Morphovascular changes after anti-VEGF intravitreal injection for a choroidal neovascularization secondary to COVID-19 infection in a pediatric patient.

Choroidal neovascularization (CNV) is a common pathologic lesion that occurs in various chorioretinopathy. Although the incidence of CNV is quite rare in children and adolescents, these lesions have a severe impact on visual acuity and quality of life over patients' lifetime. The management of CNV in pediatric patients is challenging, clear guidelines are limited due to a lack of randomized clinical trials. However, the more promising option is the use of vascular endothelial growth factor (VEGF) inhibitors. We reported a case of recurrent idiopathic choroidal neovascularization in a healthy pediatric patient after COVID 19 infection. Optical coherence tomography angiofraphy (OCTA) showed, in a non invasive way, a choroidal neovascularization at the posterior pole including macula and superior temporal arcade in the right eye, while the left eye was unaffected. In order to inactivate the neovascularization, intravitreal injections of anti-VEGF (Lucentis-Ranibizumab 0.3 mL) were performed in the right eye. Six months after the injections BCVA of the right eye was improved from 0.7 logMAR to 0.2 logMAR. OCT-A examination did not detect any signs of attivation of the preexistent neovascularization. It is reasonable to assert that Anti-VEGF could be the main treatment in case of choroidal neovascularization in young patients after COVID 19 infection due to the high chorioretinal level of VEGF-A described in these diseases.

Multiple Evanescent White Dot Syndrome and Choroidal Neovascularization following SARS-COV-2 Infection in a Patient on Dabrafenib and Trametinib.

PURPOSE: to describe multimodal imaging and electrophysiology of multiple evanescent white dot syndrome (MEWDS) concomitant with COVID-19 infection in a patient on BRAF (B Rapidly Accelerated Fibrosarcoma) and MEK (Mitogen-activated Protein Kinase) inhibitors. METHODS: observational case report and literature review. RESULTS: a 37-year-old woman affected by cutaneous melanoma on BRAF and MEK inhibitors developed visual symptoms in the right eye simultaneously with a SARS-COV-2 infection. The right eye visual acuity was hand movement, and clinical examination disclosed vitreous cells, yellow-white retinal spots, and macular yellowish material. Fundus autofluorescence and angiograms were consistent with MEWDS. Angiograms, optical coherence tomography, and optical coherence tomography angiography revealed a macular choroidal neovascular membrane. The infectious and inflammatory work-up was negative. Electrodiagnostic tests revealed cone dysfunction. MEWDS resolved and anti-VEGF treatment allowed partial vision recovery. CONCLUSION: the case illustrates the association of MEWDS and choroidal neovascularization developing after COVID-19 infection in the setting of immunotherapy.

Analyzing the effect of the COVID-19 pandemic on patient outcomes following keratorefractive surgery

Purpose : To evaluate the impact of the COVID-19 pandemic on keratorefractive surgery outcomes by comparing rates of post-operative complications prior to and during the pandemic. Methods : A retrospective cohort study was conducted using TriNetX (Cambridge, MA, USA), a federated electronic health records research network comprising multiple large health organizations in the United States. Patients were identified based on using validated CPT procedure codes for keratorefractive Surgery and were separated into two cohorts based on if they received their procedure before the pandemic protocols (Jan 1, 2019-Mar 17, 2020) or during the pandemic (Mar 18, 2020 to Dec 1, 2020). Then, 1:1 propensity score matching was utilized to create two same-sized cohorts which matched for various demographic and medical conditions. Subsequently, the relative risk for 11 specific post-operative complications between was compared between the two cohorts. Relative risks between cohorts were calculated and outcomes with p<0.05 were considered statistically significant. Results : A total of 2,626 patients were included in analysis with 1,313 in each of the prepandemic and pandemic cohorts after propensity matching. Dry eye had a greater risk (RR 1.29;95 Cl, 0.94, 1.77) among the pandemic cohort, however the results were not statically significant (P>0.113). Similarly, retinal detachment was observed to have a lower risk (RR 0.83;95% Cl, 0.36, 1.92) among the pandemic cohort but the results were not statistically significant either (P >0.663). No statistically significant differences in the remaining post-operative complications were observed including recurrent corneal erosion, secondary corneal erosion, corneal scar/opacity, diffuse lamellar keratitis, corneal neovascularization, vitreous degeneration and hemorrhage, retinal edema, and cystoid macular degeneration. Conclusions : The COVID-19 pandemic undoubtedly affected surgical practice of many ophthalmologists, and many operating rooms adopted new protocols after safety concerns for surgeons and ancillary staff. The results show that there was no statistically significant difference in the rate of post-operative complications for patients undergoing keratorefractive surgery before and during the pandemic. This suggests that despite the new safety protocols implemented in operating rooms, the quality-of-care patients received during the pandemic was not impacted.

COVID-19 is a risk factor for retinal vein occlusion in younger patients?

Retinal vein occlusions (RVOs) are thought to have more favorable outcomes in patients under-50 due to spontaneous regression. However, 20% develop severe neovascularization. In most cases, the causal link of occlusion remains elusive. Some authors report on clinical presentations typical for RVOs in the COVID-19 infection due to hypercoagulation. Management of younger patients with RVO required a complex diagnostic approach to assess systemic risk factors and obligatory evaluation of baseline retinal ischemia using fluorescein angiography (FA) or optical coherence tomography angiography (OCTA). Clinical criteria of escalating retinal ischemia are decreased central visual acuity, macular edema, increased area of ischemia, and (later) retinal and/or anterior segment neovascularization. We describe a young man with RVO after the COVID-19 infection. The COVID-19 infection had no significant effect on hemostasis parameters in this patient. Meanwhile, the COVID-19 infection cannot be ruled out as an aggravating factor in a patient with a genetic predisposition to (micro)vascular occlusions. © 2022, Medicine-Inform LLC. All rights reserved.

Intraocular injection of KH902 alleviates retinal hypoxia in a mouse model of oxygen-induced retinopathy

Inhibition of vascular endothelial growth factor (VEGF) has been widely applied in anti-neovascularization therapies. As a novel anti-VEGF agent, KH902 (conbercept) is designed to restrain pathological angiogenesis. However, the effects of KH902 on retinal hypoxia have not been well studied. In a mouse model of oxygen-induced retinopathy (OIR), we assessed retinal hypoxia at postnatal days 14 (P14) and P17, as well as retinal neovascularization (RNV) at P17. In addition, we evaluated the protein level of VEGF and galectin-1 (Gal-1). Changes of the neuroretinal structure were also examined. Our results indicated that KH902 could remit retinal hypoxia in OIR at P14 and P17, which was an exciting novel finding for KH902 function. Additionally, we confirmed that KH902 markedly reduces RNV. Our results indicated that administration of KH902 downregulated VEGF expression, as well as Gal-1. Damage of neuroretinal structure after KH902 injection was not observed, which was also an encouraging result. Our study suggests that KH902 plays a role in alleviating retinal hypoxia and that it could be used for the treatment of other ncovascular ocular diseases.

Covid-19 Impact on Macular Neovascularization and Retinal Vein Occlusion Treatment: Single-Center Experience.

PURPOSE: The aim of this study was to evaluate whether the coronavirus disease 19 (COVID-19) pandemic resulted in undertreatment and subsequent loss of visual acuity (VA) in patients with macular neovascularization (MNV) or retinal vein occlusion (RVO) regularly treated with intravitreal antivascular endothelial growth factor injections. METHODS: Single-center, retrospective study of patients scheduled for treatment between March 19 and June 1, 2020, the national mandatory quarantine period. Patients' demographics, VA, and scheduled treatment during this period were reviewed via medical records. All patients were analyzed regarding treatment attendance rates. The visual impact of COVID-19 was assessed in patients who had been treated and presented a stable VA for >6 months before the beginning of the quarantine. RESULTS: This study included 927 eyes from 769 patients. The attendance rate increased throughout the study timeframe (p < 0.001) and correlated negatively with higher patient's age (r = -0.142; p = 0.005). Patients with age-related macular degeneration (67.6%) had lower attendance rates (p = 0.007) and were older (p < 0.001). The visual impact analysis included 400 eyes from 325 patients. The average VA variation throughout this period was -1.7 ± 8.4 ETDRS letters and was similar in different retinal pathologies (p = 0.334). VA variation did not correlate with the number of missed treatments per patient (r = 0.100; p = 0.150). The prevalence of subretinal fluid and intraretinal fluid, as well as central retinal thickness decreased significantly throughout the study period (p values of <0.001, <0.001, and 0.032, respectively). CONCLUSION: The COVID-19 pandemic had a significant impact on the attendance rate of patients with MNV or RVO to their scheduled treatments, which was higher in the first week of mandatory quarantine. Nevertheless, VA did not decrease significantly during this period, with a limited VA variation regardless of primary retinal disorder and morphological parameters even improved in the eyes included in the visual impact analysis.

Update on Optical Coherence Tomography and Optical Coherence Tomography Angiography Imaging in Proliferative Diabetic Retinopathy.

Proliferative diabetic retinopathy (PDR) is a major cause of blindness in diabetic individuals. Optical coherence tomography (OCT) and OCT-angiography (OCTA) are noninvasive imaging techniques useful for the diagnosis and assessment of PDR. We aim to review several recent developments using OCT and discuss their present and potential future applications in the clinical setting. An electronic database search was performed so as to include all studies assessing OCT and/or OCTA findings in PDR patients published from 1 January 2020 to 31 May 2021. Thirty studies were included, and the most recently published data essentially focused on the higher detection rate of neovascularization obtained with widefield-OCT and/or OCTA (WF-OCT/OCTA) and on the increasing quality of retinal imaging with quality levels non-inferior to widefield-fluorescein angiography (WF-FA). There were also significant developments in the study of retinal nonperfusion areas (NPAs) using these techniques and research on the impact of PDR treatment on NPAs and on vascular density. It is becoming increasingly clear that it is critical to use adequate imaging protocols focused on optimized segmentation and maximized imaged retinal area, with ongoing technological development through artificial intelligence and deep learning. These latest findings emphasize the growing applicability and role of noninvasive imaging in managing PDR with the added benefit of avoiding the repetition of invasive conventional FA.

Mesenchymal stem cells from different sources show distinct therapeutic effects in hyperoxia-induced bronchopulmonary dysplasia in rats.

Mesenchymal stem cells (MSCs) have been shown as an effective medicinal means to treat bronchopulmonary dysplasia (BPD). The widely used MSCs were from Wharton's jelly of umbilical cord (UC-MSCs) and bone marrow (BM-MSCs). Amniotic fluid MSCs (AF-MSCs) may be produced before an individual is born to treat foetal diseases by autoplastic transplantation. We evaluated intratracheal (IT) MSCs as an approach to treat an hyperoxia-induced BPD animal model and compared the therapeutic effects between AF-, UC- and BM-MSCs. A BPD animal model was generated by exposing newborn rats to 95% O2 . The continued stress lasted 21 days, and the treatment of IT MSCs was conducted for 4 days. The therapeutic effects were analysed, including lung histology, level of inflammatory cytokines, cell death ratio and state of angiogenesis, by sacrificing the experimental animal at day 21. The lasting hyperoxia stress induced BPD similar to the biological phenotype. The treatment of IT MSCs was safe without deaths and normal organ histopathology. Specifically, the treatment was effective by inhibiting the alveolar dilatation, reducing inflammatory cytokines, inducing angiogenesis and lowering the cell death ratio. AF-MSCs had better therapeutic effects compared with UC-MSCs in relieving the pulmonary alveoli histological changes and promoting neovascularization, and UC-MSCs had the best immunosuppressive effect in plasma and lung lysis compared with AF-MSCs and BM-MSCs. This study demonstrated the therapeutic effects of AF-, UC- and BM-MSCs in BPD model. Superior treatment effect was provided by antenatal MSCs compared to BM-MSC in a statistical comparison.

Systemic dendrimer nanotherapies for targeted suppression of choroidal inflammation and neovascularization in age-related macular degeneration.

Inflammation and neovascularization are key pathological events in human age-related macular degeneration (AMD). Activated microglia/macrophages (mi/ma) and retinal pigmented epithelium (RPE) play an active role in every stage of disease progression. Systemic therapies that can target these cells and address both inflammation and neovascularization will broaden the impact of existing therapies and potentially open new avenues for early AMD where there are no viable therapies. Utilizing a clinically relevant rat model of AMD that mirrors many aspects that of human AMD pathological events, we show that systemic hydroxyl-terminated polyamidoamine dendrimer-triamcinolone acetonide conjugate (D-TA) is selectively taken up by the injured mi/ma and RPE (without the need for targeting ligands). D-TA suppresses choroidal neovascularization significantly (by >80%, >50-fold better than free drug), attenuates inflammation in the choroid and retina, by limiting macrophage infiltration in the pathological area, significantly suppressing pro-inflammatory cytokines and pro-angiogenic factors, with minimal side effects to healthy ocular tissue and other organs. In ex vivo studies on human postmortem diabetic eyes, the dendrimer is also taken up into choroidal macrophages. These results suggest that the systemic hydroxyl dendrimer-drugs can offer new avenues for therapies in treating early/dry AMD and late/neovascular AMD alone, or in combination with current anti-VEGF therapies. This hydroxyl dendrimer platform but conjugated to a different drug is undergoing clinical trials for severe COVID-19, potentially paving the way for faster clinical translation of similar compounds for ocular and retinal disorders.

Intravitreal injections of anti-VEGF agents during COVID-19 pandemic: clinical audit from Tanta University Hospital.

BACKGROUND: The aims of this study were to provide real-life data about the effect of COVID-19 pandemic on the practice of anti-VEGF injections and to evaluate the safety of the modifications in the injection protocol imposed during the ongoing pandemic on the anatomical and functional outcome of patients. METHODS: All patients attending Tanta University hospital for receiving intravitreal anti-VEGF injections were screened. Patients who were previously deferred according to a modified protocol implemented in the hospital in response to the pandemic or who demonstrated deviation from it were included for further analysis. RESULTS: During the audit period, 83 patients attending for anti-VEGF injections were screened, of whom 40 met the abovementioned criteria and were included for analysis. In the deferred subgroup (11 eyes), predeferral mean values of logMAR best corrected visual acuity (BCVA) and central retinal subfield thickness (CST) were 1 ± 0.23 and 444.57 ± 200.1 µm, respectively. There was no significant change when the patients returned for their deferred injections, with the mean BCVA and CST values being 0.8 ± 0.22 and 413.71 ± 237.7 µm, respectively (p = 0.27 and p = 0.12). Moreover, 29 patients encountered a disturbed injection schedule, particularly skipping their injection appointments due to infection fear as found in 18 patients. CONCLUSION: The COVID-19 pandemic has imposed pressing challenges in maintaining essential health care while ensuring the prevention of spread of infection. Although the modified injection protocol confirmed to be safe for patients, the pandemic caused deflection from the optimum practice in the form of successive skipping of appointments and delays in the processing of patient injection schedules.

Mesenchymal stem cell research progress for the treatment of COVID-19.

At the end of 2019, novel coronavirus (COVID-19) infection was detected in Wuhan City, Hubei Province, China. The COVID-19 infection characteristics include a long incubation period, strong infectivity, and high fatality rate, and it negatively affects human health and social development. COVID-19 has become a common problem in the global medical and health system. It is essentially an acute self-limiting disease. Patients with severe COVID-19 infection usually progress to acute respiratory distress syndrome, sepsis, metabolic acidosis that is difficult to correct, coagulation dysfunction, multiple organ failure, and even death within a short period after onset. There remains a lack of effective drugs for such patients clinically. Mesenchymal stem cells (MSCs) are expected to reduce the risk of complications and death in patients because they have strong anti-inflammatory and immunomodulatory capabilities, which can improve the microenvironment, promote neovascularization, and enhance tissue repair capabilities. China is currently conducting several clinical trials on MSCs for the treatment of COVID-19. Here, we review the research progress related to using stem cells to treat patients with COVID-19.