Management of retinal vascular diseases: a patient-centric approach

Deciphering the interplay of gut microbiota and metabolomics in retinal vein occlusion

This study aims to explore the link between retinal vein occlusion (RVO), a blinding ocular condition, and alterations in gut microbiota composition, to offer insights into the pathogenesis of RVO. Fecal samples from 25 RVO patients and 11 non-RVO individuals were analyzed using 16S rRNA sequencing and liquid chromatography-mass spectrometry (LC-MS). Significant differences in the abundance of gut microbial species were noted between RVO and non-RVO groups. At the phylum level, the RVO group showed an elevation in the ratio of Firmicutes to Bacteroidetes. At the genus level, the RVO group showed higher abundance in Escherichia_Shigella (P < 0.05) and less abundance in Parabacteroides (P < 0.01) than the non-RVO group. Functional predictions indicated reduced folate synthesis, biotin metabolism, and oxidative phosphorylation, with an increase in butyric acid metabolism in the RVO group. LC-MS analysis showed significant differences in purine metabolism, ABC transporters, and naphthalene degradation pathways, especially purine metabolism. Pearson correlation analysis revealed significant associations between bacterial genera and fecal metabolites. Enrichment analysis highlighted connections between specific metabolites and bacterial genera. The findings showed that the dysregulation of gut microbiota was observed in RVO patients, suggesting the gut microbiota as a potential therapeutic target. Modulating the gut microbiota could be a novel strategy for managing RVO and improving patient outcomes. Furthermore, the study findings suggest the involvement of gut microbial dysbiosis in RVO development, underscoring the significance of understanding its pathogenesis for effective treatment development.

IMPORTANCE

Retinal vein occlusion (RVO) is a blinding ocular condition, and understanding its pathogenesis is crucial for developing effective treatments. This study demonstrates significant differences in gut microbiota composition between RVO patients and non-RVO individuals, implicating the involvement of gut microbial dysbiosis in RVO development. Functional predictions and metabolic profiling provide insights into the underlying mechanisms, highlighting potential pathways for therapeutic intervention. These findings suggest that modulating the gut microbiota might be a promising strategy for managing RVO and improving patient outcomes.

CS-UNet: Cross-scale U-Net with Semantic-position dependencies for retinal vessel segmentation

Accurate retinal vessel segmentation is the prerequisite for early recognition and treatment of retina-related diseases. However, segmenting retinal vessels is still challenging due to the intricate vessel tree in fundus images, which has a significant number of tiny vessels, low contrast, and lesion interference. For this task, the u-shaped architecture (U-Net) has become the de-facto standard and has achieved considerable success. However, U-Net is a pure convolutional network, which usually shows limitations in global modelling. In this paper, we propose a novel Cross-scale U-Net with Semantic-position Dependencies (CS-UNet) for retinal vessel segmentation. In particular, we first designed a Semantic-position Dependencies Aggregator (SPDA) and incorporate it into each layer of the encoder to better focus on global contextual information by integrating the relationship of semantic and position. To endow the model with the capability of cross-scale interaction, the Cross-scale Relation Refine Module (CSRR) is designed to dynamically select the information associated with the vessels, which helps guide the up-sampling operation. Finally, we have evaluated CS-UNet on three public datasets: DRIVE, CHASE_DB1, and STARE. Compared to most existing state-of-the-art methods, CS-UNet demonstrated better performance.

Hyper-reflective dots in optical coherence tomography imaging and inflammation markers in diabetic retinopathy

The aim of this study is to correlate small dot hyper-reflective foci (HRF) observed in spectral domain optical coherence tomography (SD-OCT) scans of an animal model of hyperglycaemia with focal electroretinography (fERG) response and immunolabelling of retinal markers. The eyes of an animal model of hyperglycaemia showing signs of diabetic retinopathy (DR) were imaged using SD-OCT. Areas showing dot HRF were further evaluated using fERG. Retinal areas enclosing the HRF were dissected and serially sectioned, stained and labelled for glial fibrillary acidic protein (GFAP) and a microglial marker (Iba-1). Small dot HRF were frequently seen in OCT scans in all retinal quadrants in the inner nuclear layer or outer nuclear layer in the DR rat model. Retinal function in the HRF and adjacent areas was reduced compared with normal control rats. Microglial activation was detected by Iba-1 labelling and retinal stress identified by GFAP expression in Müller cells observed in discrete areas around small dot HRF. Small dot HRF seen in OCT images of the retina are associated with a local microglial response. This study provides the first evidence of dot HRF correlating with microglial activation, which may allow clinicians to better evaluate the microglia-mediated inflammatory component of progressive diseases showing HRF.

Exploring New Therapeutic Avenues for Ophthalmic Disorders: Glaucoma-Related Molecular Docking Evaluation and Bibliometric Analysis for Improved Management of Ocular Diseases

Ophthalmic disorders consist of a broad spectrum of ailments that impact the structures and functions of the eye. Due to the crucial function of the retina in the vision process, the management of eye ailments is of the utmost importance, but several unmet needs have been identified in terms of the outcome measures in clinical trials, more proven minimally invasive glaucoma surgery, and a lack of comprehensive bibliometric assessments, among others. The current evaluation seeks to fulfill several of these unmet needs via a dual approach consisting of a molecular docking analysis based on the potential of ripasudil and fasudil to inhibit Rho-associated protein kinases (ROCKs), virtual screening of ligands, and pharmacokinetic predictions, emphasizing the identification of new compounds potentially active in the management of glaucoma, and a comprehensive bibliometric analysis of the most recent publications indexed in the Web of Science evaluating the management of several of the most common eye conditions. This method resulted in the finding of ligands (i.e., ZINC000000022706 with the most elevated binding potential for ROCK1 and ZINC000034800307 in the case of ROCK2) that are not presently utilized in any therapeutic regimen but may represent a future option to be successfully applied in the therapeutic scheme of glaucoma following further comprehensive testing validations. In addition, this research also analyzed multiple papers listed in the Web of Science collection of databases via the VOSviewer application to deliver, through descriptive analysis of the results, an in-depth overview of publications contributing to the present level of comprehension in therapeutic approaches to ocular diseases in terms of scientific impact, citation analyses, most productive authors, journals, and countries, as well as collaborative networks. Based on the molecular docking study's preliminary findings, the most promising candidates must be thoroughly studied to determine their efficacy and risk profiles. Bibliometric analysis may also help researchers set targets to improve ocular disease outcomes.

Evaluation of standard-of-care intravitreal aflibercept treatment practices in patients with diabetic macular oedema in the UK: DRAKO study outcomes

BACKGROUND/OBJECTIVES

DRAKO (NCT02850263) was a 24-month, prospective, non-interventional, multi-centre cohort study enrolling patients with diabetic macular oedema (DMO) including central involvement. The study evaluated UK standard-of-care intravitreal aflibercept (IVT-AFL) treatment. This analysis describes the treatment pathway and service provision for the anti-vascular endothelial growth factor (VEGF) treatment-naïve (C1) and non-naïve patients (C2) who received prior anti-VEGF treatment for DMO other than IVT-AFL.

METHODS

Mean changes in best-corrected visual acuity and central subfield thickness were measured and stratified by baseline factors, including ethnicity and administration of five initial monthly injections within predefined windows. Clinic visits were classified as treatment only (T1), monitoring assessment only (T2), combined visits (T3) or post-injection visits with no treatment or assessment (T4).

RESULTS

Median time from decision to treat to treatment was 6 days. As a percentage of total visits, T1, T2, T3 and T4 were 7%, 42%, 48% and 3% for C1 and 11%, 39%, 48% and 2% for C2. Most IVT-AFL injections were administered by healthcare professionals (HCPs) other than doctors (C1, 57.4%; C2, 58.5%). The percentage of treatments associated with a procedure-related adverse event where at least 75% of injections were completed by the same injector role were similar for doctors and other HCPs (C1, 1.1% and 0.8%; C2, 0.7%, and 1.0%).

CONCLUSIONS

Results indicate that upon DMO diagnosis, patients were treated promptly, and most visits were combined (treatment and assessment) or monitoring only. Most IVT-AFL was administered by non-physicians with a similar treatment-related safety profile as IVT-AFL administered by physicians.

Improving retinal vascular endothelial cell tropism through rational rAAV capsid design

Vascular endothelial cells (VEC) are essential for retinal homeostasis and their dysfunction underlies pathogenesis in diabetic retinopathy (DR) and exudative age-related macular degeneration (AMD). Studies have shown that recombinant adeno-associated virus (rAAV) vectors are effective at delivering new genetic material to neural and glial cells within the retina, but targeting VECs remains challenging. To overcome this limitation, herein we developed rAAV capsid mutant vectors with improved tropism towards retinal VEC. rAAV2/2, 2/2[QuadYF-TV], and rAAV2/9 serotype vectors (n = 9, capsid mutants per serotype) expressing GFP were generated by inserting heptameric peptides (7AA) designed to increase endothelial targeting at positions 588 (2/2 and 2/2[QuadYF-TV] or 589 (2/9) of the virus protein (VP 1-3). The packaging and transduction efficiency of the vectors were assessed in HEK293T and bovine VECs using Fluorescence microscopy and flow cytometry, leading to the identification of one mutant, termed EC5, that showed improved endothelial tropism when inserted into all three capsid serotypes. Intra-ocular and intravenous administration of EC5 mutants in C57Bl/6j mice demonstrated moderately improved transduction of the retinal vasculature, particularly surrounding the optic nerve head, and evidence of sinusoidal endothelial cell transduction in the liver. Most notably, intravenous administration of the rAAV2/2[QuadYF-TV] EC5 mutant led to a dramatic and unexpected increase in cardiac muscle transduction.

Embedding Patient-Centricity by Collaborating with Patients to Transform the Rare Disease Ecosystem

What is patient-centricity? In some contexts, it has been associated with targeting therapies based on biomarkers or enabling healthcare access. There has been a surge in patient-centricity publications, and in many cases for the biopharmaceutical industry, patient engagement is used to endorse pre-held assumptions at a specific moment in time. Rarely is patient engagement used to drive business decisions. Here we describe an innovative partnership between Alexion, AstraZeneca Rare Disease and patients that allowed a deeper understanding of the biopharmaceutical stakeholder ecosystem and an empathic understanding of each patient's and caregiver's lived experience. Alexion's decision to build patient-centricity frameworks resulted in the formation of two unique organisation design platforms: STAR (Solutions To Accelerate Results for patients) and LEAP (Learn, Evolve, Activate and deliver for Patients) Immersive Simulations. These interconnected programmes required cultural, global, and organisational shifts. STAR generates global patient insights that are embedded in drug candidate and product strategies while helping to establish enterprise foundational alignment and external stakeholder engagement plans. LEAP Immersive Simulations produce detailed country-level patient and stakeholder insights that contribute to an empathetic understanding of each patient's lived experience, support country medicine launches and provide ideas to have a positive impact along the patient journey. Combined, they deliver integrated, cross-functional insights, patient-centric decision making, an aligned patient journey, and 360° stakeholder activation. Throughout these processes, the patient is empowered to dictate their needs and validate the proposed solutions. This is not a patient engagement survey. This is a partnership where the patient co-authors strategies and solutions.

Oral administration of CU06-1004 attenuates vascular permeability and stabilizes neovascularization in retinal vascular diseases

Retinal vascular diseases are the leading cause of blindness worldwide. These diseases have common disease mechanisms including vascular endothelial growth factor (VEGF) signaling, hypoxia, and inflammation. Treatment of these diseases with laser therapy, anti-VEGF injections and/or steroids has significantly improved clinical outcomes. However, these strategies do not address the underlying cause of the pathology and may have harmful side effects. Pathological processes that damage retinal vessels result in vascular occlusion and impairment of the barrier properties of retinal endothelial cells, leading to excessive vascular leakage. Therefore, a new therapeutic approach is needed for the treatment of retinal vascular disease. We were able to confirm that oral administration of CU06-1004, an endothelial dysfunction blocker, inhibited retinal vascular leakage induced by vascular endothelial growth factor (VEGF) and angiopoietin-2 (Ang2). Interestingly, oral administration of CU06-1004 prevented excessive vascular leakage in the diabetic retinopathy model. In addition, CU06-1004 inhibited angiogenesis and confirmed vascular stabilization in the oxygen-induced retinopathy model and laser-induced CNV model. Taken together, CU06-1004 could be a potential therapeutic agent for the treatment of retinal vascular diseases.

Neurovascular injury associated non-apoptotic endothelial caspase-9 and astroglial caspase-9 mediate inflammation and contrast sensitivity decline

Retinal neurovascular injuries are a leading cause of vision loss in young adults presenting unmet therapeutic needs. Neurovascular injuries damage homeostatic communication between endothelial, pericyte, glial, and neuronal cells through signaling pathways that remain to be established. To understand the mechanisms that contribute to neuronal death, we use a mouse model of retinal vein occlusion (RVO). Using this model, we previously discovered that after vascular damage, there was non-apoptotic activation of endothelial caspase-9 (EC Casp9); knock-out of EC Casp9 led to a decrease in retinal edema, capillary ischemia, and neuronal death. In this study, we aimed to explore the role of EC Casp9 in vision loss and inflammation. We found that EC Casp9 is implicated in contrast sensitivity decline, induction of inflammatory cytokines, and glial reactivity. One of the noted glial changes was increased levels of astroglial cl-caspase-6, which we found to be activated cell intrinsically by astroglial caspase-9 (Astro Casp9). Lastly, we discovered that Astro Casp9 contributes to capillary ischemia and contrast sensitivity decline after RVO (P-RVO). These findings reveal specific endothelial and astroglial non-apoptotic caspase-9 roles in inflammation and neurovascular injury respectively; and concomitant relevancy to contrast sensitivity decline.

Paeoniflorin alleviates the progression of retinal vein occlusion via inhibiting hypoxia inducible factor-1α/vascular endothelial growth factor/STAT3 pathway

Retinal vein occlusion (RVO) is a severe retinal vascular disease involving several complications, leading to weakening of vision and even blindness. Globally, over 16 million patients with RVO were found in the middle-aged population. Paeoniflorin (PF), a monomer of Taohong Siwu decoction, was reported to exhibit many pharmacological activities including anti-inflammatory, antioxidant, cardioprotective, and neuroprotective effects. However, the effect of PF on the progression of RVO remains unclear. In the current study, CCK8 assay was performed to investigate the cell viability. In addition, transwell assay and western blot were used to measure cell invasion and protein expression, respectively. Moreover, a mouse model of oxygen-induced dischemic retinopathy (OIR) was established. We found PF was able to inhibit the migration and angiogenesis of human retinal capillary endothelial cells under normoxia. Additionally, PF notably prevented hypoxia-induced angiogenesis of human retinal capillary endothelial cells via inhibiting hypoxia-inducible factor-1α (HIF-1α)/vascular endothelial growth factor (VEGF)/STAT3 pathway. Eventually, PF significantly alleviated the retinal lesions in the mouse with OIR. All in all, PF was able to alleviate the progression of retinal vein occlusion via inhibiting HIF-1α/VEGF/STAT3 pathway. These findings might provide some theoretical knowledge for exploring novel effective treatment for patients with RVO.

A 3D finite element model to study the cavitation induced stresses on blood-vessel wall during the ultrasound-only phase of photo-mediated ultrasound therapy

Photo-mediated ultrasound therapy (PUT) is a novel technique utilizing synchronized ultrasound and laser to generate enhanced cavitation inside blood vessels. The enhanced cavitation inside blood vessels induces bio-effects, which can result in the removal of micro-vessels and the reduction in local blood perfusion. These bio-effects have the potential to treat neovascularization diseases in the eye, such as age-related macular degeneration and diabetic retinopathy. Currently, PUT is in the preclinical stage, and various PUT studies on in vivo rabbit eye models have shown successful removal of micro-vessels. PUT is completely non-invasive and particle-free as opposed to current clinical treatments such as anti-vascular endothelial growth factor therapy and photodynamic therapy, and it precisely removes micro-vessels without damaging the surrounding tissue, unlike laser photocoagulation therapy. The stresses produced by oscillating bubbles during PUT are responsible for the induced bio-effects in blood vessels. In our previous work, stresses induced during the first phase of PUT due to combined ultrasound and laser irradiation were studied using a 2D model. In this work, stresses induced during the third or last phase of PUT due to ultrasound alone were studied using a 3D finite element method-based numerical model. The results showed that the circumferential and shear stress increased as the bubble moves from the center of the vessel toward the vessel wall with more than a 16 times increase in shear stress from 1.848 to 31.060 kPa as compared to only a 4 times increase in circumferential stress from 211 to 906 kPa for a 2 µm bubble placed inside a 10 µm vessel on the application of 1 MHz ultrasound frequency and 130 kPa amplitude. In addition, the stresses decreased as the bubble was placed in smaller sized vessels with a larger decrease in circumferential stress. The changes in shear stress were found to be more dependent on the bubble-vessel wall distance, and the changes in circumferential stress were more dependent on the bubble oscillation amplitude. Moreover, the bubble shape changed to an ellipsoidal with a higher oscillation amplitude in the vessel's axial direction as it was moved closer to the vessel wall, and the bubble oscillation amplitude decreased drastically as it was placed in vessels of a smaller size.

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

Purpose

The aim of this study was to evaluate whether the coronavirus disease 19 (COVID-19) pandemic resulted in undertreatment and subsequent loss of visual acuity (VA) in patients with macular neovascularization (MNV) or retinal vein occlusion (RVO) regularly treated with intravitreal antivascular endothelial growth factor injections.

Methods

Single-center, retrospective study of patients scheduled for treatment between March 19 and June 1, 2020, the national mandatory quarantine period. Patients' demographics, VA, and scheduled treatment during this period were reviewed via medical records. All patients were analyzed regarding treatment attendance rates. The visual impact of COVID-19 was assessed in patients who had been treated and presented a stable VA for >6 months before the beginning of the quarantine.

Results

This study included 927 eyes from 769 patients. The attendance rate increased throughout the study timeframe (p < 0.001) and correlated negatively with higher patient's age (r = -0.142; p = 0.005). Patients with age-related macular degeneration (67.6%) had lower attendance rates (p = 0.007) and were older (p < 0.001). The visual impact analysis included 400 eyes from 325 patients. The average VA variation throughout this period was -1.7 ± 8.4 ETDRS letters and was similar in different retinal pathologies (p = 0.334). VA variation did not correlate with the number of missed treatments per patient (r = 0.100; p = 0.150). The prevalence of subretinal fluid and intraretinal fluid, as well as central retinal thickness decreased significantly throughout the study period (p values of <0.001, <0.001, and 0.032, respectively).

Conclusion

The COVID-19 pandemic had a significant impact on the attendance rate of patients with MNV or RVO to their scheduled treatments, which was higher in the first week of mandatory quarantine. Nevertheless, VA did not decrease significantly during this period, with a limited VA variation regardless of primary retinal disorder and morphological parameters even improved in the eyes included in the visual impact analysis.

Targeting the Angiopoietin/Tie Pathway: Prospects for Treatment of Retinal and Respiratory Disorders

Anti-angiogenic approaches have significantly advanced the treatment of vascular-related pathologies. The ephemeral outcome and known side effects of the current vascular endothelial growth factor (VEGF)-based anti-angiogenic treatments have intensified research on other growth factors. The angiopoietin/Tie (Ang/Tie) family has an established role in vascular physiology and regulates angiogenesis, vascular permeability, and inflammatory responses. The Ang/Tie family consists of angiopoietins 1-4, their receptors, tie1 and 2 and the vascular endothelial-protein tyrosine phosphatase (VE-PTP). Modulation of Tie2 activation has provided a promising outcome in preclinical models and has led to clinical trials of Ang/Tie-targeting drug candidates for retinal disorders. Although less is known about the role of Ang/Tie in pulmonary disorders, several studies have revealed great potential of the Ang/Tie family members as drug targets for pulmonary vascular disorders as well. In this review, we summarize the functions of the Ang/Tie pathway in retinal and pulmonary vascular physiology and relevant disorders and highlight promising drug candidates targeting this pathway currently being or expected to be under clinical evaluation for retinal and pulmonary vascular disorders.

Development of a Preclinical Laser Speckle Contrast Imaging Instrument for Assessing Systemic and Retinal Vascular Function in Small Rodents

Purpose

To develop and test a non-contact, contrast-free, retinal laser speckle contrast imaging (LSCI) instrument for use in small rodents to assess vascular anatomy, quantify hemodynamics, and measure physiological changes in response to retinal vascular dysfunction over a wide field of view (FOV).

Methods

A custom LSCI instrument capable of wide-field and non-contact imaging in small rodents was constructed. The effect of camera gain, laser power, and exposure duration on speckle contrast variance was standardized before the repeatability of LSCI measurements was determined in vivo. Finally, the ability of LSCI to detect alterations in local and systemic vascular function was evaluated using a laser-induced branch retinal vein occlusion and isoflurane anesthesia model, respectively.

Results

The LSCI system generates contrast-free maps of retinal blood flow with a 50° FOV at >376 frames per second (fps) and under a short exposure duration (>50 µs) with high reliability (intraclass correlation R = 0.946). LSCI was utilized to characterize retinal vascular anatomy affected by laser injury and longitudinally measure alterations in perfusion and blood flow profile. Under varied doses of isoflurane, LSCI could assess cardiac and systemic vascular function, including heart rate, peripheral resistance, contractility, and pulse propagation.

Conclusions

We present a LSCI system for detecting anatomical and physiological changes in retinal and systemic vascular health and function in small rodents.

Translational Relevance

Detecting and quantifying early anatomical and physiological changes in vascular function in animal models of retinal, systemic, and neurodegenerative diseases could strengthen our understanding of disease progression and enable the identification of new prognostic and diagnostic biomarkers for disease management and for assessing treatment efficacies.

Adaptive optics ophthalmoscopy: a systematic review of vascular biomarkers

Retinal vascular diseases are a leading cause for blindness and partial sight certifications. By applying adaptive optics (AO) to conventional imaging modalities, the microstructures of the retinal vasculature can be observed with high spatial resolution, hence offering a unique opportunity for the exploration of the human microcirculation. The objective of this systematic review is to describe the current state of retinal vascular biomarkers imaged by AO flood illumination ophthalmoscopy (FIO) and AO scanning laser ophthalmoscopy (SLO). A literature research was conducted in the PubMed and Scopus databases on July 9, 2020. From 217 screened studies, 42 were eligible for this review. All studies underwent a quality check regarding their content. A meta-analysis was performed for the biomarkers reported for the same pathology in at least three studies using the same modality. The most frequently studied vascular biomarkers were the inner diameter (ID), outer diameter (OD), parietal thickness (PT), wall cross-sectional area (WCSA), and wall-to-lumen ratio (WLR). The applicability of AO vascular biomarkers has been mostly explored in systemic hypertension using AO FIO and in diabetes using AO SLO. The result of the meta-analysis for hypertensive patients showed that WLR, PT, and ID were significantly different when compared to healthy controls, while WCSA was not (P < 0.001, P = 0.002, P < 0.001, and P = 0.070, respectively). The presented review shows that, although a substantial number of retinal vascular biomarkers have been explored in AO en face imaging, further clinical research and standardization of procedures is needed to validate such biomarkers for the longitudinal monitoring of arterial hypertension and other diseases.

A Multimodal Imaging-Based Deep Learning Model for Detecting Treatment-Requiring Retinal Vascular Diseases: Model Development and Validation Study

BACKGROUND

Retinal vascular diseases, including diabetic macular edema (DME), neovascular age-related macular degeneration (nAMD), myopic choroidal neovascularization (mCNV), and branch and central retinal vein occlusion (BRVO/CRVO), are considered vision-threatening eye diseases. However, accurate diagnosis depends on multimodal imaging and the expertise of retinal ophthalmologists.

OBJECTIVE

The aim of this study was to develop a deep learning model to detect treatment-requiring retinal vascular diseases using multimodal imaging.

METHODS

This retrospective study enrolled participants with multimodal ophthalmic imaging data from 3 hospitals in Taiwan from 2013 to 2019. Eye-related images were used, including those obtained through retinal fundus photography, optical coherence tomography (OCT), and fluorescein angiography with or without indocyanine green angiography (FA/ICGA). A deep learning model was constructed for detecting DME, nAMD, mCNV, BRVO, and CRVO and identifying treatment-requiring diseases. Model performance was evaluated and is presented as the area under the curve (AUC) for each receiver operating characteristic curve.

RESULTS

A total of 2992 eyes of 2185 patients were studied, with 239, 1209, 1008, 211, 189, and 136 eyes in the control, DME, nAMD, mCNV, BRVO, and CRVO groups, respectively. Among them, 1898 eyes required treatment. The eyes were divided into training, validation, and testing groups in a 5:1:1 ratio. In total, 5117 retinal fundus photos, 9316 OCT images, and 20,922 FA/ICGA images were used. The AUCs for detecting mCNV, DME, nAMD, BRVO, and CRVO were 0.996, 0.995, 0.990, 0.959, and 0.988, respectively. The AUC for detecting treatment-requiring diseases was 0.969. From the heat maps, we observed that the model could identify retinal vascular diseases.

CONCLUSIONS

Our study developed a deep learning model to detect retinal diseases using multimodal ophthalmic imaging. Furthermore, the model demonstrated good performance in detecting treatment-requiring retinal diseases.

Trimetazidine Use in Parkinson's Disease: Is It a Resolved Problem?

Trimetazidine (TMZ), an antianginal drug, can worsen the symptoms of movement disorders, therefore, the European Medicines Agency (EMA) recommended avoiding the use of this drug in Parkinson’s disease (PD). We investigated the impact of this recommendation on the observed trend of TMZ use in PD in Hungary from 2010 to 2016 by conducting a nationwide, retrospective study of health administrative data of human subjects. Interrupted time series analyses were performed to explore changes in user trends after the EMA recommendations. We found that TMZ use in PD decreased by 6.56% in each six-month interval after the EMA intervention [a change in trend of −530.22, 95% confidence interval (CI) = −645.00 to −415.44, p < 0.001 and a decrease in level of −567.26, 95% CI = −910.99 to −223.53, p = 0.005 12 months postintervention]. TMZ discontinuation was the highest immediately after the intervention, however, its rate slowed down subsequently (a change in trend of −49.69, 95% CI = −85.14 to −14.24, p = 0.11 without significant level effects). The rate of new TMZ prescriptions did not reduce significantly, therefore, the decreased overall use was mainly attributable to the increased rate of discontinuation only. The main indications for TMZ use were circulatory system disorders, especially angina pectoris, however, off-label utilization was also considerable (40%). The EMA recommendations on TMZ use seem to be only moderately effective in Hungary. Although the number of patients with PD on the drug modestly decreased after the EMA restrictions, TMZ is still widely used in PD for both on-label and off-label indications.

Factors affecting compliance to intravitreal anti-vascular endothelial growth factor therapy in Indian patients with retinal vein occlusion, age-related macular degeneration, and diabetic macular edema

Purpose:

To evaluate the rate of compliance and the reasons for loss to follow-up in Indian patients with diabetic macular edema (DME), age-related macular degeneration (AMD), and retinal vein occlusion (RVO) being treated with anti-vascular endothelial growth factor (VEGF) therapy.

Methods:

This was a retrospective single-center study. Patients with DME, AMD, or RVO were eligible if they initiated anti-VEGF therapy between January 2013 and December 2017. Patients' data were obtained from hospital electronic records, including the number of injections received, visits, details of follow-up, missed appointments, and reasons for loss to follow-up (>365 days).

Results:

A total of 648 patients were eligible for the study, of which 334 (51.54%) patients were lost to follow-up. Overall, 343 (64.96%) were males and the overall mean (SD) age was 66.40 (7.44) years. A total of 376 (58.0%) patients had a history of diabetes and 364 (56.2%) patients had a history of hypertension. Further, 127 (38.0), 112 (33.5), and 95 (28.4) had DME, AMD, and RVO, respectively and were lost to follow-up. The most commonly reported reason for loss to follow-up was “non-affordability” (n = 120; 41.1%) followed by “no improvement in vision” (n = 83; 28.4%). “No improvement in vision” (42.2%) and “non-affordability” (37.5%) were higher among patients with DME. No association was found in gender- and treatment-wise distribution of reasons for loss to follow-up.

Conclusion:

The results showed that around half of the patients with DME, AMD, and RVO were lost to follow-up to intravitreal anti-VEGF therapy, and the most common factors were “non-affordability” and “no improvement in vision.”

Endophthalmitis following Intravitreal Anti-Vascular Endothelial Growth Factor Therapy: Changes in Incidence and Outcomes over a 9-Year Period

Aims: To evaluate whether the incidence, microbial spectrum, and visual outcomes of endophthalmitis following intravitreal injections have changed over time.Methods: Retrospective cohort study of endophthalmitis in eyes receiving intravitreal injection of anti-vascular endothelial growth factor between 2009-2012 and 2016-2017 at a single, large retina practice.Results: A total of 283,315 injections resulted in 96 suspected infectious endophthalmitis cases. Comparing 2009-2012 and 2016-2017, the rate of suspected endophthalmitis changed from 1 in 2,663 injections to 1 in 3,195 injections (p = .37). Visual outcomes 6 months after endophthalmitis were significantly better during the latter period (p = .04), with an average loss of 6.3 lines of VA in 2009-2012 compared to a loss of 3.6 lines in 2016-2017. In multivariate analysis, a "no-talking" policy during injections resulted in a trend towards a decrease in endophthalmitis incidence (p = .08). Cessation of post-injection topical antibiotic use did not independently decrease endophthalmitis incidence (p = .24) when the effect of a "no-talking" policy was taken into account. A lower rate of endophthalmitis was seen after prefilled vs. conventionally prepared ranibizumab syringe use for injection (0.014% vs. 0.035%, respectively), though this difference did not meet statistical significance (p = .16).Conclusion: The incidence of endophthalmitis after intravitreal injection decreased and visual outcomes improved between the periods of 2009-2012 and 2016-2017. A "no-talking" policy during injections was associated with a trend toward a decrease in endophthalmitis rate.

Plexus-specific retinal vascular anatomy and pathologies as seen by projection-resolved optical coherence tomographic angiography

Optical coherence tomographic angiography (OCTA) is a novel technology capable of imaging retinal vasculature three-dimensionally at capillary scale without the need to inject any extrinsic dye contrast. However, projection artifacts cause superficial retinal vascular patterns to be duplicated in deeper layers, thus interfering with the clean visualization of some retinal plexuses and vascular pathologies. Projection-resolved OCTA (PR-OCTA) uses post-processing algorithms to reduce projection artifacts. With PR-OCTA, it is now possible to resolve up to 4 distinct retinal vascular plexuses in the living human eye. The technology also allows us to detect and distinguish between various retinal and optic nerve diseases. For example, optic nerve diseases such as glaucoma primarily reduces the capillary density in the superficial vascular complex, which comprises the nerve fiber layer plexus and the ganglion cell layer plexus. Outer retinal diseases such as retinitis pigmentosa primarily reduce the capillary density in the deep vascular complex, which comprises the intermediate capillary plexus and the deep capillary plexus. Retinal vascular diseases such as diabetic retinopathy and vein occlusion affect all plexuses, but with different patterns of capillary loss and vascular malformations. PR-OCTA is also useful in distinguishing various types of choroidal neovascularization and monitoring their response to anti-angiogenic medications. In retinal angiomatous proliferation and macular telangiectasia type 2, PR-OCTA can trace the pathologic vascular extension into deeper layers as the disease progress through stages. Plexus-specific visualization and measurement of retinal vascular changes are improving our ability to diagnose, stage, monitor, and assess treatment response in a wide variety of optic nerve and retinal diseases. These applications will be further enhanced with the continuing improvement of the speed and resolution of the OCT platforms, as well as the development of software algorithms to reduce artifacts, improve image quality, and make quantitative measurements.

The Effect of Laser and Ultrasound Synchronization in Photo-Mediated Ultrasound Therapy

OBJECTIVE

Photo-mediated ultrasound therapy (PUT) is a novel, non-invasive, agent-free, highly selective, and precise anti-vascular technique. PUT removes microvessels through promoting cavitation activity precisely in targeted microvessels by applying synchronized nanosecond laser pulses and ultrasound bursts. The synchronization between laser and ultrasound is critical to the outcome of PUT.

METHODS

Through theoretical simulation and experimental study, the effect of synchronization between laser pulses and ultrasound bursts on cavitation activity during PUT is evaluated.

RESULTS

By using a theoretical model, we found that cavitation activity was enhanced when laser pulses and ultrasound bursts were synchronized such that the produced photoacoustic wave overlaid the rarefactional phase of the ultrasound wave. This finding was then verified through in vitro studies where cavitation was monitored by using a passive cavitation detector. Furthermore, we demonstrated that the in vivo treatment outcome of PUT in rabbits was directly related to the synchronization between laser and ultrasound. The anti-vascular effect could only be observed when laser and ultrasound were properly synchronized in vivo.

CONCLUSION

PUT is more efficient when the laser-induced photoacoustic wave overlays the rarefactional phase of the ultrasonic wave.

SIGNIFICANCE

This is a systematic study to investigate the synchronization effect of PUT, which would be significant for further understanding the mechanism and further improving the treatment efficiency of PUT.

Implantable anti-angiogenic scaffolds for treatment of neovascular ocular pathologies

The retinal physiology can accrue oxidative damage and inflammatory insults due to age and metabolic irregularities. Two notable diseases that involve retinal and choroidal neovascularization are proliferative diabetic retinopathy and wet age-related macular degeneration. Currently, these diseases are mainly treated with anti-VEGF drugs (VEGF = vascular endothelial growth factor), generally on a monthly dosage scheme. We discuss recent developments for the treatment of these diseases, including bioactive tissue-engineered materials, which may reduce frequency of dosage and propose a path forward for improving patient outcomes. Graphical abstract Development of materials for long-term intravitreal delivery for management of posterior segment diseases.

Validating a low-cost laser speckle contrast imaging system as a quantitative tool for assessing retinal vascular function

The ability to monitor progression of retinal vascular diseases like diabetic retinopathy in small animal models is often complicated by their failure to develop the end-stage complications which characterize the human phenotypes in disease. Interestingly, as micro-vascular dysfunction typically precedes the onset of retinal vascular and even some neurodegenerative diseases, the ability to visualize and quantify hemodynamic changes (e.g. decreased flow or occlusion) in retinal vessels may serve as a useful diagnostic indicator of disease progression and as a therapeutic outcome measure in response to treatment. Nevertheless, the ability to precisely and accurately quantify retinal hemodynamics remains an unmet challenge in ophthalmic research. Herein we demonstrate the ability to modify a commercial fundus camera into a low-cost laser speckle contrast imaging (LSCI) system for contrast-free and non-invasive quantification of relative changes to retinal hemodynamics over a wide field-of-view in a rodent model.

Association of Intravitreal Anti-Vascular Endothelial Growth Factor Therapy With Risk of Stroke, Myocardial Infarction, and Death in Patients With Exudative Age-Related Macular Degeneration

Importance

Current studies assessing the risk of stroke, myocardial infarction (MI), and death in patients undergoing intravitreal anti-vascular endothelial growth factor (VEGF) therapy are inconclusive. To our knowledge, no population-based studies have been performed to examine these potential risks.

Objective

To examine whether patients with exudative age-related macular degeneration (AMD) receiving intravitreal anti-VEGF injections have a higher incidence of MI, stroke, or death compared with control populations.

Design, Setting, and Participants

This population-based, retrospective cohort study included 504 patients from Olmsted County, Minnesota, identified through the Rochester Epidemiology Project (REP) database as receiving at least 1 intravitreal anti-VEGF injection for exudative AMD from January 1, 2004, to December 31, 2013. Three age- and sex-matched control groups of individuals who did not receive anti-VEGF treatment and were derived from the REP database were also studied: control individuals with exudative AMD in the era before anti-VEGF (January 1, 1990, to December 31, 2003), controls with dry AMD, and controls without AMD. Data analysis was performed from September 1, 2016, to September 1, 2017.

Main Outcomes and Measures

Five-year risk of stroke, MI, and death were assessed in patients compared with controls using Kaplan-Meier and multivariate analysis with Cox proportional hazards regression models.

Results

The study included 504 patients (321 female [63.7%]; mean [SD] age, 76.5 [10.0] years) who received at least 1 intravitreal anti-VEGF injection for exudative AMD during the study period. Kaplan-Meier analysis revealed a 5-year risk of 7.2% for stroke, 6.1% for MI, and 30.0% for death. Patients who received anti-VEGF had no increased risk of stroke or MI compared with controls with dry AMD (n = 504), controls with exudative AMD (n = 473), or controls without AMD (n = 504). There was an increased risk of mortality compared with controls with exudative AMD in the era prior to anti-VEGF therapy but not the other control groups on multivariate analysis (hazard ratio, 1.63; 95% CI, 1.30-2.04; P < .001).

Conclusions and Relevance

This population-based study revealed that intravitreal anti-VEGF therapy for exudative AMD was not associated with consistent increases in the risk of stroke, MI, or death compared with no therapy in patients with or without AMD. It appears to be likely the cardiac events these patients experience are not attributable to their anti-VEGF therapy.

Management of macular edema with branch retinal vein occlusion in a case of secondary polycythemia

Purpose: We report a case of polycythemia with an ocular complication of branch retinal vein occlusion associated with macular edema that was managed by anti-vascular endothelial growth factor (VEGF) and systemic management.

Methods: A 43-year-old, one-eyed male, a known case of polycythemia presented with complaints of decreased vision in the right eye. He underwent comprehensive eye evaluation, fundus photography and optical coherence tomography at the baseline visit and post intravitreal ranibizumab 1-, 3-, 4- and 11-month follow-up.

Results: A patient with polycythaemia was diagnosed in the right eye with superotemporal branch retinal vein occlusion and macular edema, which clinically and on optical coherence tomography resolved after 1 intravitreal injection of ranibizumab. However, as he discontinued systemic management, macular edema reappeared and the edema resolved well after intravitreal ranibizumab. He then became more compliant to the systemic therapy and was asymptomatic for the last 7 months.

Conclusion: In a case of retinal vein occlusion with macular edema of recognizable cause, the management of systemic disease and anti-VEGF can give satisfactory results.

Proteomic Biomarkers of Retinal Inflammation in Diabetic Retinopathy

Diabetic retinopathy (DR), a sight-threatening neurovasculopathy, is the leading cause of irreversible blindness in the developed world. DR arises as the result of prolonged hyperglycemia and is characterized by leaky retinal vasculature, retinal ischemia, retinal inflammation, angiogenesis, and neovascularization. The number of DR patients is growing with an increase in the elderly population, and therapeutic approaches are limited, therefore, new therapies to prevent retinal injury and enhance repair are a critical unmet need. Besides vascular endothelial growth factor (VEGF)-induced vascular proliferation, several other mechanisms are important in the pathogenesis of diabetic retinopathy, including vascular inflammation. Thus, combining anti-VEGF therapy with other new therapies targeting these pathophysiological pathways of DR may further optimize treatment outcomes. Technological advancements have allowed for high-throughput proteomic studies examining biofluids such as aqueous humor, vitreous humor, tear, and serum. Many DR biomarkers have been identified, especially proteins involved in retinal inflammatory processes. This review attempts to summarize the proteomic biomarkers of DR-associated retinal inflammation identified over the last several years.

Real-time photoacoustic sensing for photo-mediated ultrasound therapy

Photo-mediated ultrasound therapy (PUT) is a novel, noninvasive antimicrovascular approach that can treat neovascularization with high precision. We developed a photoacoustic (PA) sensing (PAS) system for PUT and achieved real-time PAS-guided PUT. Experiments performed on a chicken yolk sac membrane model demonstrated that PAS could monitor the treatment effect in a microvessel during PUT. Vessel shrinkage induced a decrease in the PA signal amplitude, while vessel rupture induced an abrupt increase in the PA signal amplitude. The integrated PUT and PAS system can significantly improve the safety and effectiveness of PUT, and may assist with clinical translation of this novel antimicrovascular technique.

Translational research in retinal vascular disease. An approach

The clinical presentation of the most frequent vision threatening retinal diseases is dominated by lesions indicating that disturbances in retinal blood flow are involved in the pathogenesis of these diseases. The present review describes the experience from a translational strategy pursued to investigate retinal vascular diseases with diabetic retinopathy as the main object. The normal regulation of retinal blood flow is investigated in porcine retinal vessels in vitro and ex vivo. Subsequently, the in vitro findings are translated to clinical studies in normal persons in vivo, and it is investigated whether the mechanisms are disturbed in retinal vascular disease. This is followed by clinical intervention studies on these diseases. The approach has been used to investigate pressure autoregulation, metabolic autoregulation and vasomotion in retinal vessels. The investigations have shown that retinal vascular tone can be regulated by receptor-specific agonists and antagonists to vasoactive compounds such as purines, prostaglandins and nitric oxide synthesis and that the vasoactive effects can be modulated by the concentration and the mode of administration of these compounds. Additionally, it has been shown that retinal precapillary arterioles and capillaries not visible by ophthalmoscopy may play an important role for the pathophysiology of retinal vascular disease and its treatment. Future studies should focus on investigating normal and pathological regulation of retinal blood flow in these smaller vessels.

Simultaneous interference of SP1 and HIF1α retarding the proliferation, migration, and invasion of human microvascular endothelial cells (HMEC-1) under hypoxia

OBJECTIVE

To investigate the regulation of special protein 1 (SP1) and hypoxia-inducible factor-1α (HIF1α) on human microvascular endothelial cells (HMEC-1) under hypoxic conditions.

METHODS

The expression of SP1 and HIF1α under normoxia and hypoxic conditions were assessed by Western blot. SP1 and HIF1α were knocked down by small interfering RNA (siRNA) under hypoxic conditions. The proliferation, migration, and invasion of HMEC-1 were measured by cell counting kit 8, 5-ethynyl-2'-deoxyuridine and Transwell coculture system. Western blot analysis and Immunofluorescence were carried out to study the mechanisms of simultaneously inhibiting the adenosine triphosphatase (CD39), 5'-nucleotidase (CD73), adenosine, and vascular endothelial growth factor (VEGF). We compared the inhibitory effects between groups concurrently interfering SP1, HIF-1α, and ranibizumab under hypoxic conditions.

RESULTS

Under hypoxic conditions, the protein expression of SP1 and HIF1α was increased in HMEC-1, contrarily, SP1 siRNA and HIF1α siRNA downregulated the expression. Simultaneous inhibition of SP1 and HIF1α demonstrated a much greater restraint of proliferation, migration, and invasion characteristics on HMEC-1 than respectively knocking down SP1 or HIF1α and anti-VEGF drugs (0.5 mg/mL ranibizumab) (siRNA and the VEGF inhibitor were applied separately in different groups). Meanwhile, simultaneous inhibition of SP1 and HIF1α effectively reduced the expression of CD39, CD73, adenosine, and VEGF on HMEC-1 under hypoxic conditions.

CONCLUSIONS

Our study demonstrated that both SP1 and HIF1α played important roles in HMEC-1 under hypoxia condition. Simultaneous inhibition of SP1 and HIF1α effectively decreased the activity of HMEC-1 under hypoxic conditions through the CD39-CD73-adenosine and VEGF angiogenesis pathways. Our study may provide a new approach to the treatment of retinal neovascular diseases.

Ophthalmic medicine regulatory approvals through the European Centralised Procedure, 1999-2017: Clinical efficacy considerations

OBJECTIVES

Regulatory approval of new medicines requires a thorough assessment of the potential clinical benefits and risks. Study end-points are expected to demonstrate a clinically relevant treatment effect that will translate into direct patient benefits. This study sought to review the ophthalmic medicines with European Union-wide approval granted via the Centralised Procedure and characterise the key efficacy end-points underpinning the demonstration of clinical benefit.

METHODS

This study was a retrospective review of published data pertaining to the European regulatory authorisation of centrally approved ophthalmic products between 1999 and 2017, inclusive. All sources and data consulted are in the public domain. European Public Assessment Reports published by the European Medicines Agency were consulted for data concerning the pivotal clinical efficacy studies supporting the applications. Data analyses were descriptive.

RESULTS

The European Medicines Agency have authorised 30 products via the Centralised Procedure between 1999 and 2017. For these products, a total of 24 additional approvals for line extensions or additional therapeutic indications were granted. Four products have been approved for orphan indications, including one approval 'under exceptional circumstances' and one 'Conditional Marketing Authorisation'. Approvals for products in retina (36%) and glaucoma (28%) indications together accounted for the majority of authorisations, with trial end-points predominantly based on visual acuity and intraocular pressure parameters, respectively. Products were also approved for indications in ocular surface disease, inflammation, optic neuropathy and surgical adjuncts, with a range of functional and anatomical end-points.

CONCLUSION

Approvals for ophthalmic medicines have been granted for a range of clinical indications, representing a considerable portion of available major therapeutics for practitioners. Benefit-risk assessments rely on clinical trial data demonstrating a clearly relevant patient benefit.

Ozurdex for refractory macular edema secondary to diabetes, vein occlusion, uveitis and pseudophakia

OBJECTIVE

To analyze the functional and morphological effects of the intravitreal dexamethasone implant (Ozurdex, Allergan) on patients with macular edema secondary to retinal vein occlusion (RVO), diabetic retinopathy (DME), posterior noninfectious uveitis (NIU), or pseudophakic Irvine-Gass syndrome (IGS).

METHODS

144 charts were retrospectively reviewed; 100 eyes met inclusion criteria for analysis: at least one intravitreal dexamethasone implant injection, refractory to antivascular endothelial growth factor, and had ≥6 months of follow-up postinsertion. The primary outcome was the efficacy of the dexamethasone implant in reducing macular edema as measured by reduction in central retinal thickness (CRT). Secondary outcomes included visual acuity (VA), duration of treatment efficacy (measured by time to next treatment), and safety. The Wilcoxon signed-rank test was used to compare values from baseline, and Kaplan-Meier survival curves were used to analyze time to retreatment.

RESULTS

There were 28 patients with RVO, 30 with DME, 24 with posterior NIU, and 18 with IGS. VA improved from baseline to month 6 in all groups, but was not statistically significant. CRT improved in all 4 groups, and was statistically significant for DME (p = 0.008) and NIU (p = 0.05). At 3 months, 34 patients (41.5%) required retreatment; by month 6, 46 patients (56.1%) required retreatment. There was a large variation between the groups in number of patients requiring intraocular pressure (IOP)-lowering medications. Two patients needed IOP-lowering surgery. One patient developed endophthalmitis.

CONCLUSION

The use of intravitreal dexamethasone implants in patients with refractory retinal diseases is well tolerated and results in consistently improved anatomic outcomes, but the positive anatomic outcomes are not necessarily correlated to improvements in visual function. Patients who are treated earlier in the disease process will had better outcomes. This patient population were refractory to treatment and, therefore, have less-predictable functional outcomes.

Real-World Safety of Intravitreal Bevacizumab and Ranibizumab Treatments for Retinal Diseases in Thailand: A Prospective Observational Study

BACKGROUND

There is very limited evidence examining serious systemic adverse events (SSAEs) and post-injection endophthalmitis of intravitreal bevacizumab (IVB) and intravitreal ranibizumab (IVR) treatments in Thailand and low- and middle-income countries. Moreover, findings from the existing trials might have limited generalizability to certain populations and rare SSAEs.

OBJECTIVES

This prospective observational study aimed to assess and compare the safety profiles of IVB and IVR in patients with retinal diseases in Thailand.

METHODS

Between 2013 and 2015, 6354 patients eligible for IVB or IVR were recruited from eight hospitals. Main outcomes measures were prevalence and risk of SSAEs, mortality, and endophthalmitis during the 6-month follow-up period.

RESULTS

In the IVB and IVR groups, 94 and 6% of patients participated, respectively. The rates of outcomes in the IVB group were slightly greater than in the IVR group. All-cause mortality rates in the IVB and IVR groups were 1.10 and 0.53%, respectively. Prevalence rates of endophthalmitis and non-fatal strokes in the IVB group were 0.04% of 16,421 injections and 0.27% of 5975 patients, respectively, whereas none of these events were identified in the IVR group. There were no differences between the two groups in the risks of mortality, arteriothrombotic events (ATE), and non-fatal heart failure (HF). Adjustment for potential confounding factors and selection bias using multivariable models for time-to-event outcomes and propensity scores did not alter the results.

CONCLUSIONS

The rates of SAEs in both groups were low. The IVB and IVR treatments were not associated with significant risks of mortality, ATE, and non-fatal HF.

TRIAL REGISTRATION

Thai Clinical Trial Registry identifier TCTR20141002001.

Comparative efficacy of bevacizumab, ranibizumab, and aflibercept for treatment of macular edema secondary to retinal vein occlusion: a systematic review and network meta-analysis

INTRODUCTION

Anti-vascular endothelial growth factor (VEGF) therapy has become the most commonly used treatment for macular edema secondary to retinal vein occlusion (RVO). Although its superior efficacy as compared to other interventions has been proven, there is a lack of evidence for relative efficacy among anti-VEGF drugs. Areas covered: This work systematically reviewed and compared the efficacy of intravitreal bevacizumab, ranibizumab, and aflibercept for treating macular edema due to RVO. PubMed, EMBASE, and the Cochrane Library were searched from their inception until October 2017. Eleven randomized controlled trials (18 articles; 1830 adult patients) were identified. The proportion of patients who gained at least 15 letters in best-corrected visual acuity (BCVA), mean change from baseline in BCVA, and mean change from baseline in central macular thickness (CMT) were reported and these efficacy outcomes at 6 months were analyzed in network meta-analysis. Expert commentary: Apparently, bevacizumab, ranibizumab, and aflibercept were significantly superior to sham injection in terms of BCVA improvement and CMT reduction and had good safety profiles. However, there were no statistically significant differences in any outcomes among anti-VEGF drugs. In selecting an anti-VEGF drug for individual patients, other factors including affordability, drug availability, and patient characteristics should be considered.

Intravitreal Injection of Anti-vascular Endothelial Growth Factor Agents for Ocular Vascular Diseases: Clinical Practice Guideline

PURPOSE

To provide the clinical recommendations for the administration of intravitreal anti-vascular endothelial growth factor (VEGF) drugs especially bavacizumab for ocular vascular diseases including diabetic macular edema, neovascular age-related macular degeneration, myopic choroidal neovascularization, retinal vein occlusion and central serous chorioretinopathy.

METHODS

Twenty clinical questions were developed by the guideline technical committee. Relevant websites and databases were searched to find out the pertinent clinical practice guidelines to answer the questions. The technical committee provided possible answers (scenarios) according to the available evidences for each question. All scenarios along with their levels of evidence and the supported articles were sent to the experts for external review. If the experts did not agree on any of the scenarios for one particular clinical question, the technical committee reviewed all scenarios and their pertinent evidences and made the necessary decision. After that, the experts were asked to score them again. All confirmed scenarios were gathered as the final recommendations.

RESULTS

All the experts agreed on at least one of the scenarios. The technical committee extracted the agreed scenario for each clinical question as the final recommendation. Finally, 56 recommendations were developed for the procedure of intravitreal anti-VEGF injection and their applications in the management of ocular vascular diseases.

CONCLUSION

The implementation of this guideline can standardize the management of the common ocular vascular diseases by intravitreal injection of anti-VEGF agents. It can lead to better policy-making and evidence-based clinical decision by ophthalmologists and optimal evidence based eye care for patients.

High-resolution, in vivo multimodal photoacoustic microscopy, optical coherence tomography, and fluorescence microscopy imaging of rabbit retinal neovascularization

Photoacoustic microscopy (PAM) is an emerging imaging technology that can non-invasively visualize ocular structures in animal eyes. This report describes an integrated multimodality imaging system that combines PAM, optical coherence tomography (OCT), and fluorescence microscopy (FM) to evaluate angiogenesis in larger animal eyes. High-resolution in vivo imaging was performed in live rabbit eyes with vascular endothelial growth factor (VEGF)-induced retinal neovascularization (RNV). The results demonstrate that our multimodality imaging system can non-invasively visualize RNV in both albino and pigmented rabbits to determine retinal pathology using PAM and OCT and verify the leakage of neovascularization using FM and fluorescein dye. This work presents high-resolution visualization of angiogenesis in rabbits using a multimodality PAM, OCT, and FM system and may represent a major step toward the clinical translation of the technology.

Intravitreal injection of ziv-aflibercept in the treatment of choroidal and retinal vascular diseases

PURPOSE

To investigate the short-term outcomes after intravitreal injection of ziv-aflibercept in the treatment of choroidal and retinal vascular diseases.

METHODS

Thirty-four eyes of 29 patients with age-related macular degeneration (AMD), diabetic retinopathy, and retinal vein occlusion (RVO) received a single dose intravitreal injection of 0.05 ml ziv-aflibercept (1.25 mg). Visual acuity, spectral domain optical coherence tomography (SD-OCT) activity, and possible side effects were assessed before and at 1 week and 1 month after the intervention.

RESULTS

At 1 month after treatment, mean central macular thickness (CMT) significantly decreased from 531.09 μm to 339.5 μm (P < 0.001), and no signs of side effects were observed in any subject. All patients responded to treatment in terms of reduction in CMT. The improvement in visual acuity was statistically non-significant.

CONCLUSION

Our findings suggest that a single dose intravitreal injection of ziv-aflibercept may have acceptable relative safety and efficacy in the treatment of patients with intraocular vascular disease. The trial was registered in the Iranian Registry of Clinical Trials (IRCT2015081723651N1).

TGF-β participates choroid neovascularization through Smad2/3-VEGF/TNF-α signaling in mice with Laser-induced wet age-related macular degeneration

Choroidal neovascularization(CNV) is the most severe complication in Age-related macular degeneration(AMD) and the most common cause of irreversible blindness in the elderly in developed world. The aim of this study was to identify the effect of transforming growth factor-β(TGF-β) and Smad2/3-VEGF/TNF-α signaling on CNV angiopoiesis, and to explore TGF-β inhibitors on the development of CNV in a CNV mouse model. Fundus fluorescein angiography(FFA) was used to evaluate the laser-induced CNV formation. The histology of CNV lesions stained with hematoxylin-eosin(HE) was obtained. The immunofluorescent staining was performed to determine TGF-β protein expression. The expressions of TGF-β, phosphorylated Smad2/3, VEGF and TNF-α were determined by using Western blot analysis. The CNV areas were analyzed by using fluorescein stain on RPE/choroid-sclera flat mounts. We found the levels of TGF-β protein expression increasingly reached the peak till 3rd week during the CNV development. The protein levels of VEGF and TNF-α also increased significantly in CNV mice, which were inhibited by a synthetic TGF-β inhibitor LY2157299 or a natural TGF-β inhibitor Decorin. The phosphorylated Smad2/3 levels increased significantly in CNV mice, but this response was profoundly suppressed by the TGF-β inhibitors. Here we have demonstrated that TGF-β/Smad signaling plays an important role in Laser-induced CNV formation through down-regulation of VEGF and TNF-α expressions, suggesting TGF-β inhibitors may provide an alternative to traditional methods in wet AMD treatment.

Silicone oil droplets following intravitreal bevacizumab injections

Purpose

To report the transient resurgence of symptomatic silicone oil droplets following intravitreal bevacizumab injections.

Observations

We report seven patients presenting with silicone oil droplets following intravitreal bevacizumab injections. These were the first cases noted in 10 years using the same supplier of preloaded syringes in an estimated 90,413 injections performed by 7 physicians. They occurred during a 4 month period (06–10/2016), suggesting they may have been related to a batch or batches of syringes. Symptomatic floaters attributed to the droplets were noted on an average of 6.7 ± 1.5 days following the injection and followed an average of 10.4 ± 3.75 injections over a period of 3.4 ± 1.9 years and resolved in 5 of our 7 patients within 9 months.

Conclusions and importance

Symptomatic intravitreal silicone oil droplets are a rare complication of intravitreal injections. Symptoms are generally transient and not clinically significant and hence the benefits of treating potentially blinding eye diseases in this fashion appear to outweigh the limited risk of the rare, temporary floaters. The current series may be related to a batch or batches of syringes.

Pharmacologic Vitreolysis in Vascular Diseases of the Retina

Vascular diseases of the retina such as diabetic retinopathy and vascular occlusions account for a large proportion of visual morbidity and blindness worldwide. The role of vitreous in the pathogenesis of these conditions has been increasingly recognized. Despite advances in the surgical technique of pars plana vitrectomy, the use of intravitreal agents for the lysis of vitreous has received attention, guided largely by promising results from the trials involving patients with non-vascular retinal diseases such as vitreomacular traction. The purpose of this review is to provide a comprehensive summary of the present knowledge on pathophysiologic basis of pharmacologic vitreolysis and its efficacy in vascular diseases of the retina. A review of completed and ongoing clinical trials will be presented, along with insights into future directions of this therapy.

Use of flucinolone acetonide for patients with diabetic macular oedema: patient selection criteria and early outcomes in real world setting

INTRODUCTION

Fluocinolone acetonide slow release implant (Iluvien®) was approved in December 2013 in UK for treatment of eyes which are pseudophakic with DMO that is unresponsive to other available therapies. This approval was based on evidence from FAME trials which were conducted at a time when ranibizumab was not available. There is a paucity of data on implementation of guidance on selecting patients for this treatment modality and also on the real world outcome of fluocinolone therapy especially in those patients that have been unresponsive to ranibizumab therapy.

METHOD

Retrospective study of consecutive patients treated with fluocinolone between January and August 2014 at three sites were included to evaluate selection criteria used, baseline characteristics and clinical outcomes at 3-month time point.

RESULTS

Twenty two pseudophakic eyes of 22 consecutive patients were included. Majority of patients had prior therapy with multiple intravitreal anti-VEGF injections. Four eyes had controlled glaucoma. At baseline mean VA and CRT were 50.7 letters and 631 μm respectively. After 3 months, 18 patients had improved CRT of which 15 of them also had improved VA. No adverse effects were noted. One additional patient required IOP lowering medication. Despite being unresponsive to multiple prior therapies including laser and anti-VEGF injections, switching to fluocinolone achieved treatment benefit.

CONCLUSION

The patient level selection criteria proposed by NICE guidance on fluocinolone appeared to be implemented. This data from this study provides new evidence on early outcomes following fluocinolone therapy in eyes with DMO which had not responded to laser and other intravitreal agents.

Quantitative Proteomics Analysis of Vitreous Humor from Diabetic Retinopathy Patients

Initial triggers for diabetic retinopathy (DR) are hyperglycemia-induced oxidative stress and advanced glycation end-products. The most pathological structural changes occur in retinal microvasculature, but the overall development of DR is multifactorial, with a complex interplay of microvascular, neurodegenerative, genetic/epigenetic, immunological, and secondary inflammation-related factors. Although several individual factors and pathways have been associated with retinopathy, a systems level understanding of the disease is lacking. To address this, we performed mass spectrometry based label-free quantitative proteomics analysis of 138 vitreous humor samples from patients with nonproliferative DR or the more severe proliferative form of the disease. Additionally, we analyzed samples from anti-VEGF (vascular endothelial growth factor) (bevacizumab)-treated patients from both groups. In our study, we identified 2482 and quantified the abundancy of 1351 vitreous proteins. Of these, the abundancy of 230 proteins was significantly higher in proliferative retinopathy compared with nonproliferative retinopathy. This specific subset of proteins was linked to inflammation, complement, and coagulation cascade proteins, protease inhibitors, apolipoproteins, immunoglobulins, and cellular adhesion molecules, reflecting the multifactorial nature of the disease. The identification of the key molecules of the disease is critical for the development of new therapeutic molecules and for the new use of existing drugs.

Nanoengineering of therapeutics for retinal vascular disease

Retinal vascular diseases, including diabetic retinopathy, neovascular age related macular degeneration, and retinal vein occlusion, are leading causes of blindness in the Western world. These diseases share several common disease mechanisms, including vascular endothelial growth factor (VEGF) signaling, hypoxia, and inflammation, which provide opportunities for common therapeutic strategies. Treatment of these diseases using laser therapy, anti-VEGF injections, and/or steroids has significantly improved clinical outcomes. However, these strategies do not address the underlying root causes of pathology, and may have deleterious side effects. Furthermore, many patients continue to progress toward legal blindness despite receiving regular therapy. Nanomedicine, the engineering of therapeutics at the 1-100 nm scale, is a promising approach for improving clinical management of retinal vascular diseases. Nanomedicine-based technologies have the potential to revolutionize the treatment of ophthalmology, through enabling sustained release of drugs over several months, reducing side effects due to specific targeting of dysfunctional cells, and interfacing with currently "undruggable" targets. We will discuss emerging nanomedicine-based applications for the treatment of complications associated with retinal vascular diseases, including angiogenesis and inflammation.

Incidence of myocardial infarction, stroke, and death in patients with age-related macular degeneration treated with intravitreal anti-vascular endothelial growth factor therapy

PURPOSE

To describe the rates of myocardial infarction (MI), stroke, and mortality in patients who have treatment with intravitreal anti-vascular endothelial growth factor (anti-VEGF) injections for age-related macular degeneration (AMD).

DESIGN

A retrospective population linkage study.

METHOD

We identified patients aged 40 years and above who received treatment with intravitreal anti-VEGF injections for AMD from January 1, 2008 to December 31, 2011 at the Singapore National Eye Centre. We used a national record linkage database to identify patients who developed MI, stroke, and all-cause mortality after the first injection, excluding those with previous MI or stroke at baseline from the respective analysis. We compared rates of MI, stroke, and mortality to that of the total Singapore population.

RESULTS

A total of 1182 individuals had an intravitreal anti-VEGF injection included in this analysis, with the majority receiving bevacizumab (n = 1011). Overall, 19 patients developed MI, 16 developed stroke, and there were 43 mortalities, giving an age-adjusted incidence rate of 350.2 per 100 000 person-years for MI, 299.3 per 100 000 person-years for stroke, and 778.9 per 100 000 person-years for mortality. This is comparable to the weighted incidence rates of the Singapore population (427.1 per 100 000 person-years for MI, 340.4 per 100 000 person-years for stroke, and 921.3 per 100 000 person-years for mortality).

CONCLUSION

The incidence rate of MI, stroke, and death in this cohort of AMD patients treated with anti-VEGF was low, and was not significantly higher than the age-adjusted incidence rate of these events in the Singapore population.