Glucose tolerance tests are used frequently in nonclinical research with laboratory animals, for example during characterization of obese phenotypes. Despite published standard operating procedures ...for glucose tolerance tests in rodents, how glucose doses should be calculated when obese
and lean animals are compared is not well documented. Typically the glucose dose is calculated as 2 g/kg body weight, regardless of body composition. With this approach, obese mice receive larger glucose doses than do lean animals, potentially leading to overestimation of glucose intolerance
in obese animals. In this study, we performed intraperitoneal glucose tolerance tests in mice with diet-induced obesity and their lean controls, with glucose doses based on either the total body weight or the lean body mass of the animals. To determine glucose tolerance, we determined the
blood glucose AUC during the glucose tolerance test. We found that the blood glucose AUC was increased significantly in obese mice compared with lean mice by 75% on average when glucose was dosed according to the lean body mass and by 87% when the glucose dose was calculated according to total
body weight. Therefore, mice with diet-induced obesity were approximately equally glucose intolerant between the 2 dose-calculation protocols. However, we recommend calculating the glucose dose according to the lean body mass of the mice, because doing so eliminates the concern regarding overdosing of obese animals.
To determine the ophthalmological outcome at 6.5 years of age in children treated for retinopathy of prematurity (ROP), and registered in the national Swedish National Register for ROP register.
Data ...on ROP, treatment and ophthalmological outcome were retrieved from the register. Visual acuity (VA), refractive errors and strabismus, together with visual impairment (VI) and any significant eye problem, defined as VA >0.5 logarithm of the minimal angle of resolution (logMAR) and/or strabismus and/or any refractive error were analysed. Risk factors such as sex, gestational age (GA), birth weight SD score, number of treatments and retreatments, postnatal age and postmenstrual age at first treatment were analysed.
Follow-up data were available in 232 of 270 children born between 2007 and 2014 who had been treated for ROP. VI (VA >0.5 logMAR) was found in 32 (14%), strabismus in 82 (38%), refractive errors in 114 (52%) and significant eye problem in 143 (65%) children. Retreatment was a risk factor for VI and refractive errors. Male sex and neonatal brain lesion were risk factors for strabismus. An additional week of GA at birth reduced the risk for refractive errors, strabismus and significant eye problems.
The results of the present study revealed a high number of eye problems in children treated for ROP, emphasising the need for long-term follow-up. Retreatment of ROP was a risk factor for VI, and emphasises the importance of an accurate first treatment for the long-term ophthalmological outcome.
Purpose
This study aimed to investigate various aspects of treatment for retinopathy of prematurity (ROP) in Sweden over the past 14 years, nationally and at a hospital level.
Methods
Data on ...screening and treatment for ROP in infants born in Sweden from 2008 to 2021 were extracted from the national ROP register, SWEDROP. During this period, Swedish screening guidelines were reduced from gestational age (GA) < 32 weeks to <31 weeks in 2012 and to <30 weeks in 2020.
Results
Altogether, 10 959 infants were screened and 600 infants treated for ROP during the study period. Parallel to changed guidelines, the number of screened infants decreased (p < 0.000) and the incidence of ROP and frequency of treatment increased (p < 0.001), while both remained similar in infants with a GA below 30 weeks. Among treated infants, GA and BW were reduced over the years (p < 0.001). Laser treatment (85.2% of primary treatments) became less common and anti‐VEGF injections (13.6%) became more common over time (p < 0.001). Altogether 16 eyes were treated with the encircling band and 13 with vitrectomy. The total frequency of retreatment (32.7% of treated eyes) remained similar over time but was more common after primary anti‐VEGF injection (67.7%) than laser treatment (27.2%). There were differences between the seven university hospitals regarding type of treatment and number of retreatments (p < 0.001).
Conclusion
The frequency of treatment and retreatment for ROP remained similar over time, but the type of treatment changed and anti‐VEGF injections became more common. Differences between treating hospitals emphasize the importance of centralizing the most severe cases.
IMPORTANCE: This follow-up study of extremely preterm (EPT) children (<27 weeks’ gestational age GA at birth) revealed major eye and visual problems in 37.9% (147 of 388) of all EPT infants and in ...55.4% (67 of 121) of the most immature subgroups at 6.5 years of age. These major eye and visual problems were strongly associated with treatment-requiring retinopathy of prematurity (ROP). OBJECTIVES: To investigate the ophthalmologic outcome of a national cohort of EPT children at 6.5 years of age and to evaluate the impact of prematurity and ROP. DESIGN, SETTING, AND PARTICIPANTS: All surviving EPT children born in Sweden between April 1, 2004, and March 31, 2007, were included and compared with a matched term control group, as part of a prospective national follow-up study. MAIN OUTCOMES AND MEASURES: Visual acuity, refraction in cycloplegia, and manifest strabismus were evaluated and compared with GA at birth and with treatment-requiring ROP. RESULTS: The study cohort comprised 486 participants. The mean (SD) GA of the children who were included was 25 (1) weeks, and 45.7% (222 of 486) were female. At a median age of 6.6 years, 89.3% (434 of 486) of eligible EPT children were assessed and compared with 300 control group children. In the EPT group, 2.1% (9 of 434) were blind, 4.8% (21 of 434) were visually impaired according to the World Health Organization criteria, and 8.8% (38 of 434) were visually impaired according to the study criteria. Strabismus was found in 17.4% (68 of 390) and refractive errors in 29.7% (115 of 387) of the EPT children compared with 0% (0 of 299) and 5.9% (17 of 289), respectively, of the control children (P < .001). Altogether at 6.5 years of age, 37.9% (147 of 388) of the EPT children had some ophthalmologic abnormality compared with 6.2% (18 of 290) of the matched control group (95% CI of the difference, 26.1%-37.2%). When treatment-requiring ROP was adjusted for, no significant association between GA and visual impairment could be detected. For refractive errors, the association with GA remained after adjustment for treatment-requiring ROP (odds ratio, 0.72; 95% CI, 0.58-0.91 for each 1-week increment). CONCLUSIONS AND RELEVANCE: In a Swedish national cohort of EPT children at 6.5 years of age, major eye and visual problems were frequently found. Treatment-requiring ROP was a stronger impact factor than GA on visual impairment and strabismus, but not on refractive errors, as a whole. In modern neonatal intensive care settings, ophthalmologic problems continue to account for a high proportion of long-term sequelae of prematurity.
During the last decade, improved neonatal care has resulted in increased survival of the most immature infants and improved health of more mature infants. We hypothesise that this has affected ...incidence and treatment of retinopathy of prematurity (ROP), enabling guidelines for screening to be modified.
In Sweden, all infants with gestational age (GA) at birth ≤30 weeks are screened for ROP. Results are registered in a web-based register, Swedish National ROP Register, with a coverage rate of 97%. Incidence of ROP and frequency of treatment, aspects on natural course of ROP and number of examinations, are calculated in relation to GA at birth in infants born during 2008-2017.
Of 7249 infants, 31.9% (2310) had ROP and 6.1% (440) were treated. No infant with GA 30 weeks was treated. Incidence of ROP remained similar, but frequency of treatment increased (p=0.023). Over time, GA and birth weight were reduced in infants with ROP and with treated ROP. In the most immature infants, postmenstrual age was lower and postnatal age was higher when any ROP and stage 3 ROP were first detected (p<0.001). At treatment, postmenstrual but not postnatal age of the infant was associated with GA (p<0.001). During the 10-year period, 46 038 examinations were performed.
Modification of Swedish guidelines is proposed, including only infants with a GA of <30 weeks and postponing the first examination with 1 week in infants with GA 26-29 weeks. This would spare many infants from stressful examinations and reduce eye examinations with at least 20%.
Aim
Analysis of age at time of detection and surgery of dense unilateral cataract and investigation of best‐corrected visual acuity (BCVA) in a nationwide register‐based cohort study, based on the ...routine of maternity ward eye screening.
Methods
Data were derived from the Paediatric Cataract Register (PECARE). All children (n = 54) diagnosed with dense congenital unilateral cataract between January 2007 and September 2014 who had surgery before 1 year of age, and for whom 5‐year follow‐up records were available, were included.
Results
The majority, 35/54 (65%), were detected and operated on before age 6 weeks and 30/35 (86%) were referred from maternity wards. Visual acuity (VA) ≥ 0.5 (decimal, 0.3 logMAR) was found in 7/53 (13%) of the cohort at age 5 years; further, 19 children achieved VA ≥ 0.1 (decimal, 1.0 logMAR) (36%) and 19 children VA < 0.05 (decimal, 1.30 logMAR) (36%). Ten‐year follow‐up records were available for 17/53 (32%) children; 1/17 (6%) achieved VA ≥ 0.5 (decimal, 0.3 logMAR), 4/17 (24%) VA ≥ 0.3–<0.5 (decimal, 0.52–0.30 logMAR), 3/17 (18%) VA ≥ 0.05–0.1 (decimal, 1.30–1.0 logMAR) and 10/17 (59%) VA < 0.05 (decimal, 1.30 logMAR).
Conclusion
A total of 90% of the children were detected with cataract within 100 days of birth and 80% were operated on within this period. This study showed better visual acuity in those treated for dense unilateral cataracts than previously reported in an earlier Swedish cohort study.
Purpose
The aim was to report cumulative incidence and time of onset of postoperative glaucoma in a paediatric early cataract surgery cohort.
Methods
Data were retrieved from the Pediatric Cataract ...Register (PECARE), a prospective register of Swedish cataract operations before 8 years of age. All eyes with surgery between January 2007 and December 2014 and a registered follow‐up were included. Cataracts caused by uveitis, trauma or coexisting congenital glaucoma were excluded. Glaucoma was defined as early onset if diagnosed within a year after surgery and late onset if diagnosed later.
Results
The study included 288 eyes in 207 children (106 girls), 81 with bilateral and 126 with unilateral cataracts, with a mean follow‐up of 3.31 ± 1.77 years. Of the 288, 168 (58.3%) had surgery before 3 months of age; most of these 92.3% (155/168) were defined as dense, 208 (72.2%) were below 1 year of age. Cumulative incidence of surgically treated glaucoma among individuals was 23.7% (49/207). Median time to glaucoma onset was 0.91 years (range: 0.05–4.97 years) for eyes. Early‐onset glaucoma was found in 98 % (63/64), and late onset in 2% (1/64).
Conclusion
In this paediatric cataract cohort, a majority of eyes had surgery before 3 months of age (58.3%). Secondary glaucoma‐onset peaked within the first postoperative year, with a cumulative incidence of 23.7%. Surgery performed after the first month of life, resulted in a lower glaucoma rate. Long‐term follow‐up will reveal whether the low rate of late‐onset glaucoma with early surgery will last, and if so, the consequences.
Purpose
Retinopathy of prematurity (ROP) causes childhood blindness globally in prematurely born infants. Although increased levels of oxygen supply lead to increased survival and reduced frequency ...of cerebral palsy, increased incidence of ROP is reported.
Methods
With the help of a Swedish register for ROP, SWEDROP, national and regional incidences of ROP and frequencies of treatment were evaluated from 2008 to 2015 (n = 5734), as well as before and after targets of provided oxygen changed from 85–89% to 91–95% in 2014.
Results
Retinopathy of prematurity (ROP) was found in 31.9% (1829/5734) of all infants with a gestational age (GA) of <31 weeks at birth and 5.7% of the infants (329/5734) had been treated for ROP. Analyses of the national data revealed an increased incidence of ROP during the 8‐year study period (p = 0.003), but there was no significant increase in the frequency of treatment. There were significant differences between the seven health regions of Sweden, regarding both incidence of ROP and frequency of treatment (p < 0.001). Comparison of regional data before and after the new oxygen targets revealed a significant increase in treated ROP in one region OR: 2.24 (CI: 1.11–4.49), p = 0.024 and a borderline increase in one other OR: 3.08 (CI: 0.99–9.60), p = 0.052.
Conclusion
The Swedish national ROP register revealed an increased incidence of ROP during an 8‐year period and significant regional differences regarding the incidence of ROP and frequency of treatment.
Retinopathy of prematurity (ROP) is a sight-threatening disease, requiring efficient screening and treatment. The present study aims to describe various aspects on treatment for ROP in Sweden.
Data ...on treatment for ROP in infants born in 2008-2012 were extracted from Swedish national register for retinopathy of prematurity, a web-based national register.
During 2008-2012, 3488 infants with a gestational age (GA) at birth of <31 weeks had been screened for ROP in Sweden. Altogether, 30.3% (1057/3488) of the infants developed ROP and 5.2% (181/3488) were treated. Type 1 ROP was found in at least one eye in 83.2% (149/179) of the treated infants. One third of the eyes (32.2% right, 29.9% left eyes) were treated more than once. Laser was the only treatment in 90% of the eyes. Mean number of laser spots at first laser session was 1177 and 1386 in right and left eyes, respectively. Number of laser spots correlated negatively with GA at birth (p=0.01). There was no change in frequency of treatment or number of laser spots during the 5-year period. Anti-vascular endothelial growth factor injections were performed in 28 eyes, encircling band was used in five eyes and vitrectomies were performed in seven eyes. Twenty-six retinal surgeons performed 9.4 (range 1-37) treatment sessions in the 181 infants.
The present study reveals similar incidences of ROP and frequencies of treatment during the 5-year study period. Many surgeons were involved in treatment of a rather limited number of infants. The results call for national discussions on organisation of ROP treatment.
To report on the occurrence of postoperative visual axis opacification (VAO) in children younger than 5 years of age operated for cataract in Sweden, and to analyse correlations with age at surgery ...and surgical method.
Data were derived from the Swedish Pediatric Cataract Register (PECARE). All children operated on between 1 January 2007 and 31 December 2020 were included. Follow-ups at 1, 2 and 5 years of age were analysed.
Cataract surgery were performed on 770 eyes belonging to 549 children (n = 282 boys, 51.4%); 327/770 (42.5%) of the children underwent surgery before 3 months of age and 216/770 (28%) before 6 weeks of age. Data on 881 follow-up visits were registered. At the follow up-visits at 1, 2 and 5 years of age, VAO was present in 154/349 (44.1%), 41/323 (12.7%) and 25/208 (12%). The majority of the children with VAO underwent cataract surgery before age 6 months, with a predominance before age 2 months. Primary IOL was implanted in 601/770 (78%) of eyes; 40.8% had an acrylic one-piece lens, 31.8% had a bag-in-the-lens IOL, 21.9% were aphakic and 5.2% had an acrylic three-piece lens. Implantation of a bag-in-the-lens IOL was related to a significantly lower occurrence of VAO compared to other types of IOL, including aphakia (p < 0.0002).
Our results are in accordance with the literature. Primary bag-in-the-lens IOL implantation before 2 years of age seems adequate and safe, with a low occurrence of VAO, and can thus be continued as routine in Sweden.
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