Diabetic retinopathy - ocular complications of diabetes mellitus

SIRT1: a promising therapeutic target in type 2 diabetes mellitus

A significant increase in the worldwide incidence and prevalence of type 2 diabetic mellitus (T2DM) has elevated the need for studies on novel and effective therapeutic strategies. Sirtuin 1 (SIRT1) is an NAD + dependent protein deacetylase with a critical function in the regulation of glucose/lipid metabolism, insulin resistance, inflammation, oxidative stress, and mitochondrial function. SIRT1 is also involved in the regulation of insulin secretion from pancreatic β-cells and protecting these cells from inflammation and oxidative stress-mediated tissue damages. In this regard, major SIRT1 activators have been demonstrated to exert a beneficial impact in reversing T2DM-related complications including cardiomyopathy, nephropathy, retinopathy, and neuropathy, hence treating T2DM. Therefore, an accumulating number of recent studies have investigated the efficacy of targeting SIRT1 as a therapeutic strategy in T2DM. In this review we aimed to discuss the current understanding of the physiological and biological roles of SIRT1, then its implication in the pathogenesis of T2DM, and the therapeutic potential of SIRT1 in combating T2DM.

Insights Into Visual Rehabilitation: Pan-Retinal Photocoagulation for Proliferative Diabetic Retinopathy

This review comprehensively explores pan-retinal photocoagulation (PRP) as a pivotal intervention in visually rehabilitating individuals afflicted with proliferative diabetic retinopathy (PDR). The review begins by elucidating the significance of PDR within the spectrum of diabetic retinopathy (DR), emphasizing the progressive nature of the disease and the consequential impact on visual health. A detailed analysis of PRP follows, encompassing its definition, purpose, and historical development, shedding light on the procedural intricacies and mechanisms of action. The postoperative care and follow-up section underscores the necessity of vigilant monitoring for complications, visual recovery, and the importance of regular ophthalmic check-ups. The subsequent discussion delves into patient education and counseling, stressing the need to manage expectations, encourage lifestyle modifications, and highlight the significance of follow-up appointments. The review concludes with insights into future directions, including advancements in laser technology and emerging therapies, offering a glimpse into the evolving landscape of DR management. By addressing ongoing challenges and embracing innovative approaches, this review provides a comprehensive guide for clinicians, researchers, and healthcare practitioners who visually rehabilitate individuals struggling with PDR.

The role of cadre in the community on diabetic retinopathy management and its challenges in low-middle income countries: a scoping review

INTRODUCTION

Diabetes is a serious public health problem, with low- and middle-income countries (LMICs) bearing over 80% of the burden. Diabetic retinopathy (DR) is one of the most prevalent diabetic microvascular problems, and early diagnosis through eye screening programs for people with diabetes is critical to prevent vision impairment and blindness. Community-based treatments, including non-physician cadres have been recommended to enhance DR care.

METHODS

The review protocol was determined and scoping review was conducted.The population, concept, and context were "cadre", "role of cadre in the management of DR", and LMICs". Data were collected from databases and searches, including grey literature.

RESULTS

Cadre can motivate people to attend a diabetic eye screening event when the rate of eye examinations is about six times higher than before the start of the intervention. Health education is a possible area for task sharing, and the cadre reported could also perform the task of vision testing. The cadre could be a good supporter and a good reminder for society. However, several challenges have been faced in this study and inadequate infrastructure is the foremost challenge found in this study. Other challenges encountered in the studies include poverty, lack of community awareness, trust issues, and low education levels contributing to poor health.

CONCLUSION

The current study highlighted significant gaps in the literature, which focus on the role of cadre as a community-based intervention in managing DR in LMICs. Further research is needed to develop evidence to support cost-effective screening services and cadre-related policy development in LMICs.

Association between serum heavy metal levels and diabetic retinopathy in NHANES 2011-2020

The present study utilized the National Health and Nutrition Examination Survey (NHANES) database to examine the relationship between serum levels of heavy metals and Diabetic retinopathy (DR) in individuals aged over 30 years with type 2 diabetes mellitus (T2DM) in the United States. A cross-sectional analysis was conducted on 1583 individuals with T2DM from the NHANES 2011-2020, including 331 individuals in the DR group and 1252 individuals in the non-DR group. We collected data on serum levels of heavy metals, DR, and serum albumin for descriptive statistics, linear regression, and logistical regression analysis. After adjusting for age, gender, race and other factors, there was no statistically significant association between blood cadmium, selenium, mercury, or lead and DR. However, serum manganese (Mn) and DR had a significant negative association (β = - 0.2045, 95% CI = - 0.3484, - 0.0606). Serum albumin partially modulated the indirect influence of serum Mn on the incidence of DR, accounting for 12.80% of the association between serum Mn and DR. There was a negative association between serum Mn levels and the prevalence of DR in people with T2DM. Mn intake at least in this study has a little influence on the onset and development of DR.

Exploring the Potential Benefits of Bovine Colostrum Supplementation in the Management of Diabetes and its Complications: A Comprehensive Review

Diabetes is a metabolic illness marked by elevated levels of glucose in the bloodstream due to the inadequate production or use of insulin in the body. Diabetes can result in a range of consequences, with the most prevalent being cardiovascular disease, renal failure, vision loss, and limb removal. Natural compounds isolated from different sources, like colostrum, are the most important compounds for the treatment of diabetes. Colostrum is a form of lactation produced by mammals in the first days after giving birth to their offspring, having a rich source of constituents and showing multipharmacological properties. This review was prepared on the basis of a variety of authoritative search databases, including Google Scholar, Scopus, and PubMed. In addition, the publications and other online sources were also included. In the literature search, the terms "colostrum," "diabetes," "uses," "management," "constituent," "composition," "alternative sources," "mechanism of action," "preclinical," "clinical," "marketed formulations," and "patents" were utilized as keywords and collected from last two decades. Colostrum has been utilized as a treatment for a wide variety of illnesses due to its active constituents. A variety of colostrums are available in the market, like goat colostrum, porcine colostrum, sheep colostrum, human colostrum and many more. They have the full potential of nutrients like minerals, vitamins, lactose, essential enzymes, proteins and high concentrations of immunoproteins. Mostly, the colostrums are used for treating diabetes and its complications. Preclinical and clinical studies of metabolic syndrome, especially on diabetes and its complications, were also reported at the National and International levels, which evidently prove that the use of colostrums in the long term can be beneficial for various ailments associated with diabetes. In general, the findings of this review indicate that supplementation with colostrum may hold promise as a novel therapeutic intervention for people who have diabetes and its complications; however, additional research is required to fully understand its mechanisms of action and determine the best possible dosage as well as the time period of supplementation.

Analysis of risk factors of infection in diabetic foot patients

This cross-sectional study assessed the risk factors for infection in 150 diabetic foot patients admitted to the Xiamen University Hospital between October 2020 and October 2022. Patients were categorised as infected (n = 80) or uninfected (n = 70) cohorts. The diabetic foot was evaluated using the American Diabetic Foot Grading system, whereas ulcers were categorised using Wagner's method. Analysed were patient-specific information, clinical data and risk factors including neuropathy, arterial disease and foot deformities. Our findings revealed no statistically significant differences between infected and uninfected cohorts concerning age, body mass index, gender, duration of diabetes or ankle-brachial index values (p > 0.05). However, infected group had a higher proportion of smokers and reduced socio-economic status (p < 0.05). Wagner grades indicated a greater severity in the infected group, with grade 3, grade 4 and grade 5 differing significantly (p < 0.05). Comparative analysis of ulcer characteristics revealed no statistically significant differences in ulcer surface area and depth, but the infected group had a higher prevalence of osteomyelitis and a greater number of ulcers (p > 0.05). Blood vessel complications, retinopathy, the presence of three or more ulcers, osteomyelitis and diabetic nephropathy were substantially more prevalent in the infected group, as determined by univariate analysis (p < 0.05). Subsequent multivariate logistic analysis revealed that patients with blood vessel complications, retinopathy, osteomyelitis, diabetic nephropathy and three or more ulcers were at increased risk for infection (p < 0.05). In addition, lifestyle factors, such as smoking, sedentary behaviour, inadequate foot hygiene, obesity and poor glycaemic control, were also associated with higher infection rates. A multivariate analysis of foot wound factors revealed that deeper, longer and recurrent lesions increased the likelihood of infection. Escherichia coli was the most frequently isolated bacterium from the infected group's bacterial culture, followed by Pseudomonas aeruginosa and Staphylococcus aureus. The study enhanced our comprehension of the multifactorial risk factors associated with infections in diabetic foot patients, highlighting the need for thorough clinical evaluation, lifestyle modification and vigilant infection control.

The effect of a new design of patient gowns for prone position patients after vitrectomy: A non-randomized, concurrent, controlled study

BACKGROUND

The existing patient clothing is not suitable for patients that have to maintain a prone position for a long time after vitrectomy.

OBJECTIVE

To investigate the effect of a new design of patient gowns for prone position patients after vitrectomy.

METHOD

This study designed a kind of patient's gown for prone position patients. A non-randomized, concurrent, controlled study was conducted on 212 patients who met the inclusion criteria for the prone position after vitrectomy in Grade III at a Class A hospital department of ophthalmology in Zhejiang Province from April to August 2020. The experimental group (106 patients in prone position) and the control group (106 patients in common position) were managed by the same group of nurses. The study recorded and compared the comfort degree of patients' clothing used in the course of operation rehabilitation between the two groups and the satisfaction degree of doctors with nurses to patients' clothing used in the prone position.

RESULTS

The satisfaction degree and comfort degree of patients and the health care providers in the experiment group were significantly higher than those in the control group (p< 0.001).

CONCLUSION

The process of making patient gowns for prone position patients is simple, which can improve the safety and comfort of patients when they were in the prone position. The new design also facilitated the treatment and nursing procedures of the medical staff and improved satisfaction among patients and medical staff.

Association of lactate dehydrogenase and diabetic retinopathy in US adults with diabetes mellitus

OBJECTIVES

The purpose of our investigation is to evaluate the level of relationship between lactate dehydrogenase (LDH) and the occurrence of diabetic retinopathy (DR) in adults with diabetes mellitus (DM).

METHODS

The investigation involved an analysis of five sectional data cycles acquired from the National Health and Nutrition Examination Survey from 2009 to 2018. The present study involved the selection of DM samples from a complex multistage probability sample. These samples were subsequently classified into two distinct groups, namely the No DR (NDR) and DR groups. The present study comprehensively investigated the biological and social risk factors associated with DR. The biological factors examined in this investigation included blood pressure, blood routine, hemoglobin A1c, blood glucose, and comorbidities. The social dimensions encompass education and sex.

RESULTS

After considering all factors, multivariate regression models indicated a significant relationship between DR and increased LDH (adjusted odds ratio = 1.007, 95% confidence interval: 1.003-1.011). The subgroup analysis revealed that the effect size of LDH on the existence of DR in the subgroups remained consistent, as indicated by all p values greater than .05. A statistically significant relationship was identified between elevated LDH levels > 134 U/L and a raised risk of DR in people with DM.

CONCLUSION

LDH concentrations were connected with an increased prevalence of DR in participants with DM. Our study highlights that patients with LDH > 134 U/L are distinguishably related to DM complicated by DR. DR is more common in diabetic individuals with coronary heart disease.

Identification of key genes modules linking diabetic retinopathy and circadian rhythm

Background

Diabetic retinopathy (DR) is a leading cause of vision loss worldwide. Recent studies highlighted the crucial impact of circadian rhythms (CR) on normal retinopathy in response to the external light cues. However, the role of circadian rhythms in DR pathogenesis and potential investigational drugs remains unclear.

Methods

To investigate the weather CR affects DR, differential expression analysis was employed to identify differentially expressed genes (DEGs) from the GEO database (GSE160306). Functional enrichment analysis was conducted to identify relevant signaling pathways. LASSO regression was utilized to screen pivotal genes. Weighted gene co-expression network anlaysis (WGCNA) was applied to identify different modules. Additionally, we use the Comparative Toxicogenomics Database (CTD) database to search key genes related to drugs or molecular compounds. The diabetic mouse model received three consecutive intraperitoneal injections of streptozotocin (STZ) during 3 successive days.

Results

We initially identified six key genes associated with circadian rhythm in DR, including COL6A3, IGFBP2, IGHG4, KLHDC7A, RPL26P30, and MYL6P4. Compared to normal tissue, the expression levels of COL6A3 and IGFB2 were significantly increased in DR model. Furthermore, we identified several signaling pathways, including death domain binding, insulin-like growth factor I binding, and proteasome binding. We also observed that COL6A3 was positively correlated with macrophages (cor=0.628296895, p=9.96E-08) and Th17 cells (cor=0.665120835, p=9.14E-09), while IGFBP2 showed a negatively correlated with Tgd (cor=-0.459953045, p=0.000247284) and Th2 cells (cor=-0.442269719, p=0.000452875). Finally, we identified four drugs associated with key genes: Resveratrol, Vitamin E, Streptozocin, and Sulindac.

Conclusion

Our findings revealed several key genes related to circadian rhythms and several relevant drugs in DR, providing a novel insight into the mechanism of DR and potential implications for future DR treatment. This study contributes to a better understanding of CR in DR and its implications for future therapeutic interventions.

Stem cells as a regenerative medicine approach in treatment of microvascular diabetic complications

Diabetes mellitus (DM) is a chronic metabolic disorder characterized by high blood glucose and is associated with high morbidity and mortality among the diabetic population. Uncontrolled chronic hyperglycaemia causes increased formation and accumulation of different oxidative and nitrosative stress markers, resulting in microvascular and macrovascular complications, which might seriously affect the quality of a patient's life. Conventional treatment strategies are confined to controlling blood glucose by regulating the insulin level and are not involved in attenuating the life-threatening complications of diabetes mellitus. Thus, there is an unmet need to develop a viable treatment strategy that could target the multi-etiological factors involved in the pathogenesis of diabetic complications. Stem cell therapy, a regenerative medicine approach, has been investigated in diabetic complications owing to their unique characteristic features of self-renewal, multilineage differentiation and regeneration potential. The present review is focused on potential therapeutic applications of stem cells in the treatment of microvascular diabetic complications such as nephropathy, retinopathy, and polyneuropathy.

Suprachoroidal triamcinolone versus posterior subtenon triamcinolone either alone or formulated in the management of diabetic macular edema

PURPOSE

This study aims to compare posterior subtenon triamcinolone acetonide injection either formulated or alone versus suprachoroidal triamcinolone in the management of diabetic macular edema.

METHODS

This study is a prospective interventional study that included 75 patients, divided into three groups, each group with 25 patients. Group I received a combination of triamcinolone acetonide (TA) (40 mg) and VISCOAT, which is a combination of sodium chondroitin sulfate (20 mg) and sodium hyaluronate (15 mg). The injection was done in the posterior subtenon space using the NAGATA cannula. Group II received TA (40 mg) in the posterior subtenon space. Group III underwent an injection of 4 mg/100µl of TA in the supra choroidal space.

RESULTS

We found a statistically significant difference between the three studied groups regarding BCVA (P = 0.001) and CMT at six months postoperative (P = 0.001) with the highest median BCVA and lowest median CMT observed in the formulated TA group.

CONCLUSION

We concluded that early treatment of DME by formulated TA is better than TA alone, and suprachoroidal TA in the form of increasing the BCVA and decreasing the CMT without any elevation of IOP. Trial registration number NCT05464953. Date of registration 17/7/2022 (retrospectively registered).

Evaluation of Quality of Life and Emotional Disturbances in Patients with Diabetic Retinopathy

Diabetes has detrimental effects on many organs, including the kidneys, heart, and the central nervous system, with ophthalmic involvement and Diabetic Retinopathy (DR), specifically, being among the most severe and prominent consequences. Diabetic Retinopathy and especially advanced stages of the disease, have a crucial impact on patients' quality of life and emotional status. In this context, emotional imbalance, psychological side effects and comorbidities, like anxiety disorders, could emerge, deteriorating the patients' condition further. A number of questionnaires can be employed in the evaluation of the potential impact of Diabetic Retinopathy on patients' quality of life, including the Beck Anxiety Inventory (BAI) and The National Eye Institute Visual Function Questionnaire-25 (NEI VFQ-25).

PURPOSE

The purpose of this study was to evaluate the association of Diabetic Retinopathy (DR) and diabetic macular edema with vision-related quality of life, as well as the potential association between the disease's severity, emotional status of patients and the manifestation of anxiety and psychological features.

RESULTS

Patients with fundoscopic findings had significantly lower scores in all VFQ-25 subscales, indicating worse quality of life in comparison to patients without DR. Severity of DR, greater levels of anxiety, daily sitting time, unemployment and lower education level, were all found to be significantly, negatively associated with a worse quality of life. Regarding emotional status, more years of suffering from diabetes, treatment with insulin and the hours being idle per day were associated with an increased burden of anxiety. In addition, the presence of a concomitant disease, findings in fundoscopy, diabetic macular edema and treatment with anti-VEFG injections, as well as the number of doses, were significantly associated with greater anxiety. Multivariate analysis showed that having Severe Non-Proliferative Diabetic Retinopathy or having Proliferative Diabetic Retinopathy and receiving insulin therapy (alone or in combination with another treatment), were significantly associated with higher levels of anxiety.

CONCLUSION

The well-established impact of DR on the patients' well-being, quality of life and emotional status render DR and CME prevention, stabilization or delaying progression as a necessity in order to protect patients from developing psychiatric symptoms. On the other hand, the speculated bi-directional association between emotional problems and DR progression highlights the importance of acknowledging and dealing with psychological issues with the aim of delaying DR progression.

A cohort follow-up study for diabetic retinopathy screening incidence in the North Denmark Region

AIMS

To evaluate diabetic retinopathy (DR) screening incidence in a universal healthcare system.

METHODS

Registry-based cohort study based on a Danish regional population from 2009 to 2018. Individuals with diabetes were identified by medication. Screening attendance was estimated by surrogate measures using local and nationwide databases reported by cumulative incidence.

RESULTS

18,832 patients were included. By the end of the first year, the cumulative incidence of screening for DR was 60.2% and by the end of the second year 74.2%. The cumulative incidence was 93.9% overall, 97.7% for patients with type 1 diabetes (T1D) and 93.4% for patients with type 2 diabetes. Screening proportions per 1, 2 and 5 years were calculated. Females, patients with T1D, and patients attending screening at hospitals had a higher Hazard Ratio of 1.084, 1.157, and 1.573, respectively. The Cochran-Armitage trend test indicated increased screening frequency from 2009 to 2018. Validation of DR screening was done at hospitals with a mean positive predictive value of 86.78%. Cumulative incidence curves showed a small right shift when censoring the first, second and third screening visits.

CONCLUSIONS

Nearly all patients were screened for DR over a 5-year timespan. Female patients with T1D who attended screening at hospitals were significantly more likely to be screened. Validation of screening visits at hospitals was reported with a high mean positive predictive value. Most other studies, to the best of our knowledge, only report screening attendance for patients already enrolled in a DR screening programme. This study describes the overall screening attendance for the total eligible diabetes population.

Ocular and Systemic Risk Factors for Disease Worsening Among Patients with NPDR: Post Hoc Analysis of the PANORAMA Trial

PURPOSE

Identify baseline systemic and ocular characteristics associated with nonproliferative diabetic retinopathy (NPDR) worsening, and the impact of intravitreal aflibercept injection (IAI) on these associations.

DESIGN

Post hoc analysis of PANORAMA.

PARTICIPANTS

Patients with moderately severe to severe NPDR enrolled in the prospective PANORAMA phase 3 trial.

METHODS

Associations between baseline systemic and ocular factors with events indicative of NPDR worsening at Week 100 were evaluated by multivariable analysis in sham-treated eyes. NPDR worsening was defined as development of (1) vision-threatening complications (VTCs; comprising PDR and/or anterior segment neovascularization), (2) center-involved diabetic macular edema (CI-DME), or (3) ≥ 2-step Diabetic Retinopathy Severity Scale (DRSS) worsening. Impact of IAI on identified baseline factors was evaluated using univariable analysis in combined IAI groups.

MAIN OUTCOMES MEASURES

Baseline systemic and ocular factors associated with events indicative of NPDR worsening at Week 100. The cumulative incidence and risk of developing such events at Week 100 among sham versus IAI-treated eyes.

RESULTS

Using multivariable analyses among sham-treated eyes, 5 baseline factors associated with increased risk of NPDR worsening were identified: fluorescein leakage, retinal nonperfusion area, thicker central subfield thickness, eosinophil level, and proteinuria. Considering baseline fluorescein leakage area as a prognostic indicator in detail, the risk of developing VTCs alone, VTCs and/or CI-DME, or ≥ 2-step DRSS worsening increased with increasing fluorescein leakage area in the sham group (all P < 0.05). Considering baseline retinal nonperfusion area as a prognostic indicator in detail, the risk of developing VTCs alone, CI-DME alone, or VTCs and/or CI-DME increased with increasing baseline retinal nonperfusion area in the sham group (all P < 0.05). In contrast, among IAI-treated eyes, increasing baseline fluorescein leakage or retinal nonperfusion areas did not increase the risks of NPDR worsening.

CONCLUSIONS

Within the PANORAMA trial, increased areas of fluorescein leakage and retinal nonperfusion at baseline were identified as key ocular biomarkers associated with events indicative of NPDR worsening among sham-treated patients. IAI treatment appeared to mitigate the effect of these baseline risk factors and reduced the likelihood of NPDR worsening.

Prevalence of bacillary layer detachment in diabetic macular edema and response to 3 anti-vascular endothelial growth factor treatment

Spectral-domain optical coherence tomography is widely used in maculopathy, including diabetic macular edema (DME). Bacillary layer detachment (BALAD) is a novel optical coherence tomography finding, defined as the separation of the intraretinal layer between the inner segment myoids and ellipsoids. A total of 161 treatment-naïve eyes with centrally involved DME that underwent 3 monthly loading doses of anti-vascular endothelial growth factor (anti-VEGF) intravitreal injections were enrolled and analyzed retrospectively. BALAD was found in 6.2% of eyes with concurrent subretinal fluid (SRF). All eyes were divided into 3 groups: no either group had neither SRF or BALAD; the SRF only group had SRF but no BALAD; and the BALAD group had both SRF and BALAD. A significant increase in baseline central foveal thickness (CFT) in the BALAD group was observed (no either vs SRF only vs BALAD, baseline CFT: 387.6 ± 74.29 vs 440.6 ± 106.79 vs 642.0 ± 188.86; P < .01). Total resolution of BALAD was noted after anti-VEGF therapy, along with a significant decrease in CFT in all groups (CFT decrease: 82.4 ± 87.07 vs 187.6 ± 138.88 vs 252.1 ± 127.63; P < .01). Eyes with BALAD tended to have the worst baseline visual acuity (baseline logarithm of the minimum angle of resolution VA: 0.76 ± 0.353 vs 0.63 ± 0.303 vs 1.15 ± 0.300; P = .046) but showed the most improvement after treatment (logarithm of the minimum angle of resolution VA change: -0.14 ± 0.235 vs -0.22 ± 0.275 vs -0.27 ± 0.250; P = .079). After resolution of BALAD, all eyes in the BALAD group exhibited ellipsoid zone and/or interdigitation zone disruption corresponding to the BALAD area. BALAD is a novel optical coherence tomography finding associated with a spectrum of diseases including DME. With anti-VEGF therapy, total resolution of BALAD and a significant decrease in CFT can be obtained. However, ellipsoid zone/interdigitation zone disruption tended to develop.

CHILDSTAR: CHIldren Living With Diabetes See and Thrive with AI Review

Background

Artificial intelligence (AI) appears capable of detecting diabetic retinopathy (DR) with a high degree of accuracy in adults; however, there are few studies in children and young adults.

Methods

Children and young adults (3-26 years) with type 1 diabetes mellitus (T1DM) or type 2 diabetes mellitus (T2DM) were screened at the Dhaka BIRDEM-2 hospital, Bangladesh. All gradable fundus images were uploaded to Cybersight AI for interpretation. Two main outcomes were considered at a patient level: 1) Any DR, defined as mild non-proliferative diabetic retinopathy (NPDR or more severe; and 2) Referable DR, defined as moderate NPDR or more severe. Diagnostic test performance comparing Orbis International's Cybersight AI with the reference standard, a fully qualified optometrist certified in DR grading, was assessed using the Matthews correlation coefficient (MCC), area under the receiver operating characteristic curve (AUC-ROC), area under the precision-recall curve (AUC-PR), sensitivity, specificity, positive and negative predictive values.

Results

Among 1274 participants (53.1% female, mean age 16.7 years), 19.4% (n = 247) had any DR according to AI. For referable DR, 2.35% (n = 30) were detected by AI. The sensitivity and specificity of AI for any DR were 75.5% (CI 69.7-81.3%) and 91.8% (CI 90.2-93.5%) respectively, and for referable DR, these values were 84.2% (CI 67.8-100%) and 98.9% (CI 98.3%-99.5%). The MCC, AUC-ROC and the AUC-PR for referable DR were 63.4, 91.2 and 76.2% respectively. AI was most successful in accurately classifying younger children with shorter duration of diabetes.

Conclusions

Cybersight AI accurately detected any DR and referable DR among children and young adults, despite its algorithms having been trained on adults. The observed high specificity is particularly important to avoid over-referral in low-resource settings. AI may be an effective tool to reduce demands on scarce physician resources for the care of children with diabetes in low-resource settings.

LncRNA SNHG4 sponges miR-200b to inhibit cell apoptosis in diabetic retinopathy

This study aimed to investigate the role of long non-coding RNA (lncRNA) small nucleolar RNA host gene 4 (SNHG4) in diabetic retinopathy (DR). We found that SNHG4 was downregulated in DR. SNHG4 could directly interact with miR-200b, while overexpression of miR-200b did not affect the expression of SNHG4 in human retinal pigment epithelial cells ARPE-19. In contrast, overexpression of SNHG4 led to the upregulation of oxidation resistance 1 (Oxr1), a target of miR-200b. Cell apoptosis analysis showed that overexpression of miR-200b increased the apoptotic rate of ARPE-19 cells under high glucose treatment. Oxr1 and SNHG4 played opposite roles and reduced the effects of overexpression of miR-200b. In conclusion, SNHG4 may sponge miR-200b to inhibit cell apoptosis in DR by upregulating Oxr1.

Relationship between ocular surface pain and corneal nerve loss in dry eye diabetics: a cross-sectional study in Shenyang, China

BACKGROUND

Diabetes mellitus has been associated with increased dry eye disease (DED) and exacerbates DED pathology.

OBJECTIVE

To investigate the potential relationship between corneal nerve loss and ocular pain among diabetic patients with dry eye (DE).

DESIGN

A cross-sectional study.

SETTING

He Eye Specialist Hospital, Shenyang, China.

PARTICIPANTS

This study recruited 124 eyes of 62 diabetic patients diagnosed with DED between August and October 2022.

MAIN OUTCOME MEASURES

Best-corrected visual acuity, intraocular pressure, non-invasive tear breakup time, tear meniscus height, tear film lipid layer, conjunctival hyperaemia (redness score), conjunctivocorneal epithelial staining (CS score), central corneal sensitivity and vitro confocal corneal microscopy was assessed in all subjects. The Ocular Surface Disease Index Questionnaire assessed DE symptoms and ocular pain.

RESULTS

The study's final analysis included 26 patients (52 eyes) without ocular pain and 36 patients (72 eyes) with ocular pain. The corneal nerve fibre density (CNFD), corneal nerve branch density (CNBD) and corneal nerve fibre length (CNFL) in patients with ocular pain were significantly lower than those without (p<0.001, p=0.004, and p<0.001, respectively). CNFD, CNBD and CNFL negatively correlated with ocular pain (r=-0.385, r=-0.260, r=-0.358, respectively). Moreover, CNFD, CNBD and CNFL have a significant (p<0.05) positive correlation with corneal sensitivity (r=0.523, r=0.330, r=0.421, respectively).

CONCLUSIONS

Corneal nerve loss was associated with ocular pain and decreased corneal sensitivity in diabetic patients with DE. Further studies into the neurological role of ocular surface diseases can elaborate diagnostics, prognosis and treatment of diabetic patients with DE.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov (NCT05193331).

Optimizing the OCTA layer fusion option for deep learning classification of diabetic retinopathy

The purpose of this study is to evaluate layer fusion options for deep learning classification of optical coherence tomography (OCT) angiography (OCTA) images. A convolutional neural network (CNN) end-to-end classifier was utilized to classify OCTA images from healthy control subjects and diabetic patients with no retinopathy (NoDR) and non-proliferative diabetic retinopathy (NPDR). For each eye, three en-face OCTA images were acquired from the superficial capillary plexus (SCP), deep capillary plexus (DCP), and choriocapillaris (CC) layers. The performances of the CNN classifier with individual layer inputs and multi-layer fusion architectures, including early-fusion, intermediate-fusion, and late-fusion, were quantitatively compared. For individual layer inputs, the superficial OCTA was observed to have the best performance, with 87.25% accuracy, 78.26% sensitivity, and 90.10% specificity, to differentiate control, NoDR, and NPDR. For multi-layer fusion options, the best option is the intermediate-fusion architecture, which achieved 92.65% accuracy, 87.01% sensitivity, and 94.37% specificity. To interpret the deep learning performance, the Gradient-weighted Class Activation Mapping (Grad-CAM) was utilized to identify spatial characteristics for OCTA classification. Comparative analysis indicates that the layer data fusion options can affect the performance of deep learning classification, and the intermediate-fusion approach is optimal for OCTA classification of DR.

Knowledge, Attitude, and Practice Regarding Diabetic Retinopathy Screening and Eye Management Among Diabetics in Saudi Arabia

Background Globally, one of the leading causes of blindness is diabetic retinopathy (DR). However, many patients do not participate in DR screening because of a lack of awareness. This study aims to assess the knowledge, attitude, and practice (KAP) level regarding DR screening and eye management among diabetic patients in Saudi Arabia. Methodology This cross-sectional study was conducted among diabetic patients aged 18 years or older in Saudi Arabia between October 2022 and February 2023. A validated online KAP-36 questionnaire collected information on sociodemographic data, diabetes profile, diabetes-related complications, and KAP regarding DR screening and management. Results Of the 1,391 diabetic patients, 736 (52.9%) had good knowledge about DR screening and care, while 655 (47.1%) had poor knowledge. A positive attitude toward eye examination for the early detection of DR was noticed among 1,124 (80.8%) participants. Regarding the participants' practice of regular fundus examination, 1,000 (71.9%) participants had good practice. Significant relationships were found between education level (p = 0.017), diabetes mellitus (DM) type and duration (p= 0.01, 0.02), type of treatment (p = 0.001), and a high degree of knowledge. Significant determinants of patients' favorable attitudes included their type of diabetes (p = 0.003), region of residence (p = 0.038), and work or education outside the medical field (p = 0.001). Age (p = 0.001), location of residence (p = 0.015), educational attainment (p= 0.041), and type of diabetes (p = 0.045) were the factors that determined good practice. Conclusions Many diabetic patients supported DR screening and engaged in it regularly. Unfortunately, only around half of the participants had a good understanding of DR. Type 2 diabetes mellitus (T2DM), a longer history of DM, and being highly educated were factors associated with a diabetic patient's higher level of knowledge. Positive attitudes were significantly higher among those living in the central Saudi region, employed outside of the medical field, and those with T2DM. Finally, regarding the practice of eye screening and management among diabetic patients, elderly patients living in the southern Saudi region and those with T2DM were adherent to their regular eye examinations. Consequently, the key to ensuring adequate adherence to DR screening may be intervention techniques and focused education to increase patients' knowledge of DR.

Imaging Biomarkers of Mesopic and Dark-Adapted Macular Functions in Eyes With Treatment-Naïve Mild Diabetic Retinopathy

PURPOSE

To investigate the relationship between imaging biomarkers and mesopic and dark-adapted (ie, scotopic) functions in patients with treatment-naïve mild diabetic retinopathy (DR) and normal visual acuity.

DESIGN

Prospective cross-sectional study.

METHODS

In this study, 60 patients with treatment-naïve mild DR (Early Treatment of Diabetic Retinopathy Study levels 20-35) and 30 healthy control subjects underwent microperimetry, structural optical coherence tomography (OCT), and OCT angiography (OCTA).

RESULTS

The foveal mesopic (22.4 ± 4.5 dB and 25.8 ± 2.0 dB, P = .005), parafoveal mesopic (23.2 ± 3.8 and 25.8 ± 1.9, P < .0001), and parafoveal dark-adapted (21.1 ± 2.8 dB and 23.2 ± 1.9 dB, P = .003) sensitivities were reduced in DR eyes. For foveal mesopic sensitivity, the regression analysis showed a significant topographic association with choriocapillaris flow deficits percentage (CC FD%; β = -0.234, P = .046) and ellipsoid zone (EZ) normalized reflectivity (β = 0.282, P = .048). Parafoveal mesopic sensitivity was significantly topographically associated with inner retinal thickness (β = 0.253, P = .035), deep capillary plexus (DCP) vessel length density (VLD; β = 0.542, P = .016), CC FD% (β = -0.312, P = .032), and EZ normalized reflectivity (β = 0.328, P = .031). Similarly, parafoveal dark-adapted sensitivity was topographically associated with inner retinal thickness (β = 0.453, P = .021), DCP VLD (β = 0.370, P = .030), CC FD% (β = -0.282, P = .048), and EZ normalized reflectivity (β = 0.295, P = .042).

CONCLUSIONS

In treatment-naïve mild DR eyes, both rod and cone functions are affected and they are associated with both DCP and CC flow impairment, which suggests that a macular hypoperfusion at these levels might implicate a reduction in photoreceptor function. Normalized EZ reflectivity may be a valuable structural biomarker for assessing photoreceptor function in DR. NOTE: Publication of this article is sponsored by the American Ophthalmological Society.

Postoperative opioid prescribing patients with diabetes: Opportunities for personalized pain management

BACKGROUND

Opioids are commonly prescribed for postoperative pain, but may lead to prolonged use and addiction. Diabetes impairs nerve function, complicates pain management, and makes opioid prescribing particularly challenging.

METHODS

This retrospective observational study included a cohort of postoperative patients from a multisite academic health system to assess the relationship between diabetes, pain, and prolonged opioid use (POU), 2008-2019. POU was defined as a new opioid prescription 3-6 months after discharge. The odds that a patient had POU was assessed using multivariate logistic regression controlling for patient factors (e.g., demographic and clinical factors, as well as prior pain and opiate use).

FINDINGS

A total of 43,654 patients were included, 12.4% with diabetes. Patients with diabetes had higher preoperative pain scores (2.1 vs 1.9, p<0.001) and lower opioid naïve rates (58.7% vs 68.6%, p<0.001). Following surgery, patients with diabetes had higher rates of POU (17.7% vs 12.7%, p<0.001) despite receiving similar opioid prescriptions at discharge. Patients with Type I diabetes were more likely to have POU compared to other patients (Odds Ratio [OR]: 2.22; 95% Confidence Interval [CI]:1.69-2.90 and OR:1.44, CI: 1.33-1.56, respectively).

INTERPRETATION

In conclusion, surgical patients with diabetes are at increased risk for POU even after controlling for likely covariates, yet they receive similar postoperative opiate therapy. The results suggest a more tailored approach to diabetic postoperative pain management is warranted.

SLC22A3 rs2048327 Polymorphism Is Associated with Diabetic Retinopathy in Caucasians with Type 2 Diabetes Mellitus

The Solute Carrier Family 22 Member 3 (SLC22A3) is a high-capacity, low-affinity transporter for the neurotransmitters norepinephrine, epinephrine, dopamine, serotonin, and histamine. SLC22A3 plays important roles in interorgan and interorganism small-molecule communication, and also regulates local and overall homeostasis in the body. Our aim was to investigate the association between the rs2048327 gene polymorphism and diabetic retinopathy (DR) in Slovenian patients with type 2 diabetes mellitus (T2DM). We also investigated SLC22A3 expression in the fibrovascular membranes (FVMs) of patients with proliferative DR (PDR). Our study involved 1555 unrelated Caucasians with T2DM with a defined ophthalmologic status: 577 of them with DR as the study group, and 978 without DR as the control group. The investigated polymorphisms were genotyped using the KASPar genotyping assay. The expression of SLC22A3 (organic cation transporter 3-OCT3) was examined via immunohistochemistry in human FVM from 16 patients with PDR. The C allele and CC genotype frequencies of the rs2048327 polymorphism were significantly higher in the study group compared to the controls. The logistic regression analysis showed that the carriers of the CC genotype in the recessive genetic models of this polymorphism have a 1.531-fold increase (95% CI 1.083-2.161) in the risk of developing DR. Patients with the C allele of rs2048327 compared to the homozygotes for the wild type T allele exhibited a higher density of SLC22A3 (OCT3)-positive cells (10.5 ± 4.5/mm2 vs. 6.1 ± 2.7/mm2, respectively; p < 0.001). We showed the association of the rs2048327 SLC22A3 gene polymorphism with DR in a Slovenian cohort with type 2 diabetes mellitus, indicating its possible role as a genetic risk factor for the development of this diabetic complication.

Competing risks analysis for neutrophil to lymphocyte ratio as a predictor of diabetic retinopathy incidence in the Scottish population

BACKGROUND

Diabetic retinopathy (DR) is a major sight-threatening microvascular complication in individuals with diabetes. Systemic inflammation combined with oxidative stress is thought to capture most of the complexities involved in the pathology of diabetic retinopathy. A high level of neutrophil-lymphocyte ratio (NLR) is an indicator of abnormal immune system activity. Current estimates of the association of NLR with diabetes and its complications are almost entirely derived from cross-sectional studies, suggesting that the nature of the reported association may be more diagnostic than prognostic. Therefore, in the present study, we examined the utility of NLR as a biomarker to predict the incidence of DR in the Scottish population.

METHODS

The incidence of DR was defined as the time to the first diagnosis of R1 or above grade in the Scottish retinopathy grading scheme from type 2 diabetes diagnosis. The effect of NLR and its interactions were explored using a competing risks survival model adjusting for other risk factors and accounting for deaths. The Fine and Gray subdistribution hazard model (FGR) was used to predict the effect of NLR on the incidence of DR.

RESULTS

We analysed data from 23,531 individuals with complete covariate information. At 10 years, 8416 (35.8%) had developed DR and 2989 (12.7%) were lost to competing events (death) without developing DR and 12,126 individuals did not have DR. The median (interquartile range) level of NLR was 2.04 (1.5 to 2.7). The optimal NLR cut-off value to predict retinopathy incidence was 3.04. After accounting for competing risks at 10 years, the cumulative incidence of DR and deaths without DR were 50.7% and 21.9%, respectively. NLR was associated with incident DR in both Cause-specific hazard (CSH = 1.63; 95% CI: 1.28-2.07) and FGR models the subdistribution hazard (sHR = 2.24; 95% CI: 1.70-2.94). Both age and HbA1c were found to modulate the association between NLR and the risk of DR.

CONCLUSIONS

The current study suggests that NLR has a promising potential to predict DR incidence in the Scottish population, especially in individuals less than 65 years and in those with well-controlled glycaemic status.

Clinical Outcomes of 27-Gauge Pars Plana Vitrectomy for Diabetic Tractional Retinal Detachment Repair

Purpose: To analyze the clinical outcomes of 27-gauge pars plana vitrectomy (PPV) repair of diabetic tractional retinal detachment (TRD) of various severities. Methods: This retrospective case series examined the outcomes of 27-gauge PPV to repair diabetic TRD from 2016 to 2020. The effect of medical and ophthalmologic history parameters and baseline detachment characteristics on visual acuity (VA) and retinal reattachment was analyzed. A grading system was established to stage the severity of the baseline vitreoretinal traction or detachment and compare the visual and anatomic outcomes between stages. Results: The study comprised 79 eyes (79 patients). The overall redetachment rate was 10.1% (8/79). The proportion of eyes with severe visual impairment (worse than 20/200) decreased from 81.0% (64/79) preoperatively to 56.9% (37/65) 6 months postoperatively (P < .001). Worse preoperative logMAR VA was associated with greater odds of redetachment (P = .017) and worse postoperative VA (P < .001). Insulin dependence was associated with better VA at 6 months (P = .017). A shorter known duration of diabetes (P = .026) and evidence of neovascularization of the iris (NVI) or angle (P = .004) were associated with worse visual outcomes. Eyes with detachment involving the posterior pole extending beyond the equator had worse VA at 6 months (P = .048). Conclusions: The primary reattachment rate after 27-gauge PPV was 89.9%. There was significant VA improvement, with a roughly 40% reduction in the number of eyes with severe visual impairment by the final follow-up. Insulin dependence, duration of diabetes, presence of NVI before surgery, and baseline posterior pole detachment extending beyond the equator were predictors of visual outcomes.

Proliferative Diabetic Retinopathy Diagnosis Using Varying-Scales Filter Banks and Double-Layered Thresholding

Diabetic retinopathy is one of the abnormalities of the retina in which a diabetic patient suffers from severe vision loss due to an affected retina. Proliferative diabetic retinopathy (PDR) is the final and most critical stage of diabetic retinopathy. Abnormal and fragile blood vessels start to grow on the surface of the retina at this stage. It causes retinal detachment, which may lead to complete blindness in severe cases. In this paper, a novel method is proposed for the detection and grading of neovascularization. The proposed system first performs pre-processing on input retinal images to enhance the vascular pattern, followed by blood vessel segmentation and optic disc localization. Then various features are tested on the candidate regions with different thresholds. In this way, positive and negative advanced diabetic retinopathy cases are separated. Optic disc coordinates are applied for the grading of neovascularization as NVD or NVE. The proposed algorithm improves the quality of automated diagnostic systems by eliminating normal blood vessels and exudates that might cause hindrances in accurate disease detection, thus resulting in more accurate detection of abnormal blood vessels. The evaluation of the proposed system has been carried out using performance parameters such as sensitivity, specificity, accuracy, and positive predictive value (PPV) on a publicly available standard retinal image database and one of the locally available databases. The proposed algorithm gives an accuracy of 98.5% and PPV of 99.8% on MESSIDOR and an accuracy of 96.5% and PPV of 100% on the local database.

Design, Synthesis, and Structure-Activity Relationships of Biaryl Anilines as Subtype-Selective PPAR-alpha Agonists

The role of peroxisome proliferator-activated receptor alpha (PPARα) in retinal biology is clarifying, and evidence demonstrates that novel PPARα agonists hold promising therapeutic utility for diseases like diabetic retinopathy and age-related macular degeneration. Herein, we disclose the design and initial structure-activity relationships for a new biaryl aniline PPARα agonistic chemotype. Notably, this series exhibits subtype selectivity for PPARα over other isoforms, a phenomenon postulated to be due to the unique benzoic acid headgroup. This biphenyl aniline series is sensitive to B-ring functionalization but allows isosteric replacement, and provides an opportunity for C-ring extension. From this series, 3g, 6j, and 6d were identified as leads with <90 nM potency in a cell-based luciferase assay cell and exhibited efficacy in various disease-relevant cell contexts, thereby setting the stage for further characterization in more advanced in vitro and in vivo models.

Inhibition of Galectins and the P2X7 Purinergic Receptor as a Therapeutic Approach in the Neurovascular Inflammation of Diabetic Retinopathy

Diabetic retinopathy (DR) is the most frequent microvascular retinal complication of diabetic patients, contributing to loss of vision. Recently, retinal neuroinflammation and neurodegeneration have emerged as key players in DR progression, and therefore, this review examines the neuroinflammatory molecular basis of DR. We focus on four important aspects of retinal neuroinflammation: (i) the exacerbation of endoplasmic reticulum (ER) stress; (ii) the activation of the NLRP3 inflammasome; (iii) the role of galectins; and (iv) the activation of purinergic 2X7 receptor (P2X7R). Moreover, this review proposes the selective inhibition of galectins and the P2X7R as a potential pharmacological approach to prevent the progression of DR.

Tocotrienol-rich fraction reduces retinal inflammation and angiogenesis in rats with streptozotocin-induced diabetes

BACKGROUND

Diabetic retinopathy (DR) is the second commonest microvascular complication of diabetes mellitus. It is characterized by chronic inflammation and angiogenesis. Palm oil-derived tocotrienol-rich fraction (TRF), a substance with anti-inflammatory and anti-angiogenic properties, may provide protection against DR development. Therefore, in this study, we investigated the effect of TRF on retinal vascular and morphological changes in diabetic rats. The effects of TRF on the retinal expression of inflammatory and angiogenic markers were also studied in the streptozotocin (STZ)-induced diabetic rats.

METHODS

Male Sprague Dawley rats weighing 200-250 g were grouped into normal rats (N) and diabetic rats. Diabetes was induced by intraperitoneal injection of streptozotocin (55 mg/kg body weight) whereas N similarly received citrate buffer. STZ-injected rats with blood glucose of more than 20 mmol/L were considered diabetic and were divided into vehicle-treated (DV) and TRF-treated (DT) groups. N and DV received vehicle, whereas DT received TRF (100 mg/kg body weight) via oral gavage once daily for 12 weeks. Fundus images were captured at week 0 (baseline), week 6 and week 12 post-STZ induction to estimate vascular diameters. At the end of experimental period, rats were euthanized, and retinal tissues were collected for morphometric analysis and measurement of NFκB, phospho-NFκB (Ser536), HIF-1α using immunohistochemistry (IHC) and enzyme-linked immunosorbent assay (ELISA). Retinal inflammatory and angiogenic cytokines expression were measured by ELISA and real-time quantitative PCR.

RESULTS

TRF preserved the retinal layer thickness (GCL, IPL, INL and OR; p < 0.05) and retinal venous diameter (p < 0.001). TRF also lowered the retinal NFκB activation (p < 0.05) as well as expressions of IL-1β, IL-6, TNF-α, IFN-γ, iNOS and MCP-1 (p < 0.05) compared to vehicle-treated diabetic rats. Moreover, TRF also reduced retinal expression of VEGF (p < 0.001), IGF-1 (p < 0.001) and HIF-1α (p < 0.05) compared to vehicle-treated rats with diabetes.

CONCLUSION

Oral TRF provided protection against retinal inflammation and angiogenesis in rats with STZ-induced diabetes by suppressing the expression of the markers of retinal inflammation and angiogenesis.

Inactive matrix Gla protein in relation to diabetic retinopathy in type 2 diabetes

Background and Aims

The contribution of inactive Matrix Gla protein (MGP) to ectopic vascular calcification associated with type 2 diabetes mellitus (T2DM) is well recognized. However, its role in diabetic microvascular complications remains unknown. The study aim was to identify any association between inactive MGP and diabetic retinopathy (DR). Its relation to insulin resistance was also explored.

Methods

The study included 90 participants, 65 Type 2 diabetic patients (25 without DR and 40 with DR) and 25 healthy controls. Serum inactive MGP was measured using ELISA. HOMA-IR was also assessed.

Results

Inactive MGP was significantly higher in both diabetic groups compared to controls (P < 0.001), as well as in Type 2 diabetic patients with retinopathy compared to Type 2 diabetes without retinopathy (P = 0.002). Inactive MGP was positively correlated with HbA1c, HOMA-IR, LDL-C and triglycerides (P < 0.001), and negatively correlated with HDL-C (P = 0.008) and eGFR (P < 0.001). Logistic Regression Analysis showed that inactive MGP was one of the most associated factors with DR.

Conclusions

Inactive MGP was found to be related to DR, insulin resistance and other dysmetabolic risk factors. These findings highlight that inactive MGP may be a significant contributor to the pathogenesis, evolution, and progression of DR.

The effects of resveratrol and melatonin on cardiac dysfunction in diabetic elderly female rats

We aimed to investigate the effects of melatonin and resveratrol on diabetes-related papillary muscle dysfunction and structural heart disorders. The protective effect of resveratrol and melatonin supplementation on cardiac functions was investigated in a diabetic elderly female rat model. 16-month-old rats (n=48) were allocated into 8 groups. Group1: Control, Group2: Resveratrol Control, Group3: Melatonin Control, Group4: Resveratrol and Melatonin Control, Group5: Diabetes, Group6: Diabetes Resveratrol, Group7: Diabetes Melatonin, Group8: Diabetes Resveratrol and Melatonin. Streptozotocin was injected intraperitoneally to the rats for experimental diabetes induction. Thereafter, resveratrol (intraperitoneal) and melatonin (subcutaneous) were administered for 4 weeks. Resveratrol and melatonin had a protective effect on the contractile parameters and structural properties of the papillary muscle, which was impaired by diabetes. it has been presented that diabetes impairs the contractile function of the papillary muscle for each stimulus frequency tested and the responses obtained as a result of Ca+2 uptake and release mechanisms from the Sarcoplasmic reticulum, and it has been observed that these effects are improved with resveratrol and melatonin injection. The decrease in myocardial papillary muscle strength in the diabetic elderly female rat can be reversed with the combination of resveratrol, melatonin and resveratrol+melatonin. Melatonin+resveratrol supplementation is no different from melatonin and/or resveratrol supplementation. Resveratrol and melatonin supplementation may have a protective effect on cardiac functions in a diabetic elderly female rat model.

Development of revised ResNet-50 for diabetic retinopathy detection

BACKGROUND

Diabetic retinopathy (DR) produces bleeding, exudation, and new blood vessel formation conditions. DR can damage the retinal blood vessels and cause vision loss or even blindness. If DR is detected early, ophthalmologists can use lasers to create tiny burns around the retinal tears to inhibit bleeding and prevent the formation of new blood vessels, in order to prevent deterioration of the disease. The rapid improvement of deep learning has made image recognition an effective technology; it can avoid misjudgments caused by different doctors' evaluations and help doctors to predict the condition quickly. The aim of this paper is to adopt visualization and preprocessing in the ResNet-50 model to improve module calibration, to enable the model to predict DR accurately.

RESULTS

This study compared the performance of the proposed method with other common CNNs models (Xception, AlexNet, VggNet-s, VggNet-16 and ResNet-50). In examining said models, the results alluded to an over-fitting phenomenon, and the outcome of the work demonstrates that the performance of the revised ResNet-50 (Train accuracy: 0.8395 and Test accuracy: 0.7432) is better than other common CNNs (that is, the revised structure of ResNet-50 could avoid the overfitting problem, decease the loss value, and reduce the fluctuation problem).

CONCLUSIONS

This study proposed two approaches to designing the DR grading system: a standard operation procedure (SOP) for preprocessing the fundus image, and a revised structure of ResNet-50, including an adaptive learning rating to adjust the weight of layers, regularization and change the structure of ResNet-50, which was selected for its suitable features. It is worth noting that the purpose of this study was not to design the most accurate DR screening network, but to demonstrate the effect of the SOP of DR and the visualization of the revised ResNet-50 model. The results provided an insight to revise the structure of CNNs using the visualization tool.

Normalized Blood Flow Index in Optical Coherence Tomography Angiography Provides a Sensitive Biomarker of Early Diabetic Retinopathy

Purpose

To evaluate the sensitivity of normalized blood flow index (NBFI) for detecting early diabetic retinopathy (DR).

Methods

Optical coherence tomography angiography (OCTA) images of healthy controls, diabetic patients without DR (NoDR), and patients with mild nonproliferative DR (NPDR) were analyzed in this study. The OCTA images were centered on the fovea and covered a 6 mm × 6 mm area. Enface projections of the superficial vascular plexus (SVP) and the deep capillary plexus (DCP) were obtained for the quantitative OCTA feature analysis. Three quantitative OCTA features were examined: blood vessel density (BVD), blood flow flux (BFF), and NBFI. Each feature was calculated from both the SVP and DCP and their sensitivities to distinguish the three cohorts of the study were evaluated.

Results

The only quantitative feature capable of distinguishing all three cohorts was NBFI in the DCP image. Comparative study revealed that both BVD and BFF were able to distinguish the controls and NoDR from mild NPDR. However, neither BVD nor BFF was sensitive enough to separate NoDR from the healthy controls.

Conclusions

The NBFI has been demonstrated as a sensitive biomarker of early DR, revealing retinal blood flow abnormality better than traditional BVD and BFF. The NBFI in the DCP was verified as the most sensitive biomarker, supporting that diabetes affects the DCP earlier than SVP in DR.

Translational Relevance

NBFI provides a robust biomarker for quantitative analysis of DR-caused blood flow abnormalities, promising early detection and objective classification of DR.

The cGAS-STING pathway in diabetic retinopathy and age-related macular degeneration

Diabetic retinopathy and age-related macular degeneration are common retinal diseases with shared pathophysiology, including oxidative stress-induced inflammation. Cellular mechanisms responsible for converting oxidative stress into retinal damage are ill-defined but have begun to clarify. One common outcome of retinal oxidative stress is mitochondrial damage and subsequent release of mitochondrial DNA into the cytosol. This leads to activation of the cGAS-STING pathway, resulting in interferon release and disease-amplifying inflammation. This review summarizes the evolving link between aberrant cGAS-STING signaling and inflammation in common retinal diseases and provides prospective for targeting this system in diabetic retinopathy and age-related macular degeneration. Further defining the roles of this system in the retina is expected to reveal new disease pathology and novel therapeutic approaches.

Therapeutic effects of herbal medicines in different types of retinopathies: A systematic review

Objective

Retinopathy is an ocular manifestation of systemic diseases such as diabetes and vascular diseases. Herbal drugs have been considered as an effective therapeutic option with minimal side effects for the treatment of retinopathy by reducing the symptoms and improving visual acuity. The purpose of this systematic review was to collect studies on the effectiveness of medicinal plants in the treatment or prevention of retinopathy.

Materials and Methods

A systematic literature search was performed in PubMed, Scopus, Google Scholar, and other databases in April 2021 using "herbal products" and "Retinopathy" with all their equivalent and similar terms. For this purpose, human clinical trials with the English language were included and articles with subject irrelevancy were excluded from further evaluation.

Results

Overall, 30 articles with 2324 patients were studied for possible effects of herbal therapy on retinopathy. From 30 included articles, different herbal products had been evaluated. Out of 30 selected articles, 11 articles were for the treatment of age-related macular degeneration (AMD), 14 articles covered patients with diabetic retinopathy, and the other five studies were for other retinal disorders. The outcomes in majority of the studies include changes in visual acuity (VA), fundus performance, best-corrected visual acuity (BCVA), central macular thickness (CMT), focal electroretinogram (fERG), supplements and adjuvant medications appeared to be more beneficial in patients with AMD and diabetic maculopathy.

Conclusion

Herbal therapy can be considered as a potential candidate in the adjuvant and complementary therapies of retinopathy. However, further studies are required to verify such efficiency.

Can the Future be Bright with Advances in Diabetic Eye Care?

The prevalence of diabetic retinopathy is steadily increasing as the population of patients with diabetes grows. In the past decade, the development of anti-VEGF agents has dramatically changed the treatment landscape for diabetic retinopathy and diabetic macular edema (DME). Newer agents in development aim to reduce the treatment burden of diabetic retinopathy.

Experimental Models to Study Epithelial-Mesenchymal Transition in Proliferative Vitreoretinopathy

Proliferative vitreoretinal diseases (PVDs) encompass proliferative vitreoretinopathy (PVR), epiretinal membranes, and proliferative diabetic retinopathy. These vision-threatening diseases are characterized by the development of proliferative membranes above, within and/or below the retina following epithelial-mesenchymal transition (EMT) of the retinal pigment epithelium (RPE) and/or endothelial-mesenchymal transition of endothelial cells. As surgical peeling of PVD membranes remains the sole therapeutic option for patients, development of in vitro and in vivo models has become essential to better understand PVD pathogenesis and identify potential therapeutic targets. The in vitro models range from immortalized cell lines to human pluripotent stem-cell-derived RPE and primary cells subjected to various treatments to induce EMT and mimic PVD. In vivo PVR animal models using rabbit, mouse, rat, and swine have mainly been obtained through surgical means to mimic ocular trauma and retinal detachment, and through intravitreal injection of cells or enzymes to induce EMT and investigate cell proliferation and invasion. This review offers a comprehensive overview of the usefulness, advantages, and limitations of the current models available to investigate EMT in PVD.

Mitochondrial Open Reading Frame of the 12S rRNA Type-c: Potential Therapeutic Candidate in Retinal Diseases

Mitochondrial open reading frame of the 12S rRNA type-c (MOTS-c) is the most unearthed peptide encoded by mitochondrial DNA (mtDNA). It is an important regulator of the nuclear genome during times of stress because it promotes an adaptive stress response to maintain cellular homeostasis. Identifying MOTS-c specific binding partners may aid in deciphering the complex web of mitochondrial and nuclear-encoded signals. Mitochondrial damage and dysfunction have been linked to aging and the accelerated cell death associated with many types of retinal degenerations. Furthermore, research on MOTS-c ability to revive oxidatively stressed RPE cells has revealed a significant protective role for the molecule. Evidence suggests that senescent cells play a role in the development of age-related retinal disorders. This review examines the links between MOTS-c, mitochondria, and age-related diseases of the retina. Moreover, the untapped potential of MOTS-c as a treatment for glaucoma, diabetic retinopathy, and age-related macular degeneration is reviewed.

Flavoprotein fluorescence elevation is a marker of mitochondrial oxidative stress in patients with retinal disease

Purpose

Recent studies of glaucoma, age-related macular degeneration, and diabetic retinopathy have demonstrated that flavoprotein fluorescence (FPF) can be utilized non-invasively as an indicator of mitochondrial oxidative stress in the retina. However, a comprehensive assessment of the validity and reliability of FPF in differentiating between healthy and diseased eyes across multiple disease states is lacking. Here, we evaluate the sensitivity and specificity of FPF in discriminating between healthy and diseased eyes in four leading causes of visual impairment worldwide, one of which has not been previously evaluated using FPF. We also evaluate the association between FPF and visual acuity.

Methods

A total of 88 eyes [21 eyes of 21 unaffected controls, 20 eyes from 20 retinal vein occlusion (RVO) patients, 20 eyes from 20 diabetic retinopathy (DR) patients, 17 eyes from 17 chronic exudative age-related macular degeneration (exudative AMD) patients, and 10 eyes from 10 central serous retinopathy (CSR) patients] were included in the present cross-sectional observational study. Eyes were imaged non-invasively using a specially configured fundus camera OcuMet Beacon® (OcuSciences, Ann Arbor, MI). The macula was illuminated using a narrow bandwidth blue light (455 - 470 nm) and fluorescence was recorded using a narrow notch filter to match the peak emission of flavoproteins from 520 to 540 nm. AUROC analysis was used to determine the sensitivity of FPF in discriminating between diseased eyes and healthy eyes. Nonparametric Kruskal-Wallis Tests with post-hoc Mann Whitney U tests with the Holm-Bonferroni correction were performed to assess differences in FPF intensity, FPF heterogeneity, and best corrected visual acuity (BCVA) between the five groups. Spearman rank correlation coefficients were calculated to assess the relationship between FPF and BCVA.

Results

AUROC analysis indicated that FPF intensity is highly sensitive for detecting disease, particularly for exudative AMD subjects (0.989; 95% CI = 0.963 - 1.000, p=3.0 x 107). A significant difference was detected between the FPF intensity, FPF heterogeneity, and BCVA in all four disease states compared to unaffected controls (Kruskal-Wallis Tests, p = 1.06 x 10-8, p = 0.002, p = 5.54 x 10-8, respectively). Compared to healthy controls, FPF intensity values were significantly higher in RVO, DR, exudative AMD, and CSR (p < 0.001, p < 0.001, p < 0.001, and p = 0.001, respectively). Spearman rank correlation coefficient between FPF intensity and BCVA was ρ = 0.595 (p = 9.62 x 10-10).

Conclusions

Despite variations in structural retinal findings, FPF was found to be highly sensitive for detecting retinal disease. Significant FPF elevation were seen in all four disease states, with the exudative AMD patients exhibiting the highest FPF values compared to DR, CSR, and RVO subjects. This is consistent with the hypothesis that there is elevated oxidative stress in all of these conditions as previously demonstrated by blood studies. FPF intensity is moderately correlated with the late-in disease-marker BCVA, which suggests that the degree of FPF elevation can be used as a metabolic indicator of disease severity.

Systemic C-peptide supplementation ameliorates retinal neurodegeneration by inhibiting VEGF-induced pathological events in diabetes

Diabetic retinopathy (DR) is caused by retinal vascular dysfunction and neurodegeneration. Intraocular delivery of C-peptide has been shown to be beneficial against hyperglycemia-induced microvascular leakage in the retina of diabetes; however, the effect of C-peptide on diabetes-induced retinal neurodegeneration remains unknown. Moreover, extraocular C-peptide replacement therapy against DR to avoid various adverse effects caused by intravitreal injections has not been studied. Here, we demonstrate that systemic C-peptide supplementation using osmotic pumps or biopolymer-conjugated C-peptide hydrogels ameliorates neurodegeneration by inhibiting vascular endothelial growth factor-induced pathological events, but not hyperglycemia-induced vascular endothelial growth factor expression, in the retinas of diabetic mice. C-peptide inhibited hyperglycemia-induced activation of macroglial and microglial cells, downregulation of glutamate aspartate transporter 1 expression, neuronal apoptosis, and histopathological changes by a mechanism involving reactive oxygen species generation in the retinas of diabetic mice, but transglutaminase 2, which is involved in retinal vascular leakage, is not associated with these pathological events. Overall, our findings suggest that systemic C-peptide supplementation alleviates hyperglycemia-induced retinal neurodegeneration by inhibiting a pathological mechanism, involving reactive oxygen species, but not transglutaminase 2, in diabetes.

The effects of resveratrol and melatonin on biochemical and molecular parameters in diabetic old female rat hearts

The roles of melatonin and resveratrol-enhanced activation of SIRT1 (silent information regulator 1), GLUT4 (glucose transporter type 4), and PGC-1α (peroxisome proliferator-activated receptor gamma coactivator 1-alpha) in mediating the protective effects on the heart in aged female rats with streptozotocin-induced diabetes were investigated. 16-month-old 48 Wistar female rats were separated into 8 groups with equal numbers. Group 1: Control, Group 2: Resveratrol Control, Group 3: Melatonin Control, Group 4: Resveratrol and Melatonin Control, Group 5: Diabetes, Group 6: Diabetes Resveratrol, Group 7: Diabetes Melatonin, Group 8: Diabetes Resveratrol and Melatonin. A single dose of 40 mg/kg intraperitoneal streptozotocin was injected into the rats of Groups 5, 6, 7, and 8 to induce experimental diabetes. Blood glucose levels were measured from the tail veins of the animals six days after the injections, using a diagnostic glucose kit. Rats with a blood glucose levels ≥300 mg/dl were considered diabetic. 5 mg/kg/day of resveratrol (intraperitoneal) and melatonin (subcutaneous) were administered for four weeks. At the end of the applications, SIRT1, GLUT4, PGC-1α gene expression as well as MDA and GSH levels in the heart tissues were determined by the PCR method from heart tissue samples taken under general anesthesia. The findings of our study show that suppressed antioxidant activity and decreased GLUT4, SIRT1, and PGC-1α gene expression in heart tissue can be reversed by the combination of resveratrol, melatonin, and resveratrol + melatonin in a diabetic aged female rat model. Resveratrol and melatonin supplementation may have a protective effect on cardiac functions in the diabetic aged female rat model.

A systematic review on anti-diabetic plant essential oil compounds: Dietary sources, effects, molecular mechanisms, and safety

Type 2 diabetes mellitus (T2DM) is a multifaceted metabolic syndrome defined through the dysfunction of pancreatic β-cells driven by a confluence of genetic and environmental elements. Insulin resistance, mediated by interleukins and other inflammatory elements, is one of the key factors contributing to the progression of T2DM. Many essential oils derived from dietary plants are beneficial against various chronic diseases. We reviewed the anti-diabetic properties of dietary plant-derived essential oil compounds, with a focus on their molecular mechanisms by modulating specific signaling pathways and other critical inflammatory mediators involved in insulin resistance. High-quality literature published in the last 12 years, from 2010 to 2022, was collected from the Scopus, Web of Science, PubMed, and Embase databases using the search terms "dietary plants," "essential oils," "anti-diabetic," "insulin resistance," "antihyperglycemic," "T2DM," "anti-diabetic essential oils," and anti-diabetic mechanism." According to the results, the essential oil compounds, including cinnamaldehyde, carvacrol, zingerone, sclareol, zerumbone, myrtenol, thujone, geraniol, citral, eugenol, thymoquinone, thymol, citronellol, α-terpineol, and linalool have been demonstrated to contain strong anti-diabetic effects via modulating various signal transduction pathways linked to glucose metabolism. Additionally, in diabetes-related animal models, they can also considerably reduce the expression of TNF-α, IL-1β, IL-4, IL-6, iNOS, and COX-2. The main signaling molecules regulated by these compounds include AMPK, GLUT4, Caspase-3, PPARγ, PPARα, NF-κB, p-IκBα, MyD88, MCP-1, SREBP-1c, AGEs, RAGE, VEGF, Nrf2/HO-1, and SIRT-1. They can also significantly inhibit the generation of TBARS and MDA, reduce oxidative stress, increase insulin levels, adiponectin, and glycoprotein enzymes, boost antioxidant enzymes like SOD, CAT, and GPx, as well as reduce glutathione and vital glycolytic enzymes. Besides, they can significantly lower the levels of liver enzymes and lipid profile markers. Moreover, most essential oil compounds are generally safe based on animal studies. In conclusion, dietary plant-derived essential oil compounds have potential anti-diabetic effects by influencing different signaling pathways and molecular targets linked to glucose metabolism, and should be safe and beneficial against diabetes and related complications.

18F-FP-CIT dopamine transporter PET findings in the striatum and retina of type 1 diabetic rats

PURPOSE

Noninvasive methods used in clinic to accurately detect DA neuron loss in diabetic brain injury and diabetic retinopathy have not been reported up to now. ¹⁸F-FP-CIT is a promising dopamine transporter (DAT) targeted probe. Our study first applies ¹⁸F-FP-CIT PET imaging to assess DA neuron loss in the striatum and retina of T1DM rat model.

METHODS

T1DM rat model was induced by a single intraperitoneal injection of streptozotocin (STZ) (65 mg kg^-1, ip). ¹⁸F-FP-CIT uptake in the striatum and retina was evaluated at 4 weeks, 8 weeks and 12 weeks after STZ injection. The mean standardized uptake value (SUVmean) and the maximum standardized uptake value (SUVmax) were analyzed. Western blot was performed to confirm the DAT protein levels in the striatum and retina.

RESULTS

PET/CT results showed that the SUV of ¹⁸F-FP-CIT was significantly reduced in the diabetic striatum and retina compared with the normal one from 4-week to 12-week (p < 0.0001). Western blots showed that DAT was significantly lower in the diabetic striatum and retina compared to the normal one for all three time points (p < 0.05). The results from Western blots confirmed the findings in PET imaging studies.

CONCLUSIONS

DA neuron loss in the striatum and retina of T1DM rat model can be non-invasively detected with PET imaging using ¹⁸F-FP-CIT targeting DAT. ¹⁸F-FP-CIT PET imaging may be a useful tool used in clinic for DR and diabetic brain injury diagnosis in future. The expression level of DAT in striatum and retina may act as a new biomarker for DR and diabetic brain injury diagnosis.

Thymoquinone Attenuates Retinal Expression of Mediators and Markers of Neurodegeneration in a Diabetic Animal Model

BACKGROUND

Diabetic retinopathy (DR) is a slow eye disease that affects the retina due to a long-standing uncontrolled diabetes mellitus. Hyperglycemia-induced oxidative stress can lead to neuronal damage leading to DR.

OBJECTIVE

The aim of the current investigation is to assess the protective effects of thymoquinone (TQ) as a potential compound for the treatment and/or prevention of neurovascular complications of diabetes, including DR.

METHODS

Diabetes was induced in rats by the administration of streptozotocin (55 mg/kg intraperitoneally, i.p.). Subsequently, diabetic rats were treated with either TQ (2 mg/kg i.p.) or vehicle on alternate days for three weeks. A healthy control group was also run in parallel. At the end of the treatment period, animals were euthanized, and the retinas were collected and analyzed for the expression levels of brain-derived neurotrophic factor (BDNF), tyrosine hydroxylase (TH), nerve growth factor receptor (NGFR), and caspase-3 using Western blotting techniques in the retina of diabetic rats and compared with the normal control rats. In addition, dichlorofluorescein (DCF) levels in the retina were assessed as a marker of reactive oxygen species (ROS), and blood-retinal barrier breakdown (BRB) was examined for vascular permeability. The systemic effects of TQ treatments on glycemic control, kidney and liver functions were also assessed in all groups.

RESULTS

Diabetic animals treated with TQ showed improvements in the liver and kidney functions compared with control diabetic rats. Normalization in the levels of neuroprotective factors, including BDNF, TH, and NGFR, was observed in the retina of diabetic rats treated with TQ. In addition, TQ ameliorated the levels of apoptosis regulatory protein caspase-3 in the retina of diabetic rats and reduced disruption of the blood-retinal barrier, possibly through a reduction in reactive oxygen species (ROS) generation.

CONCLUSION

These findings suggest that TQ harbors a significant potential to limit the neurodegeneration and retinal damage that can be provoked by hyperglycemia in vivo.

Genome Editing Inhibits Retinal Angiogenesis in a Mouse Model of Oxygen-Induced Retinopathy

This protocol describes a novel approach harnessing the technology of clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated (Cas) 9-based gene editing for treating retinal angiogenesis. In this system, adeno-associated virus (AAV)-mediated CRISPR/Cas9 was employed to edit the genome of vascular endothelial growth factor receptor (VEGFR)2 in retinal vascular endothelial cells in a mouse model of oxygen-induced retinopathy. The results showed that genome editing of VEGFR2 suppressed pathological retinal angiogenesis. This mouse model mimics a critical aspect of abnormal retinal angiogenesis in patients with neovascular diabetic retinopathy and retinopathy of prematurity, indicating genome editing has high potential for treating angiogenesis-associated retinopathies.

Type 2 diabetes mellitus induced autophagic response within pulmonary tissue in the rat model

Introduction: The current experiment aimed to address the impact of type 2 diabetes mellitus on autophagy status in the rat pulmonary tissue. Methods: In this study, 20 male Wistar rats were randomly allocated into two groups as follows: control and diabetic groups. To induce type 2 diabetes mellitus, rats received a combination of streptozotocin (STZ) and a high-fat diet. After confirmation of diabetic condition, rats were maintained for 8 weeks and euthanized for further analyses. The pathological changes were assessed using H&E staining. We also measured transforming growth factor-β (TGF-β), bronchoalveolar lavage fluid (BALF), and tumor necrosis factor-α (TNF-α) in the lungs using ELISA and real-time PCR analyses, respectively. Malondialdehyde (MDA) and superoxide dismutase (SOD) levels were monitored in diabetic lungs to assess oxidative status. We also measured the expression of becline-1, LC3, and P62 to show autophagic response under diabetic conditions. Using immunofluorescence staining, protein levels of LC3 was also monitored. Results: H&E staining showed pathological changes in diabetic rats coincided with the increase of TNF-α (~1.4-fold) and TGF-β (~1.3-fold) compared to those in the normal rats (P<0.05). The levels of MDA (5.6 ± 0.4 versus 6.4 ± 0.27 nM/mg protein) were increased while SOD (4.2 ± 0.28 versus 3.8 ± 0.13 U/mL) activity decreased in the diabetic rats (P<0.05). Real-time polymerase chain reaction (PCR) analysis showed the up-regulation of Becline-1 (~1.35-fold) and LC3 (~2-fold) and down-regulation of P62 (~0.8-fold) (P<0.05), showing incomplete autophagic flux. We noted the increase of LC3⁺ cells in diabetic condition compared to that in the control samples. Conclusion: The prolonged diabetic condition could inhibit the normal activity of autophagy flux, thereby increasing pathological outcomes.

DNA methylation in diabetic retinopathy: pathogenetic role and potential therapeutic targets

Background

Diabetic retinopathy (DR), a specific neuron-vascular complication of diabetes, is a major cause of vision loss among middle-aged people worldwide, and the number of DR patients will increase with the increasing incidence of diabetes. At present, it is limited in difficult detection in the early stages, limited treatment and unsatisfactory treatment effects in the advanced stages.

Main body

The pathogenesis of DR is complicated and involves epigenetic modifications, oxidative stress, inflammation and neovascularization. These factors influence each other and jointly promote the development of DR. DNA methylation is the most studied epigenetic modification, which has been a key role in the regulation of gene expression and the occurrence and development of DR. Thus, this review investigates the relationship between DNA methylation and other complex pathological processes in the development of DR. From the perspective of DNA methylation, this review provides basic insights into potential biomarkers for diagnosis, preventable risk factors, and novel targets for treatment.

Conclusion

DNA methylation plays an indispensable role in DR and may serve as a prospective biomarker of this blinding disease in its relatively early stages. In combination with inhibitors of DNA methyltransferases can be a potential approach to delay or even prevent patients from getting advanced stages of DR.

Machine Learning Models for Data-Driven Prediction of Diabetes by Lifestyle Type

The prevalence of diabetes has been increasing in recent years, and previous research has found that machine-learning models are good diabetes prediction tools. The purpose of this study was to compare the efficacy of five different machine-learning models for diabetes prediction using lifestyle data from the National Health and Nutrition Examination Survey (NHANES) database. The 1999-2020 NHANES database yielded data on 17,833 individuals data based on demographic characteristics and lifestyle-related variables. To screen training data for machine models, the Akaike Information Criterion (AIC) forward propagation algorithm was utilized. For predicting diabetes, five machine-learning models (CATBoost, XGBoost, Random Forest (RF), Logistic Regression (LR), and Support Vector Machine (SVM)) were developed. Model performance was evaluated using accuracy, sensitivity, specificity, precision, F1 score, and receiver operating characteristic (ROC) curve. Among the five machine-learning models, the dietary intake levels of energy, carbohydrate, and fat, contributed the most to the prediction of diabetes patients. In terms of model performance, CATBoost ranks higher than RF, LG, XGBoost, and SVM. The best-performing machine-learning model among the five is CATBoost, which achieves an accuracy of 82.1% and an AUC of 0.83. Machine-learning models based on NHANES data can assist medical institutions in identifying diabetes patients.

Diagnostic and predictive value of resistive / pulsatility indices of ophthalmic artery and common carotid artery for the development of diabetic retinopathy

Background

Ophthalmic artery resistive index (OA RI) was a controversial parameter to show hemodynamic changes due to diabetic retinopathy (DRP).

Purpose

To investigate the diagnostic and predictive value of resistive and pulsatility index (RI and PI, respectively) of OA and common carotid artery (CCA) for the development of DRP.

Material and Methods

A total of 60 patients with diabetes mellitus (DM) type 2 (study group) and 30 healthy participants (control group) were evaluated between January and June 2021 by Doppler ultrasonography (DUS). RI and PI values were compared between groups with a Student’s t-test. Cutoff value, sensitivity, and specificity were calculated for the significant variables with receiver operating characteristic (ROC) analysis.

Results

In total, there were 20 (22.2%) patients with DM without DRP (DMwoRP), 20 (22.2%) patients in the non-proliferative diabetic retinopathy group (NPDRP), and 20 (22.2%) patients in the proliferative diabetic retinopathy group (PDRP). The mean of CCA RI and OA RI in the PDRP group was significantly higher than in the other three groups ( P < 0.001). The mean of CCA RI and OA RI was significantly higher in the PDRP group than in the NPDRP group, and in the NPDRP group compared to the DMwoRP group. CCA RI and OA RI showed a significantly high correlation (r = 0.849; P < 0.001). Sensitivity was 95% and specificity was 100% for the diagnosis of PDRP for the 0.82 cutoff value of OA RI (AUR = 0.999, 95% confidence interval for AUC = 0.997–0.1000; P < 0.001).

Conclusion

The OA RI accurately reflects DRP-induced orbital blood flow changes and is a predictive index for DRP prognosis.

A New Pharmacological Vitreolysis through the Supplement of Mixed Fruit Enzymes for Patients with Ocular Floaters or Vitreous Hemorrhage-Induced Floaters

Purpose: Ocular floaters caused by vitreous degeneration or blood clots may interfere with various visual functions. Our study investigated the pharmacologic effects of oral supplementation of mixed fruit enzymes (MFEs) for treating spontaneous symptomatic vitreous opacities (SVOs) and those secondary to vitreous hemorrhage (VH). Methods: 224 patients with monocular symptomatic vitreous opacities (SVOs) were recruited between September and December 2017 and received oral supplementation of MFEs (190 mg bromelain, 95 mg papain, and 95 mg ficin) for 3 months in a double-blind clinical trial. Participants were divided according to the etiology of the SVOs, spontaneous (experiment 1) versus VH (experiment 2), and then randomly assigned into four treatments groups: one group received oral vitamin C, as a placebo; and the other 3 groups received 1 capsule per day (low dose), 2 capsules per day (middle dose), or 3 capsules per day (high dose) of MFEs. The number of SVOs was determined at baseline and then 1, 2, and 3 months after initiating treatment. Further, in cases secondary to VH, the changes in corrected distance visual acuity (CDVA) were assessed after 3 months. Second, we compared the free radical scavenging capabilities of each substance: vitamin C, bromelain, papain, ficin, and MFEs (combination of bromelain, papain, and ficin) by DDPH assay. Finally, SVOs-related symptoms and satisfaction with the treatments were evaluated at the last follow-up visit Results: In experiment 1, the disappearance rate of SVOs was 55%, 62.5%, and 70% after taking 1, 2, and 3 capsules daily, respectively (total p < 0.001), in a dose-dependent manner. In experiment 2, the disappearance rate of VH-induced SVOs was 18%, 25%, and 56% (p < 0.001) after 1, 2, and 3 capsules of the supplement daily, respectively. Additionally, the patients’ vision elevated from 0.63LogMAR to 0.19LogMAR (p = 0.008). Conclusions: A pharmacological approach using a high dose of oral supplementation with MFEs (bromelain, papain, and ficin) was effective in reducing vitreous opacities, even after intraocular hemorrhage. Furthermore, pharmacologic vitreolysis with MFEs supplementation showed high patient satisfaction, and also improved CDVA in patients with vitreous hemorrhage-induced floaters