In Vivo Imaging of Rodent Retina in Retinal Disease.

High-quality imaging of the retina is crucial to the diagnosis and monitoring of disease, as well as for evaluating the success of therapeutics in human patients and in preclinical animal models. Here, we describe the basic principles and methods for in vivo retinal imaging in rodents, including fundus imaging, fluorescein angiography, optical coherence tomography, fundus autofluorescence, and infrared imaging. After providing a concise overview of each method and detailing the retinal diseases and conditions that can be visualized through them, we will proceed to discuss the advantages and disadvantages of each approach. These protocols will facilitate the acquisition of optimal images for subsequent quantification and analysis. Additionally, a brief explanation will be given regarding the potential results and the clinical significance of the detected abnormalities.

Recent trends and future perspectives of photoresponsive-based mercury (II) sensors and their biomaterial applications.

Recent advancements in the field of photoresponsive-based mercury (II) sensors have witnessed a surge in research focused on enhancing detection capabilities. Leveraging innovations in materials science, particularly with quantum dots, nanomaterials, and organic semiconductors, these sensors exhibit improved selectivity and sensitivity. Beyond traditional applications, such as environmental monitoring, the integration of photoresponsive principles with emerging technologies like the internet of things (IoT) and wearable promises real-time and remote mercury (II) ion detection. The on-going efforts also explore multifunctional sensors and miniaturization for on-site applications, addressing current challenges and paving the way for broader commercialization. This dynamic landscape underscores the potential for these sensors to play a crucial role in ensuring the effective monitoring and management of mercury (II) levels in diverse settings.

Fluorescence-Guided Surgical Techniques in Adult Diffuse Low-Grade Gliomas: State-of-the-Art and Emerging Techniques: A Systematic Review.

Diffuse low-grade gliomas are infiltrative tumors whose margins are not distinguishable from the adjacent healthy brain parenchyma. The aim was to precisely examine the results provided by the intraoperative use of macroscopic fluorescence in diffuse low-grade gliomas and to describe the new fluorescence-based techniques capable of guiding the resection of low-grade gliomas. Only about 20% and 50% of low-grade gliomas are macroscopically fluorescent after 5-amino-levulinic acid (5-ALA) or fluorescein sodium intake, respectively. However, 5-ALA is helpful for detecting anaplastic foci, and thus choosing the best biopsy targets in diffuse gliomas. Spectroscopic detection of 5-ALA-induced fluorescence can detect very low and non-macroscopically visible concentrations of protoporphyrin IX, a 5-ALA metabolite, and, consequently, has excellent performances for the detection of low-grade gliomas. Moreover, these tumors have a specific spectroscopic signature with two fluorescence emission peaks, which is useful for distinguishing them not only from healthy brain but also from high-grade gliomas. Confocal laser endomicroscopy can generate intraoperative optic biopsies, but its sensitivity remains limited. In the future, the coupled measurement of autofluorescence and induced fluorescence, and the introduction of fluorescence detection technologies providing a wider field of view could result in the development of operator-friendly tools implementable in the operative routine.

Sodium fluorescein-guided resection of brain metastases: A needed approach or an option? A systematic review and meta-analysis.

PURPOSE: Brain metastases (BM) often leave residual tumors despite having visible margins, which increases the risk of local tumor recurrence and can impact overall patient survival rates. Fluorescence-guided surgery (FGS) utilizing sodium fluorescein (FL) has been reported as an effective technique in recent studies. This study aimed to evaluate the efficacy of FL FGS in improving the extent of resection of brain metastases and its impact on overall survival. METHODS: We conducted a systematic search following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. Our primary focus was on gross total resection (GTR). Additionally, we extracted survival data and evaluated the risk of bias using a modified version of the Joanna Briggs Institute critical appraisal tool. RESULTS: The study comprised 970 patients with brain metastases through eight different studies. The study found that patients who underwent FL-guided resection had a significantly higher rate of GTR (OR: 2.02, 95% CI: 1.14-3.56, p = 0.0156, I2 = 41.5%). Additionally, the study concluded that FL-guided resection is associated with better overall survival rates (HR: 0.61, 95%CI: 0.47 0.80, p = 0.0003, I2 = 41.5%). CONCLUSION: Our research suggests that the use of FL is associated with a higher rate of GTR and improved overall patient survival. None of the studies we reviewed reported significant complications associated with the use of FL in patients.

Diacylglycerol O-acyltransferase 1 inhibitor increases plasma alanine aminotransferase and aspartate aminotransferase activities via a shedding of the intestinal villi and an increase in intestinal permeability in rats.

Diacylglycerol O-acyltransferase 1 (DGAT1) is a key enzyme for fat absorption step in the enterocytes. We previously reported that DGAT1 inhibition increased plasma alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities in corn oil-loaded rats via protein kinase C (PKC) activation. In the present study, we investigated the mechanism with respect to the morphology and permeability of the small intestine, focusing on PKC function, and found that shortening of the intestinal villi and a decrease in the number of tdT-mediated dUTP-biotin nick-end labeling-positive cells in the tips of the villi were observed in the jejunum of DGAT1 inhibitor-treated rats loaded with corn oil. These results suggested that the tips of the villi were shed into the intestinal lumen. Next, fluorescein isothiocyanate-dextran, 110 kDa (FD-110) was administered intraduodenally to DGAT1 inhibitor-treated rats loaded with corn oil and we found that plasma FD-110 concentrations increased, indicating that the intestinal permeability to molecules with a molecular weight of approximately 110,000 (e.g., ALT and AST) increased. Taken together, the present results suggested that DGAT1 inhibitor-treatment in combination with corn oil causes ALT and AST to leak from the enterocytes into the blood by shedding the tips of the intestinal villi and increasing intestinal permeability.

Clinical Consensus Statement on the Use of Indocyanine Green Fluorescence-guided Surgery in Pediatric Patients.

BACKGROUND AND AIMS: Indocyanine Green Fluorescence (ICG-F)- guided surgery is becoming an increasingly helpful tool in pediatric surgical care. This consensus statement investigates the utility of ICG-F in various pediatric surgical applications, primarily focusing on its evidence base, safety, indications, use across different surgical specialties and dosing strategies. The aim is to establish an international consensus for ICG-F use in pediatric surgery. METHODS: An international panel of 15 pediatric surgeons from 9 countries was assembled. The structured process consisted of a rapid scoping review, iterative discussion sessions, mixed-methods studies with key stakeholders, and voting rounds on individual statements to create draft consensus statements. RESULTS: 100 articles were identified during the review and summarized by application. Based on this condensed evidence, consensus statements were generated after 3 iterative rounds of anonymous voting. Key areas of agreement were quality of evidence, the safety of ICG, pediatric surgical indications, utilization per surgical specialty, and dosing of ICG. CONCLUSION: This consensus statement aims to guide healthcare professionals in managing ICG-F use in pediatric surgical cases based on the best available evidence, key stakeholder consultation, and expert opinions. Despite ICG-F's promising potential, the need for higher-quality evidence, prospective trials, and safety studies is underscored. The consensus also provides a framework for pediatric surgeons to utilize ICG-F effectively. LEVEL OF EVIDENCE: III.

Investigation of keratolytic impact of synthetic bolalipids on skin penetration of a model hydrophilic permeant.

Synthetic single-chain bolalipids (SSCBs) are novel excipients in drug delivery, with potential as stabilizers or solubilizers. However, their impact on skin barrier function has not been comprehensively studied. Therefore, two SSCBs (PC-C24-PC and PC-C32-PC) were studied in aqueous systems for their impact on penetration of a model permeant into porcine skin. Concentrations of 0.05 - 5 % w/w were tested; PC-C24-PC formulations were low-viscosity liquids while PC-C32-PC formed viscous dispersions to gels at room temperature. Formulations were compared for their ability to enhance sodium fluorescein penetration (SF, 0.1 % w/w) into skin via tape stripping. Using NIR-densitometry, the effect of SSCB formulations on corneocyte cohesion was evaluated. Data were compared with phospholipid mixture Lipoid S-75, sodium dodecyl sulfate (SDS), and polyethylene glycol 12-hydroxystearate (PEG-HS), and distilled water as negative control. Contrary to the hypothesis, both SSCBs failed to increase SF penetration into the stratum corneum, but rather showed a significant decrease in penetration depth compared to water. Both SSCBs exhibited a keratolytic effect at 5 % w/w, leading to substantial removal of proteins from the skin surface. Consequently, SSCBs may not enhance penetration of hydrophilic drugs into skin, but could be used as keratolytic agents.

Angiographic characteristics in mild familial exudative vitreoretinopathy with genetically confirmed autosomal dominant inheritance.

PURPOSE: To determine the ultra-widefield fluorescein angiographic (UWFA) characteristics of patients with mild familial exudative vitreoretinopathy (FEVR) who had been confirmed to have pathogenic variants of the autosomal dominant (AD) genes of FEVR. DESIGN: Single center, observational case series. SUBJECTS AND CONTROLS: Thirty-seven patients with mild FEVR from 27 families who had pathogenic variants of the Norrin/ß-catenin genes were studied. The controls consisted of 32 family members who had been confirmed not to carry the pathogenic variants or had heterozygous variants of the autosomal recessive inheritance gene. METHODS: Sixty-four UWFA images from the patients were compared to 60 UWFA images from the controls. The relative length of the temporal retina to the peripheral avascular retina was determined. The cut-off ratio of the relative lengths for a clinically significant avascular retina (csAR) associated with AD-FEVR was determined using the receiver operating characteristic (ROC) curves. MAIN OUTCOME MEASURES: The presence or absence of six peripheral vascular changes: csAR, V-shaped vascular notch, brushy vascular ends, vascular stain, loop vessels and/or anastomosis, and capillary telangiectasia were compared between the patients and the controls. RESULTS: The csAR was set at >12% of the length from the ora serrata to the optic disc. The AD-FEVR patients had more frequent retinal changes than the controls for the V-shaped vascular notch (69% vs 2%, P <0.001), brushy vascular ends (78% vs 3%, P <0.001), csAR (83% vs 22%, P <0.001), and vascular stain (70% vs 33%, P <0.001). Loop vessels and/or anastomosis of peripheral vessels were found significantly less frequently in the patients than in the controls (39% vs 73%, P <0.001). No significant difference was found for capillary telangiectasia between the two groups. The combination of the V-shaped vascular notches, brushy vascular ends, and csAR had a sensitivity of 82.8% and specificity of 98.3% with the highest ROC curve of 0.9. CONCLUSIONS: The combination of V-shaped vascular notch, brushy vascular ends, and csAR can be used as a biomarker for AD-FEVR patients who have pathogenic variants of the Norrin/ß-catenin genes. These findings will allow more accurate segregation analysis in FEVR families and allow better genetic counseling.

Utility of Sodium Fluorescein During Peripheral Nerve Tumor Surgery: A Scoping Review of Indications, Techniques, and Outcomes.

OBJECTIVE: The primary treatment for peripheral nerve tumors involves maximal surgical resection while preserving nerve function. Sodium fluorescein shows potential for enhancing the safety and efficacy of nerve tumor surgery. This review evaluates the advantages and limitations of sodium fluorescein in this context. METHODS: PubMed, EMBASE, Web-of-Science, and Scopus were searched following the PRISMA-ScR guidelines to include studies reporting the use of sodium fluorescein in peripheral nerve tumors surgery. Intervention-related outcomes (i.e., extent of resection, clinical outcomes, complication rates, recurrence rates, and duration of surgery) were evaluated and summarized. RESULTS: A total of 4 studies encompassing 166 patients with 168 tumors were included. Patients were mostly female (98; 53.6%), 101 (69.2%) had sporadic (non-syndromic) tumors, and at histopathology, 114 (67.9%) tumors were WHO grade-1 schwannomas. Gross total resection was achieved in 146 (86.9%) tumors. Postoperative complications were reported in 16 cases (10.2%%), none related to side effects of the fluorescent dye. High tumor fluorescence was reported in 150 (94.3%) tumors, while absent and low parent nerve fluorescence was reported in 121 (79.6%) and 27 (17.8%), respectively. The median duration of surgery was 51.5 (range: 24-92) minutes. CONCLUSION: Sodium fluorescein shows promise as assisting tool in nerve tumor surgery by facilitating differentiation between the tumor, parent nerve, and surrounding soft tissue. However, multi-center randomized controlled trials are necessary to determine its effect on extent of resection rates, clinical outcomes, postoperative complication rates, and surgical duration in comparison to current standard of care.

Ultra-Wide-Field Fluorescein Angiographic Features Influencing Visual Prognosis in Coats' Disease.

Purpose: To investigate the retinal vascular abnormalities in both affected and fellow eyes of presumed unilateral Coats' disease patients using ultra-wide-field fluorescein angiography (UWF-FA) and their association with visual prognosis. Methods: A retrospective review of 30 patients diagnosed with presumed unilateral Coats' disease, evaluated with UWF-FA from March 2003 to May 2024 in a tertiary referral hospital. Clinical features and multimodal imaging findings were evaluated and factors related to final visual outcomes were analyzed. Results: All 30 patients were diagnosed with presumed unilateral Coats' disease at presentation, comprising 36.7% childhood-onset and 63.3% adult-onset patients. Retinal vascular telangiectasia was observed in 51.7% of fellow eyes. The extent of telangiectasia and exudate in the affected eyes did not significantly correlate with extent of telangiectasia in the fellow eyes. In the more affected eyes, the childhood-onset group had a significantly greater extent of capillary drop-out compared to the adult-onset group (5.0 vs 2.8 clock hours, p = 0.023). In the fellow eyes, telangiectasia tended to be more frequent in the childhood-onset group (63.6% vs. 44.4%), without significance (p = 0.160). In the multivariable regression analysis, the final best-corrected visual acuity (BCVA) in the more affected eye was significantly associated with initial BCVA. The mean extent of telangiectasia in the temporal and nasal quadrants and the initial BCVA of the more affected eyes were identified as prognostic factors for final moderate to severe visual loss (Snellen BCVA < 20/66) (OR = 12.8, p = 0.043; OR = 11.8, p = 0.024, respectively). Conclusions: About half of presumed unilateral Coats' disease cases exhibited features of bilateral disease. Visual prognosis is associated with the peripheral retinal telangiectasia in the temporal and nasal quadrants as well as initial BCVA in the affected eyes while it is not associated with retinal vascular abnormalities in the fellow eyes.

Predictive Role of Fluorescein Angiography in Retinopathy of Prematurity.

BACKGROUND: Fluorescein angiography (FA) has been a pivotal tool for studying the pathophysiology of retinopathy of prematurity (ROP) in vivo. We examined the course of ROP using FA to assess the predictive value of angiographic features. METHODS: This is an observational retrospective cohort study of eyes screened for ROP with a binocular indirect ophthalmoscope and FA. RetCam fundus imaging and video digital fluorescein angiography were performed in the neonatal intensive care unit of Santa Maria Hospital of Perugia. The masked grading of the FA images was retrospectively conducted by two ROP expert ophthalmologists. RESULTS: A total of 80 eyes of 40 patients were included for this study. Among the angiographic features evaluated, leakage, shunts, and tangles were predictive of the development of treatment-requiring ROP (p < 0.05). CONCLUSIONS: FA can add to our understanding of the evolution of vascular abnormalities in the course of ROP and can help predict which eyes will go on to treatment.

Fluorescein Angiography Parameters in Premature Neonates.

Purpose: To describe fluorescein angiography (FA) parameters observed in premature neonates with retinopathy of prematurity (ROP). Design: Retrospective case series. Subjects: Patients with ROP who underwent FA imaging using Retcam at Holtz Children's Hospital from November 2014 to October 2022. Methods: Fluorescein angiography images of the included patients were analyzed with a focus on the timing of angiography phases, including choroidal flush, retinal, and recirculation phases. Gestational age, birth weight (BW), age at imaging, treatment choice, and any FA complications were documented. Main Outcome Measures: Dose of fluorescein administered, onset and duration of each angiography phase, and FA findings in ROP-treated patients. Results: A total of 72 images of 72 eyes were reviewed. Image quality was deemed suitable for inclusion in 64 eyes (88.9%) of 43 patients. The mean gestational age and BW at birth were 24.4 ± 1.9 weeks and 607.8 ± 141.3 g, respectively. The mean postmenstrual age at FA imaging was 50.5 ± 40.8 weeks. All eyes (100%) received treatment with intravitreal injection of anti-VEGF at a mean age of 35.5 ± 2.4 weeks. The onset and duration of angiography phases were relatively variable within the cohort. Choroidal flush occurred at a mean time of 12.2 seconds (range: 6-22 seconds). A subsequent retinal phase was documented at a mean time of 11.96 seconds (range: 3-22 seconds). Recirculation phase was complete at an average time of 2.15 minutes (range: 1-5.45 minutes) postfluorescein injection. None of patients developed allergic reactions to fluorescein injection, such as rash, respiratory distress, tachycardia, fever, or local injection site reactions. Conclusions: Angiographic phases on FA in preterm infants with ROP are variable and may occur earlier than the established references for adults. Financial Disclosures: Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Combined Fluorescence-Guided Surgery with 5-Aminolevulinic Acid and Fluorescein in Glioblastoma: Technical Description and Report of 100 Cases.

BACKGROUND: Fluorescence-guided resection (FGR) of glioblastomas has been previously explored with the use of 5-amivelulinic acid (5-ALA) and sodium fluoresceine (SF), allowing us to maximize the extent of resection (EoR). In this study, we highlight the most relevant concerns regarding this technique and present the methods and results from the experience of our center. METHODS: A case series of 100 patients operated on in AOU Città della Salute e della Scienza in Turin with a histological diagnosis of glioblastoma (grade IV, according to WHO 2021) was retrospectively analyzed. Both 5-ALA and SF were administered and intraoperatively assessed with an optical microscope. RESULTS: 5-ALA is the only approved drug for FGR in glioblastoma, reporting an increased EoR. Nevertheless, SF can be positively used in addition to 5-ALA to reduce the risk of false positives without increasing the rate of adverse effects. In our experience, SF was used to guide the initial phase of resection while 5-ALA was used to visualize tumor spots within the surgical cavity. In 96% of cases, gross total resection was achieved, with supra-maximal resection in 11% of cases. CONCLUSIONS: Combined FGR using 5-ALA and SF seems to be a promising method of increasing the extent of resection and to improving the prognosis in glioblastoma patients.

Synergistic enhancement of fluorescein-K3[Fe(CN)6] CL by MoO3-x NPs for sensitive and noninvasive detection of uric acid in saliva.

MoO3-x NPs was rapidly synthesized at room temperature by an easy stirring method. It was interesting to find that MoO3-x NPs induce OH- to generate active free radicals (ROS), which is a highly promising property in chemiluminescence (CL). Benefiting from the abundant oxygen vacancy, MoO3-x NPs adsorbs H2O2 and turn it into ·OH. The oxidase activity of fluorescein under visible light had already been reported, which catalyzes dissolved oxygen to become O2-· and continue to convert to H2O2. By creating the synergy effect with fluorescein, MoO3-x NPs strengthen the CL intensity of K3[Fe(CN)6]-fluorescein system significantly. Utilizing the quench effect of uric acid for the CL intensity, we developed a rapid, simple, and highly sensitive CL platform for uric acid detection. The linear range was 5-80 µM and the detection limit (LOD) for uric acid was 3.11 µM (S/N = 3). This work expanded the application of MoO3-x NPs in the CL field and developed a simple and highly sensitive CL sensing system to detect UA in human saliva.

Categories and Profiles of Uveitis in Vogt-Koyanagi-Harada Syndrome With Systemic Correlation: Inferences From a Tertiary Multispecialty Hospital.

Introduction Vogt-Koyanagi-Harada (VKH) syndrome is a granulomatous, autoimmune panuveitis, affecting the eyes, ears, skin, and meninges. It can cause choroiditis and can progress to the retina and optic disc causing visual loss. Imaging using fundus fluorescein angiography (FFA), indocyanine green angiography (ICGA), and enhanced depth imaging-ocular coherence tomography (EDI-OCT) is required for clinical evaluation and management. Steroids and immunosuppression are the treatment modalities used. Aim The aim of this study is to report the correlation and severity of uveitis in relation to systemic manifestations. Method A retrospective study including 100 patients with VKH syndrome was carried out. They were classified based on clinical manifestations and investigations such as FFA, ICGA, B-scan ultrasonography (USG), and ocular coherence tomography (OCT). Patients were characterized as complete, incomplete, and probable VKH syndrome. Laboratory investigations were performed, and statistical analysis was done. Results Probable VKH syndrome was found to be the most common form of presentation in our study population. Defective vision was the most common complaint among the patients. Extraocular manifestations included tinnitus, vertigo, alopecia, headache, fatigue, and vitiligo and were seen in 33% of the patients. Disc edema and serous retinal detachment were seen in 85% of the patients. Improvement was noted in 25% of the patients with the use of corticosteroids. Conclusion Response to treatment with systemic corticosteroids and immunosuppression in the acute phase of uveitis is better compared to chronic uveitis. The ophthalmologist is usually first consulted in VKH syndrome due to presenting ocular complaints. A multidisciplinary approach is key to providing holistic management.

Quantitative Biomarkers of Diabetic Retinopathy Using Ultra-Widefield Fluorescein Angiography.

Introduction: Diabetic retinopathy (DR) is a leading cause of blindness. Retinal imaging is an important tool to monitor the progression of DR. While seven-standard retinal fields are the traditional method for evaluating DR, ultra-widefield (UWF) imaging allows for improved visualization of peripheral areas of nonperfusion (NP) and neovascularization (NV), which could be used as biomarkers to monitor and predict progression of DR. Methods: A retrospective, cross-sectional study was conducted on 651 eyes from 363 patients diagnosed with type 1 or type 2 diabetes who received UWF-FA over 10 years. Fluorescein Angiography (FA) images were segmented, and surface areas of NP and NV were analyzed using multivariate regression to determine if biomarkers of DR and DR severity are associated with increasing areas of NP and NV. Results: Each additional year with a diagnosis of DR was associated with a 10.75 mm2 increase in the total NP (95% CI, 1.94-19.56; P = 0.02) and 7.87 mm2 increase in NP far-periphery (95% CI, 1.62-14.13; P = 0.01). A one-unit change in severity as defined by the Early Treatment of Diabetic Retinopathy Study (ETDRS) classification was associated with a 25.75 mm2 increase in total NP (95% CI, 11.16-40.33; P = 0.001), a 13.15 mm2 increase in mid-periphery NP (95% CI, 6.93-19.38; P < 0.0001), and a 12.29 mm2 increase in far-periphery NP (95% CI, 3.62-20.97; P = 0.01). Discussion: Biomarkers identified through UWF imaging such as total and regional areas of NP can be used to monitor and predict the progression of DR. This may provide a quantitative method for prognostication in patients with DR.

Sentinel lymph node biopsy in early breast carcinoma using fluorescein sodium and methylene blue dye: A validation study.

The availability of radioisotopes for sentinel lymph node biopsy (SLNB) in breast carcinoma is limited in low- and middle-income countries and thus the need for other reliable tracers exists. We aimed to validate the effectiveness of fluorescein sodium (FS) together with methylene blue dye (MBD) for patients with node-negative early breast carcinoma in a prospective cross-sectional study. Patients underwent SLNB using FS and MBD followed by axillary dissection to validate results. Sentinel lymph node (SLN) identification rate and false negative rate were assessed for all three tracers/combinations (MBD, FS, and MBD + FS). We concluded that SLNB using a combination of FS and MBD has an acceptable rate of SLN identification but the addition of FS provided no additional benefit.