Issues with Intravitreal Administration of Anti-VEGF Drugs

Establishment of a subvisible particle profile in ophthalmic recombinant fusion protein and antibody formulations to control and monitor drug quality

The presence of subvisible particles in intravitreal injection ophthalmic formulations may affect drug efficacy and safety. Although Chapters 788 and 789 of the United States Pharmacopeia limit the concentration of particles ≥ 10 μm, particles less than 10 μm may cause blurred vision and floaters in the injected eyes. Due to limited access to ophthalmic protein formulations, few studies investigated the profile of subvisible particles in these formulations. In this study, the subvisible particle concentration, size distribution, and morphology of 11 intravitreal injection ophthalmic recombinant fusion protein and monoclonal antibody formulations at different drug clinical trial stages were characterized. In addition, there was significant difference in particle morphology, (circularity, compactness and etc) between unexpired and expired batches using Mann Whitney test, which was probably associated with the proportion change of protein and silicone oil particles and could be used for drug quality control at different clinical trial stages or on the market.

Consensus on intraocular drug preparations

The consensus between the Spanish Society of Retina and Vitreous, the Spanish Society of Hospital Pharmacy and the Spanish Society of Ophthalmology on the preparation, distribution, and administration of intraocular medications is presented, which expands the SEO-SEFH Consensus on recommendations for use and preparation of ophthalmic preparations achieved and published in 2018 in the journal "Farmacia Hospitalaria". Initially, each society appointed at least two members to form the working group that defined the objectives of the consensus. After that, they carried out a bibliographic search of both scientific articles and documentation from regulatory agencies and manufacturers to write a first draft by internal consensus. This draft was reviewed and corrected by members other than the three scientific societies, and was sent to the societies involved for their endorsement. It was verified that this version complied with the recommendations of the AGREE II guide. This consensus includes the review of the requirements that the medical devices used must meet to avoid complications such as the release of silicone drops or other lubricants, as well as a selection of products and suppliers that meet these characteristics, the validity periods for the most common preparations, and the techniques for their preparation, handling and administration.

[Translated article] Consensus on intraocular drug preparations

The consensus between the Spanish Society of Retina and Vitreous, the Spanish Society of Hospital Pharmacy and the Spanish Society of Ophthalmology on the preparation, distribution, and administration of intraocular medications is presented, which expands the SEO-SEFH Consensus on recommendations for use and preparation of ophthalmic preparations achieved and published in 2018 in the journal "Farmacia Hospitalaria". Initially, each society appointed at least two members to form the working group that defined the objectives of the consensus. After that, they carried out a bibliographic search of both scientific articles and documentation from regulatory agencies and manufacturers to write a first draft by internal consensus. This draft was reviewed and corrected by members other than the three scientific societies, and was sent to the societies involved for their endorsement. It was verified that this version complied with the recommendations of the AGREE II guide. This consensus includes the review of the requirements that the medical devices used must meet to avoid complications such as the release of silicone drops or other lubricants, as well as a selection of products and suppliers that meet these characteristics, the validity periods for the most common preparations, and the techniques for their preparation, handling and administration.

Anti-Syndecan 2 Antibody Treatment Reduces Edema Formation and Inflammation of Murine Laser-Induced CNV

Purpose

Alteration of visual acuity in wet age-related macular degeneration (AMD) is mostly driven by vascular endothelial growth factor A (VEGF-A)-induced edema from leaky newly forming blood vessels below the retina layers. To date, all therapies aimed at alleviation of this process have relied on inhibition of VEGF-A activity. Although effective in preventing vascular leak and edema, this approach also leads to the loss of normal vasculature and multiple related side effects.

Methods

We have developed an alternative strategy that uses anti-syndecan-2 polyclonal antibody (anti-Sdc2 pAb) to block VEGF-A-induced permeability without interfering with other VEGF-A activities. The effect of anti-Sdc2 pAb therapy was assessed in vitro using a transendothelial electrical resistance (TEER) assay, as well as staining of the endothelial cell junction, and in vivo in the laser-induced choroidal neovascularization (CNV) model.

Results

Anti-Sdc2 pAb blocked VEGF-A-induced permeability in vitro, and both local intravitreal injections and systemic intravenous treatments with anti-Sdc2 pAb were as effective as intravitreal anti-VEGF therapy in reducing edema, size of retinal lesions, and local inflammation in this model. Post-injury neovascularization was not affected by treatment with anti-Sdc2 pAb.

Conclusions

These findings indicate that anti-Sdc2 pAb therapy can be an effective alternative to anti-VEGF-A approaches for suppression of edema and to prevent retinal lesions in wet neovascular AMD (nAMD).

Translational Relevance

Intravitreal anti-Sdc2 treatment may avoid side effects observed with the long-term anti-VEGF therapy, and systemic treatment with an anti-Sdc2 pAb antibody can address the issues associated with repeated intravitreal injections.

Novel strategies in systemic and local administration of therapeutic monoclonal antibodies

Monoclonal antibodies (mAbs) are an evolving class of biopharmaceuticals, with advancements evident across various stages of their development. While discovery, mAb chemical optimization, production and purification processes have been thoroughly reviewed, this paper aims to offer a summary of novel strategies in administration of mAbs. At present, systemic delivery of mAbs is available through parenteral administration routes with focus on subcutaneous administration. In addition, oriented toward patient-friendly therapy, other less invasive administration routes of mAbs, such as inhalation, nasal, transdermal, and oral administration, are explored. Literature data reveals the potential for local delivery of mAbs via inhalation, nasal, transdermal, intratumoral, intravitreal and vaginal administration, offering high efficacy with fewer systemic adverse effects. However, to date, only mAb medicines are available for intravitreal administration, mainly due to higher bioavailability, and an intranasal spray is authorised as a medical device. The review highlights the promising data in approval of novel administration routes, likely through inhalation, but further intensive research considering the current obstacles, is essential.

ROS-responsive charge reversal mesoporous silica nanoparticles as promising drug delivery system for neovascular retinal diseases

Intravitreal injection of biodegradable implant drug carriers shows promise in reducing the injection frequency for neovascular retinal diseases. However, current intravitreal ocular devices have limitations in adjusting drug release rates for individual patients, thereby affecting treatment effectiveness. Accordingly, we developed mesoporous silica nanoparticles (MSNs) featuring a surface that reverse its charge in response to reactive oxygen species (ROS) for efficient delivery of humanin peptide (HN) to retinal epithelial cells (ARPE-19). The MSN core, designed with a pore size of 2.8 nm, ensures a high HN loading capacity 64.4% (w/w). We fine-tuned the external surface of the MSNs by incorporating 20% Acetyl-L-arginine (Ar) to create a partial positive charge, while 80% conjugated thioketal (TK) methoxy polyethylene glycol (mPEG) act as ROS gatekeeper. Ex vivo experiments using bovine eyes revealed the immobilization of Ar-MSNs-TK-PEG (mean zeta potential: 2 mV) in the negatively charged vitreous. However, oxidative stress reversed the surface charge to -25 mV by mPEG loss, facilitating the diffusion of the nanoparticles impeded with HN. In vitro studies showed that ARPE-19 cells effectively internalize HN-loaded Ar-MSNs-TK, subsequently releasing the peptide, which offered protection against oxidative stress-induced apoptosis, as evidenced by reduced TUNEL and caspase3 activation. The inhibition of retinal neovascularization was further validated in an in vivo oxygen-induced retinopathy (OIR) mouse model.

Clinical Outcomes and Experiences with Prefilled Syringes Versus Vials for Intravitreal Administration of Anti-VEGF Treatments: A Systematic Review

INTRODUCTION

Anti-vascular endothelial growth factor (VEGF) agents have been the standard treatment for retinal diseases for almost two decades. These treatments are administered via intravitreal injection using single-use vials or prefilled syringes (PFS). In this systematic review, we evaluate health care resource use and clinical outcomes and experiences with PFS for intravitreal injection of anti-VEGF treatments.

METHODS

MEDLINE, EMBASE, and The Cochrane Library were searched from January 1, 2015 to February 8, 2024 to identify literature reporting outcomes regarding procedural efficiency, health care resource use, patient and clinician experiences, and safety for currently approved anti-VEGFs (ranibizumab, aflibercept, brolucizumab) administered using PFS. Comparators were vial-based injections of the same anti-VEGFs.

RESULTS

A total of 36 publications met the criteria for inclusion in the systematic literature review; the majority were non-randomized studies, with a small number of reviews, case series, survey studies, and opinion articles. Publications reported that preparation times were significantly shorter for PFS (40.3-57.9 s) versus vials (ranibizumab, 62.8-98.0 s; aflibercept, 71.9-79.5 s), with no differences in product stability between PFS and vials. Clinicians expressed a preference for PFS and thought PFS were faster, easier to use, and had increased safety versus vials. Publications consistently reported significantly lower rates of endophthalmitis per injection with PFS versus vials (ranibizumab PFS, 0-0.02%; aflibercept PFS, 0.01-0.02%; ranibizumab vial, 0.02-0.05%; aflibercept vial, 0.02-0.06%). Four publications reported increased rates of transient vision loss after aflibercept PFS injection versus vial-based injection. No publications reported outcomes regarding health care resource use or patient experiences.

CONCLUSION

The available literature supports the increased procedural efficiency of PFS versus vial-based intravitreal injection of anti-VEGFs. PFS are positively perceived by clinicians and have a safety benefit in the form of a decreased risk of endophthalmitis versus vials.

Sustained Delivery of Rifampicin Nanoformulation Administration Intravitreally Into Rabbit Eyes for Ocular Tuberculosis

INTRODUCTION

Diagnosis and treatment of ocular tuberculosis is very challenging. It poses a significant and potential management dilemma after diagnosis as a primary, active, or secondary infection. The higher amounts of orally administered antitubercular drugs are needed to achieve the therapeutic concentration in the eye, which may lead to a higher risk of side effects. However, the intravitreal administration of drugs is not practiced because of the frequent administration of the injections.

METHODS

This study was carried out to develop, optimize, and characterize rifampicin-loaded poly (lactic-co-glycolic acid) (PLGA) nanoparticles to make them sustained release followed by the direct administration of plain rifampicin and rifampicin nano-formulations in the vitreous of rabbit eyes. Both groups were comparatively assessed for the sustained delivery of the two preparations in the vitreous and their systemic toxicity.

RESULTS

The characteristics of rifampicin-loaded nanoparticles were 786 nm in size with narrow size distribution along with a zeta potential of -12 mV. The drug encapsulation efficiency and loading capacity were 67.68% w/w and 42.28% w/w, respectively. The four New Zealand white rabbits were divided into two groups and given plain rifampicin (50µl volume) and PLGA nanoformulations of rifampicin (50µl volume) in each eye. In vivo, rifampicin-loaded PLGA nanoparticles produced sustained release of rifampicin for a week, even obtaining the 0.51 µg/ml levels on the seventh day in vitreous against negligible levels after one day for free rifampicin. The Cmax levels for free Rifampicin and Rifampicin nanoparticles were 0.44 µg/ml and 1.86 µg/ml, respectively.

CONCLUSION

In this experimental proof-of-concept study, we have found that rifampicin-loaded PLGA nanoparticles released rifampicin in a sustained manner for up to seven days compared to free drugs only for one day into the vitreous. The intravitreal-administered drug did not reach systemic circulation.

Endophthalmitis after Anti-VEGF Intravitreal Injections with Aqueous Chlorhexidine versus Povidone-Iodine as Ocular Antiseptics

PURPOSE

To compare the rates and outcomes of endophthalmitis after intravitreal injections (IVIs) for patients pretreated with 5% povidone-iodine (PI) and 0.05% chlorhexidine (CHX).

DESIGN

A retrospective, single-center, comparative cohort study.

PARTICIPANTS

A total of 8686 patients were included in the study, and a total of 67 695 anti-VEGF injections were performed from January 1, 2019, to November 30, 2021.

SETTING

A private retina practice of 13 retina specialists in Colorado.

METHODS

Using electronic health records, patients with preinjection preparation with PI or CHX were compiled retrospectively. Use of prefilled versus nonprefilled syringes was also tabulated. Patients with postinjection endophthalmitis (PIE) were identified among the 2 groups. Postinjection endophthalmitis is defined as an inflammation of the eye from infectious agents after an IVI. Logarithm of the minimum angle of resolution (logMAR) visual acuity (VA) was determined at the time of causative anti-VEGF injection, endophthalmitis presentation, and 3-month follow-up.

RESULTS

A total of 67 695 IVIs were administered by 13 retina specialists during the study period. A total of 13 of 32 802 (0.0396%; 1 in 2523 injections) cases of presumed endophthalmitis occurred in the PI group, and 9 of 34 893 (0.0258%; 1 in 3877 injections) cases in the CHX group (P = 0.395). For the PI group, there were 2 culture-positive endophthalmitis cases (0.0061%, 1 in 16 401), compared with 2 cases in the CHX group (0.00573%, 1 in 17 447) (P = 1.000). No significant difference was observed in the average logMAR VA of PI and CHX at causative injection (P = 0.3851), endophthalmitis encounter (P = 0.7718), and 3-month follow-up (P = 0.6152). A significant reduction in presumed endophthalmitis (P = 0.0445) and culture-positive cases (P = 0.0130) was present for prefilled IVI compared with nonprefilled injections.

CONCLUSIONS

No significant difference in the rate of endophthalmitis or visual outcomes were found in the CHX group compared with the PI group. Prefilled syringes were associated with a significant reduction in endophthalmitis rate. Further multicenter studies are needed to validate the efficacy and safety of CHX compared with PI for IVI preparation.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

[Translated article] Syringes for intraocular administration: A systematic review

OBJECTIVE

The off-label use in clinical practice of non-approved syringes for intravitreal drug administration has resulted in the detection of silicone oil drops in the vitreous of some patients. This situation derives from the lack of approved syringes for intraocular use in the Spanish market. The aim of this work is to review the use of syringes for intraocular administration, as well as to search for alternatives that meet the legal requirements for these unmet needs.

METHOD

A systematic review was performed following the PRISMA 2020 guidelines by searching PubMed with the descriptors: (silicone) AND (syringes) AND ((intraocular) OR (intravitreal)) and filtering all existing publications from January 2006 to December 2023, including all those articles dealing with silicone oil release in intravitreal injections and analysing the possible consequences.

RESULTS

Sixty-eight results were found, 23 of which were excluded because they did not deal with the subject under study, leaving a total of 45 articles for the systematic review. These were classified according to the conclusions obtained in 4 groups: the adverse reactions produced by silicone; the administration technique; the physicochemical aspects of silicone release; and the characteristics of the medical device. After reviewing the current manufacturers and technical data sheets of commercialised syringes, the existing syringes for this use have been collected, finding 2 that will probably be commercialised in Spain at the beginning of 2024: Zero Residual™ 0.2 ml SiO-free and VitreJect® Ophthalmic.

CONCLUSIONS

From the results obtained, it can be interpreted that the use of syringes and needles with silicone for intravitreal use is a concern for health professionals due to the implications and consequences that may arise in patients, the most important being adverse reactions, so it is necessary to have silicone-free syringes on the market that are specific for intraocular use. Safety and legality in the use of intraocular syringes and needles is essential to guarantee ocular integrity and patient health.

Syringes for intraocular administration: Systematic review

OBJECTIVE

The off-label use in clinical practice of non-approved syringes for intravitreal drug administration has resulted in the detection of silicone oil drops in the vitreous of some patients. This situation derives from the lack of approved syringes for intraocular use in the Spanish market. The aim of this work is to review the use of syringes for intraocular administration, as well as to search for alternatives that meet the legal requirements for these unmet needs.

METHOD

A systematic review was performed following the PRISMA 2020 Guidelines by searching PubMed with the descriptors: "silicone" AND "syringes" AND ("intraocular" OR "intravitreal") and filtering all existing publications from January 2006 to December 2023, including all those articles dealing with silicone oil release in intravitreal injections and analysing the possible consequences.

RESULTS

Sixty-eight results were found, 23 of which were excluded because they did not deal with the subject under study, leaving a total of 45 articles for the systematic review. These were classified according to the conclusions obtained in 4 groups: the adverse reactions produced by silicone, the administration technique, the physicochemical aspects of silicone release, and the characteristics of the medical device. After reviewing the current manufacturers and technical data sheets of commercialized syringes, the existing syringes for this use have been collected, finding two that will probably be commercialized in Spain at the beginning of 2024: Zero Residual™ 0.2 ml SiO-free and VitreJect® Ophthalmic.

CONCLUSIONS

From the results obtained, it can be interpreted that the use of syringes and needles with silicone for intravitreal use is a concern for health professionals due to the implications and consequences that may arise in patients, the most important being adverse reactions, so it is necessary to have silicone-free syringes on the market that are specific for intraocular use. Safety and legality in the use of intraocular syringes and needles is essential to guarantee ocular integrity and patient health.

Exosomal noncoding RNA: A potential therapy for retinal vascular diseases

Exosomes are extracellular vesicles that can contain DNA, RNA, proteins, and metabolites. They are secreted by cells and play a regulatory role in various biological responses by mediating cell-to-cell communication. Moreover, exosomes are of interest in developing therapies for retinal vascular disorders because they can deliver various substances to cellular targets. According to recent research, exosomes can be used as a strategy for managing retinal vascular diseases, and they are being investigated for therapeutic purposes in eye conditions, including glaucoma, dry eye syndrome, retinal ischemia, diabetic retinopathy, and age-related macular degeneration. However, the role of exosomal noncoding RNA in retinal vascular diseases is not fully understood. Here, we reviewed the latest research on the biological role of exosomal noncoding RNA in treating retinal vascular diseases. Research has shown that noncoding RNAs, including microRNAs, circular RNAs, and long noncoding RNAs play a significant role in the regulation of retinal vascular diseases. Furthermore, through exosome engineering, the expression of relevant noncoding RNAs in exosomes can be controlled to regulate retinal vascular diseases. Therefore, this review suggests that exosomal noncoding RNA could be considered as a biomarker for diagnosis and as a therapeutic target for treating retinal vascular disease.

Long-Acting Ocular Injectables: Are We Looking In The Right Direction?

The complex anatomy and physiological barriers of the eye make delivering ocular therapeutics challenging. Generally, effective drug delivery to the eye is hindered by rapid clearance and limited drug bioavailability. Biomaterial-based approaches have emerged to enhance drug delivery to ocular tissues and overcome existing limitations. In this review, some of the most promising long-acting injectables (LAIs) in ocular drug delivery are explored, focusing on novel design strategies to improve therapeutic outcomes. LAIs are designed to enable sustained therapeutic effects, thereby extending local drug residence time and facilitating controlled and targeted drug delivery. Moreover, LAIs can be engineered to enhance drug targeting and penetration across ocular physiological barriers.

Application of Formulation Principles to Stability Issues Encountered During Processing, Manufacturing, and Storage of Drug Substance and Drug Product Protein Therapeutics

The field of formulation and stabilization of protein therapeutics has become rather extensive. However, most of the focus has been on stabilization of the final drug product. Yet, proteins experience stress and degradation through the manufacturing process, starting with fermentaition. This review describes how formulation principles can be applied to stabilize biopharmaceutical proteins during bioprocessing and manufacturing, considering each unit operation involved in prepration of the drug substance. In addition, the impact of the container on stabilty is discussed as well.

A New Era in Ocular Therapeutics: Advanced Drug Delivery Systems for Uveitis and Neuro-Ophthalmologic Conditions

The eye's intricate anatomical barriers pose significant challenges to the penetration, residence time, and bioavailability of topically applied medications, particularly in managing uveitis and neuro-ophthalmologic conditions. Addressing this issue, polymeric nano-based drug delivery systems (DDS) have surfaced as a promising solution. These systems enhance drug bioavailability in hard-to-reach target tissues, extend residence time within ocular tissues, and utilize biodegradable and nanosized polymers to reduce undesirable side effects. Thus, they have stimulated substantial interest in crafting innovative treatments for uveitis and neuro-ophthalmologic diseases. This review provides a comprehensive exploration of polymeric nano-based DDS used for managing these conditions. We discuss the present therapeutic hurdles posed by these diseases and explore the potential role of various biopolymers in broadening our treatment repertoire. Our study incorporates a detailed literature review of preclinical and clinical studies from 2017 to 2023. Owing to advancements in polymer science, ocular DDS has made rapid strides, showing tremendous potential to revolutionize the treatment of patients with uveitis and neuro-ophthalmologic disorders.

Life Quality in Patients with Impaired Visual Acuity Undergoing Intravitreal Medication Applications

This cross-sectional study aims to examine the quality of life and difficulties in the daily functioning of patients with impaired visual acuity treated with intravitreal drugs. The survey included 180 adult respondents (78 male and 102 female). The standardized, validated questionnaire VFQ 25 version 2000 was used to measure the quality of life. Results show that, in general, regarding visual functioning, men are significantly more satisfied than women, they rate less intensity of pain, and their distance vision is better. Men report fewer restrictions than women, better color, peripheral vision, and overall visual functioning. The best vision results are in individuals under the age of 60 who also report significantly better social functioning, mental health, fewer restrictions, and less dependence on others. The only significant association between the number of drug applications and the scale of visual functioning is driving motor vehicles-the more applications of the drug they received, the less likely they are to drive a car. The quality of life in patients with chronic ophthalmic diseases treated with intravitreal drugs is reduced, particularly in elderly and female patients who have poorer visual acuity, poorer health in general, and limited social roles.

A Paradigm Shift in the Management Approaches of Proliferative Diabetic Retinopathy: Role of Anti-VEGF Therapy

Diabetic retinopathy (DR) is considered one of the leading causes of vision loss globally. It principally causes upregulation of pro-angiogenic, proinflammatory, and vascular permeability factors such as vascular endothelial growth factor (VEGF), leading to neovascularisation. The advanced stage of DR or proliferative diabetic retinopathy (PDR) is of more concern, as it leads to vitreous haemorrhage and traction retinal detachment. Various risk factors associated with PDR include hyperglycemia, hypertension, neuropathy, dyslipidemia, anaemia, nephropathy, and retinal complications of drugs used for diabetes. Current management approaches for PDR have been stratified and involve pan-retinal photocoagulation, vitrectomy, and anti-VEGF agents. Given the emerging role of anti-VEGF agents as a favourable adjunct or alternative therapy, they have a critical role in the management of PDR. The review emphasises current management approaches for PDR focusing on anti-VEGF therapy. The review also highlights the risk/benefit evaluation of the various approaches employed for PDR management in various clinical scenarios.

Prevalence and implications of the presence of intraocular silicone oil droplets in patients treated with intravitreal injections of anti-VEGF

Background

To determine the percentage of patients who have silicone droplets in the vitreous after treatment with different anti-Vascular Endothelial Growth Factor (anti-VEGF) intravitreal injections (IVI) and how symptomatic they are.

Methods

One hundred fifty-two eyes of 140 patients who had at least received an IVI were recruited for this study. Data collection included the number and type of IVI (aflibercept, ranibizumab and bevacizumab) and the follow-up time. A complete ophthalmologic examination was carried out and patients were classified in four groups according to the amount of silicone droplets found in dilated fundoscopy (nonexistent, scarce, moderate and abundant). Measurement of intraocular pressure (IOP) was also carried out. An interview was conducted to report the presence and intensity of the symptomatology.

Results

Silicone oil droplets were reported in 109 eyes (71.7%). A positive correlation was found between the number of IVIs received and the quantity of droplets found, especially when aflibercept was used. Posterior vitreous detachment (PVD) was present in 65.8% of the patients, showing a positive correlation with the number of bubbles. Regarding the symptomatology, 60 eyes (39.5%) had floaters and the disturbance was reported to be 4 out of 10. The group with a moderate amount of silicone droplets had the highest percentage of floaters (60%). No statistical differences in the IOP were found between groups, although the group with abundant droplets had a higher mean IOP.

Conclusion

A high prevalence of silicone droplets in vitreous of patients who undergo IVI treatment was found. It appears to have little impact on symptomatology and rise of IOP.

Dabigatran and Wet AMD, Results From Retinal Pigment Epithelial Cell Monolayers, the Mouse Model of Choroidal Neovascularization, and Patients From the Medicare Data Base

Background

Age-related macular degeneration (AMD), the leading cause of irreversible blindness in elderly Caucasian populations, includes destruction of the blood-retina barrier (BRB) generated by the retinal pigment epithelium-Bruch's membrane complex (RPE/BrM), and complement activation. Thrombin is likely to get access to those structures upon BRB integrity loss. Here we investigate the potential role of thrombin in AMD by analyzing effects of the thrombin inhibitor dabigatran.

Material and Methods

MarketScan data for patients aged ≥65 years on Medicare was used to identify association between AMD and dabigatran use. ARPE-19 cells grown as mature monolayers were analyzed for thrombin effects on barrier function (transepithelial resistance; TER) and downstream signaling (complement activation, expression of connective tissue growth factor (CTGF), and secretion of vascular endothelial growth factor (VEGF)). Laser-induced choroidal neovascularization (CNV) in mouse is used to test the identified downstream signaling.

Results

Risk of new wet AMD diagnosis was reduced in dabigatran users. In RPE monolayers, thrombin reduced TER, generated unique complement C3 and C5 cleavage products, led to C3d/MAC deposition on cell surfaces, and increased CTGF expression via PAR1-receptor activation and VEGF secretion. CNV lesion repair was accelerated by dabigatran, and molecular readouts suggest that downstream effects of thrombin include CTGF and VEGF, but not the complement system.

Conclusions

This study provides evidence of association between dabigatran use and reduced exudative AMD diagnosis. Based on the cell- and animal-based studies, we suggest that thrombin modulates wound healing and CTGF and VEGF expression, making dabigatran a potential novel treatment option in AMD.

Novel and investigational therapies for wet and dry age-related macular degeneration

Age-related macular degeneration (AMD) is a macular degenerative eye disease, the major cause of irreversible loss of central vision. In this review, we highlight current progress and future perspectives of novel and investigational therapeutic strategies in the drug pipeline, including anti-vascular endothelial growth factor (VEGF) agents, bispecific antibodies, biosimilars, small molecules, gene therapy, and long-acting drug delivery strategies for both dry and wet AMD. We anticipate that biologics with dual functionalities and combined therapies with long-acting capabilities will lead the wet AMD pipeline. Sustained-release platforms also show potential. However, significant breakthroughs are yet to be made for dry AMD. The personalized approach might be well suited in the scenario of diverse genetic variations in both conditions. Teaser: AMD is the leading cause of global blindness in the developed world. This article highlights investigational therapeutics, such as antibodies, Bi-specifics, small molecules, biosimilars, gene therapy and long-acting strategies (Port Delivery System), for this condition.

Safety of simultaneous bilateral intravitreal versus unilateral anti-vasculo-endothelial growth factors injection in an operating room setting

OBJECTIVES

Chorioretinal diseases requiring the use of anti-vascular endothelial growth (anti-VEGF) injections often occur in both eyes simultaneously. This can necessitate injecting both eyes together rather than one eye at a time. The purpose of the study was to determine whether simultaneous bilateral intravitreal injections of anti-VEGF agents are safe when administered in an operation theatre setting.

METHODS

Retrospective review of data was conducted. Single center study conducted in a tertiary care hospital in Karachi Pakistan. Approximately 30,000 eyes that received anti-VEGF injection during a 10-year study period were included (March 2008-February 2018). Patients who were lost to follow up prior to completion of treatment were excluded. Consecutive sampling technique was employed. The patients who received bilateral anti-VEGF injections were analysed separately from the ones who received unilateral injections. All injections were administered in operating theatre setting. The rate of endophthalmitis was measured in each group.

RESULTS

A total of 30,258 injections were administered of which 15,338 were bilateral injections. Four cases (4/30,258, 0.013%) of endophthalmitis occurred during the study period. Only one case (1/15,338, 0.0065%) of endophthalmitis occurred after the administration of simultaneous bilateral anti-VEGF injections.

CONCLUSIONS

Administration of simultaneous bilateral anti-VEGF injections was safe in our population.

Age-related macular degeneration and resource utilization in the Brazilian public healthcare system: a real-world retrospective study

Background

Age-related macular degeneration (AMD) is a disease that causes damage in the macular region of the retina, leading to irreversible blindness. This study aims to understand the profile and care of patients with AMD and its cost at the Brazilian public health system to identify AMD-care needs.

Methods

This is a retrospective observational study of AMD with real-world data from the Brazilian public healthcare system, using DATASUS claim databases. Patients with AMD were selected from 01/Jan/2014 to 31/Jan/2020; had at least one claim of ICD10 code H35.3 (Degeneration of macula and posterior pole), and were submitted to one of two procedures exclusively available for AMD patients - optical coherence tomography (OCT) and medical treatment of retinal disease (antiangiogenic); aged ≥18 years at first ICD10 claim, and presenting at least 1 year of follow-up in the database. We described patients’ characteristics, healthcare resource utilization and cost, and the antiangiogenic intravitreal treatment received by AMD patients, including the number of doses and interval time between them.

Results

Patients searching for AMD treatment since 2014 were mostly females (59%), white (61%), and a mean age of 72 years. They were mainly located in the Southeast (87%), and few patients were found in the North (1%) and Central-West (1.5%) regions, probably reflecting where the Brazilian guideline to treat AMD (Protocolo Clínico e Diretrizes Terapêuticas - PCDT) was incorporated as routine care for AMD. The average antiangiogenic dose of 2.5 antiangiogenic therapies within a year was below the expected. Most injections had an interval time of 20 to 40 days between doses, although some patients were treated more than 100 days. Another setback is that patients traveled longer distances for OCT and antiangiogenic treatment than overall AMD-healthcare, between 10 and 100 km.

Conclusions

AMD patients seem to be undertreated, as they receive a mean of 2.5 doses of antiangiogenic treatment within a year. Inequalities among regions are evident, as the Southeast and South regions comprise almost all patients receiving the treatment from the public health system, probably reflecting the region with more access to AMD care according to PCDT recommendations.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12886-021-02181-1.

Effect of Repeated Topical Povidone-Iodine and Antibiotic Applications on Meibomian Glands and Ocular Surface Parameters in Patients With Repeated Intravitreal Injections

OBJECTIVES

To assess whether meibomian glands and ocular surface parameters are affected by repeated topical povidone-iodine and antibiotic applications in patients with repeated intravitreal injections.

METHODS

Forty-five patients with at least three previous intravitreal injections and 28 healthy controls were included in the study. In the injection group, 21 patients had age-related macular degeneration and 24 patients had diabetic macular edema. For each participant, infrared meibography for the upper and lower eyelids and noninvasive tear break-up time calculation were performed with a corneal topographer. Fluorescein tear break-up time and ocular surface disease index (OSDI) scores were also obtained. Noninvasive tear break-up time, fluorescein tear break-up time, and OSDI scores were recorded for each participant and compared between the injection and control groups. These parameters were also compared as a subgroup analysis between patients with age-related macular degeneration (AMD) and diabetic macular edema (DME).

RESULTS

Upper lid meibomian gland loss, lower lid meibomian gland loss ratios, and OSDI scores were significantly higher in the intravitreal injection group compared with the control group (P=0.004, P<0.001, P<0.001, respectively). Fluorescein tear break-up time and noninvasive tear break-up time were significantly lower in the intravitreal injection group compared with the control group (P<0.001, P<0.001). There was no significant difference between the AMD and DME groups for these parameters.

CONCLUSION

This study showed for the first time that meibomian gland losses were significantly increased by repeated povidone-iodine and antibiotic applications in patients with repeated intravitreal injections. Ocular surface parameters were altered with higher ocular surface symptoms in those patients.

Evaluation of the prevalence of silicone oil droplets in the vitreous in patients treated with multiple intravitreal drug injections

Background. At present, intraocular drops of silicone oil, which is a lubricant for disposable syringes used for intravitreal injections, are being actively studied. Among the undesirable effects of their presence are patient’s complaints of visual discomfort associated with floating opacities, as well as a potential connection with episodes of intraocular inflammation and increased intraocular pressure.

The aim: to assess the prevalence of silicone oil droplets in the vitreous in patients treated with multiple intravitreal injections.

Materials and methods. A single-center retrospective cohort study was carried out. Inclusion criterion: treatment with multiple (at least 5) intravitreal injections of drug solutions performed according to registered indications. The study group consisted of 86 eyes of 85 patients (56 women, 29 men; age – from 36 to 89 y.o., average – 71.7 y.o.), who received an average of 13.2 injections of solutions of various drugs.

Results. Drops of silicone oil were detected by biomicroscopy in 57 eyes (66.28 %) and by ultrasonography in 76 (88.37 %). The coincidence of the results of applying the methods was recorded in 73.26 % of observations. Seven (8.1 %) patients had characteristic complaints. Four patients (4.7  %) had a history of aseptic vitreitis. The  hypothesis was  confirmed that the possibility of silicone oil droplets getting into the vitreous increases with the number of intravitreal injections. A similar relationship was established in relation to the possibility of the appearance of characteristic complaints in patients due to the presence of drops and episodes of aseptic vitreitis.

Conclusion. The release of drops of silicone oil from syringes during intravitreal injections is an urgent problem that requires further study. In the Russian Federation, the situation is aggravated by the lack of prefilled syringes with drugs approved for administration into the eye cavity, as well as the lack of syringe models designed for use in ophthalmology. 

Silicone microbubbles after anti-vascular endothelial growth factor injections in patients with wet age-related macular degeneration: incidence, quantification and secondary optical coherence tomography artfacts

PURPOSE

To report the incidence and quantity of silicone oil microbubbles and the relationship with the number of intravitreal anti-vascular endothelial growth factor (VEGF) injections and evaluate if microbubbles induce artefacts on optical coherence tomography (OCT) images.

METHODS

Observational, descriptive, cross-sectional study. Patients with wet age-related macular degeneration were included who had been treated for 1 year minimally with anti-VEGF injections repackaged in the hospital pharmacy. Detection and quantification of silicone microbubbles by mydriatic biomicroscopic examination were conducted 1 month after the last injection. The numbers of microbubbles were quantified on a scale of 0-3: 0, none; 1 scarce (1-10 microbubbles); 2 moderate (10-30); or 3 numerous (>30). Shadowing on OCT images was classified as 0-3: 0, none; 1 obscuring some retinal layers; 2 obscuring all retinal layers; or 3 obscuring the retinal thickness.

RESULTS

The study included 142 eyes of 98 patients (mean age, 82.4 years + 7.3; range, 65-97) treated with 2377 injections. Microbubbles were detected in 127 (89.4%) eyes, 62 (43.6%) with numerous microbubbles and 36 (25.4%) and 29 (20.4%), respectively, with scarce and moderate numbers. A positive correlation was found between the numbers of injections and intravitreal silicone (rho, 0.7). Optical coherence tomography (OCT) artefacts were detected in 11 eyes; the artefacts obscured all retinal layers in three eyes. No significant relationship could be established between the appearance of floaters and the microbubbles.

CONCLUSION

The presence and number of silicone microbubbles were correlated with the number of intravitreal injections. Microbubbles can produce OCT artefacts, which can hinder the treatment decision.

Safety of Receiving Anti-Vascular Endothelial Growth Factor Intravitreal Injection in Office-Based vs Operating Room Settings: A Meta-analysis

Importance

Compared with the operating room (OR), office-based intravitreal injection (IVI) is considered a more cost-effective and convenient approach, yet clinical outcomes of IVIs with anti-vascular endothelial growth factor (VEGF) agents in different settings (office-based vs OR) have not been systematically evaluated.

Objective

To evaluate the safety outcomes of IVI with anti-VEGF agents in the OR vs office-based setting.

Data Sources

PubMed, Embase, Cochrane Library, Web of Science, and ClinicalTrials.gov were searched from inception to July 2020.

Study Selection

Eligible studies reporting on patients who received IVIs with anti-VEGF drugs with a clearly stated injection setting of the office or OR.

Data Extraction and Synthesis

Two reviewers independently screened studies, extracted data, and assessed risk of bias. A meta-analysis was conducted to determine the rates of endophthalmitis (EO) and culture-positive EO.

Main Outcomes and Measures

Rates of EO and culture-positive EO following anti-VEGF IVIs in the OR and office-based setting.

Results

Thirty-one studies with a total of 1 275 815 injections were included. Comparative analysis suggested no difference between rates of EO after IVIs performed in the office and OR settings (odds ratio, 3.06; 95% CI, 0.07-139.75; P = .57; I2 = 80%) were identified, yet a higher rate of culture-positive EO was found in the office setting (odds ratio, 21.52; 95% CI, 2.39-193.55; P = .006; I2 = 0%). The pooled rates of EO following anti-VEGF IVIs were 0.03% (95% CI, 0.03-0.04) and 0.02% (95% CI, 0.01-0.04) in office and OR settings, respectively, and the pooled rates of culture-positive EO were 0.01% (95% CI, 0.01-0.02) and 0.01% (95% CI, 0-0.02). The pooled rates of other ocular and systemic adverse events were low.

Conclusions and Relevance

The rate of clinically suspected or culture-positive EO following anti-VEGF IVIs was low whether the procedure was performed in the office or OR setting. Bacterial spectrum could differ between the 2 settings. This meta-analysis could not determine if it is more appropriate to give treatment in the OR for safety reasons in low-income compared with higher-income regions in the world.

Silicone oil droplets in the vitreous after intravitreal injections: review of literature with clinical examples

Currently, intravitreal injections are firmly in the lead as a drug delivery method for treatment of a wide range of eye diseases. With the accumulation of clinical material, knowledge about the complications and side effects of this technique is expanding. One of the undesirable phenomena that has been actively studied recently is the ingress of silicone oil droplets from single-use syringes and needles used to perform the procedure into the vitreous cavity of patients eyes. The analysis of the results of original studies on this issue is carried out, and the currently available practical recommendations aimed at reducing the risk of this complication are presented. The article is illustrated with original clinical examples. It can be concluded that the penetration of silicone oil into the eye cavity during intravitreal injections is an urgent problem of modern ophthalmology that requires further investigation and solution.

Ocular Therapeutics and Molecular Delivery Strategies for Neovascular Age-Related Macular Degeneration (nAMD)

Age-related macular degeneration (AMD) is the leading cause of vision loss in geriatric population. Intravitreal (IVT) injections are popular clinical option. Biologics and small molecules offer efficacy but relatively shorter half-life after intravitreal injections. To address these challenges, numerous technologies and therapies are under development. Most of these strategies aim to reduce the frequency of injections, thereby increasing patient compliance and reducing patient-associated burden. Unlike IVT frequent injections, molecular therapies such as cell therapy and gene therapy offer restoration ability hence gained a lot of traction. The recent approval of ocular gene therapy for inherited disease offers new hope in this direction. However, until such breakthrough therapies are available to the majority of patients, antibody therapeutics will be on the shelf, continuing to provide therapeutic benefits. The present review aims to highlight the status of pre-clinical and clinical studies of neovascular AMD treatment modalities including Anti-VEGF therapy, upcoming bispecific antibodies, small molecules, port delivery systems, photodynamic therapy, radiation therapy, gene therapy, cell therapy, and combination therapies.

Chemical-gas Sterilization of External Surface of Polymer-based Prefilled Syringes and Its Effect on Stability of Model Therapeutic Protein

To reduce the risk of infection during intravitreal injections, the external surface of prefilled syringes (PFSs) must be sterilized. Usually, ethylene oxide (EO) gas or vaporized hydrogen peroxide (VHP) is used for sterilization. More recently, nitrogen dioxide (NO₂) gas sterilization has been developed. It is known that gas permeability is approximately zero into glass-PFSs. However, polymer-PFSs (P-PFSs) have relatively high gas permeability. Therefore, there are concerns about the potential impact of external surface sterilization on drug solutions in P-PFSs. In this study, P-PFSs [filled with water for injection (WFI) or human serum albumin (HSA) solution] were externally sterilized using EO, VHP, and NO₂ gases. For the WFI-filled syringes, the concentration of each gas that ingressed into the WFI was measured. For the HSA solution-filled syringes, the physical and chemical degradation of HSA molecules by each sterilant gas was quantified. For the EO- or VHP-sterilized syringes, the ingressed EO or hydrogen peroxide (H₂O₂) molecules were detected in the filled WFI. Additionally, EO-adducted or oxidized HSA molecules were observed in the HSA-filled syringes. In contrast, the NO₂-sterilized WFI-filled syringes exhibited essentially immeasurable ingressed NO₂, and protein degradation was not detected in HSA-filled syringes.

Metabolomics Analyses of Mouse Retinas in Oxygen-Induced Retinopathy

Purpose

Retinal neovascularization is a severe pathological process leading to irreversible blindness. This study aims to identify the altered metabolites and their related pathways that are involved in retinal neovascularization.

Methods

To reveal the global metabolomic profile change in the retinal neovascularization process, an untargeted metabolomics analysis of oxygen-induced retinopathy (OIR) mice retinas was carried out first, followed by the validation of amino acids and their derivatives through a targeted metabolomics analysis. The involved pathways were predicted by bioinformatic analysis.

Results

By untargeted metabolomics, a total of 58 and 49 metabolites altered significantly in OIR retinas under cationic and anionic modes, respectively. By bioinformatics analysis, “ABC transporters,” “central carbon metabolism in cancer.” and “alanine, aspartate, and glutamate metabolism” were the most enriched Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways associated with the changed metabolites. By targeted metabolomics, no significant change was found in the assessed amino acids and their derivatives at postnatal day (P) 12, whereas significantly altered amino acids and their derivatives were recognized at P13, P17, and P42 in OIR retinas.

Conclusions

The metabolomic profile was significantly altered in the neovascularized retinas. In particular, numerous amino acids and their derivatives were significantly changed in OIR retinas. These altered metabolites, together with their associated pathways, might be involved in the pathogenesis of retinal neovascular diseases.

Comparison of Syringes With Intravitreal Anti-VEGF Drugs: Particle Burden and Protein Aggregates in Brolucizumab, Aflibercept and Bevacizumab

Purpose

In a benchwork particle counting analytical evaluation, the number and type of particles in intravitreal injection formulations of three different agents against vascular endothelial growth factor were investigated.

Methods

Commercially available ready-to-use aflibercept and brolucizumab glass syringes, vials containing bevacizumab (off-label use in ophthalmology), and repackaged ready-to-use plastic syringes containing bevacizumab were tested without filtration. Total visible, subvisible, and nanoparticles numbers and size distributions were quantified using light obscuration, flow imaging, resonant mass measurement (RMM), tunable resistive pulse sensing, and dynamic light scattering.

Results

Repackaged bevacizumab showed overall low particle numbers, aflibercept showed high numbers of micrometer sized particles but low nanoparticle numbers, brolucizumab showed low to moderate numbers of micrometer sized particles but high nanoparticle numbers. RMM measurements identified particles in the nanometer range as either proteinaceous or silicon oil; the nature of the other particles was not further evaluated.

Conclusions

Repackaged bevacizumab shows no inferior particle quality compared to ready-to-use products. It is relevant to study nanoparticle load of the products as the micrometer-sized particle numbers do not in all cases correlate to nanoparticle counts. Particularly for the high concentration product Beovu (brolucizumab), high nanoparticle numbers were found despite low numbers of micrometer sized particles. Silicone oil droplets did not account for high particle numbers as the measured numbers were low.

Translational Relevance

Different side effects are registered in different frequencies with different intravitreal anti-VEGF-drugs and syringes, which are applied by injection by small 30G needles through the sclera directly to the intravitreal cavity. The study of nanoparticles and silicone oil droplets may be able to contribute to narrowing down the causes.

Expression of the Endoplasmic Reticulum Stress Marker GRP78 in the Normal Retina and Retinal Degeneration Induced by Blue LED Stimuli in Mice

Retinal degeneration is a leading cause of blindness. The unfolded protein response (UPR) is an endoplasmic reticulum (ER) stress response that affects cell survival and death and GRP78 forms a representative protective response. We aimed to determine the exact localization of GRP78 in an animal model of light-induced retinal degeneration. Dark-adapted mice were exposed to blue light-emitting diodes and retinas were obtained at 24 h and 72 h after exposure. In the normal retina, we found that GRP78 was rarely detected in the photoreceptor cells while it was expressed in the perinuclear space of the cell bodies in the inner nuclear and ganglion cell layers. After injury, the expression of GRP78 in the outer nuclear and inner plexiform layers increased in a time-dependent manner. However, an increased GRP78 expression was not observed in damaged photoreceptor cells in the outer nuclear layer. GRP78 was located in the perinuclear space and ER lumen of glial cells and the ER developed in glial cells during retinal degeneration. These findings suggest that GRP78 and the ER response are important for glial cell activation in the retina during photoreceptor degeneration.

Photo-mediated Ultrasound Therapy to Treat Retinal Neovascularization

This report describes a novel therapeutic technique called photo-mediated ultrasound therapy (PUT). PUT applies synchronized short pulse duration (nanosecond) laser and ultrasound burst on targeted tissue, offering high-precision localized treatment. PUT is based on controlled induction and promotion of micro-cavitation activity in the target tissue. PUT is able to safely and effectively treat retinal neovascularization in rabbits with persistent nonperfusion up to 4 weeks after PUT in the choroidal vasculature.Clinical Relevance- PUT can selectively remove retinal angiogenesis in clinically-relevant disease models in humansized eyes (rabbit) without damaging surrounding tissue.