actual y la gravedad de la ROP. 2- Determinar la frecuencia según el sexo y edad gestacional. Estudio descriptivo, de diseño longitudinal. Se analizó una población de 363 prematuros, quienes fueron explorados secuencialmente enbúsqueda de ROP, de acuerdo al protocolo estandarizado de dicha condición. La severidad de ROP fue estimada según la extensión de la lesión. Del total de los 363 prematuros evaluados en la primera consulta, 214 presentaron ROP en la primera evaluación, y de estos 102 (28%) mantuvieron un diagnóstico definitivo a través del seguimiento. No hubo diferencia de incidencia entre varones y hembras. 40,65% tuvo un peso entre 1001-1499 gramos. 97 casos (45,32%) ocurrieron en niños entre 35 y 37 semanas. La ROP extendida a zona II fue la modalidad más común (88,23%). 28% de los prematuros estudiados desarrolló definitivamente la enfermedad. La mayoría de niños afectados tuvo ROP extendida a zona II. Hubo una alta incidencia de niños prematuros tardíos afectados por la complicación

Incidence of Retinopathy of Prematurity (ROP) is associated with survival rates and severity of systemic disease in premature newborns and is influenced by several factors. To determine the incidence and severity of ROP, and its frequency by gender and gestational age. Descriptive, longitudinal study. The analyzed population included 363 premature infants, who were evaluated for ROP, according to a standardized protocol. Type of ROP was defined by extent of the lesion. 214 out of the 363 infants had ROP at the first exam, and 102 (28%) had a definitive diagnosis on follow-up. There were no differences in incidence for males and females. 40% had a birth weight between 1001 and 1499 grams. 45,33% of cases occurred in preemies between 35 and 37 weeks’ gestational age. 88% of affected children had a zone II ROP. 28% of the infants had definitive diagnosis of ROP. Zone II ROP was the most common variant. There was a high incidence of ROP in late preterm newborns

Factores nutricionales en la retinopatía del prematuro / Nutritional factors on retinopathy of prematurity

La retinopatía del prematuro es una de las complicaciones de la prematurez, numerosos factores influyen en la prevalencia y la gravedad deeste cuadro. Se revisan aspectos nutricionales y de crecimiento que se han asociado a mayor o menor incidencia y gravedad de la retinopatía.Esta información puede permitir una mejor predicción del riesgo de retinopatía y un manejo clínicoque contribuya a minimizar el daño visual.

Plus disease: Why is it important in retinopathy of prematurity?

Retinopathy of prematurity [ROP] is one of the leading causes of preventable blindness in childhood. Early posterior pole vascular signs of severe ROP have been studied since the first description of the disease. The progressive changes that take place in the posterior pole vessels of an extremely premature baby occur in a predictable fashion soon after birth. These vascular changes are described as plus disease and are defined as abnormal dilation and tortousity of the blood vessels during ROP that may go on to total retinal detachment. The ophthalmological community now has a better understanding of the pathology and cascade of events taking place in the posterior pole of an eye with active ROP. Despite many years of scientific work on plus disease, there continue to be many challenges in defining the severity and quantification of the vascular changes. It is believed that understanding of the vascular phenomenons in patients with ROP will help in designing new treatment strategies that will help in salvaging many of the eyes with severe ROP

Functional and anatomical outcomes after primary lens-sparing pars plana vitrectomy for Stage 4 retinopathy of prematurity.

Background: While lens-sacrificing vitrectomy is the standard approach to manage Stage 5 retinopathy of prematurity (ROP), scleral buckling has been used to manage some cases of Stage 4. Lens-sparing vitrectomy was popularized by Maguire and Trese in selected cases of Stage 4 disease. Purpose: To assess the functional and visual outcomes after primary lens-sparing pars plana vitrectomy for Stage 4 ROP. Materials and Methods: In a retrospective, interventional, consecutive case series, the records of 39 eyes of 31 patients presenting with Stage 4 retinal detachment secondary to ROP who underwent primary two or three-port lens-sparing vitrectomy from January 2000 to October 2006 were evaluated. The outcomes studied at the final follow-up visit were the retinal status, lens and medial clarity and visual acuity. Favorable anatomical outcome was defined as the retinal reattachment of the posterior pole at two months after the surgery; and favorable functional outcome was defined as a central, steady and maintained fixation, with the child following light. Results: At mean follow-up of 15 months, 74% of the eyes had a favorable anatomical outcome with single procedure. The visual status was favorable in 63%. The lens remained clear in all the eyes at the last follow-up, and the media clarity was maintained in 87%. Intraoperative complications included vitreous hemorrhage, pre-retinal hemorrhage and retinal break formation. Conclusions: Lens-sparing vitrectomy helps to achieve a favorable anatomical and functional outcome in selected cases of Stage 4 ROP.

Incidence, treatment and outcomes of retinopathy of prematurity at Hospital de Clínicas de Porto Alegre, Brazil / Incidência e resultados do tratamento da retinopatia da prematuridade no Hospital de Clínicas de Porto Alegre, Brasil

Objectives: This paper aims to evaluate the overall incidence of retinopathy of prematurity (ROP), the rate of treatment in severe ROP, and the six-month outcomes in all preterm infants screened for ROP at Hospital de Clínicas de Porto Alegre, Brazil, between October 2002 and October 2006, Methods: A prospective cohort study included all premature children born with birth weight *1,500 grams or a gestational age at birth *32 weeks. All patients were examined by indirect binocular ophthalmoscopy between the 4th and the 6th week of life. The examinations were repeated depending on the disease classification according the International Classification of ROP. Results: Three hundred-twenty-two preterm infants were included in this study. ROP occurred in 82 infants (25.5%). Severe ROP occurred in 18 patients (5.6%). Seventeen of these were treated by diode laser photocoagulation. Three of the treated children needed a second laser session. One patient of the re-treated group needed scleral buckling surgery with an equatorial silicon band after progression for stage 4 of ROP. One patient missed the opportunity for laser and the disease progressed to stage 5 of ROP and blindness. Conclusions: The incidence of retinopathy at our institution was similar to international results as well the as percentage of severe disease needing treatment. Laser photocoagulation was effective to stabilize the disease among 17 treated patients

Objetivos: Avaliar a incidência geral da Retinopatia da Prematuridade (ROP) e a incidência da ROP em forma severa necessitando tratamento, assim como a evolução aos seis meses de idade nos nascidos pretermo admitidos na Unidade de Terapia Intensiva Neonatal do Hospital de Clínicas de Porto Alegre entre outubro de 2002 e outubro de 2006. Métodos: Estudo de coorte, prospectivo, incluindo todos os pretermos com peso de nascimento *1.500 gramas ou com idade gestacional *32 semanas que sobreviveram até o momento do exame oftalmológico inicial. Todos foram examinados por oftalmoscopia binocular indireta entre a 4ª e a 6ª semana de vida com reavaliações periódicas de acordo com os achados baseados na Classificação Internacional da ROP. Resultados: A ROP afetou 82 pacientes (25,5%). A doença severa necessitando tratamento ocorreu em 18 pacientes (5,6%). Dezessete pacientes realizaram tratamento de fotocoagulação por laser diodo. Três das crianças tratadas necessitaram uma segunda sessão de tratamento. Um dos pacientes re-tratados evoluiu com progressão necessitando cirurgia de retinopexia com banda de silicone epi-escleral. Um paciente perdeu a oportunidade do tratamento e desenvolveu cegueira total bilateral. Conclusões: A incidência da doença bem como o percentual de crianças necessitando tratamento na instituição foi similar ao encontrado em outros centros internacionais. O tratamento foi eficiente para estabilizar e evitar a progressão para cegueira em 17 pacientes admitidos no hospital durante o período do estudo

Stratus optical coherence tomography findings in patients with Tomografia de coerência óptica em pacientes com retinopatia da prematuridade / x

PURPOSE: To describe morphological features of the macula in patients with retinopathy of prematurity. METHODS: Twelve premature babies with retinopathy of prematurity grades I, II and III underwent dilated fundus examination and optical coherence tomography evaluation. RESULTS: In all thirteen eyes of the twelve premature patients optical coherence tomography revealed a condensed retinal pigmented epithelial layer in the macular-foveal area shown by increased reflectivity. In these eyes the retinal layers were not well differentiated. Foveal depression was clearly evident in 23 percent. CONCLUSIONS: In premature patients with retinopathy of prematurity, optical coherence tomography revealed poorly differentiated layers in the macular region with increased reflectivity in retinal pigmented epithelial-choriocapillaris zone.

OBJETIVO: Descrever os aspectos morfológicos da mácula em pacientes com retinopatia da prematuridade (ROP). MÉTODOS: Doze pacientes com retinopatia da prematuridade graus I, II and III foram submetidos a mapeamento de retina e avaliação por tomografia de coerência óptica. RESULTADOS: Em todos os treze olhos de 12 pacientes a tomografia de coerência óptica mostrou a camada do epitélio pigmentar hiperrefletiva, sendo a área macular com maior intensidade. Nesses olhos as camadas da retina não estavam totalmente diferenciadas. A depressão foveal ficou claramente evidente pela tomografia de coerência óptica em 23 por cento. CONCLUSÃO: Nos pacientes prematuros com retinopatia da prematuridade, a tomografia de coerência óptica mostrou as camadas da retina pouco diferenciadas com aumento da refletividade na área macular do complexo epitélio retiniano pigmentar-coriocapilar.

The prevalence of retinopathy of prematurity in very low birth weight newborn infants

OBJECTIVE: To evaluate the prevalence of retinopathy of prematurity and the risk factors affecting very low birth weight infants at a neonatal intensive care unit. METHODS: A cross-sectional study investigating all newborn infants with birth weights > 1,500 g and/or gestational ages > 32 weeks, admitted to the Neonatal ICU at the Hospital de Clínicas de Porto Alegre, from October 2002 to March 2004. Patients underwent indirect binocular ophthalmoscopy of the fundus at six weeks postpartum. Infants who progressed to threshold disease were given laser therapy. RESULTS: One hundred and fourteen newborn infants were studied. Eighty-three patients were not diagnosed with retinopathy of prematurity, 18 had stage I retinopathy of prematurity, seven stage II retinopathy of prematurity and six patients had threshold retinopathy of prematurity. The prevalence of retinopathy of prematurity was 27.2% (95% CI: 19.28-36.32) affecting 31 newborn infants, and the prevalence of retinopathy of prematurity progressing to threshold disease was 5.26% (95% CI: 1.96-11.10), affecting six patients. Retinopathy of prematurity was confirmed in 50% of the patients with weights below 1,000 g and 71.5% of newborn infants born at gestational ages of less than 28 weeks. Gestational age and birth weight were significantly lower among patients with retinopathy of prematurity than among those without. CONCLUSIONS: Although the results of this study demonstrate that the observed prevalence was similar to that described in literature, this ROP frequency remains elevated among very low birth weight infants. The development of retinopathy of prematurity was inversely proportional to weight and gestational age at birth.

Fulminate retinopathy of prematurity - clinical characteristics and laser outcome.

PURPOSE: To analyse the clinical characteristics and treatment outcome of zone 1 Fulminate type of Retinopathy of Prematurity (ROP) and compare it to Conventional ROP. METHODS: Preterm infants from two neonatal intensive care units (NICU) born between July 2002 and November 2003 were screened for ROP. Cases with Conventional ROP were classified according to the International Classification of Retinopathy of Prematurity (ICROP) while that of Fulminate ROP according to Shapiro's classification. Threshold disease was kept the cut off for treatment for Conventional ROP and stage 3A for Fulminate ROP. RESULTS: Of the 54 cases that had treatable ROP, 36 (66.67%) had Fulminate type. The mean gestational age and birth weight was higher in Fulminate ROP compared to Conventional disease (31.75 weeks and 1554 gms vs 31 weeks 1387 gms) whereas the mean postnatal age at laser was lower (4.62 weeks vs 6.3 weeks). The average number of laser spots given was 3036.6 for Fulminate disease. CONCLUSION: Fulminate ROP had an atypical morphology which was difficult to classify according to ICROP classification and we would like to lay stress upon the importance of screening of premature infants from the age of 4 weeks and to start treatment immediately once Fulminate ROP has been diagnosed.

Ultraestructura de la retinopatía causada por la hiperoxia en ratas en desarrollo / Ultra structure of retinopathy induced by hyperoxia in developing rats

In order to evaluate the effect of postnatal hyperoxia on retinal structure, newborn rats were exposed to different oxygenation intervals (80 ± 1%) with three interruptions of 21% (30 min each). Four groups of rats were exposed from birth to the 6th, 9th, 12th and 14th postnatal day, respectively and another group was placed under normoxia. After this period all oxygenated groups and the controls remained under normoxia until they were 30 days old for the structural analysis of retina. Retinal histology was carried out using conventional techniques for transmission electron microscopy (TEM). In the ganglion cell layer of the retina from rats exposed for 9 days to hyperoxia, capillaries with large projections toward the lumen, were observed as a possible consequence of cellular edema of endothelium. The most severe damage was observed in rats exposed to hyperoxia during 12 and 14 days, showing mitochondrias swollen up and without crests in the areas surrounding the capillaries, necrosis and apoptosis processes, dense bodies, cells with swollen cytoplasms and rupture of the plasmatic membrane. The results suggest that postnatal hyperoxia causes severe damages to the retina in developing rats with a direct relationship between the time exposed to oxygen and ultra structural damages.

Con el propósito de evaluar el efecto de la hiperoxia posnatal sobre la estructura retiniana se analizaron retinas de ratas recién nacidas expuestas a diferentes periodos de oxigenación (80 ±1%), con tres interrupciones de 21% (30 min c/u). Cuatro grupos de ratas fueron expuestas desde su nacimiento hasta el 6to, 9no, 12mo y 14to días de vida y otro grupo fue mantenido en normoxia. Después de este periodo tanto los grupos expuestos a la hiperoxia como los controles permanecieron en normoxia hasta una edad de 30 días para el análisis estructural de la retina. La histología se hizo usando técnicas convencionales para microscopía electrónica de transmisión (MET). En la capa de células ganglionares de la retina de ratas expuestas a nueve días de hiperoxia, se observaron capilares con notables proyecciones hacia la luz, posiblemente como consecuencia de edema celular del endotelio. El daño más intenso fue observado en las ratas expuestas a hiperoxia durante 12 y 14 días, mostrando mitocondrias hinchadas y sin crestas en las áreas circundantes a los capilares, procesos de necrosis y apoptosis, cuerpos densos, células con citoplasmas hinchados y con ruptura de la membrana plasmática. Los resultados sugieren que la hiperoxia posnatal causa graves daños a la retina en las ratas en desarrollo, con una relación directa entre el tiempo de exposición al oxígeno y los daños ultraestructurales.

Extraocular muscle changes after cryotherapy for retinopathy of prematurity and the development of strabismus in premature infants

To find out whether the cryotherapy for the treatment of the retinopathy of prematurity (ROP) causes structural changes of the extraocular muscle (EOM), and also whether the changes are related with the occurrence of strabismus. To examine the acute stage change, we conducted a transconjunctival cryotherapy around the superior rectus muscle of a rabbit and resected it 0, 3, 7, 14, and 28 days after the cryotherapy. In observing chronic changes, we first categorized patients who had an esotropia surgery into groups, one of which combined prematurity and cryotherapy and one group affected by prematurity but without having had cryotherapy. Then we compared the change of EOM with that of a fullterm infant group. In a rabbit, edema, acute inflammatory cells and a large amount of degenerated muscle fibers were observed immediately after the cryotherapy and on the 3rd day. On the 7th day, regenerated muscle fibers were observed and on the 14th day, the inflammatory cells decreased and the amount of regenerated muscle fiber increased. On the 28th day, abnormal findings were not observed any more and the muscle was found to be normal. When chronic changes of EOM in human on 1 1/2 to 8 1/2 years after cryotherapy, there were no abnormal findings observed in three groups. From the study, we can infer that cryotherapy can cause acute inflammation and necrosis of muscle fiber but such an acute change will improve and does not result in structural change in the long term. Therefore, the occurrence of strabismus in patients with ROP is considered to be attributable to reasons other than injury of EOM.

Retinopatía del prematuro / Retinopathy of prematurity

Se realizó una revisión de la literatura acerca de la retinopatía del prematuro (RDP), su definición, epidemiología, factores de riesgo de presentación, clasificación internacional, cuadro clínico, patogénesis, diagnóstico, historial natural, pronóstico y tratamiento. Se revisaron también los reportes del estudio multicéntrico de tratamiento con crioterapia de la RDP. Se concluye que es de gran importancia conocer las alteraciones provocadas por este padecimiento, así como realizar el diagnóstico y tratamiento oportunos, para así evitar las secuelas que muchas veces llevarán al paciente a la ceguera

The outcome of cryotherapy for retinopathy of prematurity (ROP) according to ROP location

Cryotherapy has been shown to be an effective treatment for retinopathy of prematurity (ROP) stage 3+. However, the outcome of cryotherapy is less favorable in zone 1 ROP than in zone 2 ROP. We suspected whether there may be differences in the outcomes of cryotherapy if the zone of ROP is further divided. So we reviewed the records of 85 premature infants (145 eyes) who had undergone cryotherapy for ROP. The frequencies of favorable outcome were 42.9% of 14 eyes (zone 1), 78.9% of 38 eyes (posterior zone 2), 92.9% of 70 eyes (mid zone 2), and 100.0% of 23 eyes (anterior zone 2), respectively (p < 0.001). These results suggest that the more posteriorly the ROP is located, the less favorable the outcome of cryotherapy.

The components of the proliferative membranes in retinopathy of prematurity: an electron microscopic study

Electron microscopic examination of proliferative membranes in retinopathy of prematurity (ROP) was performed in order to evaluate the components of the membranes. The proliferative membranes were obtained from nine patients with ROP stage 5 during pars plicata lensectomy, vitrectomy, and delamination of membrane. Fibrous astrocytes, myofibroblasts, lymphocytes, macrophages, and calcification were found respectively in two cases, and fibroblast-like cells were found in one case. Varying amounts of collagen tissues were found in eight cases and vascular tissues in four cases. Most of membranes were hypocellular and composed mainly of collagen matrix. It is considered that fibrous astrocytes, myofibroblasts, fibroblasts, and vascular structures are involved in the formation of proliferative membranes of ROP, and that later these cells degenerate and disappear, and that finally only collagen matrix remains in the membranes.

Vitamina E no tratamento da retinopatia do prematuro (ROP)? / Vitamin E in the treatment of retinopaty of prematurity

O presente trabalho por objetivo discutir os aspectos mais importantes e atuais com relaçäo à etiologia, fatores de risco, classificaçäo, problemas associados e tratamento da ROP, especialmente questionando o uso de vitaminas E

Retinopatía del prematuro / Retinal diseases in premature infants

La Retinopatía del Prematuro continúa siendo una importante causa de ceguera en infantes. La terapia con vitamina E aparenta ser de utilidad en la disminución de la severidad en los pacientes afectados. La mejor terapia para el manejo de la Fibroplasia Retrolental Cicatricial es la vitrectomía a cielo abierto