Delayed episode of necrotising enterocolitis in an ex-preterm infant after intravitreal administration of low-dose ranibizumab for the treatment of retinopathy of prematurity.

Retinopathy of prematurity (ROP) and necrotising enterocolitis (NEC) are complications of prematurity. Despite being quite different in terms of incidence, pathogenesis and consequences, both share a pathogenic role of aberrant vascularisation: increased in ROP, deficient for NEC. Current therapy for ROP includes the use of anti-vascular endothelial growth factor (anti-VEGF) agents, which are able to interrupt retinal hypervascularity. Despite being delivered intravitreously, anti-VEGF used in ROP can be absorbed into circulation and exert systemic effects. We present here a case of an ex-27 weeks gestational age infant, presenting multiple NEC risk factors, treated at 2 months of age with low-dose ranibizumab, who developed a large bowel NEC episode in the first week after treatment. We believe that this further report of an association between anti-VEGF agents and NEC could be interesting for the identification of children at risk of severe adverse events and stimulating further research on the topic.

Efficacy of supplemental oxygen in reducing the need for laser or intravitreal bevacizumab in preterm infants with stage 2 retinopathy of prematurity.

BACKGROUND: Retinopathy of prematurity (ROP) is a disease that affects preterm infants born younger than 30 weeks of gestation. The pathophysiology of ROP involves an initial vaso-obliterative phase followed by vaso-proliferative phase that leads to disease progression. The use of supplemental oxygen during the vaso-proliferative phase of ROP has been associated with reduced disease progression, but how this impacts the need for ROP treatment is unclear. The goal of this study was to compare the rate of laser or intravitreal bevacizumab after implementation of a new supplemental oxygen therapy protocol in preterm infants with stage 2 ROP. METHODS: This is a retrospective chart review of preterm infants diagnosed with stage 2 ROP at Riley Hospital for Children between 1/2017 and 12/2022. Patients diagnosed between 1/2017 and 6/2020 were classified as Cohort A, preprotocol implementation. Patients diagnosed from 8/2020 to 12/2022 were classified as Cohort B, postprotocol implementation. In Cohort A, oxygen saturation was kept at 91-95% through the entire hospitalization. In Cohort B, oxygen saturation was increased to 97-99% as soon as Stage 2 ROP was diagnosed. Statistical analyses were performed using chi-square and Student's T test, followed by multivariate analyses to determine the impact of the oxygen protocol on the need for ROP treatment. RESULTS: A total of 211 patients were diagnosed with stage 2 ROP between 1/2017 and 12/2022. Of those patients, 122 were before protocol implementation therapy (Cohort A), and 89 were after implementation of supplemental oxygen protocol (Cohort B). Gestational age was slightly higher in Cohort B (Cohort A 25.3 ± 1.9, Cohort B 25.8 ± 1.84, p = 0.04). There was no difference in birth weight, NEC, BPD, or survival. Cohort B had lesser need for invasive mechanical ventilation and higher days on CPAP during hospitalization. Notably, Cohort A had 67 (55%) patients treated with laser photocoagulation or intravitreal bevacizumab versus 20 (22%) patients in Cohort B (OR 0.19, 0.08-0.40). CONCLUSION: The need for laser photocoagulation or intravitreal bevacizumab was significantly decreased in high-risk patients treated with the supplemental oxygen protocol. This result supports the idea that targeted supplemental oxygen therapy to keep saturations between 97 and 99% can reduce disease progression in infants with stage 2 ROP and potentially decrease the burden of additional procedures.

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.

4D label-free proteomics analysis of oxygen-induced retinopathy with or without anti-VEGF treatment.

Oxygen-induced retinopathy (OIR) animal model is widely used for retinopathy of prematurity (ROP) researches. The purpose of this study was to identify proteins and related pathways of OIR with or without anti-vascular endothelial growth factor (VEGF) treatment, for use as biomarkers in diagnosing and treating ROP. Nine samples were subjected to proteomic analysis. Retina specimens were collected from 3 OIR mice, 3 OIR mice with anti-VEGF treatment and 3 normal mice (control group). Liquid chromatography-tandem mass spectrometry analysis was performed using the 4D label-free technique. Statistically significant differentially expressed proteins, gene ontology (GO) terms, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway representations, InterPro (IPR) and protein interactions were analyzed. In total, 4585 unique proteins were identified as differentially expressed proteins (DEPs). Enrichment analysis of the GO and KEGG indicated functional clusters related to peptide biosynthetic and metabolic process, cellular macromolecule biosynthetic process and nucleic acid binding in OIR group. For anti-VEGF treatment group, DEPs were clustered in DNA replication, PI3K/Akt signaling pathway and Jak/STAT signaling pathway. Proteomic profiling is useful for the exploration of molecular mechanisms of OIR and mechanisms of anti-VEGF treatment. These findings may be useful for identification of novel biomarkers for ROP pathogenesis and treatment.

Intravitreal Aflibercept vs Laser Therapy for Retinopathy of Prematurity: Two-Year Efficacy and Safety Outcomes in the Nonrandomized Controlled Trial FIREFLEYE next.

Importance: Prospective long-term data after retinopathy of prematurity (ROP) treatment with anti-vascular endothelial growth factor injections vs laser therapy are scarce. The FIREFLEYE (Aflibercept for ROP IVT Injection vs Laser Therapy) next trial is prospectively evaluating the long-term efficacy and safety outcomes following ROP treatment with intravitreal aflibercept vs laser therapy. Objective: To evaluate 2-year ophthalmic and safety outcomes after 0.4-mg aflibercept injection or laser therapy in the 24-week randomized (2:1) FIREFLEYE trial (FIREFLEYE outcomes previously reported). Design, Setting, and Participants: This prospective nonrandomized controlled trial performed in 24 countries in Asia, Europe, and South America (2020-2025) follows up participants treated in the FIREFLEYE randomized clinical trial (2019-2021) through 5 years of age. Participants included children born very or extremely preterm (gestational age ≤32 weeks) or with very or extremely low birth weight (≤1500 g) who were previously treated with a 0.4-mg injection of aflibercept compared with laser therapy for severe acute-phase ROP. Data for the present interim analysis were acquired from March 18, 2020, to July 25, 2022. Interventions: Complications of ROP treated at investigator discretion (no study treatment). Main Outcomes and Measures: Efficacy end points included ROP status, unfavorable structural outcomes, ROP recurrence, treatment for ROP complications, completion of vascularization, and visual function. Safety end points included adverse events and growth and neurodevelopmental outcomes. Results: Overall, 100 children were enrolled (median gestational age, 26 [range, 23-31] weeks; 53 boys and 47 girls). Of these, 21 were Asian, 2 were Black, 75 were White, and 2 were of more than 1 race. At 2 years of age, 61 of 63 children (96.8%) in the aflibercept group vs 30 of 32 (93.8%) in the laser group had no ROP. Through 2 years of age, 62 of 66 (93.9%) in the aflibercept group and 32 of 34 (94.1%) in the laser group had no unfavorable structural outcomes. No new retinal detachment occurred during the study. Four children in the aflibercept group (6.1%) were treated for ROP complications before 1 year of age (2 had preexisting end-stage disease and total retinal detachment; 1 had reactivated plus disease; and 1 had recurrent retinal neovascularization not further specified). Most children were able to fix and follow a 5-cm toy (aflibercept group, 118 of 122 eyes [96.7%] among 63 children; laser group, 62 of 63 eyes [98.4%] among 33 children). High myopia was present in 9 of 115 eyes (7.8%) among 5 children in the aflibercept group and 13 of 60 eyes (21.7%) among 9 children in the laser group. No relevant differences in growth and neurodevelopmental outcomes by Bayley Scales of Infant and Toddler Development, Third Edition and Vineland Adaptive Behavior Scales, Second Edition were identified. Conclusions and Relevance: In this nonrandomized follow-up of a randomized clinical trial comparing treatment of severe acute-phase ROP with 0.4-mg injection of aflibercept and laser, disease control was stable and visual function was appropriate in children through 2 years of age. No adverse effects on safety, including growth and neurodevelopment, were identified. These findings provide clinically relevant long-term information on intravitreal aflibercept injection therapy for ROP. Trial Registration: ClinicalTrials.gov Identifier: NCT04015180.

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.

OUTCOME OF EYES TREATED FOR RETINOPATHY OF PREMATURITY IN POSTERIOR ZONE I: An Eastern India Study.

PURPOSE: To analyze the outcomes of eyes treated for retinopathy of prematurity in posterior Zone I. METHODS: In a part retrospective (9 years) and part prospective (1 year) interventional study, we analyzed eyes treated for retinopathy of prematurity in posterior Zone I with a minimum follow-up for 6 months. RESULTS: This study included 109 eyes of 56 infants; mean gestational age and birth weights were 29.3 (±2.1) weeks and 1112.5 (±381.9) g, respectively. The treatment included intravitreal anti-vascular endothelial growth factor as the initial treatment modality in 101 eyes (92.6%), either alone (27 eyes) or combined with laser or vitreous surgery (73 eyes). Laser was the initial treatment modality in eight eyes, either alone (n = 3) or in combination with surgery (n = 5). With anti-vascular endothelial growth factor alone, 30.68% (n = 27) eyes responded favorably, and the remaining 69.32% (n = 59) eyes needed retreatment (laser in the majority). At the final follow-up, 89.9% (out of 109) of eyes did well anatomically. Good outcome was significantly linked to no detachment at presentation ( P < 0.0001) and the presence of well-defined central vascular trunks ( P = 0.001). CONCLUSION: Treating the eyes before retinal detachment with bevacizumab followed by laser (and surgery, if needed) results in a favorable outcome in babies with posterior Zone I retinopathy of prematurity.

LONGITUDINAL CHANGES IN CHOROIDAL THICKNESS IN CHILDREN WITH A HISTORY OF PREMATURITY: An 18-Month Prospective Cohort Study.

PURPOSE: To evaluate choroidal changes over time in school-age children with a history of prematurity. METHODS: A study of 416 eyes of 208 eligible participants, including 88, 190, 36, 56, and 46 eyes in the full-term control, preterm, spontaneously regressed retinopathy of prematurity, intravitreal bevacizumab (injection of bevacizumab)-treated retinopathy of prematurity, and laser-treated retinopathy of prematurity groups, respectively, were enrolled in this study. The choroidal thickness was measured 4 times at 6-month intervals using optical coherence tomography. RESULTS: Of all the groups, the laser-treated children had the thinnest choroid compared with full-term children (-52.3 µ m, P = 0.04). Preterm children exhibited greater attenuation in choroidal thickness over time than did full-term children (-6.3 ± 26.9 and -1.1 ± 12.8 µ m/year, P = 0.03), whereas no difference was observed between injection of bevacizumab and laser treatments (-4.6 ± 18.9 and -2.0 ± 15.7 µ m/year, P = 0.46). In all groups, the changes in axial length were negatively associated with the changes in choroidal thickness (all P < 0.05). CONCLUSION: A greater attenuation in choroid thickness over time was observed in preterm children than in full-term children, but this attenuation did not differ between injection of bevacizumab and laser treatments. Axial elongation was associated with choroidal thinning in school-age children.

Unilateral Retinopathy in a Preterm Infant With 4q Duplication: Description and Management.

A 33-5/7, 1570 g dichorionic diamniotic twin presented with cryptorchidism, failed hearing examination (both ears), poor feeding, profound hypoglycemia, coagulopathy, conjugated hyper-bilirubinemia, hydronephrosis, and hypotension. Microarray sent with results of whole genome SNP microgray analysis detected an interstitial duplication of the chromosomal segment 4q35 1q35.2. On this basis, telemedicine screening was performed to evaluate for ocular abnormalities in association with abnormal gene testing. Unilateral advanced retinopathy was noted affecting the right eye, with mature vascularization in the left eye. This infant was managed in concordance with retinopathy of prematurity guidelines, despite not making screening criteria. Off-label intravitreal bevacizumab injection (0.625 mg in 0.025 mL) resulted in full vascular maturation assessed by fluorescein angiography 6 months later. This represents the first description and management of retinopathy in 4q duplication syndrome. [Ophthalmic Surg Lasers Imaging Retina 2024;55:228-230.].

Systemic exposure to aflibercept after intravitreal injection in premature neonates with retinopathy of prematurity: results from the FIREFLEYE randomized phase 3 study.

BACKGROUND: There are no data on pharmacokinetics, pharmacodynamics, and immunogenicity of intravitreal aflibercept in preterm infants with retinopathy of prematurity (ROP). FIREFLEYE compared aflibercept 0.4 mg/eye and laser photocoagulation in infants with acute-phase ROP requiring treatment. METHODS: Infants (gestational age ≤32 weeks or birthweight ≤1500 g) with treatment-requiring ROP in ≥1 eye were randomized 2:1 to receive aflibercept 0.4 mg or laser photocoagulation at baseline in this 24-week, randomized, open-label, noninferiority, phase 3 study. Endpoints include concentrations of free and adjusted bound aflibercept in plasma, pharmacokinetic/pharmacodynamic exploration of systemic anti-vascular endothelial growth factor effects, and immunogenicity. RESULTS: Of 113 treated infants, 75 received aflibercept 0.4 mg per eye at baseline (mean chronological age: 10.4 weeks), mostly bilaterally (71 infants), and with 1 injection/eye (120/146 eyes). Concentrations of free aflibercept were highly variable, with maximum concentration at day 1, declining thereafter. Plasma concentrations of adjusted bound (pharmacologically inactive) aflibercept increased from day 1 to week 4, decreasing up to week 24. Six infants experienced treatment-emergent serious adverse events within 30 days of treatment; aflibercept concentrations were within the range observed in other infants. There was no pattern between free and adjusted bound aflibercept concentrations and blood pressure changes up to week 4. A low-titer (1:30), non-neutralizing, treatment-emergent anti-drug antibody response was reported in 1 infant, though was not clinically relevant. CONCLUSIONS: 24-week data suggest intravitreal aflibercept for treatment of acute-phase ROP is not associated with clinically relevant effects on blood pressure, further systemic adverse events, or immunogenicity. GOV IDENTIFIER: NCT04004208.

Intra-Anterior Chamber Injection of Ranibizumab in Advanced Pediatric Vitreoretinal Diseases.

Importance: Anti-vascular endothelial growth factor (VEGF) treatment through intravitreal or subretinal administrations has been proven effective for VEGF-driven pediatric vitreoretinal diseases but are not feasible for advanced cases, such as shallow traction retinal detachments or peripheral circumferential retinal detachments which adhere to the lens. Intra-anterior chamber injection (IAcI) of anti-VEGF may be a viable alternative in such cases but needs evaluation. Objective: To investigate the effects and safety of IAcI of anti-VEGF to treat VEGF-driven pediatric vitreoretinal diseases. Design, Setting, and Participants: This was a retrospective observational case series study conducted at Xinhua Hospital, affiliated with Shanghai Jiao Tong University School of Medicine in China. The study included 14 eyes of 13 children diagnosed with vitreoretinal disease exhibiting elevated vascular activity between January and August 2023. Intervention: IAcI with ranibizumab. Main Outcomes and Measures: Retinal vascular abnormalities, vitreous hemorrhage resolution, and complications 1 month and 3 months after injection. Results: Of 13 patients included in this study, 12 were male. The mean age was 4.6 years (range, 1 month to 9 years). Six patients were diagnosed with familial exudative vitreoretinopathy, 4 with morning glory syndrome, 1 with retinopathy of prematurity, and 2 with chronic retinal detachments of unknown causes. At 1-month postoperative follow-up, vascular activity had decreased in 14 of 14 eyes. At 3-month follow-up, vascular activity had resolved in 7 of 14 eyes, persisted in 6 of 14 eyes, and reactivated in 1 of 14 eyes. On final observation, no complications were reported. Conclusions and Relevance: These findings support the possibility of treatment using IAcI with ranibizumab to decrease retinal vascular abnormalities in familial exudative vitreoretinopathy or retinopathy of prematurity or related conditions, but further studies are needed to understand more precise benefits and risks. This approach might be considered in cases where intravitreal or subretinal injection are not feasible, recognizing the limitations of these findings and that longer-term outcomes still need to be monitored.

Management of Icteric Vitreous, Retinal Opacification, and Atypical Retinopathy of Prematurity.

A dichorionic, diamniotic twin born at 24-0/7 weeks and 740 g developed hyperbilirubinemia, necrotizing enterocolitis, and sepsis. Photographic imaging documented vitreous opacification, which was absent in the fellow twin. Retinal opacification was presumed secondary to embolic sepsis and responded to systemic antibiotics. Subsequent dropout of vascularized retina corresponded to areas of retinal opacification. Type 1 retinopathy of prematurity (ROP)-Zone I, Stage 3 ROP bilateral-demonstrated a rapid and durable response to off-label intravitreal bevacizumab 0.625 mg. Retinal opacification resolved between 39 and 40 weeks postmenstrual age. Systemic comorbidities may alter the appearance, course, and management of ROP. [Ophthalmic Surg Lasers Imaging Retina 2024;55:164-167.].

A pilot optical coherence tomography angiography classification of retinal neovascularization in retinopathy of prematurity.

Extraretinal neovascularization is a hallmark of treatment-requiring retinopathy of prematurity (ROP). Optical coherence tomography angiography (OCTA) offers vascular flow and depth information not available from indirect ophthalmoscopy and structural OCT, but OCTA is only commercially available as a tabletop device. In this study, we used an investigational handheld OCTA device to study the vascular flow in and around retinal neovascularization in seven preterm infants with treatment-requiring ROP and contrasted them to images of vascular flow in six infants of similar age without neovascular ROP. We showed stages of retinal neovascularization visible in preterm infants from 32 to 47 weeks postmenstrual age: Intraretinal neovascularization did not break through the internal limiting membrane; Subclinical neovascular buds arose from retinal vasculature with active flow through the internal limiting membrane; Flat neovascularization in aggressive ROP assumed a low-lying configuration compared to elevated extraretinal neovascular plaques; Regressed neovascularization following treatment exhibited decreased vascular flow within the preretinal tissue, but flow persisted in segments of retinal vessels elevated from their original intraretinal location. These findings enable a pilot classification of retinal neovascularization in eyes with ROP using OCTA, and may be helpful in detailed monitoring of disease progression, treatment response and predicting reactivation.

A Network Meta-Analysis of Success Rates following Low Dosage Anti-VEGF for Retinopathy of Prematurity.

PURPOSE: To search the low dosage of anti-VEGF best for primary therapies on retinopathy of prematurity (ROP) in terms of success rate. METHODS: We searched Medline(Pubmed), Embase, and Cochrane Central Register of Controlled Trials (CENTRAL) databases only for randomized controlled trials that had been reported as of March 3, 2023. We included studies that used bevacizumab, aflibercept and conbercept for ROP with comparable cohorts and treatment criteria. This study was performed according the pre-specified protocol registered with PROSPERO (CRD42021270077) and the Preferred Reporting Items for Systematic Reviews and Meta-Analysis checklist. Those with animal and cell experiments, non-randomized case-control, or single case report were excluded. Frequentist network meta-analyses determined the surface under the cumulative ranking (SUCRA) of the success rate of each dose range group and compared pairs of treatments via STATA 15. RESULT: Since non-RCT research were excluded, aflflibercept and conbercept studies were excluded. Therefore, only 6 bevacizumab studies were included in final meta-analysis: Inconsistency was not detected in this study via global inconsistent model test, loop inconsistency and local inconsistent model test (p > 0.05). In addition, a consistent model test has been passed in this study (p > 0.05). Little bias was detected via funnel plot. Since bevacizumab adult standard dose of single-injection is 1.25 mg, the concentration groups were converted according to the proportion of adult standard dose, such as 1/2, [1/5, 1/6.25], [1/10, 1/12.5], [1/19.8, 1/78.1], [1/156.3, 1/625]. The SUCRA of [1/10, 1/12.5] dose group were the best of largest probability to achieve success. However, [1/156.3, 1/625] dose group was the worst dose to achieve success in the five dose groups. The success rate ranking of league chart in this study is that [1/10, 1/12.5] > [1/5, 1/6.25] > 1/2 ≈ [1/19.8, 1/78.1] > [1/156.3, 1/625]. CONCLUSIONS: [1/10, 1/12.5] were the best dosage ranges to achieve maximal medicine success. [1/156.3, 1/625] was the worst ineffective in the five dose ranges.

Retinal blood flow velocities in infants with retinopathy of prematurity after intravitreal administration of bevacizumab.

BACKGROUND/OBJECTIVES: Progression of retinopathy of prematurity (ROP) is associated with increased retinal blood flow velocities. We investigated changes of central retinal arterial and venous blood flow after intravitreal administration of bevacizumab. SUBJECTS/METHODS: Prospective observational study using serial ultrasound Doppler imaging in preterm infants with bevacizumab-treated ROP. Eyes were examined 1 [0-2] days before injection (median [interquartile range]), and at three time points after injection (1 [1-2] days, 6 [3-8] days, and 17 [9-28] days). Preterm infants with ROP stage 2 displaying spontaneous regression served as controls. RESULTS: In 21 eyes of 12 infants with bevacizumab-treated ROP, peak arterial systolic velocity declined from 13.6 [11.0-16.3] cm/s prior to intravitreal bevacizumab to 11.2 [9.4-13.9] cm/s, 10.6 [9.2-13.3] cm/s and 9.3 [8.2-11.0] cm/s at discharge (p = .002). There was also a decline of the arterial velocity time integral (from 3.1 [2.3-3.9] cm to 2.9 [2.4-3.5], 2.7 [2.3-3.2] cm and 2.2 [2.0-2.7], p = .021) and mean velocity in the central retinal vein (from 4.5 [3.6-5.8] cm/s to 3.7 [2.6-4.1] cm/s, 3.5 [3.0-4.3] cm/s, and 3.2 [2.8-4.6] cm/s, p = .012). Arterial end-diastolic velocity and resistance index remained unchanged. Blood flow velocities in bevacizumab-treated eyes examined before injection were significantly higher than those measured in untreated eyes that ultimately showed spontaneous regression of ROP. Sequential examinations in these controls did not reveal any declines of retinal blood flow velocities. CONCLUSION: Increased retinal arterial and venous blood flow velocities in infants with threshold ROP decline following intravitreal bevacizumab injection.

Evaluation of optical coherence tomography biomarkers to differentiate favourable and unfavourable responders to intravitreal anti-vascular endothelial growth factor treatment in retinopathy of prematurity.

OBJECTIVE: Evaluation of optical coherence tomography biomarkers in predicting treatment response to intravitreal injection of anti-vascular endothelial growth factor (anti-VEGF) Bevacizumab, in aggressive retinopathy of prematurity (A-ROP). METHODS: Non-contact ultra-widefield (NC-UWF) fundus imaging with integrated UWF guided swept source Optical coherence tomography (SS-OCT) was performed prospectively in preterm babies before and after intravitreal anti-VEGF (Bevacizumab) monotherapy. OCT biomarkers were analysed in eyes that reached complete vascularization versus others. RESULTS: Eyes with retinal vessels reaching near ora serrata were labelled as regressed ROP and vascularised retina (Group1). Eyes with reactivation of ROP needing laser or vitreoretinal surgery or eyes with peripheral avascular retina (PAR) at 16th week post-injection were considered as Group 2. Pre-injection baseline OCT showed a hyperreflectivity of inner retinal layers in 12 out of 46 eyes in Group 1 versus 30 out of 34 eyes in Group 2 (p value 0.002). None of the eyes in Group 1 showed choroidal thinning at posterior pole as compared to 14 out of 34 eyes in Group 2 (p value 0.001). Intraretinal hypo reflective Cystic changes at fovea were seen in 16 out of 46 eyes in Group 1 and 2 out of 34 eyes in Group 2 (p value 0.012). CONCLUSION: Pre-injection swept source OCT biomarkers could predict the treatment outcomes of anti-VEGF (Bevacizumab) monotherapy in A-ROP eyes. Hyperreflectivity of inner retinal layers and choroidal thinning had poorer and unpredictable response to anti-VEGF injection whereas, cystic changes at fovea predicted favourable response.

Role of mammalian target of rapamycin in the formation and progression of retinopathy of prematurity-like vascular abnormalities in neonatal rats.

Retinopathy of prematurity (ROP), a retinal disease that can occur in premature infants, can lead to severe visual impairment. In this study, we examined the preventive and therapeutic effects of mammalian target of rapamycin complex 1 (mTORC1) inhibition on abnormal retinal blood vessels in a rat model of ROP. To induce ROP-like vascular abnormalities, rats were subcutaneously treated with KRN633, an inhibitor of vascular endothelial growth factor (VEGF) receptor tyrosine kinase, on postnatal day 7 (P7) and P8. KRN633-treated (ROP) rats were treated subcutaneously with the mTORC1 inhibitor rapamycin according to preventive and therapeutic protocols, i.e., from P11 to P13 (P11-P13) and from P14 to P20 (P14-P20), respectively. To compare with the effects of VEGF inhibition, KRN633 was administered according to similar protocols. Changes in retinal vasculature, phosphorylated ribosomal protein S6 (pS6), a downstream indicator of mTORC1 activity, and the proliferative status of vascular cells were evaluated at P14 and P21 using immunohistochemistry. Rapamycin treatment from P11 to P13 prevented increases in arteriolar tortuosity, capillary density, and the number of proliferating vascular cells, and eliminated pS6 immunoreactivity in ROP rats. KRN633 treatment at P11 and P12 (P11/P12) also prevented the appearance of ROP-like retinal blood vessels. Rapamycin treatment from P14 to P20 failed to attenuate arteriolar tortuosity but prevented increases in capillary density and proliferating vascular cell number at the vascular front, but not at the central zone. KRN633 treatment from P14 to P20 significantly reduced abnormalities in the retinal vasculature; however, the effects were inferior to those of KRN633 treatment on P11/P12. These results suggest that activation of the mTORC1 pathway in proliferating endothelial cells contributes to the appearance and progression of ROP-like retinal blood vessels. Therefore, inhibition of mTORC1 may be a promising approach for selectively targeting abnormal retinal blood vessels in ROP.