Natural History of Retinopathy of Prematurity in Infants Born Before 27 Weeks' Gestation in Sweden

Objective: To investigate the natural history of retinopathy of prematurity (ROP) in 506 extremely preterm infants born before 27 weeks' gestation in Sweden during a 3-year period. Methods:A national population-based study was performed in Sweden from April 1, 2004, to March 31, 2007. According to the study protocol, initial eye examinations were to be performed at postnatal week 5, and examinations were repeated until the retina was completely vascularized or until criteria for treatment were met. The examinations were to be performed weekly, enabling study of the course and severity of ROP. In infants without ROP or with mild ROP without progression during the latest examinations, further examinations were performed weekly or every other week from postmenstrual age 35 weeks. Results: During the study, 368 infants (72.7%) developed ROP. Postmenstrual age at onset of ROP was significantly related to severity of ROP, even when controlling for gestational age (ie, the earlier the onset of ROP, the higher the risk of developing severe ROP). Site of onset of ROP was significantly related to gestational age at birth. The risk of nasal onset was almost doubled for every week of decrease in gestational age at birth. Nasal onset was associated with severe ROP, even after adjusting for gestational age at birth. Conclusion: This population-based study confirms results of the Cryotherapy for Retinopathy of Prematurity study and shows new correlations regarding time and site of onset of ROP, both of which are associated with disease severity

Evaluation of new guidelines for ROP screening in Sweden using SWEDROP - a national quality register

PurposeTo investigate whether recent Swedish guidelines for Retinopathy of Prematurity (ROP) screening, that is, a gestational age (GA) at birth of <31weeks (w), are applicable in a new national cohort of prematurely born infants. MethodsSWEDROP is a national register for ROP, initiated in 2006. The present paper reports on data from the register on various aspects of screening for ROP in infants born between 2010 and 2011 and compares the results with those for a previously published cohort born between 2008 and 2009. ResultsDuring the study period, 1744 infants were screened for ROP. Mean GA was 28.4w (22-31), and mean birth weight was 1239g (382-2615). Screening started at postnatal age (PNA) 5.4w (0.4-13.3) and postmenstrual age (PMA) 33.8 w (24.9-50.1) Mean number of examinations was 5.4 per infant (1-38). Mild (stages 1-2) and severe ( stage 3) ROP was found in 15.4% and 8.7%, respectively. Treatment was performed in 4.2% (73/1744) of the infants, but in none with a GA of 30weeks or more. The first treatment was performed at a mean PNA and PMA of 12.7 w (7.7-25.4) and 37.4 w (32.1-51.4), respectively. ConclusionsRecently introduced new guidelines for ROP screening in Sweden remain applicable. Reassuringly, in infants born between 2010 and 2011, incidence of ROP, frequency and timing of treatment, frequency and timing of examinations and national coverage of ROP screening remained almost identical to those for a previous cohort from 2008 to 2009. The two SWEDROP cohorts provide a basis for discussion among Swedish ophthalmologists and neonatologists on the question of further lowering the upper screening limit with 1week

Incidence of Retinopathy of Prematurity in Infants Born Before 27 Weeks' Gestation in Sweden

Objective: To determine the incidence of retinopathy of prematurity (ROP) in extremely preterm infants born before 27 weeks' gestation in Sweden during a 3-year period. Methods: A national, prospective, population-based study was performed in Sweden from April 1, 2004, to March 31, 2007. The ophthalmologic part of the study was separately organized, and screening for ROP was performed beginning postnatal week 5. The criteria for the treatment of ROP agreed with the recommendations of the Early Treatment for Retinopathy of Prematurity Cooperative Group. Results: During the study, 506 of 707 live-born infants survived until the first eye examination. Of these, 368 (72.7%) had ROP: 37.9% had mild ROP and 34.8% had severe ROP. Ninety-nine infants (19.6%) were treated. Gestational age at birth was a stronger predictor of ROP than was birth weight. A log-linear relationship between severe ROP and gestational age at birth was found in the present cohort, and the risk of ROP was reduced by 50% for each week of increase in gestational age at birth. Conclusions: Today, extremely preterm infants are surviving, and this population-based study with ROP as a primary outcome shows a higher incidence of this condition than in previously reported national cohorts

Swedish National Register for Retinopathy of Prematurity (SWEDROP) and the Evaluation of Screening in Sweden

Objectives: To evaluate screening for retinopathy of prematurity (ROP) in Sweden and to investigate possible modifications of the present screening guidelines. Methods: Infants in Sweden with a gestational age (GA) of 31 weeks + 6 days or less are screened for ROP. Data from the Swedish national register for ROP (SWEDROP) during 2008 and 2009 were extracted and compared with a national perinatal quality register. Results: In SWEDROP, there were 1791 infants born before a GA of 32weeks from January 1, 2008, through December 31, 2009. Another 70 infants were registered in the perinatal quality register but not in SWEDROP (drop-out rate, 3.8% [70 of 1861 infants]). Seven infants died before termination of screening. In the final study cohort (1784 infants), 15.6% had mild ROP and 8.5% had severe ROP. Treatment was performed in 4.4% of the infants, none of whom had a GA at birth of more than 28 weeks. Nine infants with a GA of more than 28 weeks at birth developed stage 3 ROP, which regressed spontaneously. The total number of examinations was 9286 (964 in infants with a GA of 31 weeks), and the mean (range) number of examinations of each infant was 5.2 (1-30). Conclusions: The SWEDROP, a quality register for ROP, has a national coverage (ie, participation) of 96%. Data from 2008 to 2009 show that it seems possible to reduce the upper limit for screening in Sweden by 1 week, including only infants with a GA of 30 weeks + 6 days or less. However, such a change should be combined with a strong recommendation to neonatologists to refer also severely ill and more "mature" infants

Prevalence of Severe Visual Disability Among Preterm Children With Retinopathy of Prematurity and Association With Adherence to Best Practice Guidelines

IMPORTANCE Retinopathy of prematurity (ROP) can cause severe visual disability even in high-resource settings. A better understanding of the prevalence and processes leading to ROP-induced severe visual impairment may help health care professionals design preventive measures. OBJECTIVES To determine the prevalence of severe visual disability among children born preterm in Sweden, evaluate adherence to best practice, and determine the health system's structural capacity. DESIGN, SETTING, AND PARTICIPANTS Population-based, nationwide cohort study of 1 310 227 children born between January 1, 2004, and December 31, 2015, in Sweden, of whom 17 588 (1.3%) were born very preterm (&lt;32 weeks of gestation). Children born preterm with a verified diagnosis of severe visual disability had their medical records reviewed for evaluation of ROP screening, diagnosis, and treatment. In addition, a questionnaire on structural capacity was sent to all ophthalmology departments. EXPOSURES Stages 4 and 5 ROP. MAIN OUTCOMES AND MEASURES The primary outcome was prevalence of severe visual disability (visual acuity similar to 20/200 for both eyes) associated with ROP stages 4 and 5. Secondary outcomes included adherence to national ROP guidelines using a predefined protocol with 15 key performance indicators for screening, diagnosis, and treatment; assessment of whether visual disability was deemed avoidable; and examination of structural capacity, including information on equipment and facilities, staffing, and patients. RESULTS Seventeen children (10 boys; mean [range] birth weight, 756 [454-1900] g; mean [range] gestational age, 25 [22-33] weeks) became severely visually disabled because of ROP, corresponding to a prevalence of 1 in 1000 very preterm infants (&lt; 32 weeks of gestational age) and 1 in 77 000 for all live births. Severe visual impairment was considered potentially avoidable in 11 of 17 affected children (65%) owing to untimely or no screening, missed diagnosis, or untimely and suboptimal treatment. Large variations in infrastructure (facilities, guidelines, staffing, and annual patient numbers) were also identified as potential contributors to these findings. CONCLUSIONS AND RELEVANCE Retinopathy of prematurity still causes severe visual disability in Sweden, resulting in 1 affected infant per 1000 very preterm births. In most of these infants, noncompliance with best practice was identified, indicating that a significant proportion could have been avoided

Ophthalmologic Outcome at 30 Months' Corrected Age of a Prospective Swedish Cohort of Children Born Before 27 Weeks of Gestation The Extremely Preterm Infants in Sweden Study

IMPORTANCE Follow-up at 30 months' corrected age reveals eye and visual problems in one-third of children born extremely prematurely (<27 weeks' gestation). OBJECTIVE To investigate the ophthalmologic outcome of extremely preterm children at 30 months' corrected age. DESIGN, SETTING, AND PARTICIPANTS A prospective, population-based follow-up study (Extremely Preterm Infants in Sweden Study [EXPRESS]) was conducted in Sweden. The population included extremely preterm infants (<27 weeks' gestation) born in Sweden between 2004 and 2007, of whom 491 survived until age 2.5 years. Screening for retinopathy of prematurity (ROP) was performed in the neonatal period. At 30 months' corrected age, an ophthalmologic assessment was performed in 411 of 491 children (83.7%). MAIN OUTCOMES AND MEASURES Visual acuity, manifest strabismus, and refractive errors were evaluated. RESULTS Visual impairment was identified in 3.1% of the children, and 1.0% were blind. Refractive errors, defined as myopia less than -3 diopters (D), hypermetropia greater than +3 D, astigmatism 2 D or more, and/or anisometropia 2 D or more, were found in 25.6% of the children, and 14.1% had manifest strabismus. There were significant associations between visual impairment and treated ROP (P = .02), cognitive disability (P < .001), and birth weight (P = .02). Multiple regression analyses revealed significant associations between strabismus and treated ROP (P < .001), cognitive disability (P < .01), and cerebral palsy (P = .02). Refractive errors were significantly correlated with severity of ROP (right eye, P < .001; left eye, P < .01). Children who had been treated for ROP had the highest frequency (69.0%) of eye and visual abnormalities. CONCLUSIONS AND RELEVANCE One-third of the extremely prematurely born children in this study had some kind of eye or visual problems, such as visual impairment, strabismus, or major refractive error. Despite being born extremely preterm, the present cohort has a similar prevalence of blindness and visual impairment as in previous Swedish cohorts of children born less prematurely

Obesity and thrombin-generation profiles in women with venous thromboembolism

Obesity is a known risk factor for venous and arterial thrombosis but the mechanisms are still unclear. In women, obesity is correlated with low-grade inflammation and recent data show that BMI is positively associated with thrombin generation. We explored the correlations between obesity, inflammation and thrombin generation in women with increased thrombotic risk by looking at a cohort of women with prior venous thrombosis. One hundred and fifty-six women age 18-65 years were enrolled at diagnosis of first venous thromboembolism (VTE). Plasma samples were obtained at least 3 weeks after cessation of anticoagulant treatment. Thrombin generation was determined with the calibrated automated thrombography (CAT) assay and the Innovance ETP assay. Thrombin generation started later but was more pronounced with higher endogenous thrombin generation potential (ETP) determined with CAT in patients with obesity. The Innovance ETP assay showed results consistent with CAT. Furthermore, patients with obesity had significantly higher levels of fibrinogen, C-reactive protein and plasminogen activator inhibitor-I (PAI-I) than patients without obesity. Increased levels of fibrinogen were the main determinant of the prolonged lag-time in patients with obesity whereas higher levels of prothrombin could account for the difference in the ETP between the groups. We found an association between BMI and ETP values using two different methods to measure thrombin generation. Obesity correlated with increased thrombin generation in women with VTE and the main determinants of this hypercoagulable state were increased levels of fibrinogen and prothrombin. This shows a possible link between obesity, low-grade inflammation and increased thrombin generation in women at increased risk for future thrombosis