Retinal vein thrombosis: pathogenesis and management

Autonomous screening for laser photocoagulation in fundus images using deep learning

BACKGROUND

Diabetic retinopathy (DR) is a leading cause of blindness in adults worldwide. Artificial intelligence (AI) with autonomous deep learning algorithms has been increasingly used in retinal image analysis, particularly for the screening of referrable DR. An established treatment for proliferative DR is panretinal or focal laser photocoagulation. Training autonomous models to discern laser patterns can be important in disease management and follow-up.

METHODS

A deep learning model was trained for laser treatment detection using the EyePACs dataset. Data was randomly assigned, by participant, into development (n=18 945) and validation (n=2105) sets. Analysis was conducted at the single image, eye, and patient levels. The model was then used to filter input for three independent AI models for retinal indications; changes in model efficacy were measured using area under the receiver operating characteristic curve (AUC) and mean absolute error (MAE).

RESULTS

On the task of laser photocoagulation detection: AUCs of 0.981, 0.95, and 0.979 were achieved at the patient, image, and eye levels, respectively. When analysing independent models, efficacy was shown to improve across the board after filtering. Diabetic macular oedema detection on images with artefacts was AUC 0.932 vs AUC 0.955 on those without. Participant sex detection on images with artefacts was AUC 0.872 vs AUC 0.922 on those without. Participant age detection on images with artefacts was MAE 5.33 vs MAE 3.81 on those without.

CONCLUSION

The proposed model for laser treatment detection achieved high performance on all analysis metrics and has been demonstrated to positively affect the efficacy of different AI models, suggesting that laser detection can generally improve AI-powered applications for fundus images.

Multimodal deep transfer learning to predict retinal vein occlusion macular edema recurrence after anti-VEGF therapy

Purpose

To develop a multimodal deep transfer learning (DTL) fusion model using optical coherence tomography angiography (OCTA) images to predict the recurrence of retinal vein occlusion (RVO) and macular edema (ME) after three consecutive anti-VEGF therapies.

Methods

This retrospective cross-sectional study consisted of 2800 B-scan OCTA macular images collected from 140 patients with RVO-ME. The central macular thickness (CMT) > 250 μm was used as a criterion for recurrence in the three-month follow-up after three injections of anti-VEGF therapy. The qualified OCTA image preprocessing and the lesion area segmentation were performed by senior ophthalmologists. We developed and validated the clinical, DTL, and multimodal fusion models based on clinical and extracted OCTA imaging features. The performance of the models and experts predictions were evaluated using several performance metrics, including the area under the receiver operating characteristic curve (AUC), accuracy, sensitivity, and specificity.

Results

The DTL models exhibited higher prediction efficacy than the clinical models and experts' predictions. Among the DTL models, the Vgg19 performed better than that of the other models, with an AUC of 0.968 (95 % CI, 0.943-0.994), accuracy of 0.913, sensitivity of 0.922, and specificity of 0.902 in the validation cohort. Moreover, the fusion Vgg19 model showed the highest prediction efficacy among all the models, with an AUC of 0.972 (95 % CI, 0.946-0.997), accuracy of 0.935, sensitivity of 0.935, and specificity of 0.934 in the validation cohort.

Conclusions

Multimodal fusion DTL models showed robust performance in predicting RVO-ME recurrence and may be applied to assist clinicians in determining patients' follow-up time after anti-VEGF therapy.

Anatomical and Functional Results of Early or Late Switching from Anti-VEGF to Dexamethasone Implant in Case of Poor Anatomical Response in Naïve Patients with Macular Edema Secondary to Branch Retinal Vein Occlusion

PURPOSE

To compare the outcomes of early or late switching from intravitreal (IV) anti-vascular endothelial growth factor (anti-VEGF) injection to IV Dexamethasone (DEX) implant injection in treatment-naïve patients with macular edema secondary to branch retinal vein occlusion.

METHODS

This study included 68 eyes of 68 treatment-naïve BRVO patients who started anti-VEGF treatment. After the loading dose, the patients were divided into two groups: Early DEX group (n:34) (DEX implant treatment started after 3 loading doses) and Late DEX group (n:34) (DEX implant treatment started after 6 months). Visual acuity and examination findings were recorded at baseline, 3rd, 6th, and 12th month follow-ups. Optical coherence tomography data were recorded for central macular subfield thickness assessment.

RESULTS

A total of 30 (44.1%) women and 38 (55.9%) men participated, and the average age was 67.6 ± 6.4 years. The mean letter gains at week 52 was 15.1 and 20.9 in the Early DEX and Late DEX groups, respectively. The group with the highest gain of ≥15 letters was the Late DEX group (26/34 patients) and the gain of ≥15 letters was 14/34 in the Early DEX group (p: 0.006). At week 52, the anatomical gain was 115.3 µm and 136.9 µm in the Early DEX and Late DEX groups, respectively.

CONCLUSIONS

A gain of 15 or more letters was demonstrated to be higher in patients who switched to DEX implant late after anti-VEGF treatment. If it is necessary to switch, the late switch may be more effective for more visual gain at the end of the first year.

Hypertension, hyperlipidaemia and thrombophilia as the most common risk factors for retinal vein occlusion in patients under 50 years

BACKGROUND AND AIMS

Cardiovascular (CV) diseases are the most common risk factors (RFs) for retinal vein occlusion (RVO) development in general. The aim of this study was to identify the most frequent causes of RVO in patients under 50.

METHODS

We retrospectively evaluated a group of patients with RVO under 50 years. The parameters of interest included age and sex, RVO type, presence of arterial hypertension (HT), hyperlipidaemia (HLD), diabetes mellitus (DM), congenital thrombophilic disorder (TD), obstructive sleep apnoea syndrome (OSAS), thyroid eye disease (TED), use of hormone contraception (HC) or hormone replacement therapy (HRT), glaucoma and other potential RFs. Patients with central RVO (CRVO), hemi-central RVO (HRVO), branch RVO (BRVO), impending CRVO and combined arterial-venous (AV) occlusion were included.

RESULTS

The group consisted of 110 eyes of 103 patients. CV disease was the most common systemic abnormality. 55.3% patients had HT, 17.5% had HLD. TD was the third most frequent RF (12.6%). The cohort also included patients with DM (6.8%), glaucoma (6.8%) and women using HC/HRT (26.2% of female patients). There were isolated cases of RVO due to retinal vasculitis, intense exercise, antiphospholipid syndrome and COVID-19 pneumonia. None of the patients had OSAS, TED or a haemato-oncological disease. The etiology remained unexplained in 20.4% patients. No difference was observed in RF occurrence between patients with CRVO and HRVO and those with BRVO.

CONCLUSION

The most common systemic abnormality in our cohort was CV disease, especially HT and HLD. The risk factors for central, hemi-central and branch RVOs were similar.

Controllable editing via diffusion inversion on ultra-widefield fluorescein angiography for the comprehensive analysis of diabetic retinopathy

By incorporating multiple indicators that facilitate clinical decision making and effective management of diabetic retinopathy (DR), a comprehensive understanding of the progression of the disease can be achieved. However, the diversity of DR complications poses challenges to the automatic analysis of various information within images. This study aims to establish a deep learning system designed to examine various metrics linked to DR in ultra-widefield fluorescein angiography (UWFA) images. We have developed a unified model based on image generation that transforms input images into corresponding disease-free versions. By incorporating an image-level supervised training process, the model significantly reduces the need for extensive manual involvement in clinical applications. Furthermore, compared to other comparative methods, the quality of our generated images is significantly superior.

Case series of retinal vein occlusions showing early recovery using oral l-methylfolate

This case series describes the aggregate rate of recovery in five consecutive subjects (six eyes) with retinal vein occlusion (RVO) who received l-methylfolate and other vitamins via Ocufolin®, a medical food. Subjects were followed for 10-33 months by a single ophthalmologist. Ocufolin® was prescribed at the time of diagnosis and subjects remained on the regimen throughout the time of observation. Examinations were performed in an un-masked fashion at 3-month intervals with recording of best corrected visual acuity (BCVA), average retinal nerve fiber layer (ARNFL) and central macular thickness (CMT), and fundus (examination of the retina, macula, optic nerve, and vessels) photography. Testing was done for vitamin deficiencies, vascular and coagulable risk factors, and methylenetetrahydrofolate reductase (MTHFR) polymorphisms. Vitamin deficiencies and vascular risk factors were found in all subjects, and all four tested subjects carried at least one MTHFR polymorphism. By the end of the study period BCVA in all subjects was 20/25 or better. Cystoid macular edema was identified and measured by optical coherence tomography (OCT). The percent change was calculated and plotted at 3-month intervals using the percent change in thickness from the time of diagnosis and percent change toward normative values for ARNFL and CMT. The total reduction in thickness of ARNFL and CMT from time of diagnosis was 44.19% and 30.27%, respectively. The comparison to normative data shows a reduction of ARNFL from 164.2% to 94% and CMT from 154.4% to 112.7% of normal thickness (100%). Plots showed the aggregate recovery was most rapid over the first 3 months and slowed over the next 3 months with most of the recovery taking place within 6 months of treatment. The rate of improvement in BCVA and resolution of retinal thickening was found to be better than predicted on historical grounds. No subjects progressed from nonischemic to ischemic RVO. Vitamin deficiencies, vascular risk factors, and genetic predisposition to oxidative stress were common in this RVO series. It appears that addressing these factors with Ocufolin® had a salutary effect on recovery.

Artificial intelligence in retinal imaging: current status and future prospects

INTRODUCTION

The steadily growing and aging world population, in conjunction with continuously increasing prevalences of vision-threatening retinal diseases, is placing an increasing burden on the global healthcare system. The main challenges within retinology involve identifying the comparatively few patients requiring therapy within the large mass, the assurance of comprehensive screening for retinal disease and individualized therapy planning. In order to sustain high-quality ophthalmic care in the future, the incorporation of artificial intelligence (AI) technologies into our clinical practice represents a potential solution.

AREAS COVERED

This review sheds light onto already realized and promising future applications of AI techniques in retinal imaging. The main attention is directed at the application in diabetic retinopathy and age-related macular degeneration. The principles of use in disease screening, grading, therapeutic planning and prediction of future developments are explained based on the currently available literature.

EXPERT OPINION

The recent accomplishments of AI in retinal imaging indicate that its implementation into our daily practice is likely to fundamentally change the ophthalmic healthcare system and bring us one step closer to the goal of individualized treatment. However, it must be emphasized that the aim is to optimally support clinicians by gradually incorporating AI approaches, rather than replacing ophthalmologists.

Microbiome and Retinal Vascular Diseases

The gut microbiome consists of more than a thousand different microbes and their associated genes and microbial metabolites. It influences various host metabolic pathways and is therefore important for homeostasis. In recent years, its influence on health and disease has been extensively researched. Dysbiosis, or imbalance in the gut microbiome, is associated with several diseases. Consequent chronic inflammation may lead to or promote inflammatory bowel disease, obesity, diabetes mellitus, atherosclerosis, alcoholic and non-alcoholic liver disease, cirrhosis, hepatocellular carcinoma, and other diseases. The pathogenesis of the three most common retinal vascular diseases, diabetic retinopathy, retinal vein occlusion, and retinal artery occlusion, may also be influenced by an altered microbiome and associated risk factors such as diabetes mellitus, atherosclerosis, hypertension, and obesity. Direct cause-effect relationships remain less well understood. A potential prevention or treatment modality for these diseases could be targeting and modulating the individual's gut microbiome.

Central Retinal Vein Occlusion with Three-Retinal Quadrant Involvement: Another Focus on Optic Disc Head Vascular Anatomy Variations

A 50-year-old male patient with sudden visual acuity loss in his right eye came to our clinic. Visual acuity at presentation was 1/10 in right eye and 10/10 in left. The patient was otherwise healthy Caucasian man without any history of previous systemic or ophthalmic disease. There was not any history of amblyopia and refractive error. Anterior segment findings were unremarkable. Three quadrants of retina were fully involved with central retinal vein occlusion (CRVO) features including retinal hemorrhages, retinal edema obscuring retinal details, and cotton wool spots while sparing inferior temporal quadrant. Inferior temporal quadrant sparing in this patient is due to a specific retinal vascular anatomical variation. In conclusion, in unusual presentations of retinal vascular branch obstructions, considering retinal vascular anatomy variations would help us to explain the clinical presentation more precisely in some cases.

Ophthalmologic Emergencies: Assessment and Management

There are an estimated 2-3 million emergency department (ED) visits in the United States for eye complaints. Although most patients who present to the ED have nontraumatic eye complaints, many seek treatment for eye trauma, which is a leading cause of unilateral blindness and vison impairment. Given the prevalence of eye-related emergencies, it is imperative that emergency care providers understand how to recognize and treat eye complaints to prevent permanent vision loss and disability. This article covers basic eye anatomy and physiology, discusses a systematic approach to the eye examination, and presents the evidence-based treatment of selected, common nonemergent and emergent eye complaints. For each complaint, essential history questions, examination techniques, differentials, and emergency management have been presented.

Risk of retinopathy in women with pregnancy-induced hypertension: a nationwide population-based cohort study of 9-year follow-up after delivery

BACKGROUND

The retina is potentially associated with several physiological, hormonal, and metabolic changes during pregnancy. The few available epidemiologic studies of ocular changes in pregnancy have mainly concerned retinopathies. Pregnancy-induced hypertension, which leads to ocular manifestations including blurred vision, photopsia, scotoma, and diplopia, might induce reactive changes in the retinal vessels. Although several studies have suggested the existence of pregnancy-induced hypertension-related retinal ocular disease, there are few large cohort studies on this topic.

OBJECTIVE

This study aimed to investigate the risk of major retinal diseases including central serous chorioretinopathy, diabetic retinopathy, retinal vein occlusion, retinal artery occlusion, and hypertensive retinopathy in the long-term postpartum stage according to the presence of previous pregnancy-induced hypertension in a large cohort based on the Korean National Health Insurance Database.

STUDY DESIGN

On the basis of Korean health data, 909,520 patients who delivered from 2012 to 2013 were analyzed. Among them, patients who had previous ocular diseases or hypertension and multiple births were excluded. Finally, 858,057 mothers were assessed for central serous chorioretinopathy (ICD-10: H35.70), diabetic retinopathy (ICD-10: H36.0, E10.31, E10.32, E11.31, E11.32, E12.31, E13.31, E13.32, E14.31, E14.32), retinal vein occlusion (ICD-10: H34.8), retinal artery occlusion (ICD-10: H34.2), and hypertensive retinopathy (ICD-10: H35.02) for 9 years after delivery. Enrolled patients were divided into 2 groups: 10,808 patients with and 847,249 without pregnancy-induced hypertension. The primary outcomes were the incidence of central serous chorioretinopathy, diabetic retinopathy, retinal vein occlusion, retinal artery occlusion, and hypertensive retinopathy 9 years after delivery. Clinical variables were age, parity, cesarean delivery, gestational diabetes mellitus, and postpartum hemorrhage. In addition, pregestational diabetes mellitus, kidney diseases, cerebrovascular diseases, and cardiovascular diseases were adjusted.

RESULTS

Postpartum retinal disease during the 9 years after delivery and total retinal diseases showed higher rates in patients with pregnancy-induced hypertension. In detail, the rates of central serous chorioretinopathy (0.3% vs 0.1%), diabetic retinopathy (1.79% vs 0.5%), retinal vein occlusion (0.19% vs 0.1%), and hypertensive retinopathy (0.62% vs 0.05%) were higher than those found in patients without pregnancy-induced hypertension. After adjusting for confounding factors, pregnancy-induced hypertension was associated with development of postpartum retinopathy, with a >2-fold increase (hazard ratio, 2.845; 95% confidence interval, 2.54-3.188). Furthermore, pregnancy-induced hypertension affected the development of central serous chorioretinopathy (hazard ratio, 3.681; 95% confidence interval, 2.667-5.082), diabetic retinopathy (hazard ratio, 2.326; 95% confidence interval, 2.013-2.688), retinal vein occlusion (hazard ratio, 2.241; 95% confidence interval, 1.491-3.368), and hypertensive retinopathy (hazard ratio, 11.392; 95% confidence interval, 8.771-14.796) after delivery.

CONCLUSION

A history of pregnancy-induced hypertension increases the risk of central serous chorioretinopathy, diabetic retinopathy, retinal vein occlusion, and hypertensive retinopathy according to 9-year long-term ophthalmologic follow-up.

Tetrahedral framework nucleic acids inhibit pathological neovascularization and vaso-obliteration in ischaemic retinopathy via PI3K/AKT/mTOR signalling pathway

This study aimed to explore the effect and the molecular mechanism of tetrahedral framework nucleic acids (tFNAs), a novel self-assembled nanomaterial with excellent biocompatibility and superior endocytosis ability, in inhibition of pathological retinal neovascularization (RNV) and more importantly, in amelioration of vaso-obliteration (VO) in ischaemic retinopathy. tFNAs were synthesized from four single-stranded DNAs (ssDNAs). Cell proliferation, wound healing and tube formation assays were performed to explore cellular angiogenic functions in vitro. The effects of tFNAs on reducing angiogenesis and inhibiting VO were explored by oxygen-induced retinopathy (OIR) model in vivo. In vitro, tFNAs were capable to enter endothelial cells (ECs), inhibit cell proliferation, tube formation and migration under hypoxic conditions. In vivo, tFNAs successfully reduce RNV and inhibit VO in OIR model via the PI3K/AKT/mTOR/S6K pathway, while vascular endothelial growth factor fusion protein, Aflibercept, could reduce RNV but not inhibit VO. This study provides a theoretical basis for the further understanding of RNV and suggests that tFNAs might be a novel promising candidate for the treatment of blind-causing RNV.

Central retinal vein occlusion with cerebral infarction secondary to anlotinib treatment: a case report and literature review

Purpose: We present a rare case of an elderly man with minimal pre-existing thromboses risk, who experienced central retinal vein occlusion (CRVO) and cerebral infarction after oral intake of the anti-cancer drug anlotinib, likely due to a drug-related complication. Observations: A male, aged 65 years, sought care at the ophthalmology department because of acute painless 5-day vision loss in the right eye, in combination with cerebral infarction history, after oral intake of anlotinib for hepatocellular carcinoma (HCC) for over 16 months. Clinical assessment and ancillary examination verified a right eye central retinal vein occlusion diagnosis. Anlotinib is a multi-target tyrosine kinase inhibitors (TKIs) is reported to potently suppress vascular endothelial growth factor (VEGF) receptor, in order to exert strong antitumor angiogenesis and inhibit tumor occurrence. Although anlotinib is only regarded as a possible thrombosis risk factor, it is possible that anlotinib administration markedly enhanced vaso-occlusive risk within this patient. Conclusion and significance: Herein, we present the first report of anlotinib-induced CRVO and cerebral infarction to our knowledge. Given our evidences, anlotinib usage is intricately linked to sight- and life-threatening thrombotic effects even among patients with reduced thrombophilic risk. Hence, patients receiving this drug must be carefully monitored for possible drug-related complications.

Correlation Between Imaging Morphological Findings and Laboratory Biomarkers in Patients with Retinal Vein Occlusion

INTRODUCTION

The aim of this study was to investigate the possible correlation between peripheral blood biomarkers and morphological characteristics of retinal imaging in patients with retinal vein occlusion (RVO).

METHODS

Participants in this cross-sectional observational study were 65 consecutive patients (65 eyes) with treatment-naïve RVO, who underwent spectral-domain optical coherence tomography (SD-OCT) and fundus fluorescein angiography (FFA). In addition, peripheral blood samples were taken to evaluate full blood count and biochemical parameters. The association between imaging characteristics and laboratory parameters was examined.

RESULTS

Eyes with subretinal fluid presented significantly higher neutrophil-to-lymphocyte ratios (p = 0.028). Hyperreflective foci on SD-OCT were found to be associated with higher triglyceride levels (p = 0.024). The presence of cysts on SD-OCT was associated with significantly higher triglycerides (p = 0.010). Central subfield thickness (CST) higher than 464 μm was associated with higher lymphocyte count (p = 0.016) and higher urea (p = 0.015). No significant associations were found between laboratory parameters and intraretinal fluid, ellipsoid zone and external limiting membrane condition, or epiretinal membrane and macular ischemia.

CONCLUSIONS

Specific imaging morphological characteristics were found to be associated with laboratory parameters in patients with RVO. These findings may help reveal the pathophysiology of RVO and its correlation with the development of specific clinical signs, while they could guide individualized treatment.

Endothelial contraction of retinal veins

We have previously reported that porcine retinal veins can be contracted by vasoactive factors such as endothelin-1, but it is still unknown which cells play the major role in such contraction responses. This study seeks to confirm whether retinal vein endothelial cells play a significant role in the endothelin-1 induced contraction of porcine retinal veins. This is a novel study which provides confirmation of the endothelial cells' ability to contract retinal veins using a live vessel preparation. Retinal veins were isolated from porcine retina and cannulated for perfusion. The vessels were exposed to extraluminal delivery of endothelin-1 (10^-8 M) and change in vessel diameter recorded automatically every 2 s. A phase contrast objective lens was also used to capture images of the endothelial cell morphometries. The length, width, area, and perimeter were assessed. In addition, vein histology and immuno-labeling for contractile proteins was performed. With 10^-8 M endothelin-1 contractions to 63.6% of baseline were seen. The polygonal shape of the endothelial cells under normal tone became spindle-like after contraction. The area, width, perimeter and length were significantly reduced by 54.8%, 48.1%, 28.5% and 10.5% respectively. Three contractile proteins, myosin, calponin and alpha-SMA were found in retinal vein endothelial cells. Retinal vein endothelial cells contain contractile proteins and can be contracted by endothelin-1 administration. Such contractile capability may be important in regulating retinal perfusion but could also be a factor in the pathogenesis of retinal vascular diseases such as retinal vein occlusion. As far as we are aware, this is the first study on living isolated veins to confirm that endothelial cells contribute to the endothelin-1 induced contraction.

Laser-Induced Porcine Model of Experimental Retinal Vein Occlusion: An Optimized Reproducible Approach

Retinal vein occlusion (RVO) is a frequent visually disabling condition. The management of RVO continues to challenge clinicians. Macular edema secondary to RVO is often recurrent, and patients typically require intravitreal injections for several years. Understanding molecular mechanisms in RVO is a key element in improving the treatment of the condition. Studying the molecular mechanisms in RVO at the retinal level is possible using animal models of experimental RVO. Most studies of experimental RVO have been sporadic, using only a few animals per experiment. Here, we report on 10 years of experience of the use of argon laser-induced experimental RVO in 108 porcine eyes from 65 animals, including 65 eyes with experimental branch retinal vein occlusion (BRVO) and 43 eyes with experimental central retinal vein occlusion (CRVO). Reproducibility and methods for evaluating and controlling ischemia in experimental RVO are reviewed. Methods for studying protein changes in RVO are discussed in detail, including proteomic analysis, Western blotting, and immunohistochemistry. Experimental RVO has brought significant insights into molecular changes in RVO. Testing intravitreal interventions in experimental RVO may be a significant step in developing personalized therapeutic approaches for patients with RVO.

Choroidal thickness as a possible predictor of non-response to intravitreal bevacizumab for macular edema after retinal vein occlusion

To evaluate outcomes of intravitreal bevacizumab (IVB) treating macular edema (ME) after retinal vein occlusion (RVO) following pro re nata (PRN) regimen and investigate potential predictors of non-response. Retrospective analysis of 126 treatment-naive eyes with ME after RVO. Eyes were treated initially with IVB of 1.25 mg/ml. Therapy was switched in case of non-response. Outcome measures included best-corrected visual acuity (BCVA) and central macular thickness (CMT), which were recorded over 4 years of treatment. BCVA improved significantly during first 2 years. CMT decreased significantly during the 4-year follow-up period. Switching was required in 42 eyes (33%). 34 eyes (26.9%) were switched to steroids, while 8 eyes (6.3%) were switched to other anti-VEGF due to diagnosed glaucoma. Switching occurred after 12.4 ± 8.3 months and an average of 8 ± 4.1 IVBs. Compared with the treatment-responsive group, the treatment-unresponsive group had significantly worse BCVA, higher CMT and subfoveal choroidal thickness (SFCT) at baseline. Treatment IVB following PRN regimen showed significant functional and anatomic improvement in patients with ME after RVO. Switching was required in more than one third of eyes. Higher baseline SFCT could be considered as predictor for non-response to such therapy and thus an indicator of early switching.

Assessing retinal vein occlusion based on color fundus photographs using neural understanding network (NUN)

OBJECTIVE

To develop and validate a novel deep learning architecture to classify retinal vein occlusion (RVO) on color fundus photographs (CFPs) and reveal the image features contributing to the classification.

METHODS

The neural understanding network (NUN) is formed by two components: (1) convolutional neural network (CNN)-based feature extraction and (2) graph neural networks (GNN)-based feature understanding. The CNN-based image features were transformed into a graph representation to encode and visualize long-range feature interactions to identify the image regions that significantly contributed to the classification decision. A total of 7062 CFPs were classified into three categories: (1) no vein occlusion ("normal"), (2) central RVO, and (3) branch RVO. The area under the receiver operative characteristic (ROC) curve (AUC) was used as the metric to assess the performance of the trained classification models.

RESULTS

The AUC, accuracy, sensitivity, and specificity for NUN to classify CFPs as normal, central occlusion, or branch occlusion were 0.975 (± 0.003), 0.911 (± 0.007), 0.983 (± 0.010), and 0.803 (± 0.005), respectively, which outperformed available classical CNN models.

CONCLUSION

The NUN architecture can provide a better classification performance and a straightforward visualization of the results compared to CNNs.

Optical coherence tomography angiography evaluation of retinal and optic disc microvascular morphological characteristics in retinal vein occlusion

BACKGROUND

To evaluate microvascular morphological characteristics of the retina and optic disc (OD) in retinal vein occlusion (RVO) patients using optical coherence tomography angiography (OCTA), compare the results to age- and gender-matched healthy subjects, and determine correlations between OCTA parameters and best-corrected visual acuity (BCVA) and age.

METHODS

In this retrospective study, right eyes of 53 RVO patients and 51 healthy subjects were compared regarding BCVA, as well as superficial and deep capillary plexus (SCP and DCP) vessel densities (VDs), foveal avascular zone (FAZ) parameters, outer retinal and choriocapillaris flow areas, OD whole and peripapillary VDs, and retinal nerve fiber layer thickness (RNFLT). Retinal vein occlusion patients were further divided into subgroups based on therapy and risk factors, and OCTA parameters were compared.

RESULTS

Retinal vein occlusion rate or OCTA parameters did not differ significantly by gender (p > 0.05). Retinal vein occlusion patients had significantly decreased BCVA, whole, parafoveal and perifoveal SCP and DCP VDs, as well as VDs 300 µm area around FAZ (FD-300) than healthy subjects (p < 0.001). Their choriocapillaris flow area, RNFLT, whole and peripapillary VDs were also affected. However, FAZ area did not differ significantly between groups. Superior RNFLT (p = 0.016) and whole peripapillary VD (p < 0.001) differed significantly between laser photocoagulation-treated and non-treated patients. The remaining OCTA parameters revealed no significant differences CONCLUSIONS: The RVO and its therapeutic alternatives may affect both OD and retinal VDs. Given its numerous benefits, it seems that OCTA will be used more frequently in clinics for RVO diagnosis, monitoring, and therapeutic response evaluation.

[Ischemia and laser photocoagulation in retinal vein occlusion]

BACKGROUND

Retinal vein occlusions (RVO) are associated with retinal ischemia to a highly variable extent. An ischemic retina may lead to the development of neovascularization and further to secondary complications such as neovascular glaucoma, vitreous hemorrhage or tractional retinal detachment. Numerous factors such as vascular endothelial growth factor (VEGF) and other cytokines are produced in the ischemic area, which cause macular edema. Before the introduction of intravitreal drug injections (IVI), retinal laser photocoagulation was the leading form of treatment. Macular laser photocoagulation was applied in the form of focal laser or grid laser in patients with branch retinal vein occlusion (BRVO) to treat macular edema. In patients with ischemic RVO, panretinal laser photocoagulation (PRP) was recommended for treatment of secondary neovascular complications. The value of laser treatment in the management of patients with RVO changed after the introduction of IVI treatment.

AIM

This article presents a review of the current study results and the recommendations for performing laser photocoagulation of the central and peripheral retina in patients with RVO.

CONCLUSION

Conventional focal or grid laser photocoagulation has been replaced by IVI treatment in the management of macular edema secondary to BRVO; however, macular laser treatment can still be considered in patients with BRVO if the macular edema persists despite the use of available IVI drugs. The use of central laser photocoagulation in these cases is based on the findings of fluorescein angiography. Disseminated panretinal laser photocoagulation is still indicated in RVO patients who have large areas of nonperfusion, have developed neovascularization and/or late complications. Targeted laser photocoagulation of the peripheral areas of nonperfusion has recently been recommended by several authors and is expected to improve not only the visual outcome of IVI treatment, but more importantly to also reduce the duration of treatment and the number of re-injections needed. Clear evidence for targeted laser treatment is not yet available and is a focus of currently ongoing prospective randomized studies.

Central retinal vein occlusion post ChAdOx1 nCoV-19 vaccination - can it be explained by the two-hit hypothesis?

PURPOSE

To report a case of central retinal vein occlusion (CRVO) seven days following the first dose of ChAdOx1 nCoV-19 vaccine and propose a hypothesis for the possible underlying pathogenesis.

OBSERVATION

A 31-year-old male presented with CRVO with cystoid macular edema, one week after receiving his first ChAdOx1 nCoV-19 vaccine dose. Apart from mild hyperhomocysteinemia, no major thrombophilic or systemic risk factors were found. Anti-platelet factor 4 antibodies, specific for vaccine-induced immune thrombotic thrombocytopenia, were also negative. However, he tested strongly positive (> 250 U/mL) for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) IgG spike antibodies, 2 weeks post the first dose - suggestive of a prior subclinical infection.

CONCLUSION

COVID-19 is known to be associated with an altered host one-carbon metabolism resulting in hyperhomocysteinemia. We hypothesize that a prior subclinical infection with COVID-19, the first hit, may have led to hyperhomocysteinemia in our patient and vaccination must have been the second hit that triggered the thrombotic event. Further studies, including correlation of thrombotic complications with IgG antibody titres post-vaccination, are essential in order to better understand the pathogenesis of such events.

Elevated Neutrophil Counts, Triglycerides, Monocyte/High-Density Lipoprotein Ratios, and Lower High-Density Lipoprotein in Patients with Retinal Vein Occlusion

INTRODUCTION

The aim of the study was to evaluate associations of peripheral blood immune cells and blood lipid profile levels with retinal vein occlusion (RVO).

METHODS

This retrospective study included 127 patients with RVO and 108 controls. Patients with RVO were divided into branch RVO (BRVO), central RVO (CRVO), ischemic RVO, or nonischemic RVO groups. Medical records were collected and analyzed.

RESULTS

The RVO group had higher mean neutrophil, triglyceride (TG), and monocyte/high-density lipoprotein (HDL) ratio (MHR) levels and lower HDL levels (p = 0.037, p < 0.001, p = 0.004, and p = 0.002, respectively). TG and MHR levels were significantly higher in the BRVO and CRVO groups compared with the control group (p < 0.001 and p = 0.016, respectively), but there was no difference in BRVO and CRVO group (p = 0.972 and p = 0.916, respectively). Mean HDL levels were significantly lower in the BRVO and CRVO groups than in the control group (p = 0.005), but the difference between the BRVO group and CRVO group was not significant (p = 0.290). Neutrophils, TG, and MHR were independent risk factors for RVO. HDL was an independent protective factor for RVO. Age was an independent risk factor for ischemic RVO.

CONCLUSIONS

Lower HDL, and higher neutrophil, TG, and MHR levels are associated with RVO. Age is an independent risk factor for ischemic RVO.

Anti-Vascular Endothelial Growth Factor Treatment for Macular Edema in Eyes with Branch Retinal Vein Occlusion with vs Without Glaucoma – Does Glaucoma Affect Visual Outcome in Eyes with BRVO-ME After antiVEGF Injections?

Purpose

To compare the therapeutic effects of anti-vascular endothelial growth factor (anti-VEGF) agents in eyes with macular edema associated with branch retinal vein occlusion (BRVO-ME) with glaucoma to those without glaucoma.

Patients and Methods

This retrospective study was conducted using the medical records of Mie University Hospital from 2013 to 2017. Patients were recruited if they had received anti-VEGF agents for BRVO-ME treatment and included 30 patients (30 eyes) without glaucoma (G[-] group) and 27 patients (27 eyes) with glaucoma (G[+] group). The central retinal thickness (CRT) and best-corrected visual acuity (BCVA) at 3 months after a single injection of anti-VEGF agents were compared between the two groups.

Results

Before treatment, the mean±standard deviation of the CRT was 514.2±117.3 μm for the G[-] group, which was not significantly different from that for the G[+] group (533.4±171.4 μm). The CRT in the G[-] and G[+] groups significantly reduced to 321.1±114.6 μm and 347.8±134.7 μm, respectively, at 1 month after the injection and to 360.4±159.5 μm and 352.4±151.9 μm, respectively, at 3 months after the injection (P<0.01 for each group). The difference in the degree of CRT reduction between the two groups was not significant. Before treatment, the BCVA was 0.42±0.32 logMAR units in the G[-] group and 0.57±0.33 logMAR units in the G[+] group, showing no significant difference. The BCVA in the G[-] and G[+] groups improved significantly to 0.27±0.26 logMAR units and 0.34±0.42 logMAR units, respectively, at 1 month, and to 0.18±0.20 logMAR units and 0.39±0.34 logMAR units, respectively, at 3 months (P<0.01). The BCVA in the G[-] group was significantly better than that in the G[+] group at 3 months (P=0.02).

Conclusion

The therapeutic response of anti-VEGF agents for BRVO-ME is affected by the presence of glaucoma.

Review: The Development of Risk Factors and Cytokines in Retinal Vein Occlusion

Retinal vein occlusion (RVO) is the second most prevalent retinal disease. Despite this, the pathogenic mechanisms and risk factors are not entirely clear. In this article, we review recent publications on the classification, pathogenesis, risk factors, ischemic changes, cytokines, and vital complications of RVO. Risk factors and cytokines are important for exploring the mechanisms and new treatment targets. Furthermore, risk factors are interrelated, making RVO mechanisms more complex. Cytokines act as powerful mediators of pathological conditions, such as inflammation, neovascularization, and macular edema. This review aims to summarize the updated knowledge on risk factors, cytokines of RVO and signaling in order to provide valuable insight on managing the disease.

Neurocognitive Profile of the Post-COVID Condition in Adults in Catalonia-A Mixed Method Prospective Cohort and Nested Case-Control Study: Study Protocol

The diagnosis of the post-COVID condition is usually achieved by excluding other diseases; however, cognitive changes are often found in the post-COVID disorder. Therefore, monitoring and treating the recovery from the post-COVID condition is necessary to establish biomarkers to guide the diagnosis of symptoms, including cognitive impairment. Our study employs a prospected cohort and nested case-control design with mixed methods, including statistical analyses, interviews, and focus groups. Our main aim is to identify biomarkers (functional and structural neural changes, inflammatory and immune status, vascular and vestibular signs and symptoms) easily applied in primary care to detect cognitive changes in post-COVID cases. The results will open up a new line of research to inform diagnostic and therapeutic decisions with special considerations for cognitive impairment in the post-COVID condition.

Complete Blood Count-Derived Inflammation Indices and Retinal Vein Occlusion: A Case-Control Study

Introduction

This study evaluated complete blood count-derived inflammation indices in patients with retinal vein occlusion (RVO).

Methods

Participants in this case–control study were 54 patients with RVO and 54 age- and sex-matched control subjects. All participants underwent a thorough ophthalmic examination, as well as blood sample testing for complete blood count. Comparison of all parameters derived from complete blood count as well as calculation of specific indices was performed between patients with RVO and controls.

Results

Patients with RVO presented significantly higher white blood cell count (p = 0.033), neutrophil count (p = 0.003), neutrophil-to-lymphocyte ratio (NLR, p = 0.002), red cell distribution width (RDW, p = 0.009), mean platelet volume (MPV, p = 0.023), and systemic immune-inflammatory index (SII, p = 0.007) compared to controls. Receiver operator characteristic curve (ROC) analysis showed that NLR was superior to other inflammatory indices, having the greatest area under the curve. The optimal cutoff value for NLR to predict RVO was 2.29 with 46.2% sensitivity and 77.8% specificity.

Conclusion

Patients with RVO presented increased NLR, RDW, MPV, and SII, providing evidence that inflammation plays an important role in the pathogenesis of RVO. Complete blood cell count-derived indices can be easily calculated and may serve as an easy, simple, and cost-effective tool to evaluate the degree of systemic inflammation in patients with RVO, so as to potentially guide treatment.

Early vitrectomy in eyes with non-diabetic vitreous hemorrhage

Background:

Optimal management of non-diabetic vitreous hemorrhage (NDVH) is controversial, and reliability of B-scan ultrasonography in detecting retinal tears (RTs) has been reported to be highly variable by previous literature.

Objectives:

To report outcomes of conservative versus surgical management of NDVH and reliability of B-scan ultrasonography in detecting RTs and rhegmatogenous retinal detachment (RRD).

Design:

Retrospective observational single-center cohort study.

Methods:

Ninety-six consecutive NDVH from 96 eyes (96 patients) with minimum follow-up duration of 12 months were included.

Results:

Seventy-two eyes (75%) underwent early pars plana vitrectomy (PPV), 19 (20%) were managed conservatively and 5 (5%) underwent late PPV. Initial mean best corrected visual acuities (BCVAs) were 1.95 ± 1.19, 1.19 ± 1.38, and 1.14 ± 1.04 logMAR respectively, the difference was statistically significant (p = 0.039). Mean final BCVAs were 0.92 ± 1.19, 0.59 ± 0.87, and 1.25 ± 1.89 logMAR, respectively, the difference was not significant (p = 0.447). When comparing initial and final BCVAs, the difference was significant only in the early PPV group (p = 0.00001) and was not significant in the conservative group (p = 0.066) and in the late PPV group (p = 0.46). Complications included RRD (n = 2) and re-bleed in vitrectomized cavity (n = 1) in the early surgical group, need for additional laser or cryoretinopexy to RTs (n = 2), retinal detachment (n = 1), neovascular glaucoma (n = 1), persistent vitreous hemorrhage (n = 2) in the conservative group. B-scan ultrasound showed preoperative 11.53% sensitivity and a 60.0% positive predictive value for diagnosing retinal tears (RTs) in NDVH.

Conclusion:

The benefit of early PPV in NDVH seems to outweigh the risks of surgery, especially in the context of low sensitivity of B-scan in identifying RTs, and significant improvement in final BCVA following surgery may occur. NDVH should be promptly referred to vitreoretinal services, as surgery may be a safer and more advisable option.

Altered White Matter Integrity in Patients with Retinal Vein Occlusion: A Diffusion Tensor Imaging and Tract-Based Spatial Statistics Study

Background

To investigate microstructural alterations of white matter in retinal vein occlusion (RVO) patients by tract-based spatial statistics (TBSS) and diffusion tensor imaging (DTI). Material/Methods. DTI was performed on 14 RVO patients and 14 normal controls (HCs). We measured and recorded fractional anisotropy (FA) and radial diffusivity (RD) of white matter fibers and classified them through the receiver operating characteristic (ROC) curve and correlation analysis, respectively.

Results

The mean FA value of white matter in RVO patients is lower than the HCs, and the mean RD value in RVO patients increased, especially in the bilateral posterior thalamic, bilateral sagittal stratum, body of corpus callosum, cingulum, and fornix. The ROC curve of different brain regions showed high accuracy. Moreover, the mean FA and RD values were significantly correlated with visual and psychological disorders.

Conclusion

TBSS could be regarded as an important method to reveal the alterations of white matter in RVO patients, indicating the underlying neurological mechanism of the RVO.

Retinal Vein Occlusion with COVID-19: A Case Report and Review of Literature

OBJECTIVES

To provide a case report of Retinal Vein Occlusion (RVO) with COVID-19 infection.

CASE

A 15-year-old healthy male presented with blurring of vision, 2+ vitreous cells, retinal haemorrhages and dilated and tortuous retinal vessels in the left eye within 28 days of a positive COVID-19 reverse transcriptase polymerase chain reaction (RT-PCR) assay. He was diagnosed with left non-ischaemic CRVO, with a suspected aetiology of COVID-19.

DISCUSSION

A literature review found 12 reported cases of RVO associated with COVID-19. All but one patient was younger than 60, with a mean age of 42 years. Management varied, but in the majority (8/12), visual acuity (VA) improved with follow-up, and five (42%) had a final VA of 20/20.

CONCLUSION

In the absence of other known aetiological factors, ophthalmologists should consider COVID-19 as a cause of RVO. The outcome can vary, but the majority can expect improvement in VA with time.

Neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR) are more prominent in retinal artery occlusion (RAO) compared to retinal vein occlusion (RVO)

Aim

To evaluate the association between the value of neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR), monocyte to high-density lipoprotein ratio (MHR) and the development of retinal artery occlusion (RAO) and retinal vein occlusion (RVO).

Methods

This retrospective study assessed 41 RAO, 50 RVO and 50 control (age and gender matched senile cataract) participants. The NLR, PLR and MHR parameters of patients’ peripheral blood were analyzed. A receiver operating characteristics (ROC) curve analysis and the best cutoff value were used to specify the predictive value of NLR, PLR and MHR in RAO and RVO.

Results

The NLR, PLR and MHR were significantly higher in RAO group compared to the control group (p<0.001, p<0.001 and p = 0.008; respectively). The NLR, PLR and MHR were also significantly higher in the RVO group compared to the control group (p<0.001, p = 0.001 and p = 0.012, respectively). The NLR and PLR were significantly higher in the RAO group compared to the RVO group (p<0.001 and p = 0.022, respectively). The optimal cut-off value of NLR to predict RAO was >2.99, with 90.2% sensitivity and 100% specificity. The PLR to predict RAO was > 145.52, with 75.6% sensitivity and 80.0% specificity.

Conclusion

Higher NLR, PLR and MHR are related to the occurrence of RAO and RVO. NLR and PLR are more prominent in RAO compared to RVO.

Plasma lipid levels and risk of retinal vascular occlusion: A genetic study using Mendelian randomization

The causal effects of plasma lipid levels and the risk of retinal vascular occlusion (RVO) have not been clearly identified, especially for high-density lipoprotein-cholesterol (HDL-C) and low-density lipoprotein-cholesterol (LDL-C). Here, we try to identify these causal risk factors using a two-sample Mendelian randomization (MR) analysis. Single nucleotide polymorphisms (SNPs) were chosen as instrumental variables (IVs). We obtained genetic variants associated with lipid exposure at the genome-wide significance (P<5×10^-8) level from a meta-analysis of GWAS from the Global Lipids Genetics Consortium (GLGC) based on 188,577 individuals of mostly European ancestry for MR analyses. Meanwhile, we used lipid GWAS from UK Biobank (UKB) with a sample size of 115,078 individuals as a supplement. We obtained genetic predictors of RVO from a FinnGen biobank study. We conducted both univariable and multivariable MR (MVMR) analyses to identify the causal effects of RVO. Although inverse variance weighted (IVW) was the primary method used for MR analyses, MR-Egger and weighted-median methods were used as supplements to IVW. We determined the heterogeneity of IVs using Cochrane's Q test and I² , and used the MR-Egger intercept and MR-PRESSO Global test to detect horizontal pleiotropy. A leave-one-out sensitivity analysis was conducted by removing a single variant from the analysis. Genetically predicted increased HDL-C level was associated with decreased risk of RVO from GLGC [OR=0.806; 95% CI=(0.659, 0.986); P=0.036], which was consistent with UKB results [OR=0.766; 95% CI=(0.635, 0.925); P=0.005]. MVMR analysis for plasma lipids [adjusted OR=0.639; 95% CI=(0.411, 0.992); P=0.046] or diabetes [adjusted OR=0.81; 95% CI=(0.67, 0.979); P=0.029] suggested that low HDL-C may be an independent risk factor for RVO. However, there was no evidence to support a causal association between LDL-C {GLGC [adjusted OR=1.015; 95% CI=(0.408, 2.523); P=0.975], UKB [OR=1.115; 95% CI=(0.884, 1.407); P=0.359]}, total cholesterol {GLGC [adjusted OR=0.904; 95% CI=(0.307, 2.659); P=0.854], UKB [OR=1.047; 95% CI=(0.816, 1.344); P=0.716]} or triglycerides {GLGC [OR=1.103; 95% CI=(0.883, 1.378); P=0.385], UKB [OR=1.003; 95% CI=(0.827, 1.217); P=0.098]} and RVO. Using two-sample MR analysis, our study suggested that dyslipidemia was a risk factor for RVO. Furthermore, our results indicated that a low HDL-C level may be an independent risk factor for RVO, suggesting that controlling HDL-C level may be effective in RVO development.

Hypercoagulability Testing and Hypercoagulable Disorders in Young Central Retinal Vein Occlusion Patients

PURPOSE

To determine frequency of hypercoagulability testing and hypercoagulable states in patients with central retinal vein occlusion (CRVO) younger than 50 years.

DESIGN

Retrospective cohort study.

PARTICIPANTS

Deidentified patients younger than 50 years with newly diagnosed CRVO from a national insurance claims database.

METHODS

The de-identified Clinformatics Data Mart Database (Optum) containing medical claims from a commercial and Medicare Advantage insurance database was used. All outpatient medical claims (office visits, associated diagnoses, and laboratory testing) and demographic data for each beneficiary during their enrollment were accessible.

MAIN OUTCOME MEASURES

Prevalence of (1) laboratory hypercoagulable workup within 90 days of CRVO diagnosis, (2) new diagnosis of a hypercoagulable state within 1 year of CRVO diagnosis, and (3) diagnosis of hypertension, diabetes mellitus (DM), and hyperlipidemia.

RESULTS

One thousand one hundred eighty-one patients met inclusion criteria. Six hundred seventy-one patients (56.8%) were men, 450 patients (38.1%) had undergone hypercoagulable testing within 90 days, and 136 patients (11.5%) were diagnosed with a hypercoagulable state within 1 year after CRVO diagnosis. This proportion was similar between those patients with DM, hypertension, or hyperlipidemia (10.5% [65/620]) and those without (12.7% [71/561]; P = 0.28). Of the 136 patients diagnosed with a hypercoagulability state, 68.4% (93/136) had undergone testing within 90 days of CRVO diagnosis and 31.6% (43/136) did not. Of those who had not undergone hypercoagulability testing, 5.9% (43/731) were diagnosed with a hypercoagulable state within 1 year compared with 20.7% (93/450) in those who were tested (P < 0.001).

CONCLUSIONS

The prevalence of a hypercoagulable state within 1 year of CRVO diagnosis in patients younger than 50 years was 11.5%, and the prevalence was similar between patients with atherosclerotic risk factors and those without. Rate of testing was only 38.1%. Future research should examine the usefulness of uniform hypercoagulable testing in young CRVO patients.

A retrospective study assessing the factors associated with visual outcome in retinal vein occlusion patients after anti-VEGF therapy

Background

Retinal vein occlusion (RVO) is one of the most frequent retinal vascular diseases. In this study, we aimed to investigate the predictive factors of visual outcome for RVO patients who underwent anti-vascular endothelial growth factor (VEGF) therapy.

Methods

RVO patients who underwent anti-VEGF treatment were recruited in this study from January 2018 to June 2020. Clinical data and optical coherence tomography (OCT) parameters were retrospectively reviewed. Best-corrected visual acuity (BCVA) was examined at baseline and after anti-VEGF therapy. Predictive factors associated with visual outcome were assessed by logistic regression model. Treatment-related adverse events were also recorded.

Results

The average logMAR BCVA was 0.91 at baseline and 0.70 at final examination (P = 0.003). Among 75 patients, 41 experienced visual improvement were categorized as group A, the remaining 34 patients without improved vision were categorized as group B. Patients in group A demonstrated better visual outcomes, including decreased logMAR BCVA (average logMAR BCVA: 0.53 in group A vs. 0.91 in group B, P < 0.001) and central retinal thickness (CRT) (average CRT: 230.88 µm in group A vs. 404.97 µm in group B, P < 0.001) after anti-VEGF treatment. Multivariable analysis showed that injection frequency (odds ratio [OR], 2.623; 95% confidence interval [CI], [1.282–5.366]), hypertension (odds ratio [OR], 0.189; 95% CI [0.044–0.811]), hyperlipemia (odds ratio [OR], 0.195; 95% CI [0.040–0.941]) and external limiting membrane (ELM) disruption (odds ratio [OR], 0.148; 95% CI [0.032–0.691]) were all significantly associated with the visual outcome of RVO patients who underwent anti-VEGF treatment. In general, anti-VEGF therapy was feasible for all RVO patients, though the response to anti-VEGF was suboptimal in certain patients. Prognostic factors including injection frequency, hypertension, hyperlipemia and ELM disruption may all be useful to provide predictive information of visual outcome of RVO patients in response to anti-VEGF treatment.

Background Factors Affecting Visual Acuity at Initial Visit in Eyes with Central Retinal Vein Occlusion: Multicenter Study in Japan

PURPOSE

To determine the baseline characteristics of patients with central retinal vein occlusion (CRVO) that were significantly associated with the best-corrected visual acuity (BCVA) at the initial examination.

METHODS

This was a retrospective multicenter study using the medical records registered in 17 ophthalmological institutions in Japan. Patients with untreated CRVO (≥20-years-of-age) who were initially examined between January 2013 and December 2017 were studied. The patients' baseline factors that were significantly associated with the BCVA at the initial examination were determined by univariate and multivariate linear regression analyses.

RESULTS

Data from 517 eyes of 517 patients were analyzed. Univariate analyses showed that an older age (r = 0.194, p < 0.001) and the right eye (r = -0.103, p < 0.019) were significantly associated with poorer BCVA at the initial visit. Multivariate analyses also showed that an older age (β = 0.191, p < 0.001) and the right eye (β = -0.089, p = 0.041) were significantly associated with poorer BCVA at the initial visit.

CONCLUSIONS

The results indicate that an older age, a known strong factor, and the right eye were significantly associated with poorer BCVA at the initial visit to the hospital. These results suggest that functional and/or anatomical differences between the right and left eyes may be involved in these results.

Central Retinal Vein Occlusion in patients with COVID-19 infection: A systematic review

This systematic review summarizes the evidence on patients diagnosed with central retinal vein occlusion (CRVO) secondary to COVID-19. We searched PubMed and Google Scholar from its inception till June 2021. From an initial 55 publications, 10 studies provided specific information on COVID-19 patients with CRVO. Studies described 10 patients, 60% were male and the mean age was 39.3 ± 11.6 years. Blurred vision (40%) and decreased vision (50%) were the most common presenting complain. Symptom onset ranged from 5 days to 6 weeks after initial complaint of fever. Laboratory results showed elevated inflammatory markers and D-dimers in 60% of patients included in our review. Common treatment options were intravitreal anti-VEGF injections, steroids, and anticoagulants. Traditional co-morbidities like diabetes mellites, hypertension, and morbid obesity (hyperlipidemia) were observed in only 3/10 patients. The prognosis was excellent as all patients saw improvement in their condition. Our findings highlight the importance of identifying CRVO as an important complication of COVID-19 infection. Thus, physicians should not overlook the likelihood of CRVO in patients with COVID-19 infection and offer prompt treatment.

CATASTROPHIC ANTIPHOSPHOLIPID SYNDROME AND POSTERIOR OCULAR INVOLVEMENT: Case Series of 11 Patients and Literature Review

PURPOSE

To describe the posterior ophthalmic manifestations of catastrophic antiphospholipid syndrome.

METHODS

Retrospective case series of patients presenting with catastrophic antiphospholipid syndrome and posterior segment ocular manifestations. The main outcomes were the type of posterior segment manifestations at catastrophic antiphospholipid syndrome diagnosis, specifically retinal vascular occlusion, vasculitis, or choroidopathy, and the final best-corrected visual acuity.

RESULTS

This study included 23 patients (11 cases treated by the authors and 12 published case reports); 21 (91%) of them female. Their median age at diagnosis was 28 years (range, 16-79 years). Ophthalmologic manifestations were usually bilateral (n = 19, 83%) and involved vascular occlusive retinopathy (n = 17, 74%), choroidopathy (n = 11, 48%), or retinal vasculitis (n = 1, 4%). Final best-corrected visual acuity was not significantly worse than the best-corrected visual acuity at diagnosis (P = 0.16). Retinal vascular occlusions were associated with poorer final visual acuity than choroidopathy (P = 0.002). After a median follow-up of 14 months (range, 2-132 months), nearly half the patients (n = 11, 48%) had permanent vision loss including best-corrected visual acuity of <20/400 for 4 patients.

CONCLUSION

Posterior ophthalmic manifestations of catastrophic antiphospholipid syndrome were mainly bilateral retinal vascular occlusion, which had the worst visual prognosis, followed by choroidopathy and retinal vasculitis. Permanent visual loss was common.

Retinal vessels modifications in acute and post-COVID-19

Coronavirus disease 2019 (COVID-19) is an infectious disease caused by SARS-CoV-2 primarily affecting the respiratory system which can damage vessels walls virtually in any body district. Changes affecting retinal vessels are a good marker for systemic vascular alterations. This study investigated retinal vessels during the acute phase of COVID-19 and after patients recovery. Fifty-nine eyes from 32 COVID-19 patients and 80 eyes from 53 unexposed subjects were included. Mean arteries diameter (MAD) and mean veins diameter (MVD) were assessed through semi-automatic analysis on fundus color photos at baseline and 6 months later in patients and subjects unexposed to the virus. At baseline MAD and MVD were significantly higher in COVID-19 patients compared to unexposed subjects (p < 0.0001). Both MAD and MVD significantly decreased in COVID-19 patients at follow-up (from 97.5 ± 10.9 to 92.2 ± 11.4 µm, p < 0.0001 and from 133.1 ± 19.3 to 124.6 ± 16.1 µm, p < 0.0001, respectively). Despite this reduction vessels diameter remained significantly higher in severe COVID-19 patients compared to unexposed subjects. Transient retinal vessels dilation could serve a biomarker for systemic inflammation while long-lasting alterations seen in severe COVID-19 likely reflect irreversible structural damage to the vessels walls and should be further investigated for their possible effects on tissues perfusion and function.

Effects of Antithrombotic Agents on Ophthalmological Outcomes, Cardiovascular Risk, and Mortality in Hypertensive Patients with Retinal Vein Occlusion: An Exploratory Retrospective Study

Background and objectives: Because few data are available, the aim of this study is to analyze the effects of antithrombotic agents (ATAs) on visual function and long-term risk of cardiovascular events and mortality in hypertensive patients with retinal vein occlusion (RVO). Materials and methods: Hypertensive patients with RVO were consecutively selected from 2008 to 2012 and followed for a median of 8.7 years. Ophthalmologists evaluated and treated RVO complications, and best-corrected visual acuity (BCVA) was checked at each visit during the first one year of follow-up. Survival analysis was conducted on the rate of the composite endpoint of all-cause deaths or non-fatal cardiovascular events. Results: Retrospectively, we collected data from 80 patients (age 68 ± 12 years, 39 males). Central and branch RVO was present in 41 and 39 patients, respectively, and 56 patients started ATAs (50 antiplatelet drugs, 6 warfarin, and 2 low-molecular weight heparin). Average BCVA of the cohort did not change significantly during one-year of follow-up. The only predictor of BCVA was the baseline BCVA value. There was a reduction in proportion and severity of macular edema and an increase in the cumulative proportion of retinal vein patency reestablishment during the follow-up, independent of treatment. ATAs had no effects on one-year BCVA, intraocular complications, or the composite endpoint rate. Conclusions: In this exploratory study, ATAs had no effect on BCVA during the first one year of follow-up and on the composite endpoint during the long-term follow-up. Further prospective studies need to be conducted with an accurate standardization of the intraocular and antithrombotic treatment to define the positive or negative role of ATAs in hypertensive patients with RVO.

Association between Statins and Retinal Vascular Occlusion: A Population-Based Cohort Study

Retinal vascular occlusion (RVO), including retinal arterial occlusion and retinal vein occlusion, is a common retinal vascular disease that causes visual disturbance. The exact pathogenesis of RVO remains unclear. In all types of RVO patients, hyperlipidemia is more than twofold more common than in controls. Statins have been used to control blood cholesterol levels and have been found to reduce the risk of cardiovascular morbidity and mortality. Moreover, the immunomodulatory functions of statins may play a role in treating inflammatory diseases. This study aimed to evaluate whether patients taking statins have a lower risk of developing RVO compared to patients not taking statins. Adult patients with statins usage on the index date identified from the Taiwan National Health Insurance Research Database (NHIRD) between 2000 and 2013 were included. A threefold matched group was selected using age, sex, and year of index date for comparison. During the mean follow-up period of 12.87 ± 1.88 years, the cumulative incidence of RVO was significantly lower in the statin-user group (29.96 per 105 person-years [PYs]) than in the non-statin-user group (39.35 per 105 PYs). The results showed a lower cumulative incidence rate of RVO in patients prescribed statins than in those not prescribed statins (log-rank test, p = 0.020). The adjusting hazard ratio (HR) was significantly greater for RVO in the statin-user group (adjusted HR, 0.704; 95% CI, 0.591-0.873). Statin users had a decreased risk for all types of RVO development, including central retinal artery occlusion, arterial branch occlusion, central retinal vein occlusion, and branch retinal vein occlusion. In conclusion, patients undergoing statin treatment have a lower risk of developing RVO compared to patients not taking statins.

Dexamethasone Intravitreal Implant for the Treatment of Macular Edema Following Retinal Vein Occlusion: Post Hoc Analysis of Post-Marketing Surveillance Data in the Real-World Setting in Korea

Purpose

To supplement established efficacy and safety data, this analysis evaluated the real-world use of dexamethasone (DEX) intravitreal implant 700 µg for retinal vein occlusion (RVO)-related macular edema in an Asian population and baseline factors potentially associated with DEX implant efficacy.

Patients and Methods

A prospective, observational, post-marketing surveillance study was conducted at 38 sites in South Korea in patients consecutively presenting with macular edema following branch or central RVO (BRVO, CRVO), and administered a first DEX implant. Follow-up visits and subsequent DEX or other therapies conformed with local practice. Outcome measures included best-corrected visual acuity (BCVA), change in BCVA from baseline, responder rates, and adverse events. Associations between baseline characteristics and BCVA gains were evaluated. Month-1, -2, -4, and -6 visit analysis windows were established.

Results

In all, 700 patients (79.1% BRVO, 20.9% CRVO) received 1.12 DEX implants (mean) and were followed for 101.5 days (standard deviation, 51.7); 90% received a single implant. Among patients with analyzable data, mean BCVA improved from baseline with peak changes in Month 2 of −0.193 and −0.212 LogMAR, (P < 0.0001) and remained significant in the BRVO subgroup at the Month 4 and 6 windows (P < 0.0001 and P = 0.0039, respectively). Treatment-naïve patients experienced greater BCVA increases. The proportion of patients with stable/improved BCVA tended to decrease after Month 2 through Month 6 and the decline was greater in the CRVO subgroup. At the Month-2 window, ≥1-, 2- and 3-line increases were positively associated with younger age, worse baseline BCVA, and treatment naivety. The most common adverse event was increased intraocular pressure.

Conclusion

In the real-world clinical setting in South Korea, DEX implant improved visual acuity and had a favorable safety profile similar to that reported in randomized controlled trials and observational European and North American studies. These data further support the value of DEX implant as a treatment option for RVO.

ClinicalTrials.gov Identifier

NCT01976650. Date of registration: November 6, 2013.

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.

Central retinal vein occlusion in a patient using the antipsychotic drug olanzapine: a case report

Background

We report our findings in a patient who developed central retinal vein occlusion (CRVO) and was a chronic user of olanzapine, an antipsychotic medication.

Case presentation

A 50-year-old Caucasian man, non-smoker, was referred to our clinic with the chief complaint of floater appearance in his left eye for the past 3 days. His past medical history indicated that he had been taking antipsychotic drugs (olanzapine) for about 3 years, with no other systemic disease or risk factors for CRVO.

In the examination, his best-corrected visual acuity (BCVA) was 0.7 in the left eye. The fundus showed signs of nonischemic CRVO with subhyaloid hemorrhage and intraretinal hemorrhage in the posterior pole and superior and inferior retina, without macular edema, confirmed by optical coherence tomography (OCT).

We ruled out other probable differential diagnoses and risk factors which lead to CRVO through a complete physical exam and blood analysis (complete blood count, glucose, urea, creatinine, lipid profile, erythrocyte sedimentation rate, C-reactive protein, prothrombin time, partial thromboplastin time, Bleeding time (BT), fibrinogen level, proteins, antiphospholipid antibodies, homocysteine blood level, antithrombin III, protein C and S, factor V Leiden, prothrombin mutation, angiotensin-converting enzyme level, other autoantibodies, and human leukocyte antigen [HLA]-B51). Finally, we confirmed the probable side effect of olanzapine in CRVO, which has not been previously reported. A possible pro-thrombogenic mechanism of olanzapine at the molecular level is an affinity for 5-HT_2Aserotonin receptors. Blocking these receptors results in increased platelet aggregation and increased blood coagulability.

Conclusions

These results indicate that CRVO can be a complication of chronic use of antipsychotic medications such as olanzapine, as shown for the first time in our case report. Clinicians should question patients who develop a sudden CRVO whether they are using antipsychotic medications such as olanzapine.

Treatment of retinal vein thrombosis: what about anticoagulants?

Retinal vein occlusion is an important cause of vision loss. The current treatment options are mainly directed to the prevention of neovascular complications and few studies have addressed to potential use of anticoagulant agents and other interventions targeting the coagulation system. Herein we review the general aspects of this condition focusing on the potential benefits of anticoagulant treatment.

Macular Microvascular Changes and Their Correlation With Peripheral Nonperfusion in Branch Retinal Vein Occlusion

PURPOSE

To investigate the correlation between macular microvascular alterations on optical coherence tomography angiography (OCTA) and retinal ischemia on ultra-widefield fluorescein angiography (UWF FA) in eyes with branch retinal vein occlusion (BRVO).

DESIGN

Cross-sectional study.

METHODS

This prospective study was performed from September 2019 to June 2020 at Yeungnam University Medical Center. We included 60 patients with treatment-naïve BRVO. Two independent, masked graders analyzed OCTA parameters, including vessel density, skeletal density, and fractal dimension (FD), and UWF FA parameters, including retinal nonperfusion area (NPA) and ischemic index (ISI), from various concentric regions (perimacular region, 0.5-3 mm radius; near-peripheral region, 3-10 mm; midperipheral region, 10-15 mm; far-peripheral region, >15 mm). A repeated-measures analysis of variance test and a paired t test were performed for inter-visit and inter-regional comparisons, and Pearson correlation coefficient and multivariate regression analyses were performed to examine the correlation between UWF FA and OCTA parameters.

RESULTS

The OCTA parameters from both the superficial and deep capillary plexuses (DCP) were significantly correlated with NPA and ISI in all concentric regions. Even after adjusting for several covariates, all OCTA parameters revealed a significant association with ISI on UWF FA. Moreover, OCTA parameters from DCP were significantly correlated with concentrations of placental growth factor and vascular endothelial growth factor. Although all OCTA parameters achieved excellent results of area under the curve (AUC) > 0.9 for detecting severe retinal ischemia, defined as ISI >10%, FD reduction in DCP was the most reliable parameter (AUC = 0.948, P < .001), and 5.39% was the best cut-off point for predicting ISI > 10%.

CONCLUSIONS

OCTA is a useful noninvasive tool not only for evaluation of macular microvasculature but for supposition of peripheral nonperfusion in eyes with BRVO.

Prospective trial of treat-and-extend regimen with aflibercept for branch retinal vein occlusion: 1-year results of the PLATON trial

PURPOSE

To evaluate the functional and anatomical outcomes of a treat-and-extend (TAE) regimen with aflibercept for treatment-naive macular edema (ME) secondary to branch retinal vein occlusion (BRVO).

METHODS

This was a prospective, multicenter, noncomparative, open-label clinical trial. Forty-eight eyes of 48 patients received three monthly intravitreal aflibercept injections prior to the TAE regimen. However, if the best-corrected visual acuity (BCVA) was ≥ 20/20 and the central macular thickness (CMT) was < 250 μm during the loading phase, the patient immediately proceeded to the TAE regimen. The treatment interval was adjusted by 4 weeks based on changes in CMT. The primary outcome was the mean change in BCVA from baseline to 52 weeks.

RESULTS

The mean change in BCVA was 23.6 ± 14.2 letters. The proportion of patients with BCVA gain ≥ 15 letters was 77.1% at 24 weeks and 72.9% at 52 weeks. The mean reduction in CMT was 326.2 ± 235.6 μm at 24 weeks and 324.2 ± 238.0 μm at 52 weeks. The mean number of injections was 6.7 ± 1.2 (range: 6-11, all patients received three monthly intravitreal aflibercept injections) over 52 weeks, and 34 patients (70.8%) reached the maximal extension interval of 16 weeks at 52 weeks.

CONCLUSIONS

The TAE regimen using aflibercept for ME secondary to BRVO, which has a treatment interval of up to 16 weeks, showed comparable efficacy to the fixed-dosing regimen along with reduced treatment burden.

Wide-Field Fluorescein Angiography in the Diagnosis and Management of Retinal Vein Occlusion: A Retrospective Single-Center Study

Background

The aim of this retrospective study was to evaluate the role of wide-field fluorescein angiography (WF-FA) in the diagnosis and management of retinal vein occlusion (RVO) at a single center in Poland.

Material/Methods

This study included 106 patients (112 eyes) diagnosed with RVO (102 eyes) or impending RVO (10 eyes) (54% women and 46% men, aged 26 to 86 years). The medical records of the participants were reviewed in search of documentation on ocular and systemic diseases. Results of FA of central and peripheral retina and optical coherence tomography (OCT) scans, which had been used to establish treatment indications, were analyzed. WF-FA was performed with Spectralis HRA+OCT or Optos Tx200.

Results

Actual RVO was found in 102 eyes. Of those cases, 46.1% were CRVO (central retinal vein occlusion), 40.2% branch retinal vein occlusion, 11.8% small tributary vein occlusion, and 1.9% hemispheric retinal vein occlusion. Neovascularization on an optic disc, neovascularization elsewhere, and veno-venous collateral vessels were observed in 32.3%, 17.4%, and 41.2% of the eyes, respectively. Peripheral ischemic zones were present in 59.8% of the eyes, in 20.6% of which, ischemia was not observed in the posterior pole. Dye leaks limited to peripheral vessels, peripheral vascular amputations, and central macular edema in OCT were observed in 17.6%, 43.1%, and 63.7% of the eyes, respectively. Retinal laser photocoagulation was conducted on 73.5% of the eyes.

Conclusions

Decision-making about management of patients with RVO should be done after physical examination and analysis of central and peripheral retina FA. In 20.6% of patients, assessment of the peripheral retina resulted in a change in treatment. The first changes suggestive of progression of thrombotic disease to the ischemic form appeared on the periphery in images from WF-FA.

Assessment of Spontaneous Retinal Arterial Pulsations in Acute Central Retinal Vein Occlusions

Central retinal vein occlusion (CRVO) is a common retinal disease. Recent works mentioned spontaneous retinal arterial pulsations (SRAPs) as a feature of some CRVOs. This is a retrospective study on patients presenting with CRVO who were followed up for at least 6 months. The objective was to identify SRAP in the acute phase of the disease and determine their relationship with patients' characteristics and visual prognosis. A 10-second infrared film centered on the optic disc was recorded within a month of the onset of symptoms, and SRAPs were detected in two-thirds of the cases. Patients with SRAP were significantly younger than those without SRAP. Mean central macular thickness was significantly higher in the absence of SRAP, which was translated into a more severe macular edema; however, this difference faded with time. BCVA tended to be higher in the presence of SRAP at the 6-month follow-up when adjusted to baseline. This study demonstrates that SRAPs are a frequent finding, easily detected by infrared fundus video recording, and associated with a younger age and lesser macular edema.

Impending Central Retinal Vein Occlusion in a Patient with Coronavirus Disease 2019 (COVID-19)

PURPOSE

To report a case of impending central retinal vein occlusion (iCRVO) in a COVID-19 patient.

CASE REPORT

A 54 years old woman with COVID-19 related pneumonia presented to our emergency department complaining of scotomas and decreased vision in her right eye. Funduscopic examination and multimodal imaging revealed rare retinal hemorrhages, retinal whitening, and fern-like hypo-autofluorescent appearance typical of iCRVO. She had no risk factors other than a transient hyper-coagulability status likely related to the ongoing infection. Systemic treatment with steroids normalized her inflammatory and coagulation status and the occlusion completely resolved.

CONCLUSIONS

Retinal circulation should be considered as a potential site for thromboembolic complications from COVID-19.

Intravitreal Dexamethasone Implant as a Sustained Release Drug Delivery Device for the Treatment of Ocular Diseases: A Comprehensive Review of the Literature

Drug delivery into the vitreous chamber remains a great challenge in the pharmaceutical industry due to the complex anatomy and physiology of the eye. Intravitreal injection is the mainstream route of drug administration to the posterior segment of the eye. The purpose of this review is to assess the current literature about the widening use of the intravitreal 0.7 mg dexamethasone (Dex) implant, and to provide a comprehensive collection of all the ocular disorders that benefit from Dex administration. Although anti-vascular endothelial growth-factors (VEGFs) have been largely indicated as a first-choice level, the Dex implant represents an important treatment option, especially in selected cases, such as vitrectomized eyes or patients in whom anti-VEGF failed or are contraindicated. In this article, the safety profile as well as the list of the possible complications related to intravitreal Dex injection are also discussed.