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Background: Retinitis pigmentosa (RP) is a group of hereditary retinal dystrophies characterized by progressive degeneration of photoreceptor cells, which results in debilitating visual impairment. This systematic review aims to evaluate the efficacy and safety of emerging treatment modalities for RP, including gene therapy, mesenchymal-cell-based approaches, and supplementary interventions. Methods: A comprehensive search of electronic databases was conducted to identify relevant studies published up to February 2024. Studies reporting outcomes of treatment interventions for RP, including randomized controlled trials, non-randomized studies, and case series, were included. Data extraction and synthesis were performed according to predefined criteria, focusing on assessing the quality of evidence and summarizing key findings. Results: The search yielded 13 studies meeting inclusion criteria, encompassing diverse treatment modalities and study designs. Gene therapy emerged as a promising therapeutic approach, with several studies reporting favorable outcomes regarding visual function preservation and disease stabilization. Mesenchymal-cell-based therapies also demonstrated potential benefits, although evidence remains limited and heterogeneous. Supplementary interventions, including nutritional supplements and neuroprotective agents, exhibited variable efficacy, with conflicting findings across studies. Conclusions: Despite the lack of definitive curative treatments, emerging therapeutic modalities promise to slow disease progression and preserve visual function in individuals with RP. However, substantial gaps in evidence and heterogeneity in study methodologies underscore the need for further research to elucidate optimal treatment strategies, refine patient selection criteria, and enhance long-term outcomes. This systematic review provides a comprehensive synthesis of current evidence and highlights directions for future research to advance the care and management of individuals with RP.
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Cryopreservation of human corneal stroma-derived mesenchymal stromal cells (hCS-MSCs) with dimethylsulfoxide (DMSO) as a cryoprotective agent (CPA) has not been previously compared to that with glycerol under standard conditions. The hCS-MSCs were hereby cryopreserved with both compounds using a freezing rate of 1 °C/minute. The CPAs were tested by different concentrations in complete Minimum Essential Medium (MEM) approved for good manufacturing practice, and a medium frequently used in cell laboratory culturing-Dulbecco's modified eagle serum. The hCS-MSCs were isolated from cadaveric human corneas obtained from the Norwegian Eye Bank, and immunophenotypically characterized by flow cytometry before and after cryopreservation. The survival rate, the cellular adhesion, proliferation and cell surface coverage after cryopreservation of hCS-MSCs has been studied. The hCS-MSCs were immunofluorescent stained and examined for their morphology microscopically. The results showed that cryopreservation of hCS-MSCs in MEM with 10% glycerol gives a higher proliferation rate compared to other cryopreserving media tested. Based on the results, hCS-MSCs can safely be cryopreserved using glycerol instead of the traditional use of DMSO.
Subject(s)
Cell Proliferation , Cell Survival , Corneal Stroma , Cryopreservation , Cryoprotective Agents , Mesenchymal Stem Cells , Humans , Cryoprotective Agents/pharmacology , Mesenchymal Stem Cells/cytology , Cryopreservation/methods , Corneal Stroma/cytology , Cell Proliferation/drug effects , Cell Survival/drug effects , Glycerol/pharmacology , Dimethyl Sulfoxide/pharmacology , Cells, Cultured , Cell Adhesion/drug effectsABSTRACT
To compare two screening strategies for diabetic retinopathy (DR), and to determine the health-economic impact of including optical coherence tomography (OCT) in a regular DR screening. This cross-sectional study included a cohort of patients (≥ 18 years) with type 1 or 2 diabetes mellitus (T1D or T2D) from a pilot DR screening program at Oslo University Hospital, Norway. A combined screening strategy where OCT was performed in addition to fundus photography for all patients, was conducted on this cohort and compared to our existing sequential screening strategy. In the sequential screening strategy, OCT was performed on a separate day only if fundus photography indicated diabetic macular edema (DME). The presence of diabetic maculopathy on fundus photography and DME on OCT was determined by two medical retina specialists. Based on the prevalence rate of diabetic maculopathy and DME from the pilot, we determined the health-economic impact of the two screening strategies. The study included 180 eyes of 90 patients. Twenty-seven eyes of 18 patients had diabetic maculopathy, and of these, 7 eyes of 6 patients revealed DME on OCT. When diabetic maculopathy was absent on fundus photographs, OCT could not reveal DME. Accordingly, 18 patients (20%) with diabetic maculopathy would have needed an additional examination with OCT in the sequential screening strategy, 6 (33%) of whom would have had DME on OCT. In an extended healthcare perspective analysis, the cost of the sequential screening strategy was higher than the cost of the combined screening strategy. There was a weak association between diabetic maculopathy on fundus photography and DME on OCT. The health economic analysis suggests that including OCT as a standard test in DR screening could potentially be cost-saving.
Subject(s)
Diabetic Retinopathy , Mass Screening , Tomography, Optical Coherence , Humans , Diabetic Retinopathy/diagnosis , Diabetic Retinopathy/economics , Diabetic Retinopathy/diagnostic imaging , Male , Female , Pilot Projects , Middle Aged , Tomography, Optical Coherence/economics , Tomography, Optical Coherence/methods , Cross-Sectional Studies , Mass Screening/economics , Mass Screening/methods , Aged , Macular Edema/diagnosis , Macular Edema/economics , Macular Edema/diagnostic imaging , Norway/epidemiology , Adult , Diabetes Mellitus, Type 2/complications , Diabetes Mellitus, Type 2/economics , Cost-Benefit AnalysisABSTRACT
This article offers a systematic literature review (SLR) on the use of the MiniMed 780G automated insulin delivery system (MM780G) in people with type 1 diabetes (PwT1D) during Ramadan intermittent fasting. It also presents consensus recommendations on the use of MM780G during the Ramadan period. The SLR was performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses methodology. The recommendations resulted from a consensus-forming process involving a panel of experts. The process considered evidence found in the SLR as well as the expert opinions. In total, six studies were included in the SLR. The evidence and expert opinions led to recommendations related to (a) pre-Ramadan counseling of MM780G users who plan to fast; (b) suggested MM780G settings, meal announcement strategy, and safety aspects during Ramadan (including a contingency plan); and (c) post-Ramadan transition into and out of Eid-al-Fitr festivities. The SLR findings showed that the MM780G maintains glycemic control at target in PwT1D during Ramadan (meeting continuous glucose monitoring-based clinical targets proposed by the International Consensus on Time-in-Range) while ensuring low rates of hypoglycemia and diabetic ketoacidosis. Automated insulin delivery also helps PwT1D fast more days of Ramadan compared with users of other less advanced modalities of treatment. Pre-Ramadan guidance on specific aspects of the MM780G along with the International Diabetes Federation and Diabetes and Ramadan International Alliance counseling guidelines is recommended. There is still a challenge with post-Iftar hyperglycemia, which could potentially be mitigated by following the recommendations outlined in this article.
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Purpose: Advanced hybrid closed loop (AHCL) systems have the potential to improve glycemia and reduce burden for people with type 1 diabetes (T1D). Children and youth, who are at particular risk for out-of-target glycemia, may have the most to gain from AHCL. However, no randomized controlled trial (RCT) specifically targeting this age group with very high HbA1c has previously been attempted. Therefore, the CO-PILOT trial (Closed lOoP In chiLdren and yOuth with Type 1 diabetes and high-risk glycemic control) aims to evaluate the efficacy and safety of AHCL in this group. Methods: A prospective, multicenter, parallel-group, open-label RCT, comparing MiniMed™ 780G AHCL to standard care (multiple daily injections or continuous subcutaneous insulin infusion). Eighty participants aged 7-25 years with T1D, a current HbA1c ≥ 8.5% (69 mmol/mol), and naïve to automated insulin delivery will be randomly allocated to AHCL or control (standard care) for 13 weeks. The primary outcome is change in HbA1c between baseline and 13 weeks. Secondary outcomes include standard continuous glucose monitor glycemic metrics, psychosocial factors, sleep, platform performance, safety, and user experience. This RCT will be followed by a continuation phase where the control arm crosses over to AHCL and all participants use AHCL for a further 39 weeks to assess longer term outcomes. Conclusion: This study will evaluate the efficacy and safety of AHCL in this population and has the potential to demonstrate that AHCL is the gold standard for children and youth with T1D experiencing out-of-target glucose control and considerable diabetes burden. Trial registration: This trial was prospectively registered with the Australian New Zealand Clinical Trials Registry on 14 November 2022 (ACTRN12622001454763) and the World Health Organization International Clinical Trials Registry Platform (Universal Trial Number U1111-1284-8452). Supplementary Information: The online version contains supplementary material available at 10.1007/s40200-024-01397-4.
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Cystic fibrosis (CF), also known as mucoviscidosis, is the most common autosomal recessive genetic disease in the Caucasian population, with an estimated frequency of 1:2000-3000 live births. CF results from the mutation of the cystic fibrosis transmembrane conductance regulator (CFTR) gene localized in the long arm of chromosome 7. The product of CFTR gene expression is CFTR protein, an adenosine triphosphate (ATP)-binding cassette (ABC) transporter that regulates the transport of chloride ions (Cl-) across the apical cell membrane. Primary manifestations of CF include chronic lung and pancreas function impairment secondary to the production of thick, sticky mucus resulting from dehydrated secretions. It is well known that CF can cause both anterior and posterior ocular abnormalities. Conjunctival and corneal xerosis and dry eye disease symptoms are the most characteristic manifestations in the anterior segment. In contrast, the most typical anatomical and functional changes relating to the posterior segment of the eye include defects in the retinal nerve fiber layer (RNFL), vascular abnormalities, and visual disturbances, such as reduced contrast sensitivity and abnormal dark adaptation. However, the complete background of ophthalmic manifestations in the course of CF has yet to be discovered. This review summarizes the current knowledge regarding ocular changes in cystic fibrosis.
Subject(s)
Cystic Fibrosis Transmembrane Conductance Regulator , Cystic Fibrosis , Humans , Cystic Fibrosis/metabolism , Cystic Fibrosis/genetics , Cystic Fibrosis/pathology , Cystic Fibrosis Transmembrane Conductance Regulator/genetics , Cystic Fibrosis Transmembrane Conductance Regulator/metabolism , Eye Diseases/etiology , Eye Diseases/metabolism , Eye Diseases/pathology , Mutation , AnimalsABSTRACT
We explored differences in the DNA methylation statuses of PSMA6, PSMB5, HIF1A, and KEAP1 gene promoter regions in patients with type 1 diabetes and different diabetic retinopathy (DR) stages. Study subjects included individuals with no DR (NDR, n = 41), those with non-proliferative DR (NPDR, n = 27), and individuals with proliferative DR or those who underwent laser photocoagulation (PDR/LPC, n = 46). DNA methylation was determined by Zymo OneStep qMethyl technique. The methylation of PSMA6 (NDR 5.9 (3.9-8.7) %, NPDR 4.5 (3.8-5.7) %, PDR/LPC 6.6 (4.7-10.7) %, p = 0.003) and PSMB5 (NDR 2.2 (1.9-3.7) %, NPDR 2.2 (1.9-3.0) %, PDR/LPC 3.2 (2.5-7.1) %, p < 0.01) differed across the groups. Consistent correlations were observed between the methylation levels of HIF1A and PSMA6 in all study groups. DNA methylation levels of PSMA6, PSMB5, and HIF1A genes were positively correlated with the duration of diabetes, HbA1c, and albuminuria in certain study groups. Univariate regression models revealed a significant association between the methylation level z-scores of PSMA6, PSMB5, and HIF1A and severe DR (PSMA6: OR = 1.96 (1.15; 3.33), p = 0.013; PSMB5: OR = 1.90 (1.14; 3.16), p = 0.013; HIF1A: OR = 3.19 (1.26; 8.06), p = 0.014). PSMB5 remained significantly associated with DR in multivariate analysis. Our findings suggest significant associations between the severity of DR and the DNA methylation levels of the genes PSMA6, PSMB5, and HIF1A, but not KEAP1 gene.
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Background Childhood obesity is recognized as a chronic illness with limited therapeutic options. Tackling obesity (BMI; the weight in kilograms divided by the square of the height in meters, at the 95th percentile or higher) with lifestyle interventions, especially in adolescents, has proven to be a daunting task, yielding only modest results. Research on the use of liraglutide for weight reduction in pediatric patients has yielded conflicting results. Notably, there is a lack of studies in the Middle East reporting on the outcomes of glucagon-like peptide 1 (GLP-1) receptor agonists in treating obesity in children and adolescents, with or without diabetes. This study, conducted in the Middle East, represents the first investigation into the utilization of liraglutide for weight reduction in this pediatric population. Methods This retrospective study collected data on 22 consecutive participants, aged 12 to 19 years, who were diagnosed with obesity (defined as having a BMI greater than the 95th percentile for their age and sex) and had either type 2 diabetes mellitus (T2DM) or were non-diabetic who attended endocrine clinics in Sidra Medicine, Doha, Qatar, between 2020 and 2022. The study protocol involved a liraglutide treatment period spanning 18 months (72 weeks), with scheduled follow-up appointments at six-month intervals. The primary endpoints were changes in weight and BMI from baseline to the 72-week mark. Secondary endpoints were safety measures and changes in HbA1c. Results Out of the initial cohort of 22 patients, 12 completed the full 72-week duration of the study, while 10 patients either discontinued treatment or did not adhere to the prescribed medication regimen due to side effects. Among the 12 patients who completed the study, six had a diagnosis of T2DM. At baseline, the weight, standard deviation score (SDS), BMI, and BMI standard deviation (SD) were 113.9 kg, 2.9, 40.9 kg/m2, and 2.6 respectively. At the 18-month follow-up, the weight, SDS, BMI, and BMI SD were 117.8kg, 2.6, 39kg/m2, and 2.5, respectively. Thus, no statistically significant change in the weight parameters was evident at 18 months compared to baseline. Dropout from the study and poor compliance were high (10 out of 22 patients) due to side effects, mainly gastrointestinal (nausea, abdominal pain, diarrhea, and vomiting). No statistically significant differences were observed between obese vs. obese with T2DM. No significant change in HbA1c was found between baseline and treatment follow-up in the diabetes patients. No adverse effects in terms of impairment of liver and kidney function or pancreatitis were observed. Conclusions The administration of liraglutide to adolescents with obesity, regardless of whether they had T2DM or not, in a real-life setting, did not yield statistically significant reductions in BMI/weight parameters, and HbA1c levels at the 72-week mark. Nevertheless, the study findings indicate that liraglutide is deemed safe for utilization within this age group, despite the presence of mild gastrointestinal side effects.
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Age-related macular degeneration (AMD) is the most frequent cause of blindness in developed countries. The replacement of dysfunctional human retinal pigment epithelium (hRPE) cells by the transplantation of in vitro-cultivated hRPE cells to the affected area emerges as a feasible strategy for regenerative therapy. Synthetic biomimetic membranes arise as powerful hRPE cell carriers, but as biodegradability is a requirement, it also poses a challenge due to its limited durability. hRPE cells exhibit several characteristics that putatively respond to the type of membrane carrier, and they can be used as biomarkers to evaluate and further optimize such membranes. Here, we analyze the pigmentation, transepithelial resistance, genome integrity, and maturation markers of hRPE cells plated on commercial polycarbonate (PC) versus in-house electrospun polylactide-based (PLA) membranes, both enabling separate apical/basolateral compartments. Our results show that PLA is superior to PC-based membranes for the cultivation of hRPEs, and the BEST1/RPE65 maturation markers emerge as the best biomarkers for addressing the quality of hRPE cultivated in vitro. The stability of the cultures was observed to be affected by PLA aging, which is an effect that could be partially palliated by the coating of the PLA membranes.
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BACKGROUND: Diabetic retinopathy (DR) is the leading cause of adult blindness in the working age population worldwide, which can be prevented by early detection. Regular eye examinations are recommended and crucial for detecting sight-threatening DR. Use of artificial intelligence (AI) to lessen the burden on the healthcare system is needed. PURPOSE: To perform a pilot cost-analysis study for detecting DR in a cohort of minority women with DM in Oslo, Norway, that have the highest prevalence of diabetes mellitus (DM) in the country, using both manual (ophthalmologist) and autonomous (AI) grading. This is the first study in Norway, as far as we know, that uses AI in DR- grading of retinal images. METHODS: On Minority Women's Day, November 1, 2017, in Oslo, Norway, 33 patients (66 eyes) over 18 years of age diagnosed with DM (T1D and T2D) were screened. The Eidon - True Color Confocal Scanner (CenterVue, United States) was used for retinal imaging and graded for DR after screening had been completed, by an ophthalmologist and automatically, using EyeArt Automated DR Detection System, version 2.1.0 (EyeArt, EyeNuk, CA, USA). The gradings were based on the International Clinical Diabetic Retinopathy (ICDR) severity scale [1] detecting the presence or absence of referable DR. Cost-minimization analyses were performed for both grading methods. RESULTS: 33 women (64 eyes) were eligible for the analysis. A very good inter-rater agreement was found: 0.98 (P < 0.01), between the human and AI-based EyeArt grading system for detecting DR. The prevalence of DR was 18.6% (95% CI: 11.4-25.8%), and the sensitivity and specificity were 100% (95% CI: 100-100% and 95% CI: 100-100%), respectively. The cost difference for AI screening compared to human screening was $143 lower per patient (cost-saving) in favour of AI. CONCLUSION: Our results indicate that The EyeArt AI system is both a reliable, cost-saving, and useful tool for DR grading in clinical practice.
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PURPOSE: To assess the safety and feasibility of direct vitrectomy-sparing subretinal injection for gene delivery in a large animal model. METHODS: The experimental Libechov minipigs were used for subretinal delivery of a plasmid DNA vector (pS/MAR-CMV-copGFP) with cytomegalovirus (CMV) promoter, green fluorescent protein (GFP) reporter (copGFP) and a scaffold/matrix attachment region (S/MAR) sequence. The eyes were randomized to subretinal injection of the vector following pars plana vitrectomy (control group) or a direct injection without prior vitrectomy surgery (experimental group). Intra- and post-operative observations up to 30 days after surgery were compared. RESULTS: Six eyes of three mini-pigs underwent surgery for delivery into the subretinal space. Two eyes in the control group were operated with a classical approach (lens-sparing vitrectomy and posterior hyaloid detachment). The other four eyes in the experimental group were injected directly with a subretinal cannula without vitrectomy surgery. No adverse events, such as endophthalmitis, retinal detachment and intraocular pressure elevation were observed post-operatively. The eyes in the experimental group had both shorter surgical time and recovery while achieving the same surgical goal. CONCLUSIONS: This pilot study demonstrates that successful subretinal delivery of gene therapy vectors is achievable using a direct injection without prior vitrectomy surgery.
Subject(s)
Feasibility Studies , Gene Transfer Techniques , Genetic Therapy , Genetic Vectors , Swine, Miniature , Vitrectomy , Animals , Vitrectomy/methods , Swine , Genetic Therapy/methods , Genetic Vectors/administration & dosage , Pilot Projects , Retina , Injections, Intraocular , Plasmids/administration & dosage , Disease Models, Animal , Green Fluorescent Proteins/geneticsABSTRACT
Purpose To investigate the effect of benzalkonium chloride (BAK)-preserved latanoprost and bimatoprost, polyquad (PQ)-preserved travoprost, and preservative-free (PF) latanoprost and tafluprost, all prostaglandin analogues (PGAs), on human conjunctival goblet cell (GC) survival. Furthermore, to investigate the effect of BAK-preserved and PF latanoprost on the cytokine secretion from GC. Methods Primary human conjunctival GCs were cultivated from donor tissue. Lactate dehydrogenase (LDH) and tetrazolium dye colorimetric (MTT) assays were used for the assessment of GC survival. A cytometric bead array was employed for measuring secretion of interleukin (IL)-6 and IL-8 from GC. Results BAK-preserved latanoprost and bimatoprost reduced cell survival by 28% (p = 0.0133) and 20% (p = 0.0208), respectively, in the LDH assay compared to a negative control. BAK-preserved latanoprost reduced cell proliferation by 54% (p = 0.003), BAK-preserved bimatoprost by 45% (p = 0.006), PQ-preserved travoprost by 16% (p = 0.0041), and PF latanoprost by 19% (p = 0.0001), in the MTT assay compared to a negative control. Only PF tafluprost did not affect the GCs in either assay. BAK-preserved latanoprost caused an increase in the secretion of pro-inflammatory IL-6 and IL-8 (p = 0.0001 and p = 0.0019, respectively) compared to a negative control, which PF latanoprost did not. Conclusion BAK-preserved PGA eye drops were more cytotoxic to GCs than PQ-preserved and PF PGA eye drops. BAK-preserved latanoprost induced an inflammatory response in GC. Treatment with PF and PQ-preserved PGA eye drops could mean better tolerability and adherence in glaucoma patients compared to treatment with BAK-preserved PGA eye drops. (AU)
Subject(s)
Ophthalmic Solutions/chemical synthesis , Ophthalmic Solutions/isolation & purification , Ophthalmic Solutions/therapeutic use , Prostaglandins, Synthetic , Benzalkonium Compounds , Goblet CellsABSTRACT
Purpose: The goal of this research is to investigate the characteristics and surgical techniques for repairing rhegmatogenous retinal detachment (RRD) and their influence on anatomical and functional success of the treatment with a special emphasis on the economic costs and outcome quality-adjusted life years (QALYs) of the procedures. Methods: This retrospective study analyzed data from 151 patients with RRD treated at the Department of Ophthalmology, Clinical Hospital Centre Split, Croatia, in a 3-year period, using one of three surgical techniques: pneumoretinopexy (PR), scleral buckling (SB) or pars plana vitrectomy (PPV), followed-up for at least 6 months. Demographic, pre- and post-operative ophthalmic exam parameters and surgical technique used were collected accordingly. Statistical analysis of the influence of the studied parameters upon anatomical and functional outcomes was performed, as well as health economic analysis on costs and derived utilities/QALYs of these surgical methods. Results: Of all patients, 130 (86%) were successfully operated on, and 21 patients (14%) required another surgical procedure. No statistically significant differences in the anatomical success between the 3 surgical techniques were found. However, the functional outcome (based on the final best corrected visual acuity (BCVA)) differed significantly. Despite improvement in the final BCVA, BCVA ≥ 0.5 was achieved in only 52 (34.4%) patients. The final BCVA showed significant association with the time elapsed from the onset of RRD to the surgical intervention, pre-operative BCVA, macular- and preoperative lens- status and type of surgery. The estimated diagnosis-related group (DRG) cost for day and inpatient surgery was based upon existing DRG cost for PPV, which for PR and SB was calculated accordingly. Based upon the success of the procedure and visual outcome, the overall calculated QALYs for PR and SB appeared to be similar, while the QALYs were lower for PPV. Conclusions: The success rate of treating RRD mostly depends on performing an early surgical procedure (especially in the case of attached macula), identification of all retina tears and, most importantly, choosing the appropriate surgical technique. Decisions on treatment for RRD should also be based upon cost-effective and QALYs-assessed procedures, especially in countries like Croatia, where limited healthcare resources exist. This study shows PR to be efficient and most cost-effective for RRD repairment in appropriate cases.
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PURPOSE: To compare the effect of the ocular antiseptic treatments 0.05% chlorhexidine, 5% povidone-iodine (PI) and 5% betadine on cell viability and mucin secretion of primary cultured human goblet cells (GCs). METHOD: GC viability was analysed using lactate dehydrogenase (LDH) and tetrazolium dye (MTT) colorimetric assays. Expression of mucin was visualised by immunohistochemical MUC5AC staining. RESULTS: PI and betadine significantly reduced GC survival compared to the control (mean cell survival 23 ± 6% and 23 ± 7%, respectively, p < 0.05), whereas chlorhexidine did not significantly affect GC viability (mean cell survival: 78 ± 17%), as measured by the LDH assay. Similar results were obtained from the MTT assay, where PI and betadine caused a significant loss of GCs (mean cell survival: 26 ± 12% and 26 ± 13%, respectively, p < 0.05). Chlorhexidine did not significantly alter GC survival compared to the control (mean cell survival: 79 ± 8%). PI and betadine caused a dispersion of mucin secretion, which chlorhexidine did not. CONCLUSION: The most used antiseptic treatments, PI and betadine, applied prior to ocular surgery are significantly more cytotoxic to conjunctival GCs than chlorhexidine treatment.
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This study aimed to analyze the clinical significance of signal shadowing during intraoperative optical coherence tomography (iOCT)-assisted vitreoretinal surgery caused by vitreoretinal instruments, tissue dyes, and vitreous substitutes, and to objectively quantify its impact on iOCT imaging. This is a retrospective observational study of postoperative image analysis from one hundred seventeen (117) patients who underwent iOCT-assisted vitrectomy. The image data were divided into three groups: vitreoretinal instruments, tissue dyes, and vitreous substitutes. The data was then processed using graphic software to measure the grade of picture quality distortion and compared to paired image controls without clinically perceptive interference, then analyzed statistically. The intraocular portion of all studied vitreoretinal instruments caused a high average gray level interference compared to controls ranging from 32 to 68% reduction, obscuring the area of interest significantly. The tips of the instruments produced low-grade shadowing, allowing the underlying tissue to be distinguished. The analyzed dyes demonstrated a wide interference range: ICG (- 75.12%), and triamcinolone (- 26.13%) showed dose-dependent high shadowing, while VITREODYNE™ (49.3%) and brilliant blue G (14.06%) exhibited no perceived distortions whilst increasing average gray levels. All analyzed vitreous substitutes (air, SF6, C3F8, PFCL, and silicone oil) showed an insignificant shadowing effect on iOCT. Certain dyes and vitreous substitutes produce a negligible shadowing effect compared to controls and other dyes, providing an advantage during real-time iOCT imaging. All analyzed vitreoretinal instruments showed a significant interference that should prompt the development of new imaging techniques or the implementation of materials with low-grade interference to overcome a clinically relevant shadowing effect on iOCT, maximizing the technology's visual accuracy and surgical diagnostic aid proficiency.
Subject(s)
Tomography, Optical Coherence , Vitreoretinal Surgery , Humans , Clinical Relevance , Coloring Agents , Image Processing, Computer-AssistedABSTRACT
PURPOSE: Women with hypertensive disorders of pregnancy (HDP) are at increased risk of developing premature cardiovascular disease (CVD). The mechanisms behind this are not fully understood, but microvascular alterations have been documented in retinal arterioles and venules. The aim of this study was to use non-invasive retinal imaging to investigate the structural and functional properties of arterioles, venules and capillaries in this patient group. METHODS: We examined 27 women with previous HDP and 23 controls at 3 years postpartum. The retinal microvasculature was assessed by vessel calibre measurements, retinal oximetry and optical coherence tomography angiography. Differences were analysed using non-parametric tests and multiple regression analyses, adjusted for age and body mass index. RESULTS: Median arteriolar oxygen saturation (SaO2; 94.2% vs. 93.0%), venular oxygen saturation (SvO2; 60.1% vs. 62.4%) and arteriovenous saturation difference (AV-difference; 32.8% vs. 32.3%) were similar across groups. Capillary vessel density (VD; 46.2% vs. 46.3%), skeletonised VD (VSD; 21.3 vs. 21.1 mm/mm2) and vessel diameter index (21.65 vs. 21.86) were also comparable. In the HDP group, mean arterial pressure (MAP) was positively correlated with AV-difference (R2 = 0.209) and negatively correlated with arteriolar diameter (CRAE; r2 = 0.382). CONCLUSIONS: Structural microvascular alterations appear not to be key biomarkers for CVD risk after HDP as early as 3 years postpartum in otherwise healthy women. Further studies are needed to evaluate whether such changes occur later in life. MAP was associated with AV-difference only in the HDP group, suggesting specific mechanisms affecting functional microvascular properties in these women.
Subject(s)
Fluorescein Angiography , Hypertension, Pregnancy-Induced , Oximetry , Retinal Vessels , Tomography, Optical Coherence , Humans , Female , Pregnancy , Oximetry/methods , Adult , Tomography, Optical Coherence/methods , Retinal Vessels/physiopathology , Retinal Vessels/diagnostic imaging , Hypertension, Pregnancy-Induced/physiopathology , Hypertension, Pregnancy-Induced/diagnosis , Fluorescein Angiography/methods , Microvessels/physiopathology , Microvessels/diagnostic imaging , Oxygen Saturation/physiology , Follow-Up Studies , Oxygen/blood , Fundus Oculi , Postpartum PeriodABSTRACT
Background and Aims: Carbohydrate counting is a well-established tool for self-management of type 1 diabetes (T1D) and can improve glycemic control and potentially reduce long-term complication risk. However, it can also be burdensome, error-prone, and complicated for the patient. A randomized controlled trial was conducted to investigate glycemic control with carbohydrate counting ("flex") versus simplified meal announcement ("fix") in adolescents with T1D using the MiniMed™ 780G system. The present study reports follow-up data to 12 months. Methods: Adolescents with T1D were randomly assigned 1:1 to use the MiniMed™ 780G system alongside the flex versus fix approaches. Participants were followed for 12 months with outcomes recorded at 3, 6, 9, and 12 months. The primary endpoint was the difference in time-in-range (TIR), and secondary endpoints included glycated hemoglobin (HbA1c) and other glucose and insulin metrics. Results: At 12 months, TIR (proportion of time with sensor glucose 70-180 mg/dL) was significantly lower in the fix versus flex group (72.9% vs. 80.1%, respectively; P = 0.001). There was no significant difference in HbA1c between the fix (6.8% ± 0.5%) and flex groups (6.5% ± 0.5%) at 12 months (P = 0.092), and mean HbA1c was below 7% at all time points in both arms. Conclusions: Glycemic control with simplified meal announcement was maintained over 12 months. On average, the international consensus targets were met in both arms for all time points. The simplified approach represents a viable alternative to carbohydrate counting, particularly in people who find the latter burdensome; however, carbohydrate counting resulted in superior TIR. This study is registered with ClinicalTrials.gov, number NCT05069727.
Subject(s)
Diabetes Mellitus, Type 1 , Humans , Adolescent , Diabetes Mellitus, Type 1/drug therapy , Glycated Hemoglobin , Blood Glucose , Follow-Up Studies , Insulin/therapeutic use , Glucose , Insulin Infusion Systems , Hypoglycemic Agents/therapeutic use , Blood Glucose Self-MonitoringABSTRACT
Background: The cornea, a vital component of the human eye, plays a crucial role in maintaining visual clarity. Understanding its ultrastructural organization and cell distribution is fundamental for elucidating corneal physiology and pathology. This study comprehensively examines the microarchitecture of the hydrated human cornea using contrast-enhanced micro-computed tomography (micro-CT). Method: Fresh human corneal specimens were carefully prepared and hydrated to mimic their in vivo state. Contrast enhancement with Lugol's iodine-enabled high-resolution Micro-CT imaging. The cells' three-dimensional (3D) distribution within the cornea was reconstructed and analyzed. Results: The micro-CT imaging revealed exquisite details of the corneal ultrastructure, including the spatial arrangement of cells throughout its depth. This novel approach allowed for the visualization of cells' density and distribution in different corneal layers. Notably, our findings highlighted variations in cell distribution between non-hydrated and hydrated corneas. Conclusions: This study demonstrates the potential of contrast-enhanced micro-CT as a valuable tool for non-destructive, 3D visualization and quantitative analysis of cell distribution in hydrated human corneas. These insights contribute to a better understanding of corneal physiology and may have implications for research in corneal diseases and tissue engineering.
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Regular monitoring of glycated hemoglobin (HbA1c) levels is important for the proper management of diabetes. Studies demonstrated that lower levels of HbA1c play an essential role in reducing or delaying microvascular difficulties that arise from diabetes. In addition, there is an association between elevated HbA1c levels and the development of diabetes-related comorbidities. The advanced prediction of HbA1c enables patients and physicians to make changes to treatment plans and lifestyle to avoid elevated HbA1c levels, which can consequently lead to irreversible health complications. Despite the impact of such prediction capabilities, no work in the literature or industry has investigated the futuristic prediction of HbA1c using current blood glucose (BG) measurements. For the first time in the literature, this work proposes a novel FSL-derived algorithm for the long-term prediction of clinical HbA1c measures. More importantly, the study specifically targeted the pediatric Type-1 diabetic population, as an early prediction of elevated HbA1c levels could help avert severe life-threatening complications in these young children. Short-term CGM time-series data are processed using both novel image transformation approaches, as well as using conventional signal processing methods. The derived images are then fed into a convolutional neural network (CNN) adapted from a few-shot learning (FSL) model for feature extraction, and all the derived features are fused together. A novel normalized FSL-distance (FSLD) metric is proposed for accurately separating the features of different HbA1c levels. Finally, a K-nearest neighbor (KNN) model with majority voting is implemented for the final classification task. The proposed FSL-derived algorithm provides a prediction accuracy of 93.2%.