Cumulative effect of metabolic syndrome on the risk of retinal vein occlusion in young patients: A nationwide population-based study.

This study aimed to investigate the impact of the cumulative burden of metabolic syndrome (MetS) on the incidence of retinal vein occlusion (RVO) in young adults. We included 1,408,093 subjects aged ≥20 and <40 years without a history of RVO who underwent four consecutive annual health examinations during 2009-2012 from the database of the Korean National Health Insurance Service. The metabolic burden was evaluated based on the cumulative number of MetS diagnoses at each health examination (0-4 times) and the cumulative number of each MetS component diagnosed at each health examination (0-4 times per MetS component). Cox proportional hazards models were used to estimate the risk of RVO according to metabolic burden. The risk of RVO was positively correlated with the cumulative number of MetS diagnoses over the four health examinations. All five MetS components were independently associated with an increased risk of RVO. Subgroup analysis for the impact of MetS on RVO occurrence revealed that MetS had a greater impact on female subjects (P <0.001). Prompt detection of metabolic derangements and their treatment might be important to decrease the risk of RVO in young adults, especially women.

Clinical features, management, and outcomes of patients with sterile endophthalmitis associated with intravitreal bevacizumab injection: retrospective case series.

PURPOSE: To evaluate clinical features, treatment protocol, outcomes, and complications that developed in this case series of 24 patients who had consecutive sterile endophthalmitis after intravitreal bevacizumab (IVB) injection. METHODS: In this retrospective case series, IVB was repackaged in individual aliquots from the three batches that were used on the same day. IVB was injected into 26 eyes of 26 patients due to diabetic macular edema, age-related macular degeneration, and branch retinal vein occlusion. All patients had intraocular inflammation. Patients were divided into two groups severe and moderate inflammation according to the intraocular inflammation. The medical records of all patients were reviewed. At each follow-up visit, the complete ophthalmologic examination was performed, including best corrected visual acuity (BCVA), intraocular pressure, biomicroscopy, and posterior fundus examination. RESULTS: Twenty-four of 26 patients were included in the study. Two patients were excluded from this study since they didn't come to follow-up visits. The mean BCVA was 1.00 ± 0.52 Log MAR units before IVB. At the final visit, the BCVA was 1.04 ± 0.47 Log MAR units. These differences were not significant (p = 0.58). Of the 24 eyes, 16 eyes had severe, and 8 eyes had moderate intraocular inflammation. Eleven eyes in the severe inflammation group underwent pars plana vitrectomy due to intense vitreous opacity. Smear, culture results, and polymerase chain reaction results were negative. CONCLUSION: Sterile endophthalmitis may occur after IVB injection. Differential diagnosis of sterile endophthalmitis from infective endophthalmitis is crucial to adjust the appropriate treatment and prevent long-term complications due to unnecessary treatment.

Deep learning segmentation of non-perfusion area from color fundus images and AI-generated fluorescein angiography.

The non-perfusion area (NPA) of the retina is an important indicator in the visual prognosis of patients with branch retinal vein occlusion (BRVO). However, the current evaluation method of NPA, fluorescein angiography (FA), is invasive and burdensome. In this study, we examined the use of deep learning models for detecting NPA in color fundus images, bypassing the need for FA, and we also investigated the utility of synthetic FA generated from color fundus images. The models were evaluated using the Dice score and Monte Carlo dropout uncertainty. We retrospectively collected 403 sets of color fundus and FA images from 319 BRVO patients. We trained three deep learning models on FA, color fundus images, and synthetic FA. As a result, though the FA model achieved the highest score, the other two models also performed comparably. We found no statistical significance in median Dice scores between the models. However, the color fundus model showed significantly higher uncertainty than the other models (p < 0.05). In conclusion, deep learning models can detect NPAs from color fundus images with reasonable accuracy, though with somewhat less prediction stability. Synthetic FA stabilizes the prediction and reduces misleading uncertainty estimates by enhancing image quality.

Metabonomics analysis of aqueous humor samples from cataract patients with branch retinal vein occlusion.

Cataract (CAT) has a very high incidence rate among the middle-aged and elderly, with most patients complicated by branch retinal vein occlusion (BRVO), a key cause of blindness. In this study, through metabolomic analysis of aqueous humor samples from CAT patients with BRVO, a total of 319 different metabolites were found, most of which belonged to the categories of carboxylic acids and derivatives, fatty acyls, and organooxygen compounds. The most typical metabolites were 3-methylhistidine and biliverdin, which were up-regulated, as well as the down-regulated beta-glycerophosphoric acid. Tricosanoic acid showed the most significant correlation with CAT+BRVO. According to the Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, the most commonly related keywords for differentially expressed metabolites were biosynthesis of unsaturated fatty acids and synaptic vesicle cycle. These results can not only help to further understand the pathogenesis of CAT complicated by BRVO in clinical practice, but also provide some new therapeutic research directions.

Evaluation of clinical outcomes of raised intraocular pressure following intravitreal triamcinolone acetonide injection.

Aim: To assess the incidence, risk factors, and treatment outcomes in intravitreal triamcinolone acetonide injection (IVTA) induced intraocular pressure rise and to compare IOP rise in 1-mg and 2-mg IVTA. Materials and methods: Prospective observational study conducted in all eyes receiving IVTA. Any pre-existing glaucoma and patients who received IVTA or dexamethasone implant in the last 6 months were excluded. Results: 9 between 61-70 years of age developed an IOP spike. The mean and standard deviation of age in years was 61.95 ± 8.70. Maximum eyes had ME due to Diabetic Retinopathy (53.3%). All cases of uveitic ME were reported to have an IOP spike. 2 out of 3 high myopic eyes and 1 eye with thyroid abnormality had an IOP spike. High IOP was found in 13 eyes, with more than 25 mm Hg rise in 4 eyes and more than 5 mm Hg rise from baseline IOP in 9 eyes. The mean and standard deviation of time taken for IOP raise (in days) was 46.39 ± 37.68. A total of 38 eyes received 1 mg of IVTA and the rest 22 received 2 mg of IVTA. 23.7% of 1 mg eyes experienced an IOP rise while it was 18.2% in eyes with 2 mg IVTA. The injection was repeated in 12 eyes and 41.7% developed an IOP spike among them. The independent "t" test results showed that there was a significant difference in the mean of IOP (Pre-injection) concerning the IOP rise (P=0.007*). 1 eye had IVTA crystals in the anterior chamber with raised IOP of 30 mm Hg. 1 out of 13 eyes with raised IOP needed 2 AGMs, the other 12 eyes responded well to 1 AGM. Discussion: IVTA is widely used in refractory cases of ME and steroid-induced glaucoma is the most common side effect of IVTA. To the best of our knowledge, there is a lack of literature on prospective studies on IVTA-associated risk factors, patterns of IOP elevation, and treatment outcomes. The pre-injection mean ± SD baseline IOP for uneventful eyes was 12.87±2.65 and the pre-injection mean IOP for eyes with IOP event was 15.23±2.89 (P=0.007*). Conclusion: We proposed that TA is an independent risk factor for post-intravitreal injection IOP spike. IVTA causes a maximum IOP spike at 1 to 2 months and has a protracted course that responds to anti-glaucoma medications. High baseline IOP, a repeated dose of IVTA, the presence of TA crystals in the anterior chamber, and high myopia were associated with significant IOP elevation. Abbreviations: ACD = Anterior chamber depth, AS = Anterior segment, AGM = Anti-glaucoma medications, ARMD = Age-related macular degeneration, BCVA = Best-corrected visual acuity, BRVO = Branch retinal vein occlusion, CCT = Central corneal thickness, CRVO = Central retinal vein occlusion, CME = Cystoid macular edema, CNVM = Choroidal neovascularization membrane, CSME = Clinically significant macular edema, DR = Diabetic retinopathy, ERM = Epiretinal membrane, IOP = Intraocular pressure, IGS = Irvine-Grass syndrome, GAGs = Glycosaminoglycans, IVTA = Intravitreal triamcinolone acetonide injection, ME = Macular edema, NVG = Neovascular glaucoma, OHT = Ocular hypertension, PDS = Pigment dispersion syndrome, PACG = Primary closed angle glaucoma, POAG = Primary open-angle glaucoma, PXF = Pseudoexfoliation, VA = Visual acuity, VEGF = Vascular endothelial growth factors, VH = Vonherick's grading, SD = Standard deviation, TA = Triamcinolone acetonide, TIGR = Trabecular meshwork inducible glucocorticoid response.

Investigation into safflower injection as a prophylactic treatment for retinal vein occlusion in a rabbit model.

The study aimed to assess the effect and mechanism of safflower injection in preventing retinal vein thrombosis in rabbits. Twenty healthy adult pigmented rabbits were randomly assigned to either the experimental group, receiving safflower injection, or the control group, receiving normal saline. After two weeks of treatment, blood samples were collected to analyze platelet adhesion and aggregation rates. Photodynamic therapy was applied to induce occlusion in the target retinal vein. Fundus photography and fluorescein angiography were recorded using a dynamic microscopic monitoring system, and laser speckle imaging was employed to assess blood flow in the affected vein. The experimental group exhibited significantly lower rates of platelet adhesion and aggregation compared to the control group. Following the induction of retinal vein occlusion, the experimental group showed a lower complete occlusion rate of the target retinal vein. Although initial blood flow in the target vein was similar between groups, the blood flow at 1, 3, and 5 min post-occlusion was significantly higher in the experimental group. Safflower injection delayed retinal vein thrombosis formation, preserved blood flow in the affected retinal area, and reduced platelet adhesion and aggregation. These effects facilitated vascular reperfusion within a limited timeframe.

Clinical effects of atorvastatin combined with conbercept in the treatment of patients with macular edema secondary to retinal vein occlusion and carotid plaque: study protocol for a prospective randomized controlled trial.

INTRODUCTION: Intravitreal injections of anti-vascular endothelial growth factor (anti-VEGF) drugs have been widely used in patients with macular edema (ME) secondary to retinal vein occlusion (RVO); however, recurrence is a major concern. This study aims to observe the clinical effects of atorvastatin and intravitreal therapy in the treatment of patients with branch or central RVO-ME and coexistent carotid plaques (CP). METHODS AND ANALYSIS: A prospective randomized controlled clinical trial will be conducted. Sixty-four patients diagnosed with branch or central RVO-ME and coexistent CP will be enrolled and randomly allocated in a 1:1 ratio to the control and experimental groups. The control group will be treated with intravitreal conbercept monthly for 3 months, followed by monthly evaluation and injection of pro re nata (PRN) for 12 months, while the experimental group will be treated with oral atorvastatin 20 mg daily combined with the control group treatment. If a drop of best-corrected visual acuity (BCVA) is more than five Early Treatment Diabetic Retinopathy Study (ETDRS) letters (one line) or an increment in central subfield thickness (CSFT) of 100 µm (or a 10% increment from the previous visit), intravitreal re-treatment will be performed. Outcome measurements include CSFT, BCVA, number of injections, and incidence of adverse events during the 12-month follow-up period. Differences between groups will be evaluated using Student's t-test, and comparisons between groups will be evaluated using repeated-measures analysis of variance. ETHICS AND DISSEMINATION: The study has been approved by the Institutional Review Board of Nanjing Lishui People's Hospital, Nanjing, China (approval number 2023KY0418-12, dated 18 April 2023), and has been registered on chictr.org.cn. Written informed consent will be collected from each patient and the results of this trial will be submitted to a peer-reviewed journal. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR2300071359. Registered on 12 May 2023.

Long-term dynamic changes and influencing factors of corneal morphology after multiple intravitreal injections of anti-VEGF drugs.

To observe alterations in corneal morphology caused by repeated intravitreal injections of anti-vascular endothelial growth factor (VEGF). Prospective cohort study. Seventy-seven eyes were treated with intravitreal injection of anti-VEGF from June 2021 to March 2023. There were 25 eyes of neovascular age-related macular degeneration (nAMD), 24 eyes of diabetic macular edema (DME), and 28 eyes of retinal vein occlusion (RVO). Aflibercept was used in 37 eyes and Ranibizumab was used in 40 eyes. 3 + PRN was used. Corneal endothelium and corneal thickness were measured using a corneal endothelial microscope. The data related to central corneal thickness, corneal endothelial cell density (ECD), average cell size, coefficient of variation (CV), proportion of hexagonal cells (Hex%) was collected. A comparison was also made between baseline and the dynamic changes of all indexes 1 year following the last injection. It was observed that in comparison to baseline, ECD and Hex% decreased significantly after the 3rd injection of Aflibercept and Ranibizumab. However, ECD did not decrease further and remained at the same level as after the last injection. Hex% and average cell size increased to a certain extent in comparison to the last injection. All the changes were found to be statistically significant (P < .01). After 3 injections, ECD in DME group was markedly lower than that in nAMD and RVO group, but the CV in DME group was higher than that in nAMD as well as RVO groups, and all the differences were statistically significant (P < .05). Following intravitreal anti-VEGF therapy, DME is more likely than other disorders to result in a decrease in ECD. Repeated intravitreal injections of anti-VEGF drugs can reduce the Hex% and ECD to a certain extent. After the last injection, Hex% can progressively recover, and ECD can remain stable without further declining. After injections, ECD in DME group was found to be significantly lower than that in nAMD and RVO groups, but CV in DME group was significantly higher in comparison to the other 2 groups. In patients with macular edema, repeated intravitreal injections of anti-VEGF may have certain effects on corneal morphology. Patients with diabetes mellitus in particular should pay special attention to corneal safety following repeated intravitreal injections if they have significantly reduced ECD at baseline.

Assessment of Serum Atherogenic Indices and Insulin Resistance in Retinal Vein Occlusion.

Objectives: This study aimed to investigate serum atherogenic indices as novel cardiovascular risk factors associated with retinal vein occlusion (RVO). Materials and Methods: This retrospective case-control study included 57 patients with newly diagnosed RVO whose plasma lipid profile (low-density lipoprotein cholesterol [LDL-C], high-density lipoprotein cholesterol [HDL-C], total cholesterol [TC], and triglycerides [TG]) and insulin resistance were examined. Serum atherogenic indices (LDL-C/HDL-C, TC/HDL-C, TG/HDL-C, and non-HDL-C/HDL-C ratios) and presence of insulin resistance were compared between the patients and 63 healthy subjects. Cut-off values were determined by receiver operating characteristic curve analysis. Results: The mean age of the RVO patients was 63.7±9.4 years. Plasma levels of LDL-C, HDL-C, TC, and TG showed no significant difference between the patient and control groups (p>0.05). However, LDL-C/HDL-C, non-HDL-C/HDL-C, and TC/HDL-C ratios were higher in the RVO group compared to healthy subjects (p=0.015, p=0.036, and p=0.015, respectively). Fasting insulin concentrations, plasma insulin, and homeostasis model assessment of insulin resistance (HOMA-IR) index were higher in the RVO patients compared to controls (p=0.003, p=0.001, and p=0.001, respectively). Conclusion: LDL-C/HDL-C, TC/HDL-C, and non-HDL-C/HDL-C ratios were found to be increased in RVO. Compared to the traditional plasma lipid profile, serum atherogenic indices were found to be superior predictors of RVO development. Measurement of HOMA-IR index should be taken into consideration in the evaluation of insulin resistance. High serum atherogenic indexes in RVO patients reveal the need to take precautions against the risk of cardiovascular disease and stroke.

Photocoagulation or sham laser in addition to conventional anti-VEGF therapy in macular edema associated with TelCaps due to diabetic macular edema or retinal vein occlusion (TalaDME): a study protocol for a multicentric, French, two-group, non-commercial, active-control, observer-masked, non-inferiority, randomized controlled clinical trial.

BACKGROUND: Macular edema (ME) results from hyperpermeability of retinal vessels, leading to chronic extravasation of plasma components into the retina and hence potentially severe visual acuity loss. Current standard of care consists in using intravitreal injections (IVI), which results in a significant medical and economic burden. During diabetic retinopathy (DR) or retinal vein occlusion (RVO), it has recently been shown that focal vascular anomalies (capillary macro-aneurysms, also termed TelCaps) for telangiectatic capillaries may play a central role in the onset, early recurrence, and/or persistence of ME. Since targeted photocoagulation of TelCaps may improve vision, identification, and photocoagulation of TelCaps, it may represent a way to improve management of ME. OBJECTIVE: The Targeted Laser in (Diabetic) Macular Edema (TalaDME) study aims to evaluate whether ICG-guided targeted laser (IGTL), in association with standard of care by IVI, allows reducing the number of injections during the first year of treatment compared with IVI only, while remaining non-inferior for visual acuity. METHODS: TalaDME is a French, multicentric, two-arms, randomized, sham laser-controlled, double-masked trial evaluating the effect of photocoagulation of TelCaps combined to IVI in patients with ME associated with TelCaps. Patients with vision loss related to center involved ME secondary to RVO or DR and presenting TelCaps are eligible. Two hundred and seventy eyes of 270 patients are randomized in a 1:1 ratio to standard care, i.e., IVI of anti-VEGF solely (control group) or combined with IGTL therapy (experimental group). Stratification is done on the cause of ME (i.e., RVO versus diabetes). Anti-VEGF IVI are administered to both groups monthly for 3 months (loading dose) and then with a pro re nata regimen with a monthly follow-up for 12 months. The primary endpoint will be the number of IVI and the change in visual acuity from baseline to 12 months. Secondary endpoints will be the changes in central macular thickness, impact on quality of life, cost of treatment, and incremental cost-utility ratio in each groups. KEY SAFETY: Rare but severe AE linked to the use of IVI and laser, and previously described, are expected. In the sham group, rescue laser photocoagulation may be administered by the unmasked investigator if deemed necessary at month 3. DISCUSSION: The best management of ME associated with TelCaps is debated, and there have been no randomized study designed to answer this question. Given the fact that TelCaps may affect 30 to 60% of patients with chronic ME due to DR or RVO, a large number of patients could benefit from a specific management of TelCaps. TalaDME aims to establish the clinical and medico-economic benefits of additional targeted laser. The results of TalaDME may raise new recommendations for managing ME and impact healthcare costs. TRIAL REGISTRATION: EudraCT: 2018-A00800-55/ NCT03751501. Registration date: Nov. 23, 2018.

Effect of Intravitreal Aflibercept on Corneal Endothelial Cells.

AIM:  To determine the effect of repeated intravitreal injections of aflibercept on the corneal endothelium in patients with diabetic macular edema (DME) and macular edema due to retinal vein occlusion (RVO). METHODS:  In a prospective study conducted between January 2021 and November 2023, a total of 87 treatment-naive eyes with DME and RVO were evaluated. The exclusion criteria were surgery or laser intervention during the follow-up period, contact lens wear, cataract surgery in the last 6 months, dystrophy, or other corneal condition that may cause endothelial damage. In addition to routine examinations on the day of application, we also measured the corneal endothelium using specular microscopy on the 1st, 4th and 8th day of injection. We evaluated 4 parameters: endothelial cell density (CD), hexagonality (HEX), coefficient of variability (CV) and central corneal thickness (CCT). First of all, we evaluated the entire cohort of eyes, and then divided it according to 2 criteria; the diagnosis into DME/RVO and according to the lens status into phakic/pseudophakic eyes. RESULTS:  A total of 87 eyes of 68 patients were evaluated. The average age of the patients at the time of diagnosis was 66.8 ±9.3 years. Within the cohort 51 (59%) eyes were phakic and 36 (41%) pseudophakic. A total of 61 (70%) eyes with a diagnosis of DME were treated, and 26 (30%) with RVO. During the follow-up, there were no significant changes in the average values of CD, HEX, CV, CCT due to aflibercept treatment, either in the whole group or in subgroups according to diagnosis or lens condition. CONCLUSIONS:  The results of this study suggest that intravitreal administration of aflibercept in patients with DME and RVO did not have an impact on corneal endothelial parameters, including CCT, HEX, CD and CV. These parameters were measured using endothelial microscopy during an 8-injection observation period.

Incidence rates of retinal vascular occlusive diseases from 2011 to 2020 in South Korea: a nationwide cohort study.

BACKGROUND: Retinal vascular occlusions, including retinal vein occlusion and retinal artery occlusion, are common causes of visual impairment. In order to evaluate the national medical burden and help improve ophthalmic health care policy planning, we investigated the incidence of retinal vascular occlusive diseases from 2011 to 2020 in Korea. METHODS: This study is a nationwide population-based retrospective study using data from the Korea national health claim database of the Health Insurance Review and Assessment (HIRA) service. We identified retinal vascular occlusive diseases registered from January 1, 2009, to December 31, 2020, according to the retinal vascular occlusion code (H34) and its sub-codes from international classification of disease, tenth revision diagnosis code. We used data from the entire Korean population based on the 2015 census of the population in Korea to calculate standardized incidence rates. RESULTS: We identified 348,775 individuals (male, 161,673 [46.4%]; female, 187,102 [53.6%]) with incident retinal vascular occlusion (H34), 10,451 individuals (males, 6,329 [60.6%]; females, 4,122 [39.4%]) with incident central retinal artery occlusion (H34.1), and 252,810 individuals (males, 114,717 [45.4%]; females, 138,093 [54.6%]) with incident retinal vein occlusion (H34.8) during the 10-year study period. The weighted mean incidence rate of retinal vascular occlusion was 70.41 (95% CI, 70.18-70.65) cases/100,000 person-years. The weighted mean incidence rate of central retinal artery occlusion was 2.10 (95% CI, 2.06-2.14) cases/100,000 person-years. The weighted mean incidence rate of retinal vein occlusion was 50.99 (95% CI, 50.79-51.19) cases/100,000 person-years. CONCLUSION: The total retinal vascular occlusion and retinal vein occlusion showed a decreasing trend until 2020. However, the central retinal artery occlusion decreased until 2014 and remained stable without a significant further decline until 2020. The incidence of total retinal vascular occlusion and retinal vein occlusion was higher in females than in males, while the incidence of central retinal artery occlusion was higher in males. All retinal vascular occlusive diseases showed an increasing incidence with older age; the peak age incidence was 75-79 years for total retinal vascular occlusion and retinal vein occlusion, and 80-85 years for central retinal artery occlusion.

Initial response and 12-month outcomes after commencing dexamethasone or vascular endothelial growth factor inhibitors for retinal vein occlusion in the FRB registry.

To compare baseline characteristics, initial response and 12-month efficacy and safety outcomes in eyes with branch and central retinal vein occlusion (BRVO and CRVO) treated with dexamethasone implants (DEX) or anti-vascular endothelial growth factor (anti-VEGF) we performed a multi-centre, retrospective and observational study using Fight Retinal Blindness! Registry. Of 725 eligible eyes, 10% received DEX initially with very frequent adjunctive anti-VEGF (BRVO-DEX 49%, CRVO-DEX 60%). The primary outcome of mean adjusted change in VA at 12 months with DEX and anti-VEGF initiated groups were not statistically significantly different (BRVO: DEX + 6.7, anti-VEGF + 10.6 letters; CRVO: DEX + 2.8, anti-VEGF + 6.8 letters). DEX initiated eyes had fewer injections and visits than anti-VEGF initiated eyes. The BRVO-DEX eyes had greater initial mean changes in VA and central subfield thickness (CST) and achieved inactivity sooner than BRVO-anti-VEGF eyes. The mean CST after the first three months was above 350 µm in all but the BRVO-anti-VEGF group, suggesting undertreatment. In routine care DEX is uncommonly used when available as initial treatment of BRVO and CRVO requiring supplemental anti-VEGF within the first year. The 12-month outcomes were similar, but DEX initiated eyes had fewer injections and visits but more episodes of raised IOP Vs those starting anti-VEGF.

The clinical evaluation of a widefield lens to expand the field of view in optical coherence tomography (OCT-A).

This study aimed to evaluate the clinical benefits of incorporating a widefield lens (WFL) in optical coherence tomography angiography (OCT-A) in patients with retinal vascular diseases in comparison to standard single-shot OCT-A scans. Sixty patients with retinal vascular diseases including diabetic retinopathy (DR) and retinal vein occlusion (RVO) were recruited. OCT-A imaging (PlexElite 9000) with and without WFL was performed in randomized order. The assessment included patient comfort, time, field of view (FoV), image quality and pathology detection. Statistical analysis included paired t-tests, Mann-Whitney U-tests and Bonferroni correction for multiple tests, with inter-grader agreement using the kappa coefficient. Using a WFL did not lead to statistically significant differences in DR and RVO group test times. Patient comfort remained high, with similar responses for WFL and non-WFL measurements. The WFL notably expanded the scan field (1.6× FoV increase), enhancing peripheral retinal visibility. However, image quality varied due to pathology and eye dominance, affecting the detection of peripheral issues in RVO and DR cases. The use of a WFL widens the scan field, aiding vascular retinal disease imaging with minor effects on comfort, time, and image quality. Further enhancements are needed for broader view angles, enabling improved quantification of non-perfused areas and more reliable peripheral proliferation detection.

RETINAL VEIN OCCLUSIONS BEFORE AND DURING THE COVID-19 PANDEMIC: Visual Outcomes and Treatment Patterns in a Country with no Mandatory Lockdown.

PURPOSE: To investigate the incidence, treatment patterns, and visual outcomes in patients with branch retinal vein occlusion (RVO) and central RVO before and during the COVID-19 pandemic in a country with no mandatory lockdown. METHODS: This retrospective study included 788 patients presenting with a RVO during the years 2019 to 2022 at St. Erik Eye Hospital. The control group and study groups consisted of patients presenting before and during the pandemic, respectively. RESULTS: The incidence of diagnosed RVO cases decreased from 281 patients before the pandemic to 236 patients during the first year of the pandemic ( P < 0.05). In patients with branch RVO at the end of follow-up, the best-corrected visual acuity improved 10.3 letters (95% confidence intervals [CI] 7.6-12.9) in the control group compared with 14.3 letters (95% CI 12.6-16.0) in the study groups ( P < 0.05). In patients with central RVO, the best-corrected visual acuity improved 6.3 letters (95% CI 2.7-10.0) in the control group compared with 8.6 letters (95% CI 5.7-11.4) in the study groups (p = NS). Overall, the number of intravitreal anti-vascular endothelial growth factor injections increased from 7.0 (95% CI 6.6-7.3) in the control group to 7.6 (95% CI 7.4-7.8) in the study groups ( P < 0.05). CONCLUSION: Good visual and anatomical outcomes were sustained, and the number of intravitreal anti-vascular endothelial growth factor injections increased significantly in patients with RVO during the COVID-19 pandemic.

Segmentation of Low-Light Optical Coherence Tomography Angiography Images under the Constraints of Vascular Network Topology.

Optical coherence tomography angiography (OCTA) offers critical insights into the retinal vascular system, yet its full potential is hindered by challenges in precise image segmentation. Current methodologies struggle with imaging artifacts and clarity issues, particularly under low-light conditions and when using various high-speed CMOS sensors. These challenges are particularly pronounced when diagnosing and classifying diseases such as branch vein occlusion (BVO). To address these issues, we have developed a novel network based on topological structure generation, which transitions from superficial to deep retinal layers to enhance OCTA segmentation accuracy. Our approach not only demonstrates improved performance through qualitative visual comparisons and quantitative metric analyses but also effectively mitigates artifacts caused by low-light OCTA, resulting in reduced noise and enhanced clarity of the images. Furthermore, our system introduces a structured methodology for classifying BVO diseases, bridging a critical gap in this field. The primary aim of these advancements is to elevate the quality of OCTA images and bolster the reliability of their segmentation. Initial evaluations suggest that our method holds promise for establishing robust, fine-grained standards in OCTA vascular segmentation and analysis.

Hemicentral retinal vein occlusion in a patient with a history of coronavirus disease 2019 infection: a case report and review of the literature.

BACKGROUND: Considering the various manifestations of coronavirus disease 2019 and its imperative importance in terms of the right clinical approach and early management, we sought to present a hemicentral retinal vein occlusion case, with a history of heterozygosity of methylenetetrahydrofolate reductase (MTHFR) genes and potential for clotting complications as a late manifestation of coronavirus disease 2019, and provide a brief review of reported retinal vein occlusion cases in patients with coronavirus disease 2019. CASE PRESENTATION: A 35-year-old Iranian patient presented with a visual impairment in the left eye 4 months after recovering from coronavirus disease 2019. He reported a mild blurring of vision in the same eye a few days after admission due to coronavirus disease 2019. The ophthalmic evaluation was compatible with hemicentral retinal vein occlusion. Systemic and laboratory workups were negative except for borderline protein C activity, homocysteine levels, and heterozygosity of MTHFR genes. The patient was scheduled to receive three monthly intravitreal antivascular endothelial growth factor injections. CONCLUSION: We present a case of inferior hemicentral retinal vein occlusion case with an MTHFR mutation with sequential loss of vision 4 months after coronavirus disease 2019 to make clinicians aware of the possibility of late ocular coronavirus disease 2019 manifestations.