Retinopathy of Prematurity: Evolving Treatment With Anti-Vascular Endothelial Growth Factor

Epithelial Membrane Protein 2 (EMP2) Blockade Attenuates Pathological Neovascularization in Murine Oxygen-Induced Retinopathy

Purpose

Retinopathy of prematurity (ROP) results from postnatal hyperoxia exposure in premature infants and is characterized by aberrant neovascularization of retinal blood vessels. Epithelial membrane protein-2 (EMP2) regulates hypoxia-inducible factor (HIF)-induced vascular endothelial growth factor (VEGF) production in the ARPE-19 cell line and genetic knock-out of Emp2 in a murine oxygen-induced retinopathy (OIR) model attenuates neovascularization. We hypothesize that EMP2 blockade via intravitreal injection protects against neovascularization.

Methods

Ex vivo choroid sprouting assay was performed, comparing media and human IgG controls versus anti-EMP2 antibody (Ab) treatment. In vivo, eyes from wild-type (WT) mice exposed to hyperoxia from postnatal (P) days 7 to 12 were treated with P12 intravitreal injections of control IgG or anti-EMP2 Abs. Neovascularization was assessed at P17 by flat mount imaging. Local and systemic effects of anti-EMP2 Ab treatment were assessed.

Results

Choroid sprouts treated with 30 µg/mL of anti-EMP2 Ab demonstrated a 48% reduction in vessel growth compared to control IgG-treated sprouts. Compared to IgG-treated controls, WT OIR mice treated with 4 µg/g of intravitreal anti-EMP2 Ab demonstrated a 42% reduction in neovascularization. They demonstrated down-regulation of retinal gene expression in pathways related to vasculature development and up-regulation in genes related to fatty acid oxidation and tricarboxylic acid cycle respiratory electron transport, compared to controls. Anti-EMP2 Ab-treated OIR mice did not exhibit gross retinal histologic abnormalities, vision transduction abnormalities, or weight loss.

Conclusions

Our results suggest that EMP2 blockade could be a local and specific treatment modality for retinal neovascularization in oxygen-induced retinopathies, without systemic adverse effects.

Clinical features, management, and outcomes of patients with sterile endophthalmitis associated with intravitreal bevacizumab injection: retrospective case series

PURPOSE

To evaluate clinical features, treatment protocol, outcomes, and complications that developed in this case series of 24 patients who had consecutive sterile endophthalmitis after intravitreal bevacizumab (IVB) injection.

METHODS

In this retrospective case series, IVB was repackaged in individual aliquots from the three batches that were used on the same day. IVB was injected into 26 eyes of 26 patients due to diabetic macular edema, age-related macular degeneration, and branch retinal vein occlusion. All patients had intraocular inflammation. Patients were divided into two groups severe and moderate inflammation according to the intraocular inflammation. The medical records of all patients were reviewed. At each follow-up visit, the complete ophthalmologic examination was performed, including best corrected visual acuity (BCVA), intraocular pressure, biomicroscopy, and posterior fundus examination.

RESULTS

Twenty-four of 26 patients were included in the study. Two patients were excluded from this study since they didn't come to follow-up visits. The mean BCVA was 1.00 ± 0.52 Log MAR units before IVB. At the final visit, the BCVA was 1.04 ± 0.47 Log MAR units. These differences were not significant (p = 0.58). Of the 24 eyes, 16 eyes had severe, and 8 eyes had moderate intraocular inflammation. Eleven eyes in the severe inflammation group underwent pars plana vitrectomy due to intense vitreous opacity. Smear, culture results, and polymerase chain reaction results were negative.

CONCLUSION

Sterile endophthalmitis may occur after IVB injection. Differential diagnosis of sterile endophthalmitis from infective endophthalmitis is crucial to adjust the appropriate treatment and prevent long-term complications due to unnecessary treatment.

Long-term follow-up of the cognitive function in children after intravitreal ranibizumab for retinopathy of prematurity

PURPOSE

To evaluate the long-term cognitive function in children treated with intravitreal ranibizumab (IVR) for retinopathy of prematurity(ROP), and the impact of IVR on the growth and ocular development.

METHODS

In this retrospective study, the premature children aged 4 to 9 years who received monotherapy of IVR (IVR group, n = 25) or monotherapy of laser photocoagulation (LP) (LP group, n = 33) for ROP, and the same age premature children with no ROP (Control group, n = 26) were enrolled from 2020 to 2022 in the pediatric fundus clinic of Shenzhen Eye Hospital. Main outcome measures were full-scale intelligence quotient (FSIQ) and index score using the Chinese version of the Wechsler intelligence scale for children-fourth edition (WISC-IV) and Wechsler preschool and primary scale of intelligence-fourth edition (WPPSI-IV). All children were examined and analyzed for growth and ocular development by recording the height, weight, head circumference, spherical equivalent (SE), best corrected visual acuity (BCVA) and axial length (AL).

RESULTS

There were 17 children in IVR group, 17 in LP group, and 11 in Control group who received the WISC-IV assessment. There were no significant differences in FSIQ, verbal comprehension index, perceptual reasoning index, working memory index, processing speed index, general ability index and cognitive efficiency index among the three groups. There were 8 children in IVR group, 16 in LP group, and 15 in Control group who received the WPPSI-IV assessment. There were no significant differences in FSIQ, verbal comprehension index, visuospatial index, fluid reasoning index, working memory index, non-verbal index, general ability index and cognitive efficiency index among the three groups. There was no significant difference in BCVA among the three groups (P = 0.74), however, there is an increase for AL in IVR group when compared with LP group (22.60 ± 0.58 vs. 22.13 ± 0.84, P = 0.003), and the ROP patients of IVR group have a significant increase in the AL compared to the Control group(22.60 ± 0.58 vs. 22.03 ± 0.71, P < 0.0001).

CONCLUSIONS

Children with a history of IVR have a similar cognitive function outcomes compared to those with a history of LP or were premature without ROP. ROP children with a history of IVR has longer AL than those treated with LP.

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.

The impact of blood lactic acid levels on retinopathy of prematurity morbidity

BACKGROUND

Retinopathy of prematurity (ROP) is a common disease in premature infants. In recent years, most researchers have used lactic acid as poor prognosis marker in premature infants. This study aims to explore investigate the impact of blood lactic acid levels on ROP.

METHODS

A retrospective case-control study was conducted, and infants with severe ROP born with birth weight (BW) ≤ 1500 g and gestational age (GA) ≤ 32 weeks were enrolled from November 2016 to November 2021. Infants without any stage ROP were included as controls and were matched with ROP infants (1:2) by GA and BW. All selected preterm infants were tested for heel terminal trace blood gas analysis within two weeks of life. Changes in blood lactic acid levels in the two groups were compared and analyzed by using multivariate logistic regression analysis. Sensitivity and specificity were analyzed by receiver operating characteristic (ROC) curve.

RESULTS

There were 79 infants in ROP group, and 158 infants in control group. The levels of blood lactic acid were significantly higher in the ROP group on days 1, 3, 5, and 7 compared with control group (all p < 0.05). The blood lactic acid levels on day 5 was an independent risk factor for ROP (p = 0.017). The area under the curve (AUC), sensitivity and specificity were highest on day 5 (AUC 0.716, sensitivity 77.2% and specificity 62.0%, respectively, p < 0.001), and higher on days 1, 3, and 7.

CONCLUSION

A high blood lactic acid level in the first seven days of life may be associated with increases ROP occurrence in very preterm infants, and suggest blood lactic acid level may impact the occurrence of ROP.

The incidence of retinopathy of prematurity in neonates in Germany in 2019; a nationwide epidemiological cohort study

Retinopathy of prematurity (ROP) is a leading cause of childhood blindness in preterm infants. The incidence of ROP varies widely across countries, with rates as high as 30% in some regions. This study investigated the incidence, risk factors, treatment, and mortality of ROP patients in Germany. Data were extracted from the German Federal Statistical Office (Destatis) diagnosis-related group (DRG) and Institute for the Remuneration System in Hospitals (InEK) databases. Patients with a secondary diagnosis of ROP (ICD-10 code H35.1) in the first 28 days of life were included. Data were extracted for patients admitted between January 1, 2019 and December 31, 2019. The diagnoses and procedures were determined using the German version of the International Classification of Diseases (ICD-10-GM) and the German procedure coding system (OPS). The codes 5-154.xx, 5-155.xx, 8-020.xx, 5-156.9, 6-003.(c&d), 6-007.(2&8) were utilised to denote different ocular treatments. Patient Clinical Complexity Levels were extracted and used to compare ROP with non-ROP patients. A total of 1326 patients with ROP were identified. The incidence of ROP is estimated to be 17.04 per 10,000 live births. The incidence was highest in infants with birth weights less than 500 g and decreased with increasing birth weight. The most common risk factors for ROP were low birth weight, male sex, and prematurity. Of the infants with ROP, 7.2% required ocular treatment. The most common treatment was intraocular injections, followed by photocoagulation. No surgical treatment was required for any of the infants during the study period. The mortality rate for infants with ROP was 60.33 per 10,000. This is higher than the overall neonatal death rate of 24.2 per 10,000.

CONCLUSIONS

This study found that the incidence of ROP in Germany is similar to that in other developed countries. The study also found that the mortality rate for infants with ROP is higher than the overall neonatal death rate. These findings highlight the importance of early detection and treatment of ROP in preterm infants.

WHAT IS KNOWN

• ROP is a severe eye condition often affecting preterm infants. • Previous data are limited in scope and generalizability.

WHAT IS NEW

• Based on a national database, our study found ROP incidence to be 17.04 per 10,000 new births, higher in males (17.71) than in females (16.34). • 7.2% of ROP cases required ocular treatment, inversely correlated with birth weight. • High rates of multimorbidity such as neonatal jaundice (84.69%), respiratory distress syndrome (80.84%), and apnea (78.88%) were observed.

Efficacy of an Indian Bevacizumab BIOSimilar (BEVATAS) for Type 1 and Aggressive Posterior Retinopathy of Prematurity (BIOS-ROP Study)

Purpose

To evaluate the role of an Indian bevacizumab biosimilar (Bevatas®), for the management of type 1 retinopathy of prematurity (ROP) and aggressive posterior ROP (APROP) over 24-weeks.

Patients and Methods

A retrospective, single-center, interventional study of 144 eyes of type 1 (100 eyes) and APROP (44 eyes). All eyes received a single dose of 0.625mg Bevatas injection, and were advised additional laser therapy for suboptimal response.

Results

The study population had a mean gestational age of 28.94 (±2.32) weeks, an average birth weight of 1.2 (±0.34) kg, and modest male predominance (52.05%). Complete regression of ROP was seen in 65.97% of 144 eyes after 24 weeks of bevacizumab monotherapy, and in 97.22% of eyes (140 eyes) after adding laser photocoagulation. The remaining four eyes (all had APROP) developed Stage 4 ROP and needed vitreous surgery. After monotherapy with bevacizumab biosimilar, type 1 ROP eyes had significantly higher rate of complete ROP regression than APROP eyes (87% vs 18.18%; P<0.00001). All eyes with type 1 ROP, and 90.91% of eyes with APROP, regressed after receiving additional laser therapy. The study population experienced no ocular or systemic adverse effects.

Conclusion

The BIOS-ROP study demonstrates that intravitreal bevacizumab biosimilar monotherapy offers significant benefit for type 1 ROP, but not APROP. Low-cost biosimilars can help sustain healthcare systems in lower-middle income countries (LMICs) with escalating healthcare expenditures. They can also improve healthcare equity by making vision-saving therapies like bevacizumab more affordable and accessible.

Neonatal sepsis as a cause of retinopathy of prematurity: An etiological explanation

Retinopathy of prematurity (ROP) is a complex neonatal disorder with multiple contributing factors. In this paper we have mounted the evidence in support of the proposal that neonatal sepsis meets all requirements for being a cause of ROP (not a condition, mechanism, or even innocent bystander) by means of initiating the early stages of the pathomechanism of ROP occurrence, systemic inflammation. We use the model of etiological explanation, which distinguishes between two overlapping processes in ROP causation. It can be shown that sepsis can initiate the early stages of the pathomechanism via systemic inflammation (causation process) and that systemic inflammation can contribute to growth factor aberrations and the retinal characteristics of ROP (disease process). The combined contribution of these factors with immaturity at birth (as intrinsic risk modifier) and prenatal inflammation (as extrinsic facilitator) seems to provide a cogent functional framework of ROP occurrence. Finally, we apply the Bradford Hill heuristics to the available evidence. Taken together, the above suggests that neonatal sepsis is a causal inducer of ROP.

Anti-Vascular Endothelial Growth Factor (Anti-VEGF) for the Treatment of Type I ROP

This retrospective study evaluated the trends in the use of anti-vascular endothelial growth factor (anti-VEGF) for the treatment of type-1 retinopathy of prematurity (ROP) during two periods - 2016-2019 (epoch A) and 2020-2022 (epoch B) in a neonatal unit of India. The study also compared the efficacy of anti-VEGF and laser therapies. Anti-VEGF was used in 8 (12.2%) out of 66 eyes treated during epoch A and 54 (75%) out of 72 eyes during epoch B (P = 0.001). The proportion of eyes in which ROP regressed with a single attempt of laser and anti-VEGF therapies was 8/20 (40%) and 7/15 (46.6%) respectively for the disease in zone 1 and aggressive-posterior ROP (P = 0.70) and 46/66 (69.6%) and 17/37 (45.9%) respectively for the disease in zone 2 (P = 0.018). There was a trend towards an increase in the use of anti-VEGF for ROP management over time. Anti-VEGF showed equal efficacy as laser for zone 1 ROP and AP-ROP, but laser therapy was better for zone 2 ROP.

MicroRNA-124-3p Attenuated Retinal Neovascularization in Oxygen-Induced Retinopathy Mice by Inhibiting the Dysfunction of Retinal Neuroglial Cells through STAT3 Pathway

MicroRNA (miRNA) is a non-coding RNA that can regulate the expression of many target genes, and it is widely involved in various important physiological activities. MiR-124-3p was found to associate with the normal development of retinal vessels in our previous study, but the mechanism of its anti-angiogenic effect on pathological retinal neovascularization still needed to be explored. Therefore, this study aimed to investigate the effect and mechanism of miR-124-3p on retinal neovascularization in mice with oxygen-induced retinopathy (OIR). Here, we found that intravitreal injection of miR-124-3p agomir attenuated pathological retinal neovascularization in OIR mice. Moreover, miR-124-3p preserved the astrocytic template, inhibited reactive gliosis, and reduced the inflammatory response as well as necroptosis. Furthermore, miR-124-3p inhibited the signal transducer and activator of transcription 3 (STAT3) pathway and decreased the expression of hypoxia-inducible factor-1α and vascular endothelial growth factor. Taken together, our results revealed that miR-124-3p inhibited retinal neovascularization and neuroglial dysfunction by targeting STAT3 in OIR mice.

SIRT2 inhibition attenuates the vasculopathy and vision impairment via Akt signaling in retinopathy of prematurity

Despite decades of research, the underlying mechanism of retinopathy of prematurity (ROP) remains unclear. The role of Sirt2, which is involved in both angiogenesis and inflammation, both pivotal in ROP, was investigated in an animal model of ROP known as oxygen-induced retinopathy (OIR). Our study found that Sirt2 was overexpressed and colocalized with microglia in OIR. Furthermore, it demonstrated that the level of Sirt2 was upregulated in hypoxia microglia BV-2 in vitro. Subsequently, our results elucidated that administration of the Sirt2 antagonist AGK2 attenuated the avascular and neovascular area and downregulated the expression of IGF-1. The phosphorylation of Akt and the expression of IGF-1 were upregulated in hypoxia BV-2 and conditional media collected from BV-2 under hypoxia promoted the migration and tube formation of retinal capillary endothelial cells, which were suppressed with AGK2. Notably, our findings are the first to demonstrate the deleterious role of Sirt2 in ROP, as Sirt2 inhibition led to the downregulation of Akt/IGF-1 and ameliorated vasculopathy, ultimately improving visual function. These results suggest that Sirt2 may be a promising therapeutic target for ROP.

Smartphone-based fundus imaging for evaluation of Retinopathy of Prematurity in a low-income country: A pilot study

Objectives

To evaluate the feasibility of a novel and simple smart phone-based Retinopathy of Prematurity (ROP) screening approach in a resource-constrained setting.

Methods

This cross-sectional validation study was conducted at the Department of Ophthalmology and Neonatal Intensive Care Unit (NICU) of The Aga Khan University Hospital, Pakistan, from January 2022 to April 2022. A total of 63 images of eyes with active ROP (stage-1, 2, 3, 4 and/or plus or pre-plus disease) were included in this study. The stage of ROP was documented by the principal investigator using an indirect ophthalmoscope and retinal images were obtained using this novel technique. These images were shared with two masked ROP experts who rated the image quality and determined the stage of ROP and presence of plus disease. Their reports were compared with the initial findings reported by principal investigator using indirect ophthalmoscope.

Results

We reviewed 63 images for image quality, stage of ROP and presence of plus disease. There was significant agreement between the gold standard and the Rater-1 and 2 for the presence of plus disease (Cohen's kappa was 0.84 and 1.0) and the stage of the disease (Cohen's kappa 0.65 and 1.0). There was significant agreement between the Rater for presence of plus disease and any stage of ROP (Cohen's κ: 0.84 and 0.65 for plus disease and any stage of the ROP, respectively). Rater-1 and 2 rated 96.83% and 98.41% images as excellent / acceptable respectively.

Conclusions

High quality retinal images can be captured with a smartphone and 28D lens without using any additional adapter equipment. This approach of ROP screening can form basis of telemedicine for ROP in resource constrained areas.

Refractive status and retinal morphology in children with a history of intravitreal ranibizumab for retinopathy of prematurity

This study investigated the characteristics of refractive status, visual acuity, and retinal morphology in children with a history of receiving intravitreal ranibizumab for retinopathy of prematurity (ROP). Children 4-6 years of age were enrolled and divided into the following four groups: group 1, children with a history of ROP who had been treated with intravitreal ranibizumab; group 2, children with a history of ROP who had not received any treatment; group 3, premature children without ROP; and group 4, full-term children. Refractive status, peripapillary retinal nerve fiber layer (RNFL), and macular thickness were measured. A total of 204 children were enrolled. In group 1, myopic shift was not noted, but poorer best corrected visual acuity (BCVA) and shorter axial length were observed. Significantly lower peripapillary RNFL thickness in the average total and superior quadrant, higher central subfield thickness, lower parafoveal retinal thickness in average total, superior, and nasal and temporal quadrants were observed in group 1 than in the other groups. The poor BCVA in patients with ROP was correlated with the lower RNFL thickness in the superior quadrant.   Conclusion: Children with a history of type 1 ROP treated with ranibizumab did not show a myopic shift but did show abnormal retinal morphology and the poorest BCVA among all groups. We suggest that pediatric ophthalmologists should always pay attention to visual development in patients with ROP with a history of intravitreal ranibizumab. What is Known: • Anti-VEGF is efficiently and widely used in the treatment of type 1 retinopathy of prematurity (ROP), and different anti-VEGF agents are associated with different prevalence of myopia. • Patients with ROP who receive treatment such as laser therapy or cryotherapy have abnormal macular development and retinal nerve fiber layer (RNFL) thickness. What is New: • Children with a history of ROP treated with intravitreal ranibizumab did not show a myopic shift but did show poor BCVA at 4-6 years of age. • Abnormal macular morphology and lower peripapillary RNFL thickness were found in these children.

Comparison in Retreatments between Bevacizumab and Ranibizumab Intravitreal Injections for Retinopathy of Prematurity: A Multicenter Study

PURPOSE

To compare the types and dosages of anti-vascular endothelial growth factors (VEGFs) to ascertain whether specific dosages or types of injection were associated with retreatment in clinical practice in the United States.

DESIGN

Multicenter, retrospective, consecutive series.

PARTICIPANTS

Patients with retinopathy of prematurity (ROP) treated with anti-VEGF injections from 2007 to 2021.

METHODS

Sixteen sites from the United States participated. Data collected included demographics, birth characteristics, examination findings, type and dose of anti-VEGF treatment, retreatment rates, and time to retreatment. Comparisons of retreatment rates between bevacizumab and ranibizumab intravitreal injections were made.

MAIN OUTCOME MEASURES

Relative rate of retreatment between varying types of anti-VEGF therapy, including bevacizumab and ranibizumab, and the various dosages used for each.

RESULTS

Data from 873 eyes of 661 patients (61% male and 39% female) were collected. After exclusion of 40 eyes treated with laser before anti-VEGF injection and 266 eyes re-treated with laser at or beyond 8 weeks after the initial anti-VEGF treatment, 567 eyes of 307 patients (63% male and 37% female) remained and were included in the primary analysis. There was no difference between the no retreatment and retreatment groups in terms of birthweight, gestational age, age at first injection, ROP stages, or number of involved clock hours. The retreatment group had a larger percentage of aggressive ROP (34% vs. 18%, P < 0.001) and greater percentage of zone 1 ROP (49 vs. 34%, P = 0.001) than the no retreatment group. Ranibizumab use was associated with a higher rate of retreatment than bevacizumab use (58% vs. 37%, P < 0.001), whereas the rate of retreatment was not associated with a specific dose of ranibizumab (R2 = 0.67, P = 0.32). Meanwhile, lower doses of bevacizumab were associated with higher rates of retreatment compared with the higher doses (R2 = 0.84, P = 0.01). There was a dose-specific trend with higher doses trending toward lower retreatments for bevacizumab.

CONCLUSIONS

In a multicenter study of ROP patients initially treated with anti-VEGF therapy, ranibizumab and lower-dose bevacizumab use were associated with an increased rate of retreatment when compared with higher-dose bevacizumab.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.

Hematologic Risk Factors for the Development of Retinopathy of Prematurity—A Retrospective Study

(1) Background: Retinopathy of prematurity (ROP) can cause severe visual impairment or even blindness. We aimed to assess the hematological risk factors that are associated with different stages of ROP in a cohort of preterm newborns, and to compare the clinical characteristics and therapeutic interventions between groups. (2) Methods: This retrospective study included 149 preterm newborns from a tertiary maternity hospital in Romania between January 2018 and December 2018, who were segregated into: Group 1 (with ROP, n = 59 patients), and Group 2 (without ROP, n = 90 patients). The patients that were affected by ROP were subsequently divided into the following subgroups: Subgroup 1 (Stage 1, n = 21), Subgroup 2 (Stage 2, n = 35), and Subgroup 3 (Stage 3, n = 25). The associations were analyzed using multivariate logistic regression and sensitivity analysis. (3) Results: Platelet mass indexes (PMI) that were determined in the first, seventh, and tenth days of life were significantly associated with Stage 1 ROP. PMI determined in the first day of life was also significantly associated with Stage 2 ROP. The sensitivity and specificity of these parameters were modest, ranging from 44 to 57%, and 59 to 63%. (4) Conclusions: PMI has a modest ability to predict the development of ROP.

Microglia refine developing retinal astrocytic and vascular networks through the complement C3/C3aR axis

Microglia, a resident immune cell of the central nervous system (CNS), play a pivotal role in facilitating neurovascular development through mechanisms that are not fully understood. Previous reports indicate a role for microglia in regulating astrocyte density. This current work resolves the mechanism through which microglia facilitate astrocyte spatial patterning and superficial vascular bed formation in the neuroretina during development. Ablation of microglia increased astrocyte density and altered spatial patterning. Mechanistically, we show that microglia regulate the formation of the spatially organized astrocyte template required for subsequent vascular growth, through the complement C3/C3aR axis during neuroretinal development. Lack of C3 or C3aR hindered the developmental phagocytic removal of astrocyte bodies and resulted in increased astrocyte density. In addition, increased astrocyte density was associated with elevated proangiogenic extracellular matrix gene expression in C3- and C3aR-deficient retinas, resulting in increased vascular density. These data demonstrate that microglia regulate developmental astrocyte and vascular network spatial patterning in the neuroretina via the complement axis.

Comparison of adverse events between intravitreal anti-VEGF and laser photocoagulation for treatment-requiring retinopathy of prematurity: a systematic review

PURPOSE

To synthesize existing evidence on adverse events, complications, and unfavorable outcomes of current treatment modalities for treatment-requiring retinopathy of prematurity (TR-ROP).

METHODS

PubMed, Cochrane Central Register of Controlled Trials, Scopus, EMBASE, Trip Database, and the gray literature available were searched. Randomized Clinical Trials and observational studies comparing the adverse events of intravitreal anti-VEGF injections (bevacizumab, ranibizumab, aflibercept, pegaptanib, conbercept) and laser photocoagulation (LPC) as treatment modalities for infants with TR-ROP were included. The main outcomes compared between the two treatment modalities were: 1. Refractive Errors and Biometry Parameters, 2. Adverse events, complications, and unfavorable outcomes, 3. Disease Recurrence/Disease Regression/Need for retreatment, 4. Neurodevelopmental Outcomes.

RESULTS

Higher quality studies concluded that LPC leads to greater rates of myopia than intravitreal anti-VEGF treatment while the rate of adverse events and of unfavorable neurodevelopmental outcomes is similar. However, there was controversy among the included studies concerning the rate of ROP recurrence between intravitreal anti-VEGF injections and LPC.

CONCLUSION

There is need for future primary studies assessing the adverse events of intravitreal anti-VEGF injections compared with LPC as treatment modalities for infants with TR-ROP.

Study on the Antioxidant Effect of Tanshinone IIA on Diabetic Retinopathy and Its Mechanism Based on Integrated Pharmacology

AIM

To explore the effect of tanshinone IIA on diabetic retinopathy (DR) and its mechanism.

METHODS

GeneCards and OMM databases were used to mine DR-related genes. The chemical structure of tanshinone IIA was searched by PubChem, and the potential target was predicted by PharmMapper. Cystape 3.8.2 was used to visualize and analyze the tanshinone IIA-DR protein interaction network. DAVID ver 6.8 data were used to perform enrichment analysis of the tanshinone IIA-DR protein interaction network. Then animal experiments were carried out to further explore the mechanism of tanshinone IIA in the treatment of DR. Male SD rats were intraperitoneally injected with streptozotocin to establish a diabetes model and were randomly divided into a model group, a low-dose tanshinone IIA group and a high-dose group. Normal rats served as the control group. Hematoxylin-eosin (HE) staining was used to observe the structural changes of the retina; the SOD, GSH-Px, and MDA levels in the retina were detected by the xanthine oxidase method; the expression of VEGF, IL-1β, IL-6, TNF-α, and caspase-3 mRNA were detected by qRT-PCR; and the Bcl-2, Bax, and VEGFA proteins were determined by the western blot.

RESULTS

A total of 213 tanshinone IIA potential targets and 223 DR-related genes were obtained. The enrichment analysis showed that tanshinone IIA may regulate hypoxia, oxidative stress, positive regulation of ERK1 and ERK2 cascade, steroid hormone-mediated signaling pathway, inflammatory response, angiogenesis, VEGF signaling pathway, apoptosis, PI3K-Akt signaling pathway, TNF signaling pathway, and biological processes and signaling pathways. The structure of the retina in the normal control group was clear, the retina in the model group was not clear, the nerve fiber layer was edema, the retinal cell layers of the tanshinone IIA low-dose group are arranged neatly, the inner and outer nuclear layers are slightly disordered, and the tanshinone IIA low-dose group was large. The structure of the mouse retina was further improved compared with the low-dose tanshinone IIA group. Compared with the model group, the retinal tissue SOD and GSH-PX of rats in the tanshinone IIA group increased, and the MDA level decreased (P < 0.05). Compared with the model group, the expression of VEGF, IL-1β, IL-6, TNF-α, and caspase-3 mRNA in the retina of tanshinone IIA groups was significantly reduced (P < 0.01). Compared with the model group, the Bcl-2 protein in the tanshinone IIA groups increased, while the Bax and VEGFA proteins decreased (P < 0.05).

CONCLUSION

Tanshinone IIA may improve the morphological performance of the retina of diabetic rats and inhibit DR, the mechanism of which may be anti-inflammatory, antiangiogenesis, etc.

Clinical characteristics, risk factors and short-term prognosis of retinopathy of prematurity complicated with retinal hemorrhage

PURPOSE

To investigate the incidence, clinical characteristics and short-term prognosis of retinal hemorrhage (RH) in premature infants with retinopathy of prematurity (ROP).

METHODS

From July 2015 to December 2021, the incidence and clinical characteristics of RH in premature infants with ROP diagnosed in a NICU of China before treatment were retrospectively analyzed.

RESULTS

A total of 670 premature infants were diagnosed with ROP, including 406 males and 254 females, with a mean gestational age (GA) of 29.51 ± 2.15w and a mean birth weight of 1240.56 ± 292.97g, excluding 10 premature infants who had progressed to stage 4 or 5 at the time of transfer and receiving vitrectomy. Of them, 322 (48.8%) premature infants had Type 1 ROP and received laser or anti-VEGF therapy, and 142 (21.3%) premature infants developed RH before treatment. The GA and birth weight of RH group were lower than those of non-RH group (29.19 ± 2.19w vs. 29.60 ± 2.13w; 1178.11 ± 282.01g vs. 1257.69 ± 293.85g, both P < 0.05), and the proportion of premature infants receiving treatment was also higher than that of non-RH group (97/142, 68.3% vs. 225/518, 43.4%). The lower the GA and the birth weight, the higher the incidence of RH. The incidence of RH was 45.5% in GA <26w and 30.5% in birth weight <1000g. After treatment, 7 eyes (2.6%) of 5 cases (3.5%) in RH group developed retinal detachment vs. 4 eyes (0.4%) of 3 cases (0.6%) in non-RH group, showing a significant difference between the two groups (χ2 = 8.043, P < 0.01). Regression analysis showed that RH, Zone I lesions, plus lesions, and the postnatal time of ocular lesions were independent risk factors for Type 1 ROP.

CONCLUSION

The lower the GA and the birth weight, the higher the incidence of ROP complicated with RH. RH is an indicator of severe ROP associated with poor retinal prognosis.

Analgesia for retinopathy of prematurity screening: A systematic review

BACKGROUND AND AIMS

Premature neonates require regular ophthalmological examination, generally indirect ophthalmoscopy, to screen for retinopathy of prematurity (ROP). Conventional analgesia is provided with topical anesthetic eyedrops and oral sugar solution, but neonates still experience significant pain. Here, the literature base was examined to evaluate the usefulness of other pharmacological analgesics.

MATERIALS AND METHODS

A systematic review was undertaken, adhering to a PROSPERO preregistered protocol in accordance with PRISMA guidelines (identifier CRD42022302459). Electronic databases were searched for primary research articles on pharmacological pain interventions used for ROP screening in neonates. The primary outcome measure was pain scores recorded using validated pain scoring tools, with and without pharmacological interventions in neonates during eye examination. For analysis, studies were separated into two categories: topical anesthesia and alternative pharmacological treatments.

RESULTS

Eleven studies met the inclusion criteria. Topical analgesia, oral paracetamol, and intranasal fentanyl were found to be effective in reducing the pain of eye examination. Oral morphine and inhaled nitrous oxide had no significant effect on premature infant pain profile (PIPP) scores during indirect ophthalmoscopy.

DISCUSSION

In addition to topical anesthesia, premedication with oral paracetamol is recommended during screening examination for ROP. The routine use of fentanyl is not recommended due to the risk of potential side effects. Non-pharmacological measures, such as sweet oral solutions and comfort techniques should also be employed. Further research is required to determine whether the use of nitrous oxide has a role, and to develop a safe and effective analgesic strategy to fully ameliorate the pain of ROP screening.

Retinopathy of Prematurity: A Global Perspective and Recent Developments

Retinopathy of prematurity (ROP) is a significant cause of potentially preventable blindness in preterm infants worldwide. It is a disease caused by abnormal retinal vascularization that, if not detected and treated in a timely manner, can lead to retinal detachment and severe long term vision impairment. Neonatologists and pediatricians have an important role in the prevention, detection, and management of ROP. Geographic differences in the epidemiology of ROP have been seen globally over the last several decades because of regional differences in neonatal care. Our understanding of the pathophysiology, risk factors, prevention, screening, diagnosis, and treatment of ROP have also evolved over the years. New technological advances are now allowing for the incorporation of telemedicine and artificial intelligence in the management of ROP. In this comprehensive update, we provide a comprehensive review of pathophysiology, classification, diagnosis, global screening, and treatment of ROP. Key historical milestones as well as touching upon the very recent updates to the ROP classification system and technological advances in the field of artificial intelligence and ROP will also be discussed.

miR-429 negatively regulates the progression of hypoxia-induced retinal neovascularization by the HPSE-VEGF pathway

Heparanase (HPSE) and vascular endothelial growth factor (VEGF) are believed to play a vital role in hypoxia-induced retinal neovascularization (RNV). HPSE is a target gene of miR-429. Our study aimed to investigate the effect of the miR-429-HPSE-VEGF pathway on hypoxia-induced RNV. The gene and protein expression of miR-429, HPSE and VEGF in human retinal endothelial cells and retinas was determined by real-time PCR and Western blot assays. The effects of miR-429 on human retinal endothelial cells and retinal neovascularization under hypoxia condition were verified by in vitro and in vivo experiments. First, we studied the effect of the miR-429-HPSE-VEGF pathway in HRECs under hypoxic conditions. HREC functions such as migration and tube formation were enhanced under hypoxic conditions. Overexpression of miR-429 in HRECs reversed these changes. Then, we investigated the effect of miR-429 on hypoxia-induced RNV in vivo. When miR-429 agomirs were injected into the vitreous cavity of mice with oxygen-induced retinopathy to overexpress miR-429, the mRNA and protein expression of VEGF was significantly reduced. In addition, indicators of retinal neovascularization, such as the retinal avascular area, and morphology of vessels, were reduced significantly in the miR-429 overexpression group. In this study, our data showed that miR-429 plays an important role by inhibiting the HPSE-VEGF pathway in hypoxia-induced retinopathy.

Long-term visual outcomes of children screened for retinopathy of prematurity with telemedicine in New Zealand

CLINICAL RELEVANCE

Children with a history of regressed retinopathy of prematurity (ROP) are at increased risk of peripheral avascular retina. Wide-field digital retinal imaging and telemedicine is an effective tool for ROP screening. Ophthalmologists and Optometrists should have a high level of clinical suspicion for peripheral retinal changes in children screened for ROP.

BACKGROUND

Retinopathy of prematurity, a vaso-proliferative disorder of the pre-term retina, is a preventable cause of childhood visual impairment. The Auckland Regional Telemedicine ROP (ART-ROP) network, established in 2006, utilises wide-field digital imaging and telemedicine to screen at-risk infants for ROP. This prospective observational study reports the long-term ocular outcomes of ART-ROP network infants.

METHODS

A comprehensive paediatric eye examination including cycloplegic autorefraction and wide-field retinal imaging was completed on all participants. Participants had been screened for ROP by the ART-ROP network between May 2008 and October 2011.

RESULTS

A total of 69 children, with a mean age of 5 to 8 years old were assessed and divided into two groups: those with or without a history of ROP, 44 and 25 children, respectively. Infants with a history of ROP had significantly lower gestational age (26.6 ± 1.9 vs. 29.1 ± 1.6 weeks, p < 0.001) and birth weight (937 ± 237 vs. 1177 ± 311 grams, p = 0.001). No significant differences were detected between the two groups for visual acuity (p = 0.596), stereopsis (p = 0.219), refractive error (p = 0.472), or strabismus. Clinically significant refractive error was noted in 10 participants; none with moderate or high myopia. Retinal imaging exposed asymptomatic, persistent, peripheral avascular retina in four children, all of whom had a history of regressed ROP.

CONCLUSION

Visual and ocular outcomes did not vary based on history of ROP, with no participant having reduced vision as a result of undetected or untreated ROP. Further research is required into the long-term implication of persistent avascular retina in regressed ROP.

The Inhibitory Effect of Selected D2 Dopaminergic Receptor Agonists on VEGF-Dependent Neovascularization in Zebrafish Larvae: Potential New Therapy in Ophthalmic Diseases

Pathological angiogenesis is correlated with many ophthalmic diseases. The most common are exudative age-related macular degeneration and proliferative diabetic retinopathy. The current treatment for these diseases is based on regularly administered anti-VEGF antibodies injections. In the study, we investigated selected D₂ dopaminergic receptor agonists, namely bromocriptine, cabergoline and pergolide, on hypoxia-induced neovascularization. We used the zebrafish laboratory model, specifically three-day post fertilization (dpf) Tg(fli-1: EGFP) zebrafish larvae. To induce abnormal angiogenesis of hyaloid-retinal vessels (HRVs) and intersegmental vessels (ISVs), the larvae were treated with cobalt chloride (II) (CoCl₂) (a hypoxia-inducing agent) from 24 h post fertilization. The inhibitory role of D₂ dopaminergic receptor agonists was investigated using confocal microscopy and qPCR. Additionally, the results were compared to those obtained in the group treated with CoCl₂ followed by bevacizumab, the well-known antiangiogenic agent. Confocal microscopy analyses revealed severe deformation of vessels in the CoCl₂ treated group, while co-incubation with bromocriptine, cabergoline, pergolide and bevacizumab, respectively, significantly inhibited abnormalities of angiogenesis. The qPCR analyses supported the protective role of the chosen dopaminergic agonists by demonstrating their influence on CoCl₂-derived upregulation of vegfaa expression. The present results suggest that the D₂ receptor agonists can be considered as a new direction in research for antiangiogenic therapy.

Planned Preterm Delivery and Treatment of Severe Infantile FEVR With Osteoporosis-Pseudoglioma Syndrome

Familial exudative vitreoretinopathy (FEVR) is a rare hereditary vitreoretinopathy resulting from mutations in the wnt signaling pathway leading to abnormalities in fetal retinal vasculogenesis, angiogenesis, and retinal vascular maintenance. Severe FEVR may result in congenital retinal detachment resembling Norrie disease. The authors report the first case of planned preterm delivery and treatment of a patient with severe FEVR from biallelic LRP5 mutations whose siblings had congenital tractional retinal detachments with light perception vision outcomes after conventional care. Early intervention allowed laser ablation of avascular retina and functional visual outcome despite a successfully repaired unilateral tractional retinal detachment. [Ophthalmic Surg Lasers Imaging Retina. 2022;53(4):228-232.].

Morphology and Vessel Density of the Macula in Preterm Children Using Optical Coherence Tomography Angiography

Background: Retinal morphology changes may be associated with prematurity and can lead to visual impairment. Optical coherence tomography angiography may contribute to understanding the pathomechanism of structural and vascular retinal impairment in premature children. The aim of this study was to assess an influence of prematurity, neonatal clinical characteristics, and a history of retinopathy of prematurity (ROP) on the morphology and retinal vascularity of macula in children. Methods: A case−control study of 123 preterm children and 86 full-term children was performed. The age of the subjects was 10.45 years (IQR: 8.12−12.77), while the age of the control group was 11.78 years (IQR: 8.81−13.79). Optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA, angio-OCT) were performed using RTVueXR Avanti (Optovue, Fremont, CA, USA). Ganglion cell complex (GCC), foveal thickness (FT), parafoveal thickness (PFT), size of foveal avascular zone (FAZ) in superficial plexus, superficial capillary vessel density (sVD), deep capillary vessel density (dVD), central choroidal thickness (CCT), and presence of macular hypoplasia were analyzed. The association between OCT/angio-OCT results and clinical characteristics including the degree of ROP and therapy requirements was assessed in preterm infants. Results: Foveal morphology was affected in preterm children with high incidence of foveal hypoplasia (24.77%). GCC was thinner in preterm children compared to controls: avgGG 93 μm vs. 100 μm, p < 0.001. No associations between GCC and gestational age (R = −0.085; p = 0.228) and birth weight (R = −0.054; p = 0.446) were found. FAZ in preterm group was smaller than in controls (0.13 ± 0.09 vs. 0.22 ± 0.09; p < 0.001). FAZ area correlated with gestational age (R = 0.456; p < 0.001) and birth weight (R = 0.472; p < 0.001). Deep vessel density in the fovea was higher in preterm children than in control group (p < 0.001). PFT was significantly lower in preterm children compared to control group. However, increased thickness in the fovea was noted in preterm children (p < 0.001). FT was inversely correlated with gestational age (R = −0.562; p < 0.001) and birth weight (R = −0.508, p < 0.001). CCT was lower in preterm children (312 μm vs. 337.5 μm, p < 0.001) Parameters of GCC and FT were higher in patients with ROP required treatment compared to patients without ROP and spontaneously regressed retinopathy. FAZ was smaller in patients with retinopathy than in preterm children without ROP. Conclusion: Prematurity has a significant negative impact on GCC, macular morphology, and vascularization. In premature children, decreased FAZ, increased FT, and vessel density were strongly associated with gestational age, birth weight, Apgar score, ROP stage, and treatment requirement. Optical coherence tomography angiography is a useful tool for detecting retinal changes in premature children.

Effect of Probenecid on Endothelial Cell Growth Rate and Retinal Angiogenesis in an Oxygen-Induced Retinopathy Model

Objectives: Probenecid is an anion transport inhibitor, which, according to the connectivity map (CMap; a biological application database), interferes with hypoxia-induced gene expression changes in retinal vascular endothelial cells (ECs). Here, we investigated the influence of probenecid on retinal EC cytotoxicity and retinal neovascularization in a murine oxygen-induced retinopathy (OIR) model.

Methods: The retinal EC growth rate in the presence of hypoxia-mimicking concentrations of cobalt chloride (CoCl₂) was determined using the thiazolyl blue tetrazolium bromide (MTT) assay and proliferating cell nuclear antigen (PCNA) expression. In OIR rats, probenecid was administered by intraperitoneal injection (i.p.) from postnatal day (P) 1 to P7. The concentrations of vitreous humor vascular endothelial growth factor (VEGF), hypoxia-inducible factor (HIF)-1α, and placental growth factor (PlGF) were determined by using the ELISA kit at P21. The amount of newly formed vascular lumen was evaluated by histopathological examination. Retinopathy and neovascularization were assessed by scoring isolectin B4 fluorescein–stained retinal flat mounts. Western blots for liver tissue HIF-1α and hepcidin (HAMP) were performed.

Results:In vitro, probenecid led to the recession of the hypoxia-induced EC growth rate. In vivo, compared to the OIR retina, the upregulation of VEGF, HIF-1α, and PlGF in phase II retinopathy of prematurity (ROP) was inhibited by probenecid administration. Moreover, probenecid ameliorated neovascularization and resulted in significantly reduced relative leakage fluorescence signal intensity in fluorescein-stained retinal flat mounts (p < 0.05). Probenecid alleviated the liver overactivation of HAMP and downregulation of HIF-1α in OIR rats.

Conclusions: This is the first demonstration that implies that probenecid might be a protective compound against retinal angiogenesis in OIR. These changes are accompanied with decreased hyperoxia-mediated hepcidin overproduction. Although the relevance of the results to ROP needs further research, these findings may help establish potential pharmacological targets based on the CMap database.

Antiproliferative and Mitochondrial Protective Effects of Apigenin in an Oxygen-Induced Retinopathy In Vivo Mouse Model

Purpose: To investigate the effects of a common dietary flavonoid apigenin on retinal endothelial cell proliferation, retinal morphological structure, and apoptotic cell death in an oxygen-induced retinopathy (OIR) mouse model to evaluate the possibility of the use of apigenin in the treatment of ocular neovascular diseases (ONDs). Methods: Ninety-six newborn C57BL/6J mice were included. Eight groups were randomized, each including 12 mice. Two negative control groups were kept in room air: the first without any injection and the second received intravitreal (IV) dimethyl sulfoxide (DMSO), which is the solvent we used. The OIR groups were exposed to 75% ± 2% oxygen from postnatal days (PD) 7 to 12. On PD 12, the mice were randomly assigned to 6 groups: 2 OIR control groups (1 received no injection, 1 received IV-DMSO), 2 IV-apigenin groups (10 and 20 μg/mL), and 2 intraperitoneal (IP)-apigenin groups (10 and 20 mg/kg). We quantified retinal endothelial cell proliferation by counting neovascular tufts in cross-sections and examined histological and ultrastructural changes through light and electron microscopy. We evaluated apoptosis by terminal deoxynucleotidyl transferase-mediated nick end-labeling (TUNEL). Results: We detected a significant increase in endothelial cell proliferation in the OIR groups. Groups receiving apigenin, both IP and IV, had significant decreases in endothelial cells, atypical mitochondrion count, and apoptotic cells compared with the groups receiving no injections. None of the apigenin-injected groups revealed cystic degeneration or cell loss. Conclusions: Apigenin suppresses neovascularization, has antiapoptotic and antioxidative effects in an OIR mouse model, and can be considered a promising agent for treating OND. Clinical trial (Project number: DA15/19).

Neonatal Platelet Transfusions: Starting Again

Preterm neonates with severe thrombocytopenia are frequently prescribed prophylactic platelet transfusions despite no evidence of benefit. Neonatal platelet transfusion practice varies, both nationally and internationally. Volumes and rates of transfusion in neonatology are based on historic precedent and lack an evidence base. The etiology of harm from platelet transfusions is poorly understood. Neonates are expected to be the longest surviving recipients of blood produce transfusions, and so avoiding transfusion associated harm is critical in this cohort. This article reviews the evidence for and against platelet transfusion in the neonate and identifies areas of future potential neonatal platelet transfusion research.

80 Years of vision: preventing blindness from retinopathy of prematurity

Retinopathy of prematurity (ROP) is one of the leading yet preventable causes of childhood blindness worldwide. The purpose of this review is to provide a practical template for observational and treatment methods in order to reduce the overall incidence of any ROP and to improve both short-term and long-term outcomes once Type 1 ROP (treatable ROP) develops.

Systemic conbercept pharmacokinetics and VEGF pharmacodynamics following intravitreal injections of conbercept in patients with retinopathy of prematurity

BACKGROUND

Data on serum vascular endothelial growth factor (VEGF) and drug levels in patients with retinopathy of prematurity (ROP) following intravitreal injections of conbercept (IVC) are lacking.

METHODS

Multicentre, prospective, non-randomised study of patients with aggressive posterior retinopathy of prematurity (APROP) or type 1 ROP who had not received other treatment. All infants received therapy in both eyes plus intravitreal IVC 0.25 mg/0.025 mL in one eye and had at least 6 months of follow-up. Blood samples were collected before and 1 week and 4 weeks after IVC. The main outcome measures were serum conbercept and VEGF concentrations.

RESULTS

Forty infants with APROP or type 1 ROP were enrolled. The mean serum VEGF at baseline and 1 week and 4 weeks after a total of 0.25 mg of IVC was 953.35±311.90 pg/mL, 303.46±181.89 pg/mL and 883.12±303.89 pg/mL, respectively. Serum VEGF 1 week after IVC was significantly lower (p<0.05) than baseline, and at 4 weeks after IVC, it was significantly higher (p<0.05) than at 1 week. There was no significant difference (p>0.05) between baseline and 4 weeks. Serum conbercept was below the limit of quantitation (BLOQ) at baseline and 4 weeks and was 19.81±7.60 ng/mL at 1 week.

CONCLUSION

Serum VEGF 1 week after IVC was significantly lower than baseline but returned to baseline at 4 weeks. Serum conbercept increased at 1 week and was BLOQ at 4 weeks.

Prostaglandin E2 promotes pathological retinal neovascularisation via EP4R-EGFR-Gab1-AKT signaling pathway

Proliferative retinopathies, such as proliferative diabetic retinopathy (PDR) and retinopathy of prematurity (ROP) are major causes of visual impairment and blindness in industrialized countries. Prostaglandin E2 (PGE2) is implicated in cellular proliferation and migration via E-prostanoid receptor (EP4R). The aim of this study was to investigate the role of PGE2/EP4R signaling in the promotion of retinal neovascularisation. In a streptozotocin (STZ)-induced diabetic model and an oxygen-induced retinopathy (OIR) model, rats received an intravitreal injection of PGE2, cay10598 (an EP4R agonist) or AH23848 (an EP4R antagonist). Optical coherence tomography, retinal histology and biochemical markers were assessed. Treatment with PGE2 or cay10598 accelerated pathological retinal angiogenesis in STZ and OIR-induced rat retina, which was ameliorated in rats pretreated with AH23848. Serum VEGF-A was upregulated in the PGE2-treated diabetic rats vs non-treated diabetic rats and significantly downregulated in AH23848-treated diabetic rats. PGE2 or cay10598 treatment also significantly accelerated endothelial tip-cell formation in new-born rat retina. In addition, AH23848 treatment attenuated PGE2-or cay10598-induced proliferation and migration by repressing the EGF receptor (EGFR)/Growth factor receptor bound protein 2-associated binder protein 1 (Gab1)/Akt/NF-κB/VEGF-A signaling network in human retinal microvascular endothelial cells (hRMECs). PGE2/EP4R signaling network is thus a potential therapeutic target for pathological intraocular angiogenesis.

Artificial Intelligence: the unstoppable revolution in ophthalmology

Artificial Intelligence (AI) is an unstoppable force that is starting to permeate all aspects of our society as part of the revolution being brought into our lives (and into medicine) by the digital era, and accelerated by the current COVID-19 pandemic. As the population ages and developing countries move forward, AI-based systems may be a key asset in streamlining the screening, staging, and treatment planning of sight-threatening eye conditions, offloading the most tedious tasks from the experts, allowing for a greater population coverage, and bringing the best possible care to every patient. This paper presents a review of the state of the art of AI in the field of ophthalmology, focusing on the strengths and weaknesses of current systems, and defining the vision that will enable us to advance scientifically in this digital era. It starts with a thorough yet accessible introduction to the algorithms underlying all modern AI applications. Then, a critical review of the main AI applications in ophthalmology is presented, including Diabetic Retinopathy, Age-Related Macular Degeneration, Retinopathy of Prematurity, Glaucoma, and other AI-related topics such as image enhancement. The review finishes with a brief discussion on the opportunities and challenges that the future of this field might hold.

Analysis of the etiologies, treatments and prognoses in children and adolescent vitreous hemorrhage

AIM

To determine the etiologies, treatment modalities and visual outcomes of vitreous hemorrhage (VH; range from birth to 18y).

METHODS

A total of 262 eyes from 210 patients between January 2010 and September 2016 were included. All children underwent an appropriate ocular and systemic examination. Data collected included demographics, clinical manifestations, details of the ocular and systemic examination, management details, final fundus anatomy and visual acuity (VA).

RESULTS

The most common etiologies were non-traumatic VH (64.89%), most of which were due to retinopathy of prematurity (ROP; 37.10%); while traffic accidents, including 16 (21.00%) eyes, was the most common ocular traumas. Surgery, performed in 143 (54.58%) eyes, was the most common management modality. The initial mean baseline visual acuity was 2.77±0.21 logarithm of the minimal angle of resolution (logMAR) in children and adolescent with traumatic VH, which was significantly improved to 2.15±1.31 logMAR (P<0.05).

CONCLUSION

VH in children and adolescent has a complicated and diverse etiology. ROP is the primary cause of non-traumatic VH, which is the most common etiology. Appropriate treatment of traumatic VH is associated with obvious improvement in visual acuity. The initial VA is one of most important predictors of outcome.

Plasma levels of amino acids and derivatives in retinopathy of prematurity

Background: Retinopathy of prematurity (ROP) is a retinal disease that causes blindness in premature infants. This study aimed to reveal the changes in amino acids and derivatives in the plasma of ROP patients compared with premature infants without ROP. Methods: Metabolomics targeting amino acids and their derivatives was conducted to assess their plasma levels in ROP patients (n=58) and premature infants without ROP (n=25), and KEGG pathway analysis was used to identify the involved pathways. Results: Among the 31 assessed metabolites, the levels of 4 amino acids were significantly altered in the ROP group. Creatinine was downregulated in the plasma of the ROP patients, while the levels of citrulline, arginine, and aminoadipic acid were upregulated in the ROP group. Significant correlations were identified between the ROP stage and plasma levels of citrulline, creatinine, and aminoadipic acid. The involved pathways included biosynthesis of amino acids, arginine and proline metabolism, and arginine biosynthesis. Conclusion: The plasma levels of citrulline, creatinine, arginine, and aminoadipic acid were significantly changed in ROP patients. These metabolites could be considered potential biomarkers of ROP, and their related metabolic pathways might be involved in ROP pathogenesis.