Ocular blood flow in preterm neonates.

Retinopathy of prematurity (ROP) is a disorder affecting low birthweight, preterm neonates. In the preterm eye, the retina is not fully developed and neovascularization may occur at the margin between the developed vascular retina and undeveloped avascular retina. Without timely treatment by laser or intravitreal anti-vascular endothelial growth factor (VEGF) therapy, this can lead to tractional retinal detachment and blindness. Visualization of the retina in regular examinations by indirect ophthalmoscopy is hence the current standard of care, but the exams are stressful and interpretation of images is subjective. The upregulation of VEGF in ROP would suggest an increase in ocular blood flow. In this report, we evaluate the potential of ultrafast plane-wave Doppler ultrasound (PWU) to detect increased flow velocities in the orbital vessels supplying the eye in a gentle exam with objective findings. We imaged both eyes of 50 low-birthweight preterm neonates using 18 MHz PWU. Flow velocity in the central retinal artery (CRA) and vein (CRV), and the short posterior ciliary arteries were determined and values at each ROP Stage compared. We found significantly increased velocities in the CRA and CRV in Stage 3 ROP eyes, where intervention would be considered. We compared multivariate models for identifying Stage 3 eyes comprised solely of clinical factors, solely of Doppler parameters, and clinical plus Doppler parameters. The respective models provided areas under their respective ROC curves of 0.760, 0.812, and 0.904. PWU Doppler represents a gentle, objective means for identifying neonates at risk for ROP that could complement ophthalmoscopy.

Non-surgical treatment of stage 4A retinopathy of prematurity.

BACKGROUND: Retinopathy of prematurity (ROP) is a major cause of visual impairment in premature infants, often requiring surgical interventions in advanced stages. This retrospective case series study investigates non-surgical management for Stage 4A ROP, specifically the use of combined laser therapy and intravitreal anti-vascular endothelial growth factor (VEGF) injections. METHODS: Ten eyes from five infants with Stage 4A ROP were treated with a combined laser and anti-VEGF approach. Comprehensive follow-up examinations were conducted to evaluate the treatment outcomes. RESULTS: The study demonstrated successful retinal attachment without complications, showcasing the efficacy and safety of this non-surgical method. A comparison with surgical interventions highlighted the potential benefits in terms of reduced adverse effects. DISCUSSION: This combined treatment emerges as a promising first-choice option for Stage 4A ROP, offering rapid regression without surgical intervention, particularly in early stages. However, larger randomized clinical trials are necessary to validate these findings and establish definitive guidelines for managing this complex condition. CONCLUSION: Combined laser and anti-VEGF therapy proved to be an effective and safe non-surgical approach for Stage 4A ROP, with the potential to reduce the need for surgery, especially in its early presentation. Further research is required to confirm these findings and provide comprehensive recommendations for clinical practice.

Postnatal weight gain and retinopathy of prematurity in preterm infants: a population-based retrospective cohort study.

OBJECTIVE: Infants who meet the screening guidelines for retinopathy of prematurity (ROP) based on birth weight and gestational age undergo serial ophthalmological examinations for its detection and treatment. However, <10% of patients require treatment, and less than half develop ROP. Poor postnatal weight gain has been reported to be a strong indicator of ROP development; however, the information regarding this is unclear. Therefore, this study aimed to determine the relationship between postnatal weight gain and ROP development in preterm infants. METHODS: The data of 675 preterm infants with gestational age ≤32 weeks, who were hospitalized in our neonatal intensive care unit, were obtained retrospectively from file records. The infants' demographic characteristics, clinical findings, and weekly weight gain (g/kg/day) during the first 8 weeks were recorded. The univariate was used to examine the risk factors for ROP followed by multivariate regression. RESULTS: The incidence of ROP in the infants included in the study was 41% (n = 278) and 13.3% (n = 37) of them required treatment. In the infants of the group that developed ROP, the mean birth weight and gestational age were significantly lower than those in the group that did not develop ROP (973 ± 288 and 1301 ± 349 g, p = 0.001 and 28.48 ± 1.95 and 30.08 ± 1.60 weeks, p = 0.001, respectively). As the gestational week and birth weight decreased, ROP development and the risk of ROP-requiring treatment increased. In the infants of the group that developed ROP, the mean weight gain in the postnatal third week was detected as significantly lower compared to those in the group that did not develop ROP (13.9 ± 8.2 and 15.4 ± 6.8 g, p = 0.034). On multiple logistic regression analysis, birth weight (<750 g) (odds ratio [OR], 8.67; 95% confidence interval [CI], 3.99-18.82, p = 0.001), blood transfusion (OR, 2.39; 95% CI, 1.34-4.24, p = 0.003), necrotizing enterocolitis (OR, 4.79; 95% CI, 1.05-26.85, p = 0.045), bronchopulmonary dysplasia (OR, 2.03; 95% CI, 1.22-3.36, p = 0.006), antenatal steroid therapy (OR, 1.60; 95% CI, 1.05-2.43, p = 0.028), surfactant administration (OR, 2.06; 95% CI, 1.32-3.2, p = 0.001) were independent risk factors for ROP development. CONCLUSION: Postnatal weight gain may not be an accurate predictor of ROP development after adjusting for confounding factors. However, the analysis of independent risk factors that influenced the development of ROP revealed a statistically significant effect in cases of low birth weight, blood transfusion, necrotizing enterocolitis, bronchopulmonary dysplasia, and antenatal steroid and surfactant therapies. These findings may help ophthalmologists and neonatologists to pay special attention to this patient group during ROP scanning.

Critical period of oxygen supplementation and invasive ventilation: implications for severe retinopathy of prematurity.

BACKGROUND: Several studies have identified graded oxygen saturation targets to prevent retinopathy of prematurity (ROP), a serious complication in preterm infants. We aimed to analyze the critical period of oxygen supplementation and/or invasive ventilation associated with severe ROP. METHODS: This retrospective case-control study included neonates with a gestational age (GA) < 29 weeks. Participants were divided into two groups: treated retinopathy and untreated/no retinopathy. Time-weighted average FiO2 (TWAFiO2) and weekly invasive ventilation were compared between groups by postnatal age (PNA) and postmenstrual age (PMA). The association of treated retinopathy with TWAFiO2 and invasive ventilation was analyzed. RESULTS: Data from 287 neonates were analyzed; 98 were treated for ROP and had lower GAs (25.5 vs. 27.4 weeks, p < 0.01) and lower birthweights (747.6 vs. 1014 g, p < 0.001) than those with untreated/no ROP. TWAFiO2 was higher from PMA 26-34 weeks, except for PMA 31 weeks in treated ROP, and higher in the first nine weeks of life in treated ROP. On multiple logistic regression, TWAFiO2 and invasive ventilation were associated with ROP treatment during the first seven weeks PNA. Invasive ventilation was associated with ROP treatment from PMA 26-31 weeks; no association was found for TWAFiO2 and PMA. CONCLUSIONS: Amount of oxygen supplementation and/or invasive ventilation during the first 7 weeks of life or up to 31 weeks PMA was associated with development of severe ROP. This period might be candidate timing for strict oxygen supplementation strategies in preterm infants, while concerns of mortality with low oxygen supplementation should be further explored.

Effect of Nasal Continuous Positive Airway Pressure on Retinopathy of Prematurity in Preterm Newborns: A Comparative Analysis with Mechanical Ventilation and High-Flow Nasal Cannula Therapy.

BACKGROUND Retinopathy of prematurity (ROP), originally described as retrolental fibroplasia, represents an abnormal growth of blood vessels in the premature retina that can occur in response to oxygen therapy. The association between ROP and invasive mechanical ventilation has been widely studied in the literature; however, the relationships between different types of ventilation and ROP have not been as well documented. This study aimed to compare the association of ROP incidence with mechanical ventilation (MV), nasal continuous positive airway pressure (nCPAP), and high-flow nasal cannula (HFNC) therapies in 130 pre-term infants with gestational ages <32 weeks. MATERIAL AND METHODS The study includes 130 premature newborns, out of which 54 underwent MV therapy, either alone or in combination with nCPAP or HFNC therapy, 63 underwent nCPAP therapy, either alone or in combination with MV or HFNC therapy, and 23 underwent HFNC therapy, either alone or in combination with MV or nCPAP therapy. The relationships between ROP and the 3 types of ventilation were analyzed by univariate followed by multivariate logistic regression. RESULTS When adjusting for covariates, only nCPAP and birth weight were significantly associated with ROP, the former being a strong risk factor, with an adjusted odds ratio (AOR) of 7.264 (95% CI, 2.622-20.120; P<0.001), and the latter being a weak protective factor, with an AOR of 0.998 (95% CI, 0.996-0.999; P<0.05). CONCLUSIONS The results showed nCPAP was a strong ROP risk factor, birth weight was a weak ROP protective factor, and MV and HFNC were not significantly associated with increased ROP risk.

Delineating morbidity patterns in preterm infants at near-term age using a data-driven approach.

BACKGROUND: Long-term survival after premature birth is significantly determined by development of morbidities, primarily affecting the cardio-respiratory or central nervous system. Existing studies are limited to pairwise morbidity associations, thereby lacking a holistic understanding of morbidity co-occurrence and respective risk profiles. METHODS: Our study, for the first time, aimed at delineating and characterizing morbidity profiles at near-term age and investigated the most prevalent morbidities in preterm infants: bronchopulmonary dysplasia (BPD), pulmonary hypertension (PH), mild cardiac defects, perinatal brain pathology and retinopathy of prematurity (ROP). For analysis, we employed two independent, prospective cohorts, comprising a total of 530 very preterm infants: AIRR ("Attention to Infants at Respiratory Risks") and NEuroSIS ("Neonatal European Study of Inhaled Steroids"). Using a data-driven strategy, we successfully characterized morbidity profiles of preterm infants in a stepwise approach and (1) quantified pairwise morbidity correlations, (2) assessed the discriminatory power of BPD (complemented by imaging-based structural and functional lung phenotyping) in relation to these morbidities, (3) investigated collective co-occurrence patterns, and (4) identified infant subgroups who share similar morbidity profiles using machine learning techniques. RESULTS: First, we showed that, in line with pathophysiologic understanding, BPD and ROP have the highest pairwise correlation, followed by BPD and PH as well as BPD and mild cardiac defects. Second, we revealed that BPD exhibits only limited capacity in discriminating morbidity occurrence, despite its prevalence and clinical indication as a driver of comorbidities. Further, we demonstrated that structural and functional lung phenotyping did not exhibit higher association with morbidity severity than BPD. Lastly, we identified patient clusters that share similar morbidity patterns using machine learning in AIRR (n=6 clusters) and NEuroSIS (n=8 clusters). CONCLUSIONS: By capturing correlations as well as more complex morbidity relations, we provided a comprehensive characterization of morbidity profiles at discharge, linked to shared disease pathophysiology. Future studies could benefit from identifying risk profiles to thereby develop personalized monitoring strategies. TRIAL REGISTRATION: AIRR: DRKS.de, DRKS00004600, 28/01/2013. NEuroSIS: ClinicalTrials.gov, NCT01035190, 18/12/2009.

Early Single-Examination Optical Coherence Tomography Biomarkers for Treatment-Requiring Retinopathy of Prematurity.

Purpose: Optical coherence tomography (OCT) is an emerging adjunct imaging modality to evaluate retinopathy of prematurity (ROP). From an 11-year research database, we identify early OCT biomarkers that predict treatment-requiring ROP (TR-ROP). Methods: For preterm infants with acceptable OCT images at 32 ± 1 weeks postmenstrual age (PMA), we extracted the following measures: total retina, inner retinal layer (IRL), and outer retinal layer (ORL) thicknesses at the fovea and the parafovea, inner nuclear layer (INL) and choroidal thickness, parafovea/fovea (P/F) ratio, and presence of macular edema. Using univariable and multivariable logistic regression models, we evaluated the association between retinal and choroidal OCT measurements at 32 ± 1 weeks PMA and development of TR-ROP. Results: Of 277 eyes (145 infants) with usable OCT images, 67 eyes had TR-ROP. Lower P/F ratio (P < 0.0001), thicker foveal IRL (P = 0.0001), and thinner choroid (P = 0.03) were associated with TR-ROP in univariable analysis, but lost significance of association when adjusted for gestational age and race. Absence of macular edema was associated with TR-ROP when adjusted for gestational age and race (P = 0.01). In 185 eyes without macular edema, P/F ratio was associated with TR-ROP in both univariable analysis (P < 0.0001) and multivariable analysis (P = 0.02) with adjustment for gestational age and race. Conclusions: Presence of macular edema at 32 ± 1 weeks PMA in infants with lower gestational age may be protective against TR-ROP. In infants without macular edema, P/F ratio may be an early OCT biomarker for development of TR-ROP. Incorporation of early OCT biomarkers may be useful in prediction of TR-ROP.

Transient activation of retinopathy of prematurity secondary to erythrocyte suspension transfusion.

Retinopathy of prematurity (ROP) is a serious retinal vascular disorder that needs prompt diagnosis, and treatment to prevent undesired visual outcomes. Due to its shorter period of disease progression, it is important to be hasty in treating ROP. Erythrocyte suspension (ES) aggravates the progression of ROP. However, this progression may be transient as in the present case reports. This case report aimed to present two cases that developed type 1 ROP after erythrocyte suspension transfusion. Clinical findings of the patients were resolved within a few days without any intervention. Premature infants receiving ES treatment can be observed for 24-48 hours, and the treatment can be planned after determining the persistence of the plus sign. Abbreviations: ES = Erythrocyte suspension, ROP = Retinopathy of prematurity, NICU = neonatal intensive care unit.

Automated diagnosis of plus disease in retinopathy of prematurity using quantification of vessels characteristics.

The condition known as Plus disease is distinguished by atypical alterations in the retinal vasculature of neonates born prematurely. It has been demonstrated that the diagnosis of Plus disease is subjective and qualitative in nature. The utilization of quantitative methods and computer-based image analysis to enhance the objectivity of Plus disease diagnosis has been extensively established in the literature. This study presents the development of a computer-based image analysis method aimed at automatically distinguishing Plus images from non-Plus images. The proposed methodology conducts a quantitative analysis of the vascular characteristics linked to Plus disease, thereby aiding physicians in making informed judgments. A collection of 76 posterior retinal images from a diverse group of infants who underwent screening for Retinopathy of Prematurity (ROP) was obtained. A reference standard diagnosis was established as the majority of the labeling performed by three experts in ROP during two separate sessions. The process of segmenting retinal vessels was carried out using a semi-automatic methodology. Computer algorithms were developed to compute the tortuosity, dilation, and density of vessels in various retinal regions as potential discriminative characteristics. A classifier was provided with a set of selected features in order to distinguish between Plus images and non-Plus images. This study included 76 infants (49 [64.5%] boys) with mean birth weight of 1305 ± 427 g and mean gestational age of 29.3 ± 3 weeks. The average level of agreement among experts for the diagnosis of plus disease was found to be 79% with a standard deviation of 5.3%. In terms of intra-expert agreement, the average was 85% with a standard deviation of 3%. Furthermore, the average tortuosity of the five most tortuous vessels was significantly higher in Plus images compared to non-Plus images (p ≤ 0.0001). The curvature values based on points were found to be significantly higher in Plus images compared to non-Plus images (p ≤ 0.0001). The maximum diameter of vessels within a region extending 5-disc diameters away from the border of the optic disc (referred to as 5DD) exhibited a statistically significant increase in Plus images compared to non-Plus images (p ≤ 0.0001). The density of vessels in Plus images was found to be significantly higher compared to non-Plus images (p ≤ 0.0001). The classifier's accuracy in distinguishing between Plus and non-Plus images, as determined through tenfold cross-validation, was found to be 0.86 ± 0.01. This accuracy was observed to be higher than the diagnostic accuracy of one out of three experts when compared to the reference standard. The implemented algorithm in the current study demonstrated a commendable level of accuracy in detecting Plus disease in cases of retinopathy of prematurity, exhibiting comparable performance to that of expert diagnoses. By engaging in an objective analysis of the characteristics of vessels, there exists the possibility of conducting a quantitative assessment of the disease progression's features. The utilization of this automated system has the potential to enhance physicians' ability to diagnose Plus disease, thereby offering valuable contributions to the management of ROP through the integration of traditional ophthalmoscopy and image-based telemedicine methodologies.

Macular Curvature in Adults Born Preterm With and Without ROP: Results from the Gutenberg Prematurity Eye Study.

Purpose: This study investigated the effects of prematurity and retinopathy of prematurity (ROP) as well as the associations of the ocular geometry with macular curvature in adults. Methods: The Gutenberg Prematurity Eye Study is a retrospective cohort study of preterm and full-term participants aged 18 to 52 years with a prospective ophthalmologic examination. The main outcome measure was the macular curvature in the central foveal optical coherence tomography (OCT) scan and its associations with gestational age (GA), birth weight and birth weight percentile, ROP occurrence, ROP treatment, and other perinatal factors were evaluated in univariable and multivariable linear regression analyses. Furthermore, a second model assessed the association of ocular geometry with macular curvature. Results: In the present study, 550 eyes of 284 adults born preterm and 277 eyes of 139 adults born full-term were examined (aged = 28.7 ± 8.7 years, 240 female subjects). In multivariable analyses for perinatal parameters, ROP treatment (B = -52.44, P = 0.023) and maternal smoking during pregnancy (B = 26.41, P = 0.019) showed an association with macular curvature. Regarding ocular geometric parameters, posterior segment length (B = 9.07, P < 0.001) and subfoveal choroidal thickness (B = -0.26, P < 0.001) were associated with macular curvature, central corneal thickness, anterior chamber depth, lens thickness, and foveal retinal thickness were not associated. Conclusions: Adults treated for ROP had relatively more negative curvature values compared to the full-term group, indicating a macular protrusion toward the vitreous cave. A thicker subfoveal choroidal thickness was associated with a flatter macular curvature, whereas a longer posterior segment length was associated with a steeper macular curvature indicating the characteristics of the myopic elongation of the eye.

Comparing reactivation and retreatment for three doses of bevacizumab in type 1 retinopathy of prematurity.

PURPOSE: To determine timing and rates of reactivation and retreatment of type 1 retinopathy of prematurity (ROP) after treatment with either 0.125 mg, 0.250 mg, or 0.500 mg of intravitreal bevacizumab (IVB). METHODS: Retrospective data, including demographic information, past medical history, and ROP characteristics were analyzed for babies with type 1 ROP treated with IVB at Riley Hospital for Children for the perioed 2014-2021. RESULTS: A total of 84 patients met inclusion criteria: 29 patients received 0.125 mg of IVB; 39, 0.250 mg; and 16, 0.500 mg. Of the 84, 67 (80%) had additional laser treatment because of late reactivation (n = 52) or persistent avascular retina (PAR) (n = 15). Subsequent laser treatment was more common with lower doses: 0.125 mg (n = 27 [93%]); 0.250 mg (n = 31 [80%]); 0.500 mg (n = 9 [57%]) (P = 0.012). There was no difference between groups with regard to reason for subsequent laser treatment (reactivation vs PAR). The 0.125 mg group required retreatment because of reactivation 3.8 weeks sooner than the other dosing groups (P = 0.047). CONCLUSIONS: The outcomes comparing three doses of IVB for severe ROP showed a difference in the timing of secondary treatment, with the lower dosing group requiring laser for reactivation earlier.

Comparison of prematurity-related outcomes and complications in very low birth weight (VLBW) neonates fed with mother`s own milk versus donor milk: a comparative study.

BACKGROUND: When mother`s own milk (MOM) is unavailable or insufficient, donor milk (DM) from a human milk bank serves as an alternative feeding option. Our study sought to investigate and compare the outcomes and complications of very low birth weight (VLBW) preterm infants who receive MOM versus DM. METHODS: In this retrospective cohort study conducted between 2018 and 2022, we compared 70 VLBW preterm infants exclusively fed with DM to 70 randomly selected counterparts fed with MOM. Both groups began enteral feeding within 72 hours of birth. Various clinical outcomes were investigated during a three-month follow-up. The clinical outcomes were compared via independent t-tests, Mann-Whitney U, and Fisher`s exact test. RESULTS: The mean gestational age of the infants who were included was 29.6 ± 1.6 weeks, 84 (60%) were males, and the average birth weight was 1217 ± 151 grams. Both groups had similar baseline characteristics. The results of the study demonstrated no statistically significant differences between the groups in terms of hospital length of stay (37±16.3 days in MOM vs 40.3±16.9 days in DM group, P= 0.17), growth rate (13±4 gram/day in MOM vs 13±4 gram/day in DM group, P=0.51), growth velocity (9.8±3.0g/kg/d in MOM vs 9.5±3.2 g/kg/d in DM group), infants with in-hospital vomiting (51 cases in MOM vs 59 cases in DM group, P=0.15),vomiting frequency (1.3±1.1 times in MOM vs 1.5±1.0 times in DM group), incidence of retinopathy of prematurity (ROP) (4 cases in MOM vs 5 cases in DM group, P > 0.999) and incidence of bronchopulmonary dysplasia (BPD) (7 cases in MOM vs 6 cases in DM group, P > 0.999). CONCLUSION: Our study findings indicate that the utilization of DM didn`t have a substantial negative impact on infants` outcomes nor any complications in comparison with MOM.

Multinational External Validation of Autonomous Retinopathy of Prematurity Screening.

Importance: Retinopathy of prematurity (ROP) is a leading cause of blindness in children, with significant disparities in outcomes between high-income and low-income countries, due in part to insufficient access to ROP screening. Objective: To evaluate how well autonomous artificial intelligence (AI)-based ROP screening can detect more-than-mild ROP (mtmROP) and type 1 ROP. Design, Setting, and Participants: This diagnostic study evaluated the performance of an AI algorithm, trained and calibrated using 2530 examinations from 843 infants in the Imaging and Informatics in Retinopathy of Prematurity (i-ROP) study, on 2 external datasets (6245 examinations from 1545 infants in the Stanford University Network for Diagnosis of ROP [SUNDROP] and 5635 examinations from 2699 infants in the Aravind Eye Care Systems [AECS] telemedicine programs). Data were taken from 11 and 48 neonatal care units in the US and India, respectively. Data were collected from January 2012 to July 2021, and data were analyzed from July to December 2023. Exposures: An imaging processing pipeline was created using deep learning to autonomously identify mtmROP and type 1 ROP in eye examinations performed via telemedicine. Main Outcomes and Measures: The area under the receiver operating characteristics curve (AUROC) as well as sensitivity and specificity for detection of mtmROP and type 1 ROP at the eye examination and patient levels. Results: The prevalence of mtmROP and type 1 ROP were 5.9% (91 of 1545) and 1.2% (18 of 1545), respectively, in the SUNDROP dataset and 6.2% (168 of 2699) and 2.5% (68 of 2699) in the AECS dataset. Examination-level AUROCs for mtmROP and type 1 ROP were 0.896 and 0.985, respectively, in the SUNDROP dataset and 0.920 and 0.982 in the AECS dataset. At the cross-sectional examination level, mtmROP detection had high sensitivity (SUNDROP: mtmROP, 83.5%; 95% CI, 76.6-87.7; type 1 ROP, 82.2%; 95% CI, 81.2-83.1; AECS: mtmROP, 80.8%; 95% CI, 76.2-84.9; type 1 ROP, 87.8%; 95% CI, 86.8-88.7). At the patient level, all infants who developed type 1 ROP screened positive (SUNDROP: 100%; 95% CI, 81.4-100; AECS: 100%; 95% CI, 94.7-100) prior to diagnosis. Conclusions and Relevance: Where and when ROP telemedicine programs can be implemented, autonomous ROP screening may be an effective force multiplier for secondary prevention of ROP.

Role of microglia/macrophage polarisation in intraocular diseases (Review).

Macrophages form a crucial component of the innate immune system, and their activation is indispensable for various aspects of immune and inflammatory processes, tissue repair, and maintenance of the balance of the body's state. Macrophages are found in all ocular tissues, spanning from the front surface, including the cornea, to the posterior pole, represented by the choroid/sclera. The neural retina is also populated by specialised resident macrophages called microglia. The plasticity of microglia/macrophages allows them to adopt different activation states in response to changes in the tissue microenvironment. When exposed to various factors, microglia/macrophages polarise into distinct phenotypes, each exhibiting unique characteristics and roles. Furthermore, extensive research has indicated a close association between microglia/macrophage polarisation and the development and reversal of various intraocular diseases. The present article provides a review of the recent findings on the association between microglia/macrophage polarisation and ocular pathological processes (including autoimmune uveitis, optic neuritis, sympathetic ophthalmia, retinitis pigmentosa, glaucoma, proliferative vitreoretinopathy, subretinal fibrosis, uveal melanoma, ischaemic optic neuropathy, retinopathy of prematurity and choroidal neovascularization). The paradoxical role of microglia/macrophage polarisation in retinopathy of prematurity is also discussed. Several studies have shown that microglia/macrophages are involved in the pathology of ocular diseases. However, it is required to further explore the relevant mechanisms and regulatory processes. The relationship between the functional diversity displayed by microglia/macrophage polarisation and intraocular diseases may provide a new direction for the treatment of intraocular diseases.

Melatonin and its bioisosteres as potential therapeutic agents for the treatment of retinopathy of prematurity.

We conducted a study on the impact of intraperitoneal injections of melatonin and its three bioisosteres (compounds 1-3) on the development of oxygen-induced retinopathy in newborn rats during a 21-day experiment. It was demonstrated that melatonin and its analogues 1-3 effectively reduce the total protein concentration in the vitreous body of rat pups, decrease concentration of VEGF-A, and lower the level of oxidative stress (as indicated by normalization of antioxidant activity in the vitreous body). Melatonin and its analogues 1-3 equally normalize the level of VEGF-A. Analogues 1 and 2 even exceed melatonin in their ability to reduce protein influx into the vitreous body. However, analogue 2 had no effect on antioxidant activity, while analogues 1 and 3 caused a significant increase in this parameter, with analogue 3 even slightly exceeding melatonin. Thus, it can be concluded that analogues 1-3 are comparable to melatonin and can be utilized as potential therapeutic agents for the treatment of retinopathy of prematurity.

Active versus restrictive ligation strategy for patent ductus arteriosus - A retrospective two-center study of extremely preterm infants born between 22 + 0 and 25 + 6 weeks of gestational age.

BACKGROUND: Patent ductus arteriosus (PDA) in premature infants is associated with adverse clinical outcomes. Mode and timing of treatment are still controversial. Data are limited in the most extremely premature infants <26 weeks of gestational age (GA), where clinical problems are most significant and patients are most vulnerable. AIMS: To investigate whether different approaches to surgical closure of PDA in two large Swedish centers has an impact on clinical outcomes including mortality in extremely preterm infants born <26 weeks GA. STUDY DESIGN: Retrospective, two-center, cohort study. SUBJECTS: Infants born at 22+0-25+6 weeks GA between 2010 and 2016 at Uppsala University Children's Hospital (UUCH; n = 228) and Queen Silvia Children's Hospital Gothenburg (QSCHG; n = 220). MAIN OUTCOME MEASURES: Survival, bronchopulmonary dysplasia (BPD), and retinopathy of prematurity (ROP). RESULTS: Surgical closure of PDA was more common and performed earlier at QSCHG (50 % vs 16 %; median age 11 vs 44 days; p < 0.01). Survival was similar in both centres. There was a higher incidence of severe BPD and longer duration of mechanical ventilation at UUCH (p < 0.01). There was a higher incidence of ROP, IVH and sepsis at QSCH (p < 0.05, p < 0.01 and p < 0.01). A sub-group analysis matching all surgically treated infants at QSCHG with infants at UUCH with the same GA showed similar results as the total cohort. CONCLUSION: Earlier and higher rate of surgical PDA closure in this cohort of extremely preterms born <26 weeks GA did not impact mortality but was associated with lower rates of severe BPD and higher rates of severe ROP.

The association of microRNAs in the development of retinopathy of prematurity.

INTRODUCTION: Retinopathy of prematurity (ROP) is one of the main reasons of preventable childhood blindness. In the development of ROP, MicroRNAs may be effective in the balance of factors that inhibit and activate angiogenic factors. We aimed to determine the changes in the blood levels of miR-146a, miR-143, miR-210, miR-21, miR-126, miR-211, miR-221, miR-106 and let 7f and to investigate their association with ROP. We hypothesed that the level of these miRNAs changed significantly in ROP cases. MATERIALS AND METHODS: This observational study was conducted prospectively in preterm infants with ROP. Serum levels of 8 miRNAs were measured. The relationship between disease stage and progression with miRNA gene expression was analysed. Preterm infants without ROP were taken as the control group. RESULTS: 47 patients with ROP and 14 controls, were included in the study. In the ROP group, miR-210, miR-146a, miR-21 were statistically significantly lower. In the ROP group the expression level of miR-143 was insignificantly lower, miRNA-221 was insignificantly higher, and miR-106, miR-126 and let 7f were variable. CONCLUSION: It was observed that miR-210, miR-146a, miR-21 and miR-143 were significantly lower in patients with ROP compared to the control group. However, no association could be established between the type of miRNA and stage of ROP. These miRNAs may be used as adjunctive biomarkers for diagnosis of ROP.

Visual impairment burden in retinopathy of prematurity: trends, inequalities, and improvement gaps.

Retinopathy of prematurity (ROP) is an important cause of avoidable childhood visual impairment, and the increase in number and survival of premature infants may inflate its burden globally. We aimed to comprehensively assess the trends and inequalities in the burden of ROP-related visual impairment and to identify improvement gaps to facilitate appropriate actions in neonatal care systems. We obtained ROP data from the Global Burden of Disease 2019 study. We employed joinpoint regression analysis to assess the trends of the burden of ROP-related visual impairment, measured by age-standardised prevalence rates, health equity analysis methods to evaluate cross-country burden inequalities, and data envelopment and stochastic frontier analyses to identify improvement gaps based on the development status, i.e., sociodemographic index (SDI). Between 1990 and 2019, the age-standardised prevalence rates of ROP-related visual impairment significantly increased worldwide (average annual percentage change: 0.23 [95% confidence interval, 0.21-0.26] among males and 0.26 [0.25-0.27] among females), primarily in developed regions. Although significant SDI-related cross-country inequalities were identified, these reduced over time (slope index of inequality: -57.74 [-66.22 to -49.25] in 1990 to -29.68 [-38.39 to -20.97] in 2019; health concentration index: -0.11 [-0.13 to -0.09] in 1990 to -0.07 [-0.09 to -0.06] in 2019). Notably, some less-developed countries exhibited superior performance despite limited resources, whereas others with a higher SDI delivered lagging performance.  Conclusion: The global burden of ROP-related visual impairment has steadily increased between 1990 and 2019, with disproportionate burden concentration among less-developed countries, requiring appropriate preventive and intervention measures. What is Known: • Retinopathy of prematurity (ROP) is an important cause of avoidable childhood visual impairment. • The prevalence of ROP is anticipated to increase due to the growing number of extremely premature infants. What is New: • The prevalence of ROP-related visual impairment has increased worldwide, primarily in developed regions, with declining but persisting cross-country inequalities. • The increasing burden of ROP-related visual impairment should be considered as part of global and national health agendas, requiring interventions with proven efficacy.

Lensectomy as treatment for refractory or progressive retinopathy of prematurity narrow-angle glaucoma.

We present the case of a patient with a history of laser-treated retinopathy of prematurity (ROP) who developed narrow angles and intermittent angle closure. Despite laser peripheral iridotomy/iridoplasty, 1 year later, the patient had recurrent narrowing that resolved following clear lens extraction with intraocular lens placement. This case highlights the importance of continued monitoring for narrow angles in patients with ROP history.