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Background/objectives: With the increasing survival of premature infants, there is an increased demand to provide adequate retinopathy of prematurity (ROP) services. Wide field retinal imaging (WFDRI) and artificial intelligence (AI) have shown promise in the field of ROP and have the potential to improve the diagnostic performance and reduce the workload for screening ophthalmologists. The aim of this review is to systematically review and provide a summary of the diagnostic characteristics of existing deep learning algorithms., Subject/methods: Two authors independently searched the literature, and studies using a deep learning system from retinal imaging were included. Data were extracted, assessed and reported using PRISMA guidelines., Results: Twenty-seven studies were included in this review. Nineteen studies used AI systems to diagnose ROP, classify the staging of ROP, diagnose the presence of pre-plus or plus disease, or assess the quality of retinal images. The included studies reported a sensitivity of 71%-100%, specificity of 74-99% and area under the curve of 91-99% for the primary outcome of the study. AI techniques were comparable to the assessment of ophthalmologists in terms of overall accuracy and sensitivity. Eight studies evaluated vascular severity scores and were able to accurately differentiate severity using an automated classification score., Conclusion: Artificial intelligence for ROP diagnosis is a growing field, and many potential utilities have already been identified, including the presence of plus disease, staging of disease and a new automated severity score. AI has a role as an adjunct to clinical assessment; however, there is insufficient evidence to support its use as a sole diagnostic tool currently., (© 2022. Crown.)

Competing Interests: Disclosure of interest: The authors completed the ICMJE Disclosure of Interest Form (available upon request from the corresponding author) and disclose no relevant interests.

Aim: Retinopathy of prematurity (ROP) is a biphasic vaso-proliferative disease that has the potential to cause blindness. In addition to prematurity and hyperoxia, perinatal infection and inflammation have been reported to play a critical role in the pathogenesis of ROP. The aim of this study was to assess the association between placental inflammation and the severity of ROP., Methods: A retrospective study of infants (<30 weeks of gestational age) born at the King Edward Memorial Hospital, a tertiary perinatal center in Western Australia., Results: A total of 878 infants were included in this study (ROP stage 0-2 = 829; 3 or more = 49). The presence of maternal chorioamnionitis appeared to show signs of an association with reduced odds of severe ROP: mild chorioamnionitis OR=0.43 (95% CI: 0.17, 1.05) and severe chorioamnionitis OR=0.68 (95% CI: 0.29, 1.60). A strong association was observed for oxygen supplementation at 36 weeks (OR: 5.16; p  < 0.001), exposure to postnatal steroids (OR: 6.65; p  < 0.001), and receipt of platelet transfusion (OR: 8.21; p  < 0.001)., Conclusion: Maternal chorioamnionitis or fetal chorioamnionitis was associated with reduced odds of severe ROP. A strong association was found in infants who needed oxygen supplementation at 36 weeks and those who required steroids or platelets in the postnatal period., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© 2023 Athikarisamy, Lam, Cooper and Strunk.)

Importance: The currently recommended method for screening for retinopathy of prematurity (ROP) is binocular indirect ophthalmoscopy, which requires frequent eye examinations entailing a heavy clinical workload. Weight gain-based algorithms have the potential to minimize the need for binocular indirect ophthalmoscopy and have been evaluated in different setups with variable results to predict type 1 or severe ROP., Objective: To synthesize evidence regarding the ability of postnatal weight gain-based algorithms to predict type 1 or severe ROP., Data Sources: PubMed, MEDLINE, Embase, and the Cochrane Library databases were searched to identify studies published between January 2000 and August 2021., Study Selection: Prospective and retrospective studies evaluating the ability of these algorithms to predict type 1 or severe ROP were included., Data Extraction and Synthesis: Two reviewers independently extracted data. This meta-analysis was performed according to the Cochrane guidelines and reported according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis of Diagnostic Test Accuracy Studies (PRISMA-DTA) guidelines., Main Outcomes and Measures: Ability of algorithms to predict type 1 or sever ROP was measured using statistical indices (pooled sensitivity, specificity, and summary area under the receiver operating characteristic curves, as well as pooled negative likelihood ratios and positive likelihood ratios and diagnostic odds ratios)., Results: A total of 61 studies (>37 000 infants) were included in the meta-analysis. The pooled estimates for sensitivity and specificity, respectively, were 0.89 (95% CI, 0.85-0.92) and 0.57 (95% CI, 0.51-0.63) for WINROP (Weight, IGF-1 [insulinlike growth factor 1], Neonatal, ROP), 1.00 (95% CI, 0.88-1.00) and 0.60 (95% CI, 0.15-0.93) for G-ROP (Postnatal Growth and ROP), 0.95 (95% CI, 0.71-0.99) and 0.52 (95% CI, 0.36-0.68) for CHOP ROP (Children's Hospital of Philadelphia ROP), 0.99 (95% CI, 0.73-1.00) and 0.49 (95% CI, 0.03-0.74) for ROPScore, 0.98 (95% CI, 0.94-0.99) and 0.35 (95% CI, 0.22-0.51) for CO-ROP (Colorado ROP). The original PINT (Premature Infants in Need of Transfusion) ROP study reported a sensitivity of 0.98 (95% CI, 0.91-0.99) and a specificity of 0.36 (95% CI, 0.30-0.42). The pooled negative likelihood ratios were 0.19 (95% CI, 0.13-0.27) for WINROP, 0.0 (95% CI, 0.00-0.32) for G-ROP, 0.10 (95% CI, 0.02-0.53) for CHOP ROP, 0.03 (95% CI, 0.00-0.77) for ROPScore, and 0.07 (95% CI, 0.03-0.16) for CO-ROP. The pooled positive likelihood ratios were 2.1 (95% CI, 1.8-2.4) for WINROP, 2.5 (95% CI, 0.7-9.1) for G-ROP, 2.0 (95% CI, 1.5-2.6) for CHOP ROP, 1.9 (95% CI, 1.1-3.3) for ROPScore, and 1.5 (95% CI, 1.2-1.9) for CO-ROP., Conclusions and Relevance: This study suggests that weight gain-based algorithms have adequate sensitivity and negative likelihood ratios to provide reasonable certainty in ruling out type 1 ROP or severe ROP. Given the implications of missing even a single case of severe ROP, algorithms with very high sensitivity (close to 100%) and low negative likelihood ratios (close to zero) need to be chosen to safely reduce the number of unnecessary examinations in infants at lower risk of severe ROP.

Introduction: Retinopathy of prematurity (ROP) is the most common disease leading to blindness in extreme preterm infants. Current screening guidelines recommend frequent eye examinations. There is a dearth of trained ophthalmologists for these frequent screening procedures. The ANZNN neonatal network report (2013) found that only 6.4% of all screened infants had severe ROP and less than half received treatment. WINROP (online prediction model, Sweden) uses the postnatal weight gain (surrogate marker for low insulin-like growth factor IGF-1 and poor retinal vascular growth) to identify ROP requiring treatment and aims to reduce the number of examinations. Our objective was to validate the WINROP model in an Australian cohort of preterm infants., Methods: Birth weight, gestational age, and weekly weight measurements were retrieved retrospectively along with the final ROP outcomes and plotted on the online WINROP software., Results: The sensitivity, specificity, positive predictive value, and negative predictive value of WINROP were 85.7%, 59.0%, 6.98%, and 99.1% respectively for a cohort of 221 preterm infants (Median birth weight, 1040 g; Gestational age, 27.9 weeks). WINROP alarm was signaled in 42.6% of all infants. WINROP did not signal an alarm in one infant who needed treatment. This infant had intra ventricular hemorrhage grade 3-4 and temporary ventricular dilatation., Conclusions: This is the first Australian study validating WINROP model. Our findings suggest that it lacked sensitivity to be used alone. However, adjusting the algorithm for the Australian population may improve the efficacy and reduce the number of examinations when used along with the current screening guidelines.

Objectives: Retinopathy of prematurity (ROP) is a vasoproliferative disease of the preterm retina with the potential to cause irreversible blindness. Timely screening and treatment of ROP are critical. Neonatal nurses trained in wide field digital retinal photography (WFDRP) for screening may provide a safe and effective strategy to reduce the burden of ophthalmologists in performing binocular indirect ophthalmoscopy (BIO). The objective of the study was to determine the diagnostic accuracy of WFDRP in the diagnosis of referral warranting ROP (RWROP)., Design: Prospective diagnostic accuracy study., Setting: A tertiary neonatal intensive care unit in Perth, Western Australia., Participants: Preterm infants who fulfilled the Australian ROP screening criteria (gestational age (GA) <31 weeks, birth weight (BW) <1250 g)., Intervention: Sets of 5-6 images per eye (index test) were obtained within 24-48 hours prior to or after the BIO (reference standard), and uploaded onto a secured server. A wide field digital camera (RetCam, Natus, Pleasanton, California, USA) was used for imaging. A paediatric ophthalmologist performed the BIO. The ophthalmologists performing BIO versus reporting the images were masked to each other's findings., Primary Outcome: The area under the receiver operating characteristic (ROC) curve was used as a measure of accuracy of WFDRP to diagnose RWROP., Results: A total of 85 infants (mean BW; 973.43 g, mean GA; 29 weeks) underwent a median of two sessions of WFDRP. There were 188 episodes of screening with an average of five images per eye. WFDRP identified RWROP in 7.4% (14/188 sessions) of examinations. In one infant, BIO showed bilateral plus disease and WFDRP did not pick up the plus disease. WFDRP image interpretation had a sensitivity of 80%, specificity of 94.5% for the detection of RWROP. The 'area under the ROC curve' was 88% when adjusted for covariates., Conclusions: WFDRP by neonatal nurses was feasible and effective for diagnosing RWROP in our set up., Trial Registration Number: ACTRN12616001386426., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2020. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Importance: Early diagnosis of retinoblastoma, the most common intraocular cancer, can save both a child's life and vision. However, anecdotal evidence suggests that many children across the world are diagnosed late. To our knowledge, the clinical presentation of retinoblastoma has never been assessed on a global scale., Objectives: To report the retinoblastoma stage at diagnosis in patients across the world during a single year, to investigate associations between clinical variables and national income level, and to investigate risk factors for advanced disease at diagnosis., Design, Setting, and Participants: A total of 278 retinoblastoma treatment centers were recruited from June 2017 through December 2018 to participate in a cross-sectional analysis of treatment-naive patients with retinoblastoma who were diagnosed in 2017., Main Outcomes and Measures: Age at presentation, proportion of familial history of retinoblastoma, and tumor stage and metastasis., Results: The cohort included 4351 new patients from 153 countries; the median age at diagnosis was 30.5 (interquartile range, 18.3-45.9) months, and 1976 patients (45.4%) were female. Most patients (n = 3685 [84.7%]) were from low- and middle-income countries (LMICs). Globally, the most common indication for referral was leukocoria (n = 2638 [62.8%]), followed by strabismus (n = 429 [10.2%]) and proptosis (n = 309 [7.4%]). Patients from high-income countries (HICs) were diagnosed at a median age of 14.1 months, with 656 of 666 (98.5%) patients having intraocular retinoblastoma and 2 (0.3%) having metastasis. Patients from low-income countries were diagnosed at a median age of 30.5 months, with 256 of 521 (49.1%) having extraocular retinoblastoma and 94 of 498 (18.9%) having metastasis. Lower national income level was associated with older presentation age, higher proportion of locally advanced disease and distant metastasis, and smaller proportion of familial history of retinoblastoma. Advanced disease at diagnosis was more common in LMICs even after adjusting for age (odds ratio for low-income countries vs upper-middle-income countries and HICs, 17.92 [95% CI, 12.94-24.80], and for lower-middle-income countries vs upper-middle-income countries and HICs, 5.74 [95% CI, 4.30-7.68])., Conclusions and Relevance: This study is estimated to have included more than half of all new retinoblastoma cases worldwide in 2017. Children from LMICs, where the main global retinoblastoma burden lies, presented at an older age with more advanced disease and demonstrated a smaller proportion of familial history of retinoblastoma, likely because many do not reach a childbearing age. Given that retinoblastoma is curable, these data are concerning and mandate intervention at national and international levels. Further studies are needed to investigate factors, other than age at presentation, that may be associated with advanced disease in LMICs.

Impact Statement: Using two inhibitory methods, we demonstrated that hypoxia-inducible factor (HIF) plays an important role in vascularizing and oxygenating modularly-assembled engineered tissues. Each inhibitory technique elucidated a different mechanism by which this occurred. Whereas systemic inhibition negatively impacted early recruitment of host-derived cells, genetic inhibition in grafted endothelial cells was detrimental to their survival. Taken together, our study suggests that methods of HIF-mediated mechanisms could be harnessed to tune the extent and rate of vascularization in engineered tissue constructs.

Objective: This study aims to evaluate the presenting characteristics, management, outcomes and complications for paediatric traumatic hyphaema in Western Australia., Methods and Analysis: A retrospective review of medical records was conducted for consecutive patients ≤16 years of age admitted for traumatic hyphaema to Princess Margaret Hospital for Children (Perth, Australia) between January 2002 and December 2013 (n=82). From this sample, a cohort whose injury occurred ≥5 years prior attended a prospective ocular examination (n=16). Hospital records were reviewed for patient demographics, injury details, management, visual outcomes and complications. The prospective cohort underwent examination for visual and structural outcomes., Results: Most injuries (72%) resulted from projectile objects. Angle recession was present in 53% and was associated with projectiles (p=0.002). Most eyes (81%) achieved a final visual acuity of 0.3 logarithm of the minimum angle of resolution (logMAR) (20/40) or better. Age ≤5 years and posterior segment injury were significant predictors of final visual acuity poorer than 0.3 logMAR. At ≥5 years post-trauma, injured eyes had greater intraocular pressure (IOP) (p=0.024) and anterior chamber depth (ACD) (p=0.022) compared with sound eyes. IOP asymmetry was associated with angle recession (p=0.008) and ACD asymmetry (p=0.012)., Conclusion: Poorer visual outcomes are associated with younger age at injury and posterior segment injury. Angle recession and ACD asymmetry are associated with IOP asymmetry 5-12 years after injury., Competing Interests: Competing interests: None declared.

Aim: This study evaluated the correlation between retinopathy of prematurity (ROP), anaemia and blood transfusions in extremely preterm infants., Methods: We included 227 infants born below 28 weeks of gestation at King Edward Memorial Hospital, Perth, Australia, from 2014-2016. Birth characteristics and risk factors for ROP were retrieved, and anaemia and severe anaemia were defined as a haemoglobins of <110 g/L and <80 g/L, respectively. Logistic regression was used for the analysis., Results: Retinopathy of prematurity treatment was needed in 11% of cases and the mean number of blood transfusions (p < 0.01), and mean number of weeks of anaemia (p < 0.001) and of severe anaemia (p < 0.05), had positive associations with ROP cases warranting treatment. In the multivariate logistic regression analysis, the best-fit model of risk factors included anaemic days during first week of life, with an odds ratio (OR) of 1.46% and 95% confidence interval (CI) of 1.16-1.83 (p < 0.05), sepsis during the first 4 weeks of life (OR 3.14, 95% CI 1.10-9.00, p < 0.05) and days of ventilation (OR 1.03, 95% CI 1.01-1.06, p < 0.05)., Conclusion: The duration of anaemia during the first week of life was an independent risk factor for ROP warranting treatment and preventing early anaemia may decrease this risk., (©2017 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.)

Endothelial cell (EC)-enriched protein coding genes, such as endothelial nitric oxide synthase (eNOS), define quintessential EC-specific physiologic functions. It is not clear whether long noncoding RNAs (lncRNAs) also define cardiovascular cell type-specific phenotypes, especially in the vascular endothelium. Here, we report the existence of a set of EC-enriched lncRNAs and define a role for s pliced- t ranscript e ndothelial- e nriched lncRNA (STEEL) in angiogenic potential, macrovascular/microvascular identity, and shear stress responsiveness. STEEL is expressed from the terminus of the HOXD locus and is transcribed antisense to HOXD transcription factors. STEEL RNA increases the number and integrity of de novo perfused microvessels in an in vivo model and augments angiogenesis in vitro. The STEEL RNA is polyadenylated, nuclear enriched, and has microvascular predominance. Functionally, STEEL regulates a number of genes in diverse ECs. Of interest, STEEL up-regulates both eNOS and the transcription factor Kruppel-like factor 2 (KLF2), and is subject to feedback inhibition by both eNOS and shear-augmented KLF2. Mechanistically, STEEL up-regulation of eNOS and KLF2 is transcriptionally mediated, in part, via interaction of chromatin-associated STEEL with the poly-ADP ribosylase, PARP1. For instance, STEEL recruits PARP1 to the KLF2 promoter. This work identifies a role for EC-enriched lncRNAs in the phenotypic adaptation of ECs to both body position and hemodynamic forces and establishes a newer role for lncRNAs in the transcriptional regulation of EC identity., Competing Interests: The authors declare no conflict of interest.

Background: The aim was to investigate the characteristics and outcomes of ocular and adnexal injuries requiring hospitalisation in children in Perth, Western Australia., Methods: This is a hospital-based retrospective review of children admitted to Princess Margaret Hospital for Children with diagnoses of ocular and/or adnexal trauma from 2002-2013. Hospital charts were reviewed for demographic information, injury and management details, follow-up and visual outcome. Final visual acuity was categorised into three groups: 6/12 or better, from 6/12 to 6/60, worse than 6/60. Ordinal logistic regression was used to compute odds ratios and predicted probabilities for each category of final visual outcome., Results: Over the 12-year time period, 482 children were admitted with ocular or adnexal injuries - an average of 40 admissions per year. The mean age of the cohort was 7.1 years (range 0.09 to 16.47 years) with a male to female ratio of 2.6:1.0. There were 185 closed-globe injuries, 72 open-globe injuries and 293 adnexal injuries. Fourteen per cent of the cohort sustained a combined globe and adnexal injury. Children in the up to five-year age group were most susceptible to injury. Eighty-two per cent of the group had a final visual acuity of 6/12 or better. Factors associated with poor visual outcomes included younger age (p < 0.01), open-globe injury (p < 0.01) and lens injury (p < 0.01)., Conclusions: Based on the outcomes of our review, paediatric ocular and adnexal trauma are significant causes for hospital attendance in childhood. Identifying associated risk factors will help develop injury prevention strategies to promote eye safety for children., (© 2016 Optometry Australia.)

Enhancement of tissue vascularization is a therapeutic target for many ischemic conditions, and is crucial for successful engraftment of therapeutic cells for tissue regeneration. The authors present opportunities for using these platforms for dissecting the role of angiogenic mechanisms and highlight recent gene and drug delivery strategies for enhancing vascularization of engineered tissues. Modular tissue engineering is featured as an example., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Accurate prediction of the acoustics of fluid-structure interaction is important in devising quieting designs for engineering systems equipped with extensive flow duct networks where the thin duct wall panels are in contact with the flowing fluid. The flow unsteadiness generates acoustic waves that propagate back to the source region to modify the flow process generating them. Meanwhile the unsteady flow pressure excites the thin panels to vibrate, which in turn modifies the flow processes. Evidently a strong coupling between the fluid aeroacoustics and the panel structural dynamics exists. Such coupled physical processes have to be thoroughly understood; otherwise, effective quieting design is never achieved. This paper reports an analysis, using a time-domain numerical methodology the authors have recently developed, of the nonlinear aeroacoustic-structural interaction experienced by a flexible panel in a duct carrying a uniform mean flow. With no mean flow, the numerical results agree well with existing theories and reveal the physics of duct transmission loss. Four regimes of aeroacoustic-structural interaction are identified when the duct flow velocity increases from low subsonic to low supersonic values. Insight in the underlying physics of duct transmission loss at different velocities are highlighted and discussed.

A critical aspect of creating vascularized tissues is the remodelling that occurs in vivo, driven in large part by the host response to the tissue construct. Rather than a simple inflammatory response, a beneficial tissue remodelling response results in the formation of vascularised tissue. The characteristics and dynamics of this response are slowly being elucidated, especially as they are modulated by the complex interaction between the biomaterial and cellular components of the tissue constructs and the host. This process has elements that are similar to both wound healing and tumour development, and its features are illustrated by reference to the bottom-up generation of a tissue using modular constructs. These modular constructs consist of mesenchymal stromal cells (MSC) embedded in endothelial cell (EC)-covered collagen gel rods that are a few hundred microns in size. Particular attention is paid to the role of hypoxia and macrophage recruitment, as well as the paracrine effects of the MSC and EC in this host response.

Retinopathy of prematurity (ROP) is one of the leading and preventable causes of blindness. The investigation of choice for diagnosing ROP is binocular indirect ophthalmoscope (BIO) done by ophthalmologists. Since the number of ophthalmologists available to do BIO examination is limited, especially in developing countries, there is a need for an alternate, cheap, reliable and feasible test. Telemedicine imaging with Digital Retinal Photography (DRP) is one such alternate diagnostic test which can be performed easily by non-ophthalmologists, with adequate training. Our objective was to conduct a systematic review to evaluate the accuracy of DRP performed by trained personnel (non-ophthalmologists) in diagnosing clinically significant ROP. Medline, EMBASE, CINAHL and Cochrane databases were searched independently by two authors. Eligible studies were assessed using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS)-2, an evidence-based tool for the assessment of quality in systematic reviews of diagnostic accuracy studies. Six were included in the review (three prospective; N=120, three retrospective; N=579). Studies had methodological limitations on QUADAS-2. Because of the heterogeneity of studies, data could not be pooled to derive single-effect size estimates for sensitivity and specificity. The included studies reported sensitivity of 45.5-100% with the majority being more than 90%; specificity 61.7-99.8% with the majority being more than 90%, positive predictive value 61.5-96.6% and negative predictive value of 76.9-100% for diagnosing clinically significant ROP. We conclude that diagnostic accuracy of DRP must be established in prospective studies with adequate sample size where DRP is compared against the simultaneously performed BIO examination., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.)

A better understanding of the factors governing the vascularization of engineered tissues is crucial for their advancement as therapeutic platforms. Here, we studied the effect of implant volume and cell densities on the in vivo vascularization of modular engineered tissue constructs. Sub-millimeter collagen modules containing adipose-derived mesenchymal stromal cells (adMSC) and enveloped by human umbilical vein endothelial cells (HUVEC) were subcutaneously implanted in severe-combined immunodeficient mice with a beige-mutation (SCID-bg) mice. Implant volume and cell density was varied relative to a base case, defined as a 0.01 mL implant containing 1.5×10(7) adMSC/mL and 3.9×10(6) HUVEC/mL. At 7 and 14 days post-transplantation, the constructs were harvested for immunohistochemical analysis of total (CD31(+)) and graft-derived (UEA1(+)) vessel formation, hypoxia-inducible factor 1-alpha (HIF1α) expression, infiltration of host-derived leukocytes (CD45), and macrophages (F4/80). Implant volume and cell density affected the relative contributions of host- versus graft-derived vascularization, highlighting that different mechanisms underlie the two processes. Graft-derived vessel formation was most rapid and robust in implants with high HIF1α expression, namely large volume implants and implants with high adMSC and HUVEC density (p<0.01 compared to base case at day 7). Many HIF1α(+) cells were vessel-lining HUVEC, suggesting that HIF1 activation may be key to vessel assembly in the graft. Host vessel ingrowth, however, dominated the vascularization of small volume implants (of high and low adMSC density alike), which showed low HIF1α expression at day 7. Host vessels were sustained to day 14 when adMSC density alone was increased, presumably due to increased paracrine secretions. This study points to a potential role of HIF1 activation in the vascularization of tissue constructs, which may be harnessed to engineer robust vessels for therapeutic applications.

Aim: To evaluate vascularisation of the peripheral retina using fluorescein angiography (FA) digital recordings of infants who had been treated with intravitreal bevacizumab (IVB) as sole therapy for zone I and posterior zone II retinopathy of prematurity (ROP)., Methods: A retrospective evaluation was performed of medical records, RetCam fundus images and RetCam fluorescein angiogram videos of 10 neonates (20 eyes) who received intravitreal bevacizumab injections as the only treatment for zone I and posterior zone II ROP between August 2007 and November 2012., Results: All eyes had initial resolution of posterior disease after IVB injection as documented by RetCam colour fundus photographs. Using a distance of 2 disc diameters from the ora serrata to vascular termini as the upper limit of allowable avascular retina in children, the FA of these infants demonstrated that 11 of 20 eyes had not achieved normal retinal vascularisation., Conclusions: Although bevacizumab appears effective in bringing resolution of zone I and posterior zone II ROP and allowing growth of peripheral retinal vessels, in our series of 20 eyes, complete normal peripheral retinal vascularisation was not achieved in half of the patients.

Objective: To evaluate the feasibility of using three-dimensional (3D) ultrasound to assess the anatomy of the airway., Methods: 11 young volunteers were recruited for 3D ultrasound and MRI of the airway. 3D ultrasound data were obtained from the level of the true vocal cords, cricoid cartilage and upper trachea. Multiplanar 3D ultrasound images were rendered and compared visually with corresponding MRI and cadaver anatomical sections. The anteroposterior (AP) and transverse diameter of the subglottic space and transverse diameter of the upper trachea were also measured in the 3D ultrasound and MR images and compared., Results: The airway anatomy was clearly delineated in the multiplanar 3D ultrasound images. It was also possible to identify the cricothyroid junction, and a simple method to measure the AP diameter of the subglottic space using this landmark is described. We were also able to accurately measure the transverse diameter of the upper trachea, but the transverse diameter of the subglottic space was overestimated using ultrasound. There was a strong correlation for the AP diameter measurement (r=0.94, p<0.05) and moderate correlation for the transverse diameter measurement (r=0.82, p=0.002) of the subglottic space, and a strong correlation for the transverse diameter measurement (r=0.91, p<0.05) of the upper trachea, in the ultrasound and MR images., Conclusion: The anatomy of the adult airway can be assessed using 3D ultrasound. It can also be used to accurately measure the AP diameter of the subglottic space and the transverse diameter of the upper trachea., Advances in Knowledge: This is the first report to describe the use of 3D ultrasound to evaluate the anatomy of the upper airway and accurately measure the AP diameter of the subglottic space and the transverse diameter of the upper trachea.

This paper reports a numerical study of the aeroacoustics of merging flow at T-junction. The primary focus is to elucidate the acoustic generation by the flow unsteadiness. The study is conducted by performing direct aeroacoustic simulation approach, which solves the unsteady compressible Navier-Stokes equations and the perfect gas equation of state simultaneously using the conservation element and solution element method. For practical flows, the Reynolds number based on duct width is usually quite high (>10(5)). In order to properly account for the effects of flow turbulence, a large eddy simulation methodology together with a wall modeling derived from the classical logarithm wall law is adopted. The numerical simulations are performed in two dimensions and the acoustic generation physics at different ratios of side-branch to main duct flow velocities VR (=0.5,0.67,1.0,2.0) are studied. Both the levels of unsteady interactions of merging flow structures and the efficiency of acoustic generation are observed to increase with VR. Based on Curle's analogy, the major acoustic source is found to be the fluctuating wall pressure induced by the flow unsteadiness occurred in the downstream branch. A scaling between the wall fluctuating force and the efficiency of the acoustic generation is also derived.

Many of the aches and pains of adults are the result of the long-term effects of bad posture or body misalignment. Postural kyphosis in adolescence, which is an excessive rounding of the upper spine, may be one of the effects of poor standing and sitting habits. A smart garment, consisting of a harness and two data-sensor loggers, was developed to monitor and provide vibration feedback to wearers to improve their posture during daily activities. Laboratory tests verified that the garment could provide an accuracy of 2 ± 2° during static measurement and 3 ± 2° during stable or slowly changing posture activities and 4 ± 4° during rapidly changing posture activities. Four volunteers wore the system for 3 h per day and for 4 consecutive days. The feedback was provided on the last 2 days and the kyphotic angle reduced by 8 ± 1° and 8 ± 2° on the last 2 days, respectively. Although the long-term effects of reminding the subjects' posture is still not clear, a short-term result shows promise that the smart garment may be able to improve the kyphosis.

Purpose: To evaluate the safety and efficacy of a 25-gauge vitrectomy system for the management of congenital cataract in children younger than 1 year., Setting: Princess Margaret Hospital for Children, Western Australia, Australia., Methods: Children in a tertiary pediatric hospital and private practice had cataract extraction using a 25-gauge vitrectomy system between January 2005 and June 2008. Each eye had anterior vitrectorhexis, lens aspiration, posterior vitrectorhexis, and anterior vitrectomy through two 25-gauge limbal side ports. The ports were created with a 25-gauge trocar or a 0.6 mm paracentesis knife. The eyes were left aphakic., Results: Nineteen (95%) of the 20 eyes (14 children) had a successful surgical outcome with the 25-gauge vitrectomy system. One eye was converted to the 20-gauge system because of an unusually tough and fibrous lens capsule. The limbal side ports in 16 of 17 eyes created with the 25-gauge trocar required suturing to seal the ports; none of the 3 eyes with side ports created with the paracentesis knife required suturing. There were no significant intraoperative or postoperative complications other than ocular hypertension in 1 eye., Conclusions: The 25-gauge vitrectomy system appears safe and effective for the management of infantile cataract. Advantages include more precise manipulations with smaller instruments in infant eyes, a more stable anterior chamber, and less postoperative astigmatism.

Current research has provided a more comprehensive understanding of Adolescent Idiopathic Scoliosis (AIS) as a three-dimensional spinal deformity, encompassing both lateral and rotational components. Apart from quantifying curve severity using the Cobb angle, vertebral rotation has become increasingly prominent in the study of scoliosis. It demonstrates significance in both preoperative and postoperative assessment, providing better appreciation of the impact of bracing or surgical interventions. In the past, the need for computer resources, digitizers and custom software limited studies of rotation to research performed after a patient left the scoliosis clinic. With advanced technology, however, rotation measurements are now more feasible. While numerous vertebral rotation measurement methods have been developed and tested, thorough comparisons of these are still relatively unexplored. This review discusses the advantages and disadvantages of six common measurement techniques based on technology most pertinent in clinical settings: radiography (Cobb, Nash-Moe, Perdriolle and Stokes' method) and computer tomography (CT) imaging (Aaro-Dahlborn and Ho's method). Better insight into the clinical suitability of rotation measurement methods currently available is presented, along with a discussion of critical concerns that should be addressed in future studies and development of new methods.

The transmission of sound from a slanted side branch into an infinitely long rectangular duct is studied numerically using the method of finite element with absorptive domain exit boundaries. The sound transmission coefficients associated with various acoustic modes are investigated in details. The results show that the plane wave assumption is only valid at very low frequency. It is also found that the intensities of the higher modes are stronger than that of the plane wave once they are excited. Besides, a critical side-branch slant angle is found over which a significant change of sound propagation mode takes place. This affects substantially the energy distribution between various acoustic modes inside the main duct. A simplified model is proposed to explain the phenomenon and the relationship of this critical angle with the width ratio between the side branch and the main duct is established.

Haemostatic deficiencies, common among cirrhotic patients, may deteriorate further after hepatectomy, increasing the bleeding risk associated with the use of thoracic epidural analgesia. We describe two patients who enjoyed immediate post-operative tracheal extubation and satisfactory analgesia using mainly right thoracic paravertebral analgesia after right lobe hepatectomy.

This article describes the roadside traffic noise surveys conducted in heavily built-up urban areas in Hong Kong. Noise measurements were carried out along 18 major roads in 1999. The measurement data included L10, L50, L90, Leq, Lmax, the number of light vehicles, the number of heavy vehicles, the total traffic flow, and the average speed of vehicles. Statistical analysis using the analysis of variance (ANOVA) and Tukey test (p<0.05) reveals that the total traffic flow and the number of heavy vehicles are the most significant factors of urban traffic noise. Multiple regression was used to derive a set of empirical formulas for predicting L10 noise level due to road traffic. The accuracy of these empirical formulas is quantified and compared to that of another widely used prediction model in Hong Kong--the Calculation of Road Traffic Noise. The applicability of the selected multiple regression model is validated by the noise measurements performed in the winter of 2000.

Purpose: Povidone-iodine 5% solution decreases the incidence of postoperative endophthalmitis when used on the eye for preoperative preparation. We sought to determine whether it also minimized conjunctival bacterial flora immediately after surgery by preventing bacteria present on the surface of the eye from entering surgical wounds., Methods: In 42 eyes of 40 patients, at the conclusion of surgery, on an alternating basis, each patient received either a drop of a broad-spectrum antibiotic solution (polymyxin B sulfate-neomycin sulfate-gramicidin) or a 5% povidone-iodine solution in the operated-on eye. Bacterial cultures were taken before and after surgery and 24 hours later. The 38 unoperated-on eyes in the unilateral cases served as control eyes., Results: Relative to the control group, povidone-iodine was effective in preventing an increase in the number of colony-forming units (P = .035), while the antibiotic was not. At 24 hours after surgery, the species count was lower in the eyes receiving povidone-iodine than in the antibiotic-treated eyes (P = .034) and was increased in the antibiotic group since the completion of surgery (P = .013), but was lower in the povidone-iodine and antibiotic groups than in the control eyes for both groups (P < .01)., Conclusions: Povidone-iodine 5% solution applied to the eye at the conclusion of surgery was more effective at minimizing the number of colony-forming units and species for the first postoperative day than was a broad-spectrum antibiotic. While not true for the antibiotic, the antimicrobial effect of povidone-iodine lasted for at least 24 hours after the completion of surgery.

Background: Vertical rectus muscle injury is commonly cited as a cause of strabismus after cataract surgery. Injury to the inferior oblique muscle or nerve as a complication of cataract surgery has not been described previously., Methods: Four patients without pre-existing strabismus who had diplopia after cataract surgery were studied. Analysis included prism and cover testing, Lancaster red-green testing, and fundus torsion assessment., Results: Three patients had a delayed-onset hypertropia with fundus extorsion in the eye that underwent surgery, which is consistent with inferior oblique muscle overaction secondary to presumed contracture. The fourth patient had an immediate-onset hypotropia with fundus intorsion in the eye that underwent surgery, which is consistent with inferior oblique muscle paresis. Damage to a vertical rectus muscle or "unmasking" of a pre-existing superior oblique muscle paresis could not explain the history and findings in this group of four patients., Conclusion: The inferior oblique muscle contracture observed in three patients may have been caused by local anesthetic myotoxicity, whereas the paresis observed in one patient may have been due to mechanical trauma or anesthetic toxicity directly to the nerve innervating the muscle. Inferior oblique muscle or nerve injury should be considered as another possible cause of postoperative strabismus, especially when significant fundus torsion accompanies a vertical deviation.

Esotropia from chronic sixth nerve palsy or paresis usually requires surgery. Chemodenervation of the antagonist medial rectus muscle, while popular for the treatment of acute sixth nerve palsies and pareses, has not been used extensively for chronic cases. In this study, 22 patients with sixth nerve palsies or partially recovered palsies of greater than 5 months duration were treated with chemodenervation. The etiologies of the sixth nerve palsies were trauma (n = 7), tumor (n = 4), infection/inflammation (n = 3), nerve compression from aneurysm or increased intracranial pressure (n = 4), congenital (n = 1), ischemia (n = 2), and idiopathic (n = 1). The mean preinjection deviation was 41 prism diopters. A total of 38 injections were administered (mean, 1.7 per patient). Each patient received an injection of 2.5 to 7.5 units (mean, 4.1) of botulinum neurotoxin A to the ipsilateral medial rectus muscle. Treatment success was assessed 6 months after the last injection. A course of chemodenervation significantly improved the alignment of 9 of the 22 patients (41%). The mean postinjection deviation was 8 delta. Seven patients (32%) had single binocular vision in primary position restored. These patients had a mean horizontal binocular field of 70 degrees (range, 40 degrees to 100 degrees). Thirteen patients (59%) had only modest improvement and required surgery. The data suggest that injection of botulinum neurotoxin A is a useful treatment for some patients with chronic sixth nerve weakness. A course of chemodenervation therapy compares less favorably with transposition surgery with concomitant neurotoxin injection for the treatment of these difficult problems.

Background: It is taught that amblyopia must be fully reversed before surgery for esotropia is undertaken to achieve the best surgical outcome. In some cases, this means delaying surgery for many months. The alternative of operating early, before the completion of amblyopia therapy, and continuing to treat the amblyopia postoperatively has not been evaluated previously., Methods: Forty-seven children younger than 8 years of age were identified with a history of both amblyopia and esotropia. They had no other ocular, medical, or neurologic abnormalities. They had no prior strabismus surgery. Of these 47 patients, 26 had their amblyopia fully treated before surgery, and 21 underwent surgery before completing amblyopia therapy. Five of the latter group did not require amblyopia therapy after surgery even though they were still amblyopic before operation. The motor outcome was assessed by comparing the motor alignment at 6 and 0.33 m using accommodative targets in primary position before surgery, at 6 months after surgery, and at the child's most recent visit. Motor success was defined in this study as a postoperative deviation at distance fixation of 8 prism diopters or less. The sensory result was assessed by comparing the frequency of detectable stereoacuity., Results: The treatment groups did not differ significantly in age, depth of amblyopia, refractive error, or preoperative angle. There was no significant difference detected in motor or sensory outcome whether amblyopia was fully or only partially treated before surgery., Conclusion: Performing corrective surgery in children with esotropia before full resolution of amblyopia is safe and efficient if the amblyopia therapy is continued after surgery. This strategy permits earlier surgery without postponing the operation until full resolution of amblyopia. The finding that five patients did not require amblyopia therapy after surgery suggests that eye re-alignment itself can help reverse amblyopia in some cases.

A six-year follow-up of nine of 13 eyes treated by therapeutic keratoplasty for suppurative keratitis is described. One of the thirteen cases died three years after surgery and three were lost to follow-up. Two of the nine refused reoperation after early graft failure. Of the remaining seven, three had retained good functional visual acuity. Three of the penetrating keratoplasties required regrafting two to four years later, when conditions were less critical. Long-term results indicate that therapeutic keratoplasty may be an alternative modality for the management of suppurative keratitis with satisfactory long-term optical results.