The acute and chronic effects of intravitreal anti-vascular endothelial growth factor injections on intraocular pressure: A review

The Development of a Novel Aflibercept Formulation for Ocular Delivery

Aflibercept is a recombinant fusion protein that is commercially available for several ocular diseases impacting millions of people worldwide. Here, we use a case study approach to examine alternative liquid formulations for aflibercept for ocular delivery, utilizing different stabilizers, buffering agents, and surfactants with the goal of improving the thermostability to allow for limited storage outside the cold chain. The formulations were developed by studying the effects of pH changes, substituting amino acids for sucrose and salt, and using polysorbate 80 or poloxamer 188 instead of polysorbate 20. A formulation containing acetate, proline, and poloxamer 188 had lower rates of aggregate formation at 4, 30, and 40°C when compared to the marketed commercial formulation containing phosphate, sucrose, sodium chloride, and polysorbate 20. Further studies examining subvisible particles after exposure to a transport stress and long-term stability at 4°C, post-translational modifications by multi-attribute method, purity by reduced and non-reduced capillary electrophoresis, and potency by cell proliferation also demonstrated a comparable or improved stability for the enhanced formulation of acetate, proline, and poloxamer 188. This enhanced stability could enable limited storage outside of the cold chain, allowing for easier distribution in low to middle income countries.

Exploring the Spectrum of VEGF Inhibitors' Toxicities from Systemic to Intra-Vitreal Usage in Medical Practice

The use of Vascular Endothelial Growth Factor inhibitors (VEGFi) has become prevalent in the field of medicine, given the high incidence of various pathological conditions necessitating VEGF inhibition within the general population. These conditions encompass a range of advanced neoplasms, such as colorectal cancer, non-small cell lung cancer, renal cancer, ovarian cancer, and others, along with ocular diseases. The utilization of VEGFi is not without potential risks and adverse effects, requiring healthcare providers to be well-prepared for identification and management. VEGFi can be broadly categorized into two groups: antibodies or chimeric proteins that specifically target VEGF (bevacizumab, ramucirumab, aflibercept, ranibizumab, and brolucizumab) and non-selective and selective small molecules (sunitinib, sorafenib, cabozantinib, lenvatinib, regorafenib, etc.) designed to impede intracellular signaling of the VEGF receptor (RTKi, receptor tyrosine kinase inhibitors). The presentation and mechanisms of adverse effects resulting from VEGFi depend primarily on this distinction and the route of drug administration (systemic or intra-vitreal). This review provides a thorough examination of the causes, recognition, management, and preventive strategies for VEGFi toxicities with the goal of offering support to oncologists in both clinical practice and the design of clinical trials.

[Topical application of hypotensive drugs for the prevention of intraocular pressure elevation after intravitreal injections of anti-VEGF drugs]

The management protocol for patients with neovascular age-related macular degeneration (nAMD) involves multiple intravitreal injections (IVI) of anti-VEGF drugs. The ability to reduce the peak intraocular pressure (IOP) rise is greatly important in clinical practice.

PURPOSE

This study evaluates the effect of topical hypotensive drugs on the short-term IOP rise after IVI of anti-VEGF drugs in patients with nAMD.

MATERIAL AND METHODS

The prospective study included 80 patients with newly diagnosed nAMD. Before the start of treatment, the patients were divided into 4 groups of 20 people each: 1st - controls, who received no prophylactic drugs, in the 2nd, 3rd and 4th groups local instillations of one drop of hypotensive drugs brinzolamide 1%, brinzolamide-timolol, brimonidine-timolol were performed in the conjunctival sac twice: 1 day before the injection (at 20:00) and on the day of the injection 2 hours before the manipulation (at 08:00), respectively. IOP was measured in each patient using ICare Pro non-contact tonometer before injection, as well as 1 min, 30 and 60 min after injection.

RESULTS

Prophylactic use of hypotensive drugs was associated with a significant decrease in IOP immediately after IVI compared to the same parameter in the 1st group (p<0.001), the maximum decrease in IOP values was observed when using a fixed combination of brimonidine-timolol by 12.1 mm Hg compared to the controls (p<0.001), the combination of brinzolamide-timolol reduced IOP by 8.5 mm Hg (p<0.001), brinzolamide 1% led to the smallest decrease in IOP - by 5.1 mm Hg (p<0.001).

CONCLUSION

Study patients that received instillations of brimonidine-timolol combination of one drop into the conjunctival sac 1 day before the injection and on the day of the injection showed the maximum decrease in IOP compared to patients of the other groups.

Immediate effect of anti-VEGF injections on optic nerve head: Correlation between intraocular pressure and anatomical peripapillary changes

PURPOSE

This study was designed to investigate retinal nerve fiber layer (RNFL) and radial peripapillary capillaries (RPC) changes on optical coherence tomography (OCT) angiography and OCT thickness alterations associated with acutely increased intraocular pressure after intravitreal injections.

METHODS

This observational clinical study was conducted on 35 eyes (35 patients) with treatment-naïve age-related macular degeneration (AMD) and type 1 or type 2 MNV were enrolled. All patients underwent anti-vascular endothelial grow factor (VEGF) intravitreal injections with 0.05-mL aflibercept (2 mg) between January 2022 and October 2022. Peripapillary OCT angiography perfusion density, retinal nerve fiber layer thickness, and intraocular pressure (IOP) were measured before and immediately after intravitreal injections. In particular, the analysis was performed at the following visits: (T0) 5 to 15 min before the injection of aflibercept; (T1) 2 to 5 min after the injection of aflibercept. Paired t-test was used to compare pre-injection and post-injection values.

RESULTS

The mean baseline IOP (T0) value was 17.26 ± 2.4 mmHg and the immediate post-injection IOP (T1) mean value was 34.7 ± 11.50 mmHg (P < 0.01). The mean global RNFL thickness before and immediately after the injection was 100.9 ± 18.8 m and 98.6 ± 17.4 m (P = 0.001). Furthermore, the topographical RNFL analysis showed significant thickness reduction of the nasal and inferior sectors after the procedure when compared to T0 (P = 0.046 and P = 0.001). On the contrary, the mean RCP density changes at T1 did not reach statistically significant (P = 0.636). Furthermore, we found a significant negative correlation between the retinal nerve fiber layer global thickness and the IOP changes (Pearson's correlation = -0.126; P = 0.031). In particular, the nasal RNFL region showed a significant negative correlations with IOP values (Pearson's correlation = -0.198, P = 0,046).

CONCLUSIONS

We reported acute IOP changes that are associated with reduced RNFL thickness in a group of patients undergoing intravitreal injections of anti-VEGF drugs for neovascular age-related macular degeneration. Moreover, topographical sub-analysis revealed that the nasal RNFL region is most prone to IOP fluctuations. This finding may explain the sudden visual acuity change in patients immediately after injection and may sustain injuries to optic nerve head structures producing glaucomatous damage.

Research progress of VEGFR small molecule inhibitors in ocular neovascular diseases

Angiogenesis is the biological process in which existing blood vessels generate new ones and it is essential for body growth and development, wound healing, and granulation tissue formation. Vascular endothelial growth factor receptor (VEGFR) is a crucial cell membrane receptor that binds to VEGF to regulate angiogenesis and maintenance. Dysregulation of VEGFR signaling can lead to several diseases, such as cancer and ocular neovascular disease, making it a crucial research area for disease treatment. Currently, anti-VEGF drugs commonly used in ophthalmology are mainly four macromolecular drugs, Bevacizumab, Ranibizumab, Conbercept and Aflibercept. Although these drugs are relatively effective in treating ocular neovascular diseases, their macromolecular properties, strong hydrophilicity, and poor blood-eye barrier penetration limit their efficacy. However, VEGFR small molecule inhibitors possess high cell permeability and selectivity, allowing them to traverse and bind to VEGF-A specifically. Consequently, they have a shorter duration of action on the target, and they offer significant therapeutic benefits to patients in the short term. Consequently, there is a need to develop small molecule inhibitors of VEGFR to target ocular neovascularization diseases. This review summarizes the recent developments in potential VEGFR small molecule inhibitors for the targeted treatment of ocular neovascularization diseases, with the aim of providing insights for future studies on VEGFR small molecule inhibitors.

Immediate Rise in Intraocular Pressure After First-Time Intravitreal Injection of Bevacizumab

Objective This study aims to report an immediate change in intraocular pressure (IOP) after the first injection of bevacizumab. Materials and methods An interventional case series was carried out at Isra Postgraduate Institute of Ophthalmology, Al-Ibrahim Eye Hospital, Karachi, from November 2018 to April 2020. All patients with various chorioretinal diseases requiring anti-VEGF treatment were included in the study. Patients with a history of previous anti-VEGF or steroid injections and personal or family history of glaucoma were excluded. Bevacizumab in a dose of 1.25 mg (0.05 ml) was injected intravitreally under topical anesthesia maintaining sterile aseptic conditions in the operating room. IOP was checked one hour prior to the injection, and hourly monitoring of it was continued for the next six hours. Data were analyzed using SPSS Statistics to compare the mean IOP readings before and after injection. Results A total of 191 eyes of 147 patients were included in the study. Among them, 92 (62.58%) were male and 55 (37.41%) were female with a mean age of 45.5 ± 8.8 years. The mean pre-injection IOP was measured as 12.12 ± 2.11 mmHg. The frequency of IOP elevation of ˃ 21 mmHg was observed in 169 (88.5%) eyes at five minutes, 104 (54.5%) eyes at 30 minutes, 33 (17.3%) eyes at one hour, and 16 (8.4%) eyes at two hours. The raised mean post-operative IOP was 30.44 ± 6.53 mmHg at five minutes, 26.27 ± 4.65 mmHg at 30 minutes, 26.12 ± 3.31 mmHg at one hour, and 25.63 ± 3.03 mmHg at two hours. The IOP reduced to pre-injection value at three hours measuring 12.12 ± 2.11 mmHg and continued to stay at that level for the next three hours. Conclusions The majority of the eyes receiving first-time intravitreal bevacizumab injection showed a significant increase in IOP level within five minutes to two hours post-injection.

JP1, a polypeptide specifically targeting integrin αVβ3, ameliorates choroidal neovascularization and diabetic retinopathy in mice

Anti-vascular endothelial growth factor (VEGF) drugs have revolutionized the treatment of neovascular eye diseases, but responses are incomplete in some patients. Recent evidence shows that integrins are involved in the pathogenesis of neovascular age-related macular degeneration and diabetic retinopathy. JP1, derived from an optimized seven-amino-acid fragment of JWA protein, is a polypeptide specifically targeting integrin αVβ3. In this study we evaluated the efficacy of JP1 on laser-induced choroidal neovascularization (CNV) and retinal vascular leakage. CNV mice received a single intravitreal (IVT) injection of JP1 (10, 20, 40 µg) or ranibizumab (RBZ, 10 µg). We showed that JP1 injection dose-dependently inhibited laser-induced CNV; the effect of RBZ was comparable to that of 20 µg JP1; a combined IVT injection of JP1 (20 μg) and RBZ (5 μg) exerted a synergistic effect on CNV. In the 3rd month after streptozotocin injection, diabetic mice receiving IVT injection of JP1 (40 µg) or RBZ (10 µg) once a week for 4 weeks showed significantly suppressed retinal vascular leakage. In both in vivo and in vitro experiments, JP1 counteracted oxidative stress and inflammation via inhibiting ROS/NF-κB signaling in microglial cells, and angiogenesis via modulating MEK1/2-SP1-integrin αVβ3 and TRIM25-SP1-MMP2 axes in vascular endothelial cells. In addition, intraperitoneal injection of JP1 (1, 5 or 10 mg) once every other day for 3 times also dose-dependently inhibited CNV. After intraperitoneal injection of FITC-labeled JP1 (FITC-JP1) or FITC in laser-induced CNV mice, the fluorescence intensity in the CNV lesion was markedly increased in FITC-JP1 group, compared with that in FITC group, confirming that JP1 could penetrate the blood-retinal barrier to target CNV lesion. We conclude that JP1 can be used to design novel CNV-targeting therapeutic agents that may replace current invasive intraocular injections.

Tunable degrees of neurodegeneration in rats based on microsphere-induced models of chronic glaucoma

This study compares four different animal models of chronic glaucoma against normal aging over 6 months. Chronic glaucoma was induced in 138 Long-Evans rats and compared against 43 aged-matched healthy rats. Twenty-five rats received episcleral vein sclerosis injections (EPIm cohort) while the rest were injected in the eye anterior chamber with a suspension of biodegradable microspheres: 25 rats received non-loaded microspheres (N-L Ms cohort), 45 rats received microspheres loaded with dexamethasone (MsDexa cohort), and 43 rats received microspheres co-loaded with dexamethasone and fibronectin (MsDexaFibro cohort). Intraocular pressure, neuroretinal function, structure and vitreous interface were evaluated. Each model caused different trends in intraocular pressure, produced specific retinal damage and vitreous signals. The steepest and strongest increase in intraocular pressure was seen in the EPIm cohort and microspheres models were more progressive. The EPIm cohort presented the highest vitreous intensity and percentage loss in the ganglion cell layer, the MsDexa cohort presented the greatest loss in the retinal nerve fiber layer, and the MsDexaFibro cohort presented the greatest loss in total retinal thickness. Function decreased differently among cohorts. Using biodegradable microspheres models it is possible to generate tuned neurodegeneration. These results support the multifactorial nature of glaucoma based on several noxa.

Morphological and Functional Assessment of the Optic Nerve Head and Retinal Ganglion Cells in Dry vs Chronically Treated Wet Age-Related Macular Degeneration

Purpose

The aim of the study comprised the anatomical and functional assessment of the optic nerves and macular ganglion cells in the population of patients with unilateral wet age-related macular degeneration (wAMD) and comparison of its results to those obtained from the fellow eye with non-advanced dry age-related macular degeneration (dAMD). Furthermore, we aimed to determine if the number of administered injections contributed to the potential differences between the examined eyes.

Methods

The study was based on 104 eyes of 52 patients in a cross-sectional study. The eyes with chronically treated wAMD were the main subject of the study, while fellow eyes affected with non-advanced dAMD served as the control group. Primary morphological outcomes comprised differences in peripapillary retinal nerve fiber layer (RNFL) and GCC layers between the studied groups (treated and control). In turn, primary functional outcomes included differences in implicit times and amplitudes of the P100 wave of pattern visual evoked potentials (PVEP) and N95 wave of pattern electroretinogram (PERG) between treated and control groups.

Results

We did not find any differences in total RNFL thickness between wAMD and dAMD groups. The number of injections only affected the RNFL in the nasal quadrant of the optic disc (p = 0.023). We did not find any differences regarding GCL thickness in both groups. In the study group, a longer implicit time of the P100 of PVEP (p = 0.014) and a shorter amplitude of the P50-N95 wave of PERG (p = 0.005) were detected. The total number of injections had no significant effect on these two values.

Conclusion

We detected worse functional parameters of the optic nerve and retinal ganglion cells in eyes with wAMD, with lack of significant differences in anatomical (RNFL, GCL) parameters compared to the control group. However, the number of injections did not contribute to the differences found.

miR-125a-5p attenuates macrophage-mediated vascular dysfunction by targeting Ninjurin1

Ninjurin1 (Ninj1), an adhesion molecule, regulates macrophage function in hyaloid regression, multiple sclerosis, and atherosclerosis. However, its biological relevance and the mechanism underlying its function in vascular network integrity have not been studied. In this study, we investigated the role of Ninj1 in physiological (postnatal vessel formation) and pathological (endotoxin-mediated inflammation and diabetes) conditions and developed a strategy to regulate Ninj1 using specific micro (mi)RNAs under pathological conditions. Ninj1-deficient mice exhibited decreased hyaloid regression, tip cell formation, retinal vascularized area, recruitment of macrophages, and endothelial apoptosis during postnatal development, resulting in delayed formation of the vascular network. Five putative miRNAs targeting Ninj1 were selected using the miRanda algorithm and comparison of expression patterns. Among them, miR-125a-5p showed a profound inhibitory effect on Ninj1 expression, and miR-125a-5p mimic suppressed the cell-to-cell and cell-to-matrix adhesion of macrophages and expression of pro-inflammatory factors mediated by Ninj1. Furthermore, miR-125a-5p mimic inhibited the recruitment of macrophages into inflamed retinas in endotoxin-induced inflammation and streptozotocin-induced diabetes in vivo. In particular, miR-125a-5p mimic significantly attenuated vascular leakage in diabetic retinopathy. Taken together, these findings suggest that Ninj1 plays a pivotal role in macrophage-mediated vascular integrity and that miR-125a-5p acts as a novel regulator of Ninj1 in the management of inflammatory diseases and diabetic retinopathy.

Correlation between the progression of diabetic retinopathy and inflammasome biomarkers in vitreous and serum – a systematic review

Activation of the NOD-like receptor protein 3 (NLRP3) inflammasome pathway has been implicated in Diabetic retinopathy (DR) pathogenesis, but its impact on DR development and progression remains unclear. Therefore, the primary aim of this systematic literature review was to determine the role of the inflammasome in DR development. Furthermore, the secondary aim was to determine whether systemic inflammasome activity can be used to predict DR progression. Studies measuring vitreous and/or serum inflammasome biomarkers in DR patients with Type 2 Diabetes Mellitus (T2DM) were searched systematically using online databases EMBASE, PubMed and Web of Science with the last search conducted on 29^th of September 2021. The risk of bias was assessed using the Newcastle Ottawa Scale and 20 studies were eligible for narrative analysis. Limitations included the heterogeneity in detection assays used, the small and uneven sample size, a lack of vitreous data in earlier disease stages, and not accounting for patients with other systemic co-morbidities. Analysis showed that inflammasome biomarkers IL-1β and IL-18 increased significantly from non-proliferative DR to proliferative DR in both vitreous and serum, suggesting the inflammasome pathway is activated as DR progresses and that serum inflammasome levels could be explored as potential biomarkers for DR progression.

Comparison of risks of arterial thromboembolic events and glaucoma with ranibizumab and aflibercept intravitreous injection: A nationwide population‐based cohort study

Background

To compare intravitreal aflibercept injection with intravitreal ranibizumab injection for the risk of major arterial thromboembolic events (ATEs) and glaucoma.

Methods

This retrospective, nationwide cohort study investigated 15 611 and 3867 patients aged >50 years with at least one pharmacy claim for intravitreal ranibizumab injection and aflibercept injection between 2011 and 2016, respectively. The inverse probability of treatment weighting method was performed to adjust the baseline difference between the two groups and the hazard risk of adverse events was estimated using the Cox proportional regression model.

Results

No significant difference was noted between intravitreal ranibizumab and aflibercept injection for arterial thromboembolic risk, including ischemic stroke and acute myocardial infarction, during a 2-year follow-up (adjusted hazard ratio (HR): 0.87, 95% confidence interval (CI): 0.53–1.42; P = .583). Subgroup analyses revealed that patients age >65 years (adjusted HR: 0.64, 95% CI: 0.45–0.92) and those without coronary artery disease (adjusted HR: 0.59, 95% CI: 0.37–0.95) had significantly lower arterial thromboembolic risk in the aflibercept group than in the ranibizumab group. Additionally, the risk of glaucoma development after intravitreal injection did not significantly differ between the two groups (adjusted HR: 0.63, 95% CI: 0.37–1.06; P = .084).

Conclusions

No significant differences in the risk of major ATEs and glaucoma were found between ranibizumab and aflibercept, and aflibercept might be safe for use in elderly patients.

Photonic Crystal-Embedded Molecularly Imprinted Contact Lenses for Controlled Drug Release

As a noninvasive eye disease detection and drug delivery device, contact lenses can improve eye bioavailability and enable continuous drug delivery. In order to monitor the release of drugs in real time, molecularly imprinted contact lenses (MICLs) based on photonic crystals (PCs) were prepared for the treatment of diabetes-related diseases. The specific adsorption of molecularly imprinted polymers on dexamethasone sodium phosphate (DSP) increased the drug loading and optimized the drug release behavior. At the same time, the drug release ensures the rapid color report during the loading and releasing of drugs due to the volume and refractive index change of the hydrogel matrix. The continuous and slow release of DSP by MICLs in artificial tears was successfully monitored through structural color changes, and the cytotoxicity test results showed that the MICL had good biocompatibility. Therefore, MICLs with a PC structure color have great biomedical potentiality in the future.

Disease progression pathways of wet AMD: opportunities for new target discovery

INTRODUCTION

Age-related macular degeneration (AMD) is the leading cause of irreversible blindness among people age 60 years or older in developed countries. Current standard-of-care anti-vascular endothelial growth factor (VEGF) therapy, which inhibits angiogenesis and vascular permeability, has been shown to stabilize choroidal neovascularization and increase visual acuity in neovascular AMD. However, therapeutic limitations of anti-VEGF therapy include limited durability with consequent need for frequent intravitreal injections, and a ceiling of efficacy. Current strategies under investigation include targeting VEGF-C and VEGF-D, integrins, tyrosine kinase receptors, and the Tie2/angiopoietin-2 pathway. A literature search was conducted through November 30, 2021 on PubMed, Medline, Google Scholar, and associated digital platforms with the following keywords: wet macular degeneration, age-related macular degeneration, therapy, VEGF-A, VEGF-C, VEGF-D, integrins, Tie2/Ang2, and tyrosine kinase inhibitors.

AREAS COVERED

The authors provide a comprehensive review of AMD disease pathways and mechanisms involved in wet AMD as well as novel targets for future therapies.

EXPERT OPINION

With novel targets and advancements in drug delivery, there is potential to address treatment burden and to improve outcomes for patients afflicted with neovascular AMD.

[Prevention of intraocular pressure elevation following intravitreal injections]

Determining the role of vascular endothelial growth factor (VEGF) in the pathogenesis of intraocular neovascularization prompted the development of anti-VEGF therapy. In general, these intravitreal injections (IVI) are considered relatively safe. One of the side effects that can occur after IVI of anti-VEGF agents is ocular hypertension, it can be acute or persistent. Numerous studies investigating the prevention of ophthalmic hypertension have been carried out in connection with the proven risk of short-term intraocular pressure (IOP) elevation after anti-VEGF injections. Scientific literature describes several methods of preventing intraocular pressure spikes after IVI: prophylactic medications, anterior chamber paracentesis, scleral decompression. Despite the significant number of publications, there is no universal consensus on the necessity of prevention measures for IVI of anti-VEGF drugs since the clinical benefits of slightly reducing the short-term IOP spikes remain unclear. This literature review analyzes the prospects of preventing ocular hypertension after IVI of anti-VEGF agents.

Add-On Effect of Simultaneous Intravitreal Dexamethasone to Intravitreal Bevacizumab in Patients with Macular Edema Secondary to Branch Retinal Vein Occlusion

Purpose: To report the effect of simultaneous dexamethasone and bevacizumab combination treatment in patients with macular edema secondary to branch retinal vein occlusion (BRVO). Methods: Treatment-naive patients who had a macular edema secondary to BRVO with a duration of less than 1 month were treated either with intravitreal bevacizumab (Group-1) or intravitreal bevacizumab simultaneously combined with dexamethasone intravitreal implant (Group-2). In both groups, patients received monthly bevacizumab injection during the first 3 months. Between months 3 and 12, all patients were allowed to receive pro-re-nata bevacizumab. In Group-2, the first dexamethasone implant injection was simultaneously received with first bevacizumab injections. The patients were evaluated for re-treatment after 6 months and 11 months for second and third dexamethasone simultaneously with intravitreal bevacizumab. Results: In Group-1, 35 eyes of 35 patients and in Group-2, 32 eyes of 32 patients were treated. The mean gains in BCVA were +10.7 letters in the Group-1 and +21.3 letters in the Group-2 (P = 0.021) at month 12. The mean reduction in Central Macular Thickness (CMT) from the baseline were -173.74 μm in the Group-1 and -257.97 μm in the Group-2 (P = 0.0018). In Group-1, the mean intravitreal bevacizumab injection number was 7.18 ± 1.05. In Group-2, the mean intravitreal bevacizumab and dexamethasone injection number was 5.15 ± 1.24. There was a significant difference in mean injection numbers between 2 groups (P = 0.044). Conclusion: In the early period of macular edema adding dexamethasone to bevacizumab therapy does improve visual acuity and CMT, and reduce the injection frequency more than bevacizumab alone.

The 12- and 24-Month Effects of Intravitreal Ranibizumab, Aflibercept and Bevacizumab on Intraocular Pressure: A Network Meta-Analysis

TOPIC

To investigate the effect of anti-vascular endothelial growth factor (VEGF) intravitreal injections on intraocular pressure (IOP) 12- and 24-months after initiation.

CLINICAL RELEVANCE

It is unclear whether serial anti-VEGF injections result in sustained increases in IOP.

METHODS

Randomized control trials (RCTs) comparing anti-VEGF agents to each other or to a control for the treatment of neovascular age-related macular degeneration, retinal vein occlusions or diabetic macular edema were included. Pairwise meta-analysis and Bayesian network meta-analysis were performed examining the proportion of patients at 12- and 24-months whose IOP: a) increased ≥5mmHg from baseline on consecutive visits, b) increased ≥10mmHg from baseline at any visit, c) was ≥21mmHg on consecutive visits, d) was ≥25mmHg at any visit, e) was ≥30mmHg at any visit, f) prompted initiation of IOP lowering medications and g) increased as per the clinicians' discretion. Certainty of evidence was informed by Cochrane Collaboration's Risk of Bias Tool and GRADE (Grading of Recommendations Assessments, Development and Evaluations) guidelines.

RESULTS

26 RCTs of 12,522 eyes were included. Aflibercept (2.0mg), bevacizumab (1.25mg), ranibizumab (0.3mg and 0.5mg) and non-injection controls were analyzed. 83 of 84 network estimates for comparisons between anti-VEGF agents demonstrated no statistically significant difference between groups (low to moderate certainty of evidence). Ranibizumab 0.5mg had higher rates than bevacizumab of IOP measurements ≥30mmHg at 12-months (low certainty of evidence). 53 of 56 network estimates for comparisons between anti-VEGF agents and controls demonstrated no statistically significant difference between groups (low to moderate certainty of evidence). Ranibizumab 0.5mg had higher rates of consecutive IOP increases ≥ 5mmHg at 24-months (low certainty of evidence) and higher rates of IOP increases as per the clinicians' discretion at 12 and 24 months (low and very low certainty of evidence respectively). The 95% credible intervals in all comparisons without statistically significant effects did not rule out important clinical effects. The certainty of evidence in these comparisons is limited by imprecision.

CONCLUSION

Evidence from our network meta-analysis does not show any clear difference between anti-VEGF agents and controls when examining IOP increases 12- and 24-months after treatment initiation. Imprecision precludes definitive conclusions with the available data.

Anterior Chamber Paracentesis Offers a Less Painful Experience During Intravitreal Anti-vascular Endothelial Growth Factor Administration: An Intraindividual Study

Introduction: In order to improve comfort and compliance to treatment of the patient during the intravitreal injections (IVIs), relieving pain may help and provide getting better results. The purpose of the study was to evaluate the efficacy of anterior chamber paracentesis on pain perception and the factors related to pain perception during intravitreal injection procedures.

Material and methods: This prospective randomized study includes 212 eyes of 106 patients scheduled for bilateral IVI of ranibizumab 0.5 mg/0.05 cc under topical anesthesia. All patients underwent full ophthalmologic examination, including intraocular pressure (IOP), anterior chamber depth (ACD), and axial length (AL) measurements. Group 1 received IVI following anterior chamber paracentesis (ACP) and group 2 received IVI without ACP. Intraocular pressure was measured five minutes and 30 minutes after the procedure. Pain perception was assessed by visual analogue scale (VAS) grading from 0 to 10.

Results: Mean VAS score for groups 1 and 2 was recorded as 0.51±1.00 and 1.32±1.50, respectively. Correlation analysis revealed a positive correlation between VAS score and history of previous IVI, preinjection IOP values, and an inverse correlation with the presence of reflux in both groups, in addition to inverse correlation with ACD in group 2.

Conclusions: ACP may offer a comfortable, effective, and less painful alternative to prevent the acute rise in IOP after IVI, especially in patients with small anterior chambers, small vitreous volumes, with a history of multiple injections, and in patients with advanced glaucomatous optic neuropathy.

CM082, a novel VEGF receptor tyrosine kinase inhibitor, can inhibit angiogenesis in vitro and in vivo

The goal of this study was to evaluate the effects of CM082, a novel vascular endothelial growth factor (VEGF) receptor-2 tyrosine kinase inhibitor, on human umbilical vein endothelial cells (HUVECs), and oxygen-induced retinopathy (OIR) mice. HUVECs were stimulated with rHuVEGF165 and then treated with CM082 to assess the antiangiogenic effects of CM082; subsequently, proliferation, wound-healing migration, Transwell invasion, tube formation assays, and Western blotting were performed in vitro. Retinal neovascularization tufts, avascular area, and TUNEL assays were estimated for OIR mice after intraperitoneal injection with CM082. CM082 significantly inhibited proliferation, migration, invasion, and tube formation induced by stimulation of HUVECs with rHuVEGF165; this inhibitory effect was mediated by blocking VEGFR2 activation. CM082 significantly inhibited retinal neovascularization and avascular area and did not increase apoptosis in the retina of OIR mice. The findings demonstrated that CM082 exhibits highly antiangiogenic effects in HUVECs and OIR mice. Thus, it may serve as an alternative treatment for neovascular eye disease in the future.

A Novel Small Peptide H-KI20 Inhibits Retinal Neovascularization Through the JNK/ATF2 Signaling Pathway

Purpose

Abundant evidence has shown benefits of antivascular endothelial growth factor (anti-VEGF) therapies in neovascular eye diseases. However, the high cost, side effects, and inconvenience of frequent injections demand alternative novel drug candidates. This study aimed to analyze antiangiogenic effects of peptide H-KI20 and illustrated signaling mechanisms.

Methods

Live cell culture and tracing, wound healing assay, and tube formation were performed in human retinal microvascular endothelial cells (HRECs). The chick embryo chorioallantoic membrane and mouse oxygen-induced ischemic retinopathy model were applied to examine the effects of H-KI20 in vivo. The intracellular signaling pathways were examined. Molecular docking and surface plasmon resonance assay were used to validate the direct interaction of H-KI20 and c-Jun N-terminal kinase 2 (JNK2).

Results

H-KI20 had high penetration ability in vitro and in vivo. It inhibited motility, migration, and tube formation of HRECs, without cytotoxicity, and inhibited angiogenesis in vivo. Furthermore, H-KI20 treatment reduced the phosphorylation level of activating transcription factor 2 (ATF2) stimulated by VEGF via downregulating p-JNK. H-KI20 bound to JNK2 directly with a dissociation constant value of 83.68 µM. The knockdown of ATF2 attenuated VEGF-induced tube formation and decreased the movement speed of HRECs.

Conclusions

H-KI20 inhibited angiogenesis both in vitro and in vivo. The ratios of p-ATF2/ATF2 and p-JNK/JNK stimulated by VEGF were decreased by H-KI20, and H-KI20 targeted JNK2 directly. In addition, the pivotal role of ATF2 in VEGF-induced retinal neovascularization was elucidated for the first time. Taken together, H-KI20 displays potential for pathological retinal angiogenesis as a sustained and low-toxic peptide.

Prophylactic effect of brinzolamide-brimonidine fixed combination on intraocular pressure spikes after intravitreal anti-VEGF injections

PURPOSE

To evaluate the effect of topical prophylaxis with brinzolamide-brimonidine fixed combination on short-term intraocular pressure (IOP) elevation after intravitreal injections of anti-vascular endothelial growth factors (anti-VEGF).

METHODS

This prospective comparative study included 56 eyes of 47 patients treated with intravitreal injections of anti-VEGF, and they were randomly divided into two groups. In control group (25 eyes), no prophylactic medication was used, whereas in case group (31 eyes) one drop of a fixed combination of brinzolamide-brimonidine was instilled two hours before the injection. IOP was measured before the injection and at 1 min, 10 min and 30 min post-injection in all eyes.

RESULTS

The mean IOP before injection at 1 min, 10 min and 30 min post-injection was 16,6 ± 2,8 mmHg, 53,4 ± 12 mmHg, 26,4 ± 5,5 mmHg and 17,9 ± 4 mmHg, respectively, in control group and 15,1 ± 3,4 mmHg, 42,6 ± 8,4 mmHg, 21,4 ± 5,5 mmHg and 12,4 ± 3,5 mmHg, respectively, in case group. At 1 min, 10 min and 30 min post-injection, the mean IOP was significantly lower in case group compared with control group (p < 0,001, p = 0,0014 and p < 0,0001, respectively), but no difference at the pre-injection IOP between the two groups was found (p = 0,09).

CONCLUSIONS

The prophylactic administration of one drop of brinzolamide-brimonidine fixed combination significantly reduces the IOP spikes during the first 30 min after the intravitreal anti-VEGF injection.

The Effect of Acute Rises in Intraocular Pressure after Intravitreal Bevacizumab Injection on the Peripapillary Retinal Nerve Fiber Layer Thickness and the Role of Anterior Chamber Paracentesis

Purpose:

To evaluate acute changes in intraocular pressure (IOP) and their short-term effects on the peripapillary retinal nerve fiber layer (RNFL) thickness after intravitreal bevacizumab (IVB) injection.

Methods:

Fifty-eight eyes of 37 patients with treatment-naïve diabetic macular edema or exudative age-related macular degeneration were included in the study. Patients were divided into two groups, and the participants of each group received 3 monthly injections of IVB. IOP was measured right before the injection, immediately after the injection, and 5 min and 20 min after each injection. Peripapillary, RNFL thickness was measured before the injection and 1 month after the third injection. In the second group, anterior chamber (AC) paracentesis was performed before IVB injection.

Results:

IOP values after injection in all sessions were significantly higher in the first group (P < 0.001). The peripapillary RNFL thickness changes 1 month after the third injection was not statistically significantly different in each group (P = 0.816 and 0.773 for the first and second groups, respectively).

Conclusion:

AC paracentesis is an effective modality to reduce the acute rise in IOP. The effect of acute IOP elevation on the peripapillary RNFL thickness was not statistically significant.

Reflux, Intraocular Pressure Variation and Pain Following Intravitreal Ranibizumab Injections Using 30-Gauge or 32-Gauge Needles for Patients With Retinal Pathologies: A Randomized Clinical Trial

PURPOSE

To compare reflux, intraocular pressure (IOP) variation and pain following intravitreal (IV) injections using 30-gauge and 32-gauge needles in patients with retinal pathologies in Saudi Arabia.

METHODS

A double-blind randomized clinical trial was conducted in 2018. Participants were randomized to receive IV injections of Ranibizumab using 30-gauge (Gr₁) or 32-gauge (Gr₂) needles. The amount of reflux of injected material, IOP before (IOP₁) and five minutes after injection (IOP₂) were measured. The patient-perceived pain score was assessed using a visual analogue score (VAS). Outcome variables were compared.

RESULTS

The study sample was comprised of 86 eyes (86 patients) in each group. Gender (P=0.76), laterality (P=0.55) and age (P=1.0) were not different between groups. The reflux in Gr₁ [34.9% (95% confidence interval {CI}, 24.8; 45.0)] was significantly higher compared to Gr₂ [22.1% (95% CI, 13.3; 30.9)] (P=0.007). The median pain score was 1 in both Gr₁ [interquartile range (IQR) 1.0: 3.0] and Gr₂ (IQR 0.0; 2.0) (P=0.04). Among 56 eyes without reflux in Gr₁, the IOP₁ and IOP₂ were 13.6±2.7 mmHg and 16.4±5.0 mmHg, respectively. Among 67 eyes without reflux in Gr₂, the IOP₁ and IOP2 were 13.6±2.9 mmHg and 17.0±5.2 mmHg, respectively. The change in percentage in IOP in Gr₁ and Gr₂ was not significantly different (Mann Whiney P=0.3).

CONCLUSIONS

IV injection given by 30-gauge needle compared to 32-gauge needle resulted in greater patient-perceived pain and more reflux of injected material from the injection site. An increase in IOP was not associated with the gauge of the needle used for IV injection.

Role of mammalian target of rapamycin in regulating HIF-1α and vascular endothelial growth factor signals in glaucoma

Hypoxia inducible factor subtype 1α (HIF-1α) in retinal tissues is involved in the development of glaucoma. This study examined the role played by mammalian target of rapamycin (mTOR) in regulating expression of HIF-1α and its downstream pathway, vascular endothelial growth factor (VEGF). Glaucoma was induced by chronic elevation of intraocular pressure using laser burns in rats. ELISA and western blot analysis were employed to determine the levels of HIF-1α, VEGF and mTOR in retinal tissues of eyes with high intraocular pressure. In results, HIF-1α, VEGF and VEGF receptor subtype 2 were increased in laser eyes. The p-mTOR, mTOR-mediated phosphorylation of 4E-binding protein 4, p70 ribosomal S6 protein kinase 1 were also amplified in retina of laser eyes. Blocking mTOR using rapamycin attenuated HIF-1α-VEGF pathways, accompanied with downregulation of apoptotic Caspase-3. Our data revealed potential signalling pathways engaged in the development of glaucoma, including the activation of mTOR and HIF-1α-VEGF mechanism.

Mesenchymal Stromal Cells Promote Retinal Vascular Repair by Modulating Sema3E and IL-17A in a Model of Ischemic Retinopathy

Ischemic retinopathies (IRs), such as retinopathy of prematurity and diabetic retinopathy, are characterized by an initial phase of microvascular degeneration that results in retinal ischemia, followed by exaggerated pathologic neovascularization (NV). Mesenchymal stromal cells (MSCs) have potent pro-angiogenic and anti-inflammatory properties associated with tissue repair and regeneration, and in this regard exert protection to neurons in ischemic and degenerative conditions; however, the exact mechanisms underlying these functions remain largely unknown. Class III Semaphorins (A–G) are particularly implicated in regulating neural blood supply (as well as neurogenesis) by suppressing angiogenesis and affecting myeloid cell function; this is the case for distinct neuropillin-activating Sema3A as well as PlexinD1-activating Sema3E; but during IR the former Sema3A increases while Sema3E decreases. We investigated whether retinal vascular repair actions of MSCs are exerted by normalizing Semaphorin and downstream cytokines in IR. Intravitreal administration of MSCs or their secretome (MSCs-conditioned media [MSCs-CM]) significantly curtailed vasoobliteration as well as aberrant preretinal NV in a model of oxygen-induced retinopathy (OIR). The vascular repair effects of MSCs-CM in the ischemic retina were associated with restored levels of Sema3E. Vascular benefits of MSCs-CM were reversed by anti-Sema3E; while intravitreal injection of anti-angiogenic recombinant Sema3E (rSema3E) in OIR-subjected mice reproduced effects of MSCs-CM by inhibiting as expected preretinal NV but also by decreasing vasoobliteration. To explain these opposing vascular effects of Sema3E we found in OIR high retinal levels, respectively, of the pro- and anti-angiogenic IL-17A and Sema3A-regulating IL-1β; IL-17A positively affected expression of IL-1β. rSema3E decreased concentrations of these myeloid cell-derived pro-inflammatory cytokines in vitro and in vivo. Importantly, IL-17A suppression by MSCs-CM was abrogated by anti-Sema3E neutralizing antibody. Collectively, our findings provide novel evidence by which MSCs inhibit aberrant NV and diminish vasoobliteration (promoting revascularization) in retinopathy by restoring (at least in part) neuronal Sema3E levels that reduce pathological levels of IL-17A (and in turn other proinflammatory factors) in myeloid cells. The ability of MSCs to generate a microenvironment permissive for vascular regeneration by controlling the production of neuronal factors involved in immunomodulatory activities is a promising opportunity for stem cell therapy in ocular degenerative diseases.

Dual-acting therapeutic proteins for intraocular use

Intravitreally injected antibody-based medicines have revolutionised the treatment of retinal disease. Bispecific and dual-functional antibodies and therapeutic proteins have the potential to further increase the efficacy of intraocular medicines.

Relief of Cystoid Macular Edema-Induced Focal Axonal Compression with Anti-Vascular Endothelial Growth Factor Treatment

Purpose

To evaluate the mechanical compression of retinal nerve fiber layer (RNFL) by intraretinal cysts in macular edema and its relief with anti-vascular endothelial growth factor (anti-VEGF) treatment.

Methods

Optical coherence tomography scans were used to measure RNFL thickness and reflectance at seven preselected points at and around the peak of the edema before and after anti-VEGF treatment in 10 patients (11 eyes) with branch retina vein occlusion (BRVO) and diabetic macular edema (DME). Scans through nonedematous retina and from the fellow eyes were taken as controls. Correlations were sought between the changes in retinal and RNFL thickness, RNFL reflectance, and the size of the intraretinal cysts.

Results

Postinjection RNFL thickness decreased significantly only at peak point of the edema (18.1 ± 2.7 vs. 13.8 ± 1.2 µm; P = 0.038), at its nasal edge (20.1 ± 2.7 vs. 15.5 ± 1.4 µm; P = 0.026), and 500 µm away from its nasal border (35.7 ± 6.0 vs. 20.1 ± 2.7 µm; P = 0.006) suggesting focal stagnation of the axoplasmic flow owing to compression at its peak point. Significant postinjection decreases in RNFL reflectivity were also noted at peak point of the cyst (164.9 ± 10.3 vs. 141.5 ± 12.6 arbitrary units [AU]; P = 0.037), at its nasal edge (166.8 ± 7.8 vs. 135.1 ± 10.2 AU; P = 0.02), and 1500 µm away from temporal edge (160.2 ± 6.2 vs. 141.1 ± 6.4 AU; P = 0.022). Cyst proximity to RNFL (D₅₀ = 50 µm) was the only determinant significantly affecting the magnitude of the RNFL thickness change after anti-VEGF treatment (P = 0.001).

Conclusions

Intraretinal cysts due to BRVO and DME locally compress overlying axons and induce anatomic changes suggestive of axoplasmic stagnation. This compression can be relieved with anti-VEGF treatment.

Translational Relevance

Focal compression of RFNL by retinal cysts may indicate a need for early treatment of macular edema to prevent axonal loss, especially in patients with low axonal reserve

Injectable in-situ gel depot system for targeted delivery of biologics to the retina

In current clinical settings, frequent intravitreal (IVT) injections of anti-vascular endothelial growth factors are used due to their short in-vivo half-life and rapid clearance from the back of the eye. The IVT injections are associated with pain, risk of infection, retinal detachment, and financial burden. Biologics molecules can undergo physical, chemical, and enzymatic degradation during formulation development and in the biological environment. Moreover, the complex ocular structures also act as a rate-limiting barrier for these biologics. Thus, delivering stable and clinically relevant biologics concentration to the back of the eye is still a challenge. Compare to other drug delivery platforms, injectable in-situ gelling depot systems (IISGDs) have emerged as an effective system for biologics delivery. In this review, we have discussed various biologics used in ocular therapeutics and their associated challenges. Different routes of delivery and associated tissue barriers are also discussed. Different types of IISGDs developed to date for biologics delivery to the back of the eye were also covered. To conclude, various critical parameters related to the formulation development process and injectable depot systems that need careful consideration and further investigations were highlighted.

Short-time effect of intravitreal injections on retinal vascular oxygenation and vessel diameter in patients with diabetic macular oedema or neovascular age-related macular degeneration

PURPOSE

To investigate the short-time effect of intravitreal injections (IVI) of the vascular endothelial growth factor inhibitors ranibizumab and aflibercept on retinal arterial and venous oxygen saturation (SO2a and SO2v), arteriovenous oxygen saturation difference (AVD) and vessel diameter (VDa and VDv) in patients with diabetic macular oedema (DME) and patients with choroidal neovascularization (CNV) due to age-related macular degeneration.

METHODS

Uncontrolled prospective observational study in 100 eyes. Retinal vessel oxygen saturation and diameters were assessed using a retinal oximeter before and minutes after IVI of ranibizumab or aflibercept.

RESULTS

40 eyes with CNV and 34 eyes with DME were included in the analysis. At baseline, SO2a and SO2v were significantly higher in DME (p = 0.043 and p = 0.009, respectively). After IVI, SO2a significantly decreased in CNV and DME eyes by 2.6% (p = 0.016) and 4.6% (p = 0.002) and SO2v decreased by 14.0% (p = 0.004) and 12.4% (p = 0.017), respectively. However, a significant increase in AVD was only found in CNV (15.7%, p = 0.001). VDa decreased significantly only in DME by 5.7% (p = 0.010). No medication-specific disease effect was found and vice versa.

CONCLUSIONS

The observed changes can be interpreted as signs of increased metabolic demand during the physiological stress after an IVI. The abnormal arterial constriction and the abolished increase in AVD seen only in eyes with DME indicate an impairment of vascular autoregulation and oxygen distribution and a reduced neuroretinal metabolism in the diabetic retina with a significant impact on inner retinal oxygen consumption shortly after IVI.

Critical analysis of techniques and materials used in devices, syringes, and needles used for intravitreal injections

Intravitreal injections have become the most commonly performed intraocular treatments worldwide. Because intravitreal injections may induce severe adverse events, such as infectious and noninfectious endophthalmitis, cataract, ocular hypertension, vitreous hemorrhage, or retinal detachment, appropriate awareness of the materials and techniques used are essential to reduce these sight-threatening complications. This review provides insights into the needles, syringes, silicone oil coating, sterilization methods, devices to assist intravitreal injections, scleral piercing techniques using needles, syringe handling, anesthesia, and safety issues related to materials and techniques. It is paramount that physicians be aware of every step involved in intravitreal injections and consider the roles and implications of all materials and techniques used. The ability to understand the theoretical and practical circumstances may definitely lead to state-of-the-art treatments delivered to patients. The most important practical recommendations are: choosing syringes with as little silicone oil as possible, or, preferably, none; avoiding agitation of syringes; awareness that most biologics (e.g., antiangiogenic proteins) are susceptible to changes in molecular properties under some conditions, such as agitation and temperature variation; understanding that improper materials and techniques may lead to complications after intravitreal injections, e.g., inflammation; and recognizing that some devices may contribute to an enhanced, safer, and faster intravitreal injection technique.

Ghost cell glaucoma after intravitreous injection of ranibizumab in proliferative diabetic retinopathy

Background

The development of ghost cell glaucoma in patients with proliferative diabetic retinopathy (PDR) after intravitreous injection (IV) was rare. Here we reported a series of patients with PDR who received Intravitreous Ranibizumab (IVR) and developed ghost cell glaucoma and analyzed the potential factors that might be related to the development of ghost cell glaucoma.

Methods

Retrospective case series study. The medical records of 71 consecutive eyes of 68 PDR patients who received vitrectomy after IVR from January 2015 to January 2017 were reviewed. The development of ghost cell glaucoma after IVR was recorded. Characteristics of enrolled patients were retrieved from their medical charts. Factors associated with ghost cell glaucoma were compared between eyes with the development of ghost cell glaucoma and eyes without the development of ghost cell glaucoma. Variables were further enrolled in a binary backward stepwise logistic regression model, and the model that had the lowest AIC was chosen.

Results

There were 8 out of 71 eyes of the PDR patients developed ghost cell glaucoma after they received IVR. The interval between detection of elevation of intraocular pressure (IOP) and IV ranged from 0 to 2 days. Among them, after IVR, there were two eyes had IOP greater than 30 mmHg within 30 min, four eyes showed normal IOP at 30 min, and then developed ghost cell glaucoma within 1 day, two eyes developed ghost cell glaucoma between 24 and 48 h. The mean IOP was 46.5 ± 8.0 mmHg. All patients gained normal IOP after vitrectomy without medicine for lowering IOP. The presence of ghost cell glaucoma was associated with tractional retinal detachment (RR = 4.60 [2.02 ~ 8.48], p = 0.004) and fibrovascular membrane involving disk (RR = -3.57 [− 7.59 ~ − 0.92], p = 0.03) (AIC = 39.23, AUC = 0.88) in a logistic regression model.

Conclusion

Attention to postoperative IOP should be paid to patients with PDR undergoing vitrectomy who receive a preoperative IV of anti-VEGF agents. PDR patients with tractional retinal detachment or fibrovasucular membrane involving optic disc are more likely to develop ghost cell glaucoma after IV.

Treatment Course of Patients with Exudative Age-Related Macular Degeneration Using Ocular Hypotensives

Purpose

To characterize the visual outcomes and the treatment course of patients with exudative age-related macular degeneration (AMD) based on ocular hypotensive use.

Design

A matched retrospective cohort study of patients enrolled in Kaiser Permanente Southern California health plan was conducted. Patients taking ocular hypotensives were identified using pharmacy dispensing data and were matched to controls to compare visual acuity, number of anti-VEGF injections, and conversation to secondary anti-VEGF agents in the first year of treatment. Subgroup analysis was performed based on the number of ocular hypotensive agents (0, 1, 2 or 3+ agents) and drug class (aqueous suppressants and prostaglandin analogs).

Results

A total of 234 patients patients were examined. Baseline and final visual acuity did not significantly differ between drop users and controls, including on subgroup analysis. The average number of anti-VEGF injections did not differ between drop users and controls (6.1 vs 6.2, p=0.97), nor did the percentage of patients who were switched to a second-line anti-VEGF agent (23.9% vs 17.9%, p=0.26). Subgroup analysis did not reveal significant differences in the number of anti-VEGF injections and the percentage of patients switched to secondary agents, with patients receiving 6 ±1 injections across regardless of the number or class of ocular hypotensive agents used.

Conclusion

Patients with concurrent glaucoma and exudative AMD have similar visual outcomes and treatment courses compared to those not taking ocular hypotensives. Although aqueous suppressants have been suggested to prolong anti-VEGF residence time, patients using these agents did not demonstrate visual benefit or a reduced injection burden in this series.

Iatrogenic ophthalmic artery occlusion and retinal artery occlusion

Iatrogenic ophthalmic artery occlusion (IOAO) is a rare but devastating ophthalmic disease that may cause sudden and permanent visual loss. Understanding the possible etiologic modalities and pathogenic mechanisms of IOAO may prevent its occurrence. There are numerous medical etiologies of IOAO, including cosmetic facial filler injection, intravascular procedures, intravitreal gas or drug injection, retrobulbar anesthesia, intraarterial chemotherapy in retinoblastoma. Non-ocular surgeries and vascular events in arteries that are not directly associated with the ophthalmic artery, can also cause IOAO. Since IOAO has a limited number of treatment modalities, which lead to poor final visual prognosis, it is imperative to acknowledge the information regarding medical procedures that are etiologically associated with IOAO. We accumulated all searchable and available IOAO case reports (our cases and previous reported cases from the literature), classified them according to their mechanisms of pathogenesis, and summarized treatment options and responses of each of the causes. Various sporadic cases of IOAO can be categorized into three mechanisms as follows: intravascular event, orbital compartment syndrome, and increased intraocular pressure. Embolic IOAO, which is considered the primary cause of the condition, was classified into three subgroups according to the pathway of embolic movement (retrograde pathway, anterograde pathway, pathway through collateral channels). Despite the practical limitations of treating spontaneous (non-iatrogenic) retinal artery occlusion, this article will contribute in predicting and improving the prognosis of IOAO by recognizing the treatable factors. Furthermore, it is expected to provide clues to future research associated with the treatment of retinal artery occlusion.

Effect of prior glaucoma surgery on intraocular pressure immediately after anti-vascular endothelial growth factor injection

BACKGROUND

To characterize how prior incisional glaucoma surgery affects the intraocular pressure (IOP) elevation immediately following intravitreal anti-VEGF injections (IVI).

METHODS

Single institution, experimental study. Patients with a history of incisional glaucoma surgery who were receiving anti-VEGF injections were recruited as well as control eyes. Pre- and post-injection IOP measurements were compared as well as time to recovery to within 5 and 10 mmHg of baseline IOP.

RESULTS

Ten eyes with a history of glaucoma surgery and 29 control eyes receiving anti-VEGF injections were included. The most common indication for intravitreal anti-VEGF injection was proliferative diabetic retinopathy in both surgical and control eyes (50% vs 45%, p = 1.00). Post-injection IOP was significantly decreased compared to baseline IOP after anti-VEGF injection in surgical versus control eyes (26.5 ± 8.9 mmHg vs 44.2 ± 8.5 mmHg, respectively, p < 0.001). The mean change in IOP following intravitreal anti-VEGF injection was lower in surgical eyes (10.7 ± 6.6 mmHg vs 28.6 ± 8.3 mmHg, p < 0.001). The mean time for the IOP to return to within 10 mmHg of pre-injection IOP was less in surgical eyes (5.2 ± 4.1 min vs 13.3 ± 7.6 min, p = 0.002).

CONCLUSIONS

Eyes with prior incisional glaucoma surgery demonstrated a significantly lower post-injection IOP elevation and a faster recovery to within 10 mmHg of their pre-injection IOP. Incisional glaucoma surgery may be considered for patients where the attenuation of post-injection IOP elevation is needed and other less invasive measures have failed.

Innovative therapies for neovascular age-related macular degeneration

Introduction: Investigational anti-VEGF treatments for neovascular age-related macular degeneration (nAMD) aim to improve visual outcomes and reduce treatment burden; these include long-acting agents, combination strategies, topical agents, sustained-release, and genetic therapies. Areas covered: The authors provide a comprehensive review of investigational therapies for nAMD, focusing on therapies currently in clinical trial. Expert opinion: Long-acting anti-VEGF agents have demonstrated promising results in phase 3 studies, and include Brolucizumab, a single-chain antibody fragment, and Abicipar, a designed ankyrin repeat protein (DARPin). Other unique anti-VEGF agents in current trials include Conbercept - a fusion protein of the VEGF receptor domains, KSI-301 - an anti-VEGF antibody biopolymer conjugate, and OPT-302 - an inhibitor of VEGF-C/D. Strategies to activate the Tie-2 receptor, some in combination with VEGF inhibition, are of interest, with recent trials of Faricimab, ARP-1536, and nesvacumab. Topical anti-VEGF ± anti-PDGF agents, such as pazopanib, squalamine lactate, regorafenib, and LHA510 have shown limited efficacy and/or have not been advanced, although PAN-90806 continues to advance with promising initial results. Sustained-release anti-VEGF treatments, to address treatment burden, include the ranibizumab Port Delivery System, GB-102, NT-503, hydrogel depot, Durasert, and ENV1305. Similarly, genetic therapies, including RGX-314 and ADVM-022, aim to provide sustained anti-VEGF expression from the retina.

Anterior chamber paracentesis during intravitreal injections in observational trials: effectiveness and safety and effects

A paracentesis prior to an intravitreal injection is a very safe procedure and can prevent IOP-spikes after injections. As these spikes pose the risk of inducing glaucomatous changes particularly in patients with frequent injections and/or with a risk profile, a regular paracentesis prior to an injection may be considered and discussed with the patient.

Therapeutic Effect of Traditional Chinese Medicine on a Rat Model of Branch Retinal Vein Occlusion

Branch retinal vein occlusion (BRVO) is a common retinal vascular disorder leading to visual impairment. Currently, the general strategies for BRVO are symptomatic therapies. Cardiovascular aspects are essential risk factors for BRVO. The traditional Chinese medicine hexuemingmu (HXMM), consisting of tanshinol and baicalin, dilates the vasculature and accelerates microcirculation. Therefore, the aim of this study was to determine the efficacy and possible mechanism of HXMM in a BRVO rat model established by laser photocoagulation. Successful BRVO rat models were treated with different doses of HXMM. Fundus photography and fluorescein fundus angiography (FFA) of the animals were applied. The retinal layers were measured by optical coherence tomography (OCT). Full-field electroretinography (ffERG) was applied to evaluate the retinal function. The ear vein flow velocity was measured via a microcirculation detector. The expression of the vascular endothelial growth factor (VEGF-α) was measured via western blotting and immunofluorescent staining. Our study found that retinal edema predominantly occurred in the inner nuclear layer (INL) and outer nuclear layer (ONL). The retinal edema of the treated groups was significantly relieved in the early stage of BRVO as visualized via OCT detection and HE staining. The amplitudes of the b wave and oscillatory potentials (OPs) waves of ffERG in the treated groups were increased compared with those of the control group at several detection points (3, 5, 7, 10, 14, and 21 d postocclusion). The expression of VEGF-α was reduced in the treated groups at an early stage of BRVO. Furthermore, the ear vein flow velocity of the HXMM treatment groups was faster than that of the control group. Thus, our study indicates that the traditional Chinese medicine HXMM could ameliorate retinal edema and rescue the retinal structure and function in BRVO models through promoting occluded vein recanalization, improving microcirculation, and regulating the expression of VEGF-α.

Hypotensive efficacy of topical brimonidine for intraocular pressure spikes following intravitreal injections of antivascular endothelial growth factor agents: a randomised crossover trial

PURPOSE

To determine the effect of topical brimonidine tartrate prophylaxis on intraocular pressure (IOP) spikes following intravitreal injection of antivascular endothelial growth factor (anti-VEGF) agents.

METHODS

This is a randomised crossover trial of consecutive non-glaucomatous eyes receiving intravitreal anti-VEGF injections between December 2016 and July 2017. All eyes were randomly assigned to no prophylaxis or topical brimonidine tartrate 0.15 % administered 20 min prior to injection in one of two consecutive visits. Measurements of IOP were obtained immediately (T0), 10 min (T10) and 20 min (T20) after injection during the visits with and without prophylaxis.

RESULTS

Among the 58 eyes of 55 patients (116 visits), the mean (SD) age was 74.3 (11.6), and 62% were female. The mean baseline IOP was 15.3 (2.3) mm Hg (range: 11-20). On average, the immediate postinjection IOP during the visit without prophylaxis was 41.6 (12) mm Hg (range: 17-81). Compared with no prophylaxis, the visit with preadministered topical brimonidine tartrate had a lower IOP at T0 (p<0.001), T10 (p=0.001) and T20 (p=0.043), and a smaller proportion of eyes with IOP elevation of greater than 20 mm Hg from preinjection (p=0.002) and IOP greater than 50 mm Hg at T0 (p=0.036). Without prophylaxis, two eyes (two patients) had an IOP of greater than 70 mm Hg at T0 and thus underwent anterior chamber paracentesis.

CONCLUSION

Topical brimonidine tartrate prophylaxis for intravitreal injection of anti-VEGF agents effectively reduces IOP spikes in non-glaucomatous eyes and may be easily incorporated into ophthalmologists' current practice.

TRIAL REGISTRATION NUMBER

NCT03513172.

Evaluation of optic nerve head blood flow in response to increase of intraocular pressure

The time course of the changes in the optic nerve head (ONH) blood flow in response to changes in the ocular perfusion pressure (OPP) induced by an artificial elevation of the intraocular pressure (IOP) has not been determined. We measured the blood flow, represented by the mean blur rate (MBR), on the ONH determined by laser speckle flowgraphy. The MBR was determined before, during, and after the IOP was elevated by 20 or 30 mmHg by pressure applied on the eye by an ophthalmodynamometer in a total of 27 healthy eyes. For an IOP elevation of 20 mmHg, the percentage reduction in the MBR-vessel was −24.7%, and in the MBR-tissue was −16.0% (P < 0.001). For an IOP elevation of 30 mmHg, the percentage reduction of the MBR-vessel was −35.3% and the MBR-tissue was −24.7% (P < 0.001). During the 30 mmHg IOP elevation for 10 minutes, both the MBR-vessel and MBR-tissue began returning to the baseline level from 1 minute after the beginning of the IOP elevation (P < 0.01, P < 0.05, respectively) and continued returning during the 10 minutes IOP elevation (P < 0.001, P < 0.01, respectively). We conclude that the ONH can autoregulate its blood flow in response to experimental changes in OPP induced by IOP elevations.

Intravitreal Delivery of VEGF-A165-loaded PLGA Microparticles Reduces Retinal Vaso-Obliteration in an In Vivo Mouse Model of Retinopathy of Prematurity

PURPOSE

Retinopathy of prematurity (ROP) is a condition of abnormal retinal vascularization with reduced levels of vascular endothelial growth factor (VEGF) causing vaso-obliteration (Phase I), followed by abnormal neovascularization from increased VEGF (Phase II). We hypothesized that intravitreal pro-angiogenic VEGF-A in microparticle form would promote earlier retinal revascularization in an oxygen-induced ischemic retinopathy (OIR) mouse model.

MATERIALS AND METHODS

Wildtype mice (39) were exposed to 77% oxygen from postnatal day 7 (P7) to P12. VEGF-A₁₆₅-loaded poly(lactic-co-glycolic acid) (PLGA) (n = 15) or empty PLGA (n = 14) microparticles were fabricated using a water-in-oil-in-water double emulsion method, and injected intravitreally at P13 into mice right eyes (RE). Left eyes (LE) were untreated. At P20, after retinal fluorescein angiography, vascular parameters were quantified. Retinal VEGF levels at P13 and flatmounts at P20 were performed separately.

RESULTS

VEGF-A₁₆₅-loaded microparticles had a mean diameter of 4.2 μm. with a loading level of 8.6 weight.%. Retinal avascular area was reduced in VEGF-treated RE (39.5 ± 9.0%) compared to untreated LE (52.6 ± 6.1%, p < 0.0001) or empty microparticle-treated RE (p < 0.001) and untreated LEs (p = 0.001). Retinal arteries in VEGF-treated RE were less tortuous than untreated LE (1.08 ± 0.05 vs. 1.18 ± 0.08, p < 0.001) or empty-microparticles-treated RE (p = 0.02). Retinal arterial tortuosity was similar in the LE of VEGF and empty microparticle-treated mice (P > 0.05). Retinal vein width was similar in VEGF-treated and empty microparticle-treated RE (P > 0.9), which were each less dilated than their contralateral LE (p < 0.01). VEGF levels were higher in P13 OIR mice than RA mice (p < 0.0001). Retinal flatmounts showed vaso-obliteration and neovascularization.

CONCLUSIONS

Endogenous retinal VEGF is suppressed in OIR mice. Exogenous intravitreal VEGF-A₁₆₅-loaded microparticles in OIR mice reduced retinal vaso-obliteration and accelerated recovery from vein dilation and arterial tortuosity. This may be beneficial in preventing Phase II ROP without systemic effects.