Proteomic study of vitreous in proliferative diabetic retinopathy patients after treatment with aflibercept: a quantitative analysis based on 4D label-free technique

AIM

To identify different metabolites, proteins and related pathways to elucidate the causes of proliferative diabetic retinopathy (PDR) and resistance to anti-vascular endothelial growth factor (VEGF) drugs, and to provide biomarkers for the diagnosis and treatment of PDR.

METHODS

Vitreous specimens from patients with diabetic retinopathy were collected and analyzed by Liquid Chromatography-Mass Spectrometry (LC-MS/MS) analyses based on 4D label-free technology. Statistically differentially expressed proteins (DEPs), Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway representation and protein interactions were analyzed.

RESULTS

A total of 12 samples were analyzed. The proteomics results showed that a total of 58 proteins were identified as DEPs, of which 47 proteins were up-regulated and 11 proteins were down-regulated. We found that C1q and tumor necrosis factor related protein 5 (C1QTNF5), Clusterin (CLU), tissue inhibitor of metal protease 1 (TIMP1) and signal regulatory protein alpha (SIRPα) can all be specifically regulated after aflibercept treatment. GO functional analysis showed that some DEPs are related to changes in inflammatory regulatory pathways caused by PDR. In addition, protein-protein interaction (PPI) network evaluation revealed that TIMP1 plays a central role in neural regulation. In addition, CD47/SIRPα may become a key target to resolve anti-VEGF drug resistance in PDR.

CONCLUSION

Proteomic analysis is an approach of choice to explore the molecular mechanisms of PDR. Our data show that multiple proteins are differentially changed in PDR patients after intravitreal injection of aflibercept, among which C1QTNF5, CLU, TIMP1 and SIRPα may become targets for future treatment of PDR and resolution of anti-VEGF resistance.

Impact of GLP-1 Agonists and SGLT-2 Inhibitors on Diabetic Retinopathy Progression: An Aggregated Electronic Health Record Data Study

PURPOSE

To examine the effects of GLP-1 agonists compared to SGLT-2 inhibitors on diabetic retinopathy.

DESIGN

Retrospective clinical cohort study using TriNetX (Cambridge, MA, USA), a federated electronic health records network comprising multiple healthcare organizations.

METHODS

Patients with an International Classification of Diseases, Tenth Revision (ICD-10) code of non-proliferative diabetic retinopathy and monotherapy treatment, excluding insulin, with GLP-1 agonists or SGLT-2 inhibitors. Patients with history of proliferative diabetic retinopathy prior to initiation of treatment were excluded. Rate of progression to proliferative diabetic retinopathy and rate of development of diabetic macular edema were compared between patients on GLP-1 agonists compared to those on SGLT-2 inhibitors. The groups were propensity score matched for age, gender, ethnicity, race, type of diabetes, and severity of non-proliferative diabetic retinopathy. Main outcomes included rate and relative risk of progression to proliferative diabetic retinopathy and risk of diabetic macular edema in the GLP-1 agonist group versus the SGLT-2 inhibitor group.

RESULTS

A total of 6481 patients were identified in the GLP-1 cohort and the SGLT-2 inhibitor cohort after propensity score matching. At 1 year and 3 years after initiation of therapy, a higher rate of progression of proliferative diabetic retinopathy was noted (RR: 1.26, CI 1.04-1.51, p=0.017 at 1 year, RR: 1.284, CI 1.1-1.499, p=0.002 at 3 years) in the GLP-1 agonist cohort compared to the SGLT-2 inhibitor cohort. There was a higher rate of diabetic macular edema noted at 3 months (RR: 1.192, CI 1.059-1.276, p=0.002), 6 months (RR: 1.22, CI 1.13-1.32, p<0.001), 1 year (RR: 1.24, CI 1.15-1.33, p<0.001), and at 3 years (RR: 1.29, CI 1.21-1.38, p<0.001) in the GLP-1 agonist cohort compared to the SGLT-2 inhibitor cohort.

CONCLUSIONS

A higher rate of progression of proliferative diabetic retinopathy and risk of new-onset diabetic macular edema was observed in patients on monotherapy with GLP-1 agonists compared to those on SGLT-2 inhibitors. It is important for clinicians to be aware of these potential effects and to consider the current retinopathy status when initiating treatment with newer hypoglycemic agents to ensure these patients are appropriately monitored for developing potential vision threatening complications.

The Natural History of Retinal Sensitivity Loss in Diabetic Macular Ischemia over One Year Evaluated by Microperimetry

Background/Objectives: This one-year prospective observational study, conducted at two centers, aimed to report the natural history of retinal sensitivity (RS) loss in diabetic macular ischemia (DMI). Methods: Patients with stable-treated proliferative diabetic retinopathy (PDR) were recruited if there was evidence of DMI on optical coherence tomography angiography, defined as a foveal avascular zone ≥ 0.5 mm2 or parafoveal capillary dropout ≥ 1 quadrant. The minimal visual acuity required for performing microperimetry (MP) was ≥54 Early Treatment Diabetic Retinopathy Study letters (Snellen equivalent 20/80). The overall RS (oRS) and pointwise sensitivity (PWS) within the 3 × 3 mm macula were assessed at baseline and twelve months. A value <25 decibels (dB) was defined as impaired RS, and a decrease of 2 and 7 dB was regarded as mild and severe loss, respectively. Results: A total of 88 patients (97 eyes) were included. No statistically significant MP changes were detected at one year. However, 10% of the cohort lost oRS ≥ 2 dB, and 73% lost ≥2 dB PWS in ≥5 loci, whereas 1% lost oRS ≥ 7 dB, and 4% lost ≥7 dB PWS in ≥5 loci. The foveola and temporal parafovea were the most vulnerable to severe RS loss. Compared to their counterpart, eyes with baseline oRS ≥ 25 dB had significantly more RS loss in the macula and superior parafovea (55% versus 32% and 53% versus 28%, both p = 0.01). Conclusions: Rather than oRS loss, ≥2 dB loss in PWS in ≥5 loci is a more feasible outcome measure for clinical trials in DMI.

The incidence and prevalence of diabetic macular edema and proliferative diabetic retinopathy, their progression to visual impairment and patterns in their intravitreal treatment in the Finnish population

PURPOSE

The worldwide prevalence of diabetes mellitus (DM) continues to increase. As DM is linked to various ophthalmological comorbidities, it is crucial to understand the incidence and the treatment patterns of these complications to minimise the treatment burden for the patient and the healthcare system. This study aims to evaluate the incidence and prevalence of diabetic macular oedema (DME) and proliferative diabetic retinopathy (PDR) and to analyse intravitreal (IVT) treatment patterns and responses in the Finnish population with diabetes.

METHODS

A nationwide data register containing details of over 20-year-old individuals with diabetes was used in the analyses.

RESULTS

The incidence and prevalence of DME and PDR among the Finnish population with diabetes either declined or remained stable during 2007-2017 (Incidence rate: DME -40.8%, PDR -65.3%; prevalence rate: DME +4.7%, PDR -11.2%). During the same period, number of persons suffering from diabetes increased by +58.3%. The total number of IVT injections increased by 261.7%; the number of patients receiving IVT treatments increased by 133.6% from 2011 to 2017, reflecting changes in patient numbers in the ophthalmology departments. Furthermore, irrespective of the rising number of patients with diabetes, the numbers with visual impairment declined by 75.8% among DME and by 75.7% among PDR patients in 2007-2017.

CONCLUSIONS

Regardless of the considerable increase in the workload of ophthalmology departments, the healthcare system has been able to reduce both the age and sex standardised incidence of DME and PDR among the diabetic population suffering from a visual impairment associated with this disease.

The Anatomic and Functional Outcomes of Ozurdex-Aided Vitrectomy in Proliferative Diabetic Retinopathy

Purpose

To investigate the 3-months outcomes of patients who underwent intraoperative intravitreal injection of Ozurdex for proliferative diabetic retinopathy (PDR).

Methods

This is a prospective randomized controlled clinical trial (ChiCTR2100043399). Seventy-one patients with PDR who had indications for surgery without intravitreal injection history within 3 months preoperatively were enrolled. Patients were randomly divided into three groups based on the medicine injected intraoperatively: Ozurdex, Conbercept, and Control group. The primary outcome is the best-corrected visual acuity (BCVA) within 3 months postoperatively. The secondary outcomes include the intraocular pressure (IOP), mean sensitivity, central retinal thickness and vessels perfusion.

Results

The BCVA and the mean sensitivity improved in the three groups (F = 130.8, P < 0.0001; F = 34.18, P < 0.0001), but there was no statistical difference among the three groups (F = 0.858, P = 0.552; F = 0.964, P = 0.452). The IOP was no significant differences among the three groups within 3 months postoperatively (F = 0.881, P = 0.533). Compared with the other two groups, central retinal thickness (CRT) and outer retinal layer (ORL) thickness decreased significantly in patients of the Ozurdex group (F = 3.037, P = 0.008; F = 2.626, P = 0.018), especially in the diabetic macular edema (DME) patients (F = 2.761, P = 0.0164; F = 2.572, P = 0.0240). In macular region, superficial vascular plexus (SVP), intermediate capillary plexus (ICP) and deep capillary plexus (DCP) perfusion were not shown statistical difference at 3 months postoperatively in the all three groups compared with 1 day postoperatively (P > 0.05).

Conclusion

Compared with the other two groups, anatomical outcomes was improved significantly in Ozurdex group for DR patients. Ozurdex may help to improve the visual acuity and visual sensitivity, and there is no significant difference in the change of IOP and microvascular improvement.

Clinical Trial Registration

This trial is registered with the Chinese Clinical Trial Registry (http://www.chictr.org.cn, registration number ChiCTR2100043399).

Reperfusion of retinal nonperfusion by neovascular-vascular anastomosis in proliferative diabetic retinopathy

BACKGROUND

Retinal nonperfusion is a significant cause of vision loss in patients with proliferative diabetic retinopathy (PDR). Therefore, reperfusion of a nonperfusion has been a matter of strong interest, but few previous studies have demonstrated the potential benefits of reperfusion.

CASE REPORTS

Here, we report longitudinal optical coherence tomography angiographic analysis of two cases of PDR, in which the retinal neovascularization (RNV) that developed in response to retinal ischemia formed anastomoses with pre-existing physiological retinal vessels, resulting in both superficial and deep capillary reperfusion within the nonperfusion. We named this interesting finding "neovascular-vascular anastomosis." Retinal reperfusion due to neovascular-vascular anastomosis differed from recanalization, defined as reperfusion of once-occluded blood vessels, and has not been reported previously.

CONCLUSION

Our observation highlights the potential of RNV to rescue retinal ischemia by the formation of neovascular-vascular anastomoses.

Eye Pain During Hemodialysis in Severe Proliferative Diabetic Retinopathy With Neovascular Glaucoma

Purpose: To report a case of severe eye pain developing during dialysis. Methods: A case report was performed. Results: A 41-year-old man with uncontrolled type 2 diabetes and end-stage nephropathy developed severe pain in the left eye during hemodialysis. A decline in vision in both eyes was reported over the preceding year, with blindness in the left eye for 6 months. The best-corrected visual acuity was 20/150 OD and light perception OS. The intraocular pressure was 14 mm Hg and 59 mm Hg, respectively. An examination found disc neovascularization with a "volcanic eruption" of vitreous hemorrhage from the optic nerve in the right eye and significant corneal edema and iris neovascularization with no posterior view in the left eye. The patient required urgent cyclophotocoagulation for neovascular glaucoma (NVG) in the left eye, bilateral antivascular endothelial growth factor injections, and panretinal photocoagulation in the right eye for proliferative diabetic retinopathy. Conclusions: Worsening eye pain during hemodialysis in a patient with NVG indicates severely limited outflow capacity and requires immediate intervention.

Optical Coherence Tomography Angiography as a Diagnostic Tool for Diabetic Retinopathy

Diabetic retinopathy (DR) is the most common microvascular complication of diabetes mellitus, leading to visual impairment if left untreated. This review discusses the use of optical coherence tomography angiography (OCTA) as a diagnostic tool for the early detection and management of DR. OCTA is a fast, non-invasive, non-contact test that enables the detailed visualisation of the macular microvasculature in different plexuses. OCTA offers several advantages over fundus fluorescein angiography (FFA), notably offering quantitative data. OCTA is not without limitations, including the requirement for careful interpretation of artefacts and the limited region of interest that can be captured currently. We explore how OCTA has been instrumental in detecting early microvascular changes that precede clinical signs of DR. We also discuss the application of OCTA in the diagnosis and management of various stages of DR, including non-proliferative diabetic retinopathy (NPDR), proliferative diabetic retinopathy (PDR), diabetic macular oedema (DMO), diabetic macular ischaemia (DMI), and pre-diabetes. Finally, we discuss the future role of OCTA and how it may be used to enhance the clinical outcomes of DR.

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.

Single-cell transcriptome profiling highlights the role of APP in blood vessels in assessing the risk of patients with proliferative diabetic retinopathy developing Alzheimer's disease

Introduction: The incidence of diabetic retinopathy (DR) has been found to be associated with the risk of developing Alzheimer's disease (AD). In addition to the common properties of neurodegeneration, their progressions are involved with abnormal vascular functions. However, the interactions between them have not been fully understood. This study aimed to investigate the key factor for the underlying interactions and shared signaling pathways in the vasculature of DR and AD. Methods: We retrieved single-cell RNA sequencing (scRNA-seq) data regarding human fibrovascular membrane (FVM) of proliferative diabetic retinopathy (PDR) and human hippocampus vessels of AD from the NCBI-GEO database. GSEA analysis was performed to analyze AD-related genes in endothelial cells and pericytes of PDR. CellChat was used for predicting cell-cell communication and the signaling pathway. Results: The data suggested that amyloid-beta precursor protein (APP) signaling was found crucial in the vasculature of PDR and AD. Endothelial cells and pericytes could pose influences on other cells mainly via APP signaling in PDR. The endothelial cells were mainly coordinated with macrophages in the hippocampus vasculature of AD via APP signaling. The bulk RNA-seq in mice with PDR validated that the expression of APP gene had a significant correlation with that of the AD genome-wide association studies (GWAS) gene. Discussion: Our study demonstrates that the vasculopathy of PDR and AD is likely to share a common signaling pathway, of which the APP-related pathway is a potential target.

Renal impairment may indicate postoperative low vision in young patients with proliferative diabetic retinopathy undergoing vitrectomy

Objective

To innovatively evaluate the impact of renal impairment in young work age patients with proliferative diabetic retinopathy (PDR) on their visuality after vitrectomy.

Methods

To find out whether it is possible to better predict the improvement of visual acuity after vitrectomy in working-age people without adding additional preoperative testing. In view of the fact that diabetic retinopathy and diabetic nephropathy are common diabetic complications of microvascular damage, it is considered whether preoperative renal function can be used as this evaluation index. This paper studies the design under this theme. This retrospective study included 306 patients (306 eyes) diagnosed with PDR and undergoing vitrectomy in our hospital from January 2016 to June 2023. Relevant baseline data were collected, including age, history of kidney disease and clinical laboratory test results. According to the International Standard Logarithmic Visual Acuity Checklist, the best corrected visual acuity was tested on the first day of admission and one month after surgery, and the difference between the two was subtracted. A difference >0 was defined as "vision improved". Patients were classified as vision-improved group (n=245) and non-improved group (n=61). The differences in baseline serum urea nitrogen, creatinine, uric acid, Cystatin C, estimated glomerular filtration rate (eGFR) and urine protein distribution between the two groups were statistically analyzed, binary regression analysis was performed for meaningful parameters, and random forest model ranked the characteristics in importance.

Results

1.A higher level of serum cystatin C [1.02(0.80,1.48) mg/L vs 0.86(0.67,1.12) mg/L, P<0.001] and a lower eGFR [82.3(50.33, 115.11) ml/(min/1.73m²) vs 107.69(73.9, 126.01) ml/(min/1.73m²), P=0.002] appeared in the non-(vision-)improved group compared with the vision-improved group. 2. The occurrence of preoperation proteinuria history of nephropathy take a larger proportion in non-improved group. 3. Univariate regression analysis showed history of nephrology (OR=1.887, P=0.028), preoperative serum urea nitrogen (OR=0.939, P=0.043), cystatin C (Cys-C) concentration (OR=0.75, P=0.024), eGFR (OR=1.011, P=0.003) and proteinuria (OR=3.128, P<0.001) were influencing factors to postoperative visual acuity loss in young working age PDR patients. Excluding other confounding factors, preoperative proteinuria is an independent risk factor for postoperative vision improvement in working-age PDR populations (OR=2.722, P=0.009). 4. The accuracy of the prediction random forst model is 0.81. The model appears to be superior in terms of positive prediction.

Conclusion

In young work aged PDR patients undergoing vitrectomy, preoperative urine protein can be an independent indicator of postoperative visual loss. Aggressive correction of kidney injury before surgery may help improve postoperative vision in patients with PDR.

Late postoperative vitreous cavity hemorrhage after vitrectomy for proliferative diabetic retinopathy-observation versus intervention

PURPOSE

To analyze the outcome of intervention versus observation for vitreous cavity hemorrhage occurring after a 2-month period of blood-free cavity (late postoperative vitreous cavity hemorrhage-POVCH) in eyes operated by vitrectomy for complications of proliferative diabetic retinopathy (PDR).

METHODS

This study was a 10-year retrospective, observational, multi-center study involving eight major vitreoretinal surgical centers across India from January 2010 to December 2019. The primary objective of the study was to assess the visual and clinical outcomes of various management approaches for late POVCH. The key secondary objective was to determine the best management option that prevented recurrence. Patients with follow-up of less than 6 months of POVCH management were excluded.

RESULTS

The occurrence of late POVCH was studied in 261 eyes. The median time to occurrence was 7 months (range: 2-87) postvitrectomy/silicone oil removal. The majority (58%) experienced a single, nonrecurring POVCH event. Visual acuity outcome was independent of all management approaches (P = 0.179; mean follow-up 20.7 ± 14.1 months). With watchful observation, spontaneous resolution was noted in 83% (60/72 eyes) of eyes in 81.5 days (interquartile range, 169.75). Silicone oil injection was most effective in preventing recurrence (P < 0.001).

CONCLUSION

The current treatment practice of late POVCH management in PDR suggests that watchful observation for at least 3 months could be as efficacious as any surgical intervention.

Regression of Neovascularization after Panretinal Photocoagulation Combined with Anti-VEGF Injection for Proliferative Diabetic Retinopathy-A Review

Proliferative diabetic retinopathy (PDR) poses a significant therapeutic problem that often results in severe visual loss. Panretinal photocoagulation (PRP) has long been a mainstay treatment for this condition. Conversely, intravitreal anti-VEGF therapy has served as an alternative treatment for PDR. This review aimed to evaluate the effects of PRP combined with anti-VEGF therapy on the regression of neovascularization (NV), including functional outcomes and incidence of complications. The MEDLINE database was searched for articles evaluating regression of NV using a combination of the following terms: "proliferative diabetic retinopathy", "anti-VEGF", "panretinal photocoagulation", and "combined treatment". The search yielded a total of 22 articles. The analysis of their results indicated PRP combined with ant-VEGF therapy as superior over PRP alone in the management of PDR. Combination treatment yields better and faster regression of NV and a lower incidence of serious complications, such as vitreous hemorrhage and the need for pars plana vitrectomy. Nevertheless, complete regression of NV is not achieved in a significant proportion of patients. Further research is needed to establish the most effective schedule for intravitreal injections as an adjunct to PRP. The current literature shows that in some cases, cessation of anti-VEGF injection in combination treatment for PDR can lead to relapse of NV.

Clinical Efficacy of Preoperative and Intraoperative Intravitreal Ranibizumab as Adjuvant Therapy of Ahmed Glaucoma Valve Implantation Combined with Vitrectomy in the Management of Neovascular Glaucoma with Diabetic Vitreous Hemorrhage

Neovascular glaucoma (NVG) secondary to proliferative diabetic retinopathy (PDR) is a devastating ocular disease with poor prognosis. Intravitreal ranibizumab injection (IVR) has been used as adjuvant therapy of surgical interventions preoperatively or intraoperatively. This study aimed to determine the efficacy and safety of combined IVR as adjuvant therapy in treating NVG with vitreous hemorrhage (VH) in PDR. A total of 39 NVG patients with VH (39 eyes) received IVR 3 to 5 days before surgery, and then they were assigned to either pars plana vitrectomy (PPV) + Ahmed glaucoma valve (AGV) implantation (Group 1, n = 22) or PPV + AGV implantation + intraoperative IVR (Group 2, n = 17). Patients were followed up for at least 9 months. Intraocular pressure (IOP), anti-glaucoma medications, best corrected visual acuity (BCVA), surgical success rates and postoperative complications were compared. Results showed that IOP decreased promptly after surgery and was notably maintained at a mid-term follow-up in both groups, and no significant differences were observed (all p > 0.05). Additional intraoperative IVR significantly reduced postoperative recurrent VH and iris neovascularization (p = 0.047, p = 0.025, respectively). There was no remarkable difference in postoperative anti-glaucoma medications, BCVA and complications between two groups (all p > 0.05). In conclusion, preoperative and intraoperative IVR as adjuvant therapy of AGV implantation combined with PPV could be a safe and effective treatment for NVG with VH in PDR. An additional intraoperative anti-VEGF injection could significantly reduce postoperative VH and iris neovascularization.

Intravitreal Conbercept

PURPOSE

To compare long-term real-world outcomes of corneal thickness (CT) alterations in proliferative diabetic retinopathy (PDR) patients treated with panretinal photocoagulation (PRP) and intravitreal conbercept (IVC).

METHODS

This retrospective study included 69 eyes of 69 patients with PDR (42 PRP and 27 IVC). Full corneal thickness (FCT), corneal epithelial thickness (CET) and corneal stromal thickness (CST) measured by anterior segment optical coherence tomography at baseline were compared between groups. These CT changes at last follow-up from baseline were also compared between groups and within each group.

RESULTS

During a mean follow-up of more than two years, the IVC group demonstrated a significantly increased corneal thickness from baseline compared to the PRP group in some areas (PRP vs. IVC: FCT 0-2 mm: -0.59 ± 9.31 vs. 5.59 ± 9.23 μm, p = 0.009; CST 0-2 mm: -2.05 ± 8.79 vs. 3.48 ± 7.52 μm, p = 0.015; CST 2-5 mm: -1.78 ± 13.27 vs. 5.68 ± 14.53 μm, p = 0.046). In within-group comparisons, a significantly increased FCT from baseline was found in the 0-2 mm area in the IVC group (p = 0.004), but no significant change was observed in the PRP group (p = 0.691). For CET changes, a significantly increased CT was observed in the 0-2 mm, 2-5 mm and 5-7 mm areas in both groups respectively (all p < 0.05). Regarding CST, an increased CT was found in the 0-2 mm area in the IVC group (p = 0.037), while a decreased trend was observed in 0-2 mm and 2-5 mm areas in the PRP group (all p > 0.05).

CONCLUSION

When using PRP or IVC in the long-term management of PDR, CT changes should be considered. This may provide evidence for corneal protection during PDR treatment.

Early effects of intravitreal anti-VEGF agents on cornea and visual acuity in patients with diabetic retinopathy

PURPOSE

This study aimed to investigate the early effects of intravitreal anti-vascular endothelial growth factor (anti-VEGF) agents on the cornea and visual acuity in patients with diabetic retinopathy (DR).

METHODS

This retrospective study enrolled patients who were administered conbercept or ranibizumab to treat DR. Fundus photograph, fluorescein angiograph, and optical coherence tomography were preoperatively performed. The patients were classified into two groups: nonproliferative DR (NPDR) and PDR. Best-corrected visual acuity (BCVA), specular microscopy, central corneal thickness (CCT), and intraocular pressure were obtained before injection and at 1 day and 7 days after injection. The effects of anti-VEGF agents on BCVA and CCT were compared between the groups receiving conbercept and ranibizumab and between NPDR and PDR eyes.

RESULTS

A total 38 eyes (30 patients) were enrolled in this study. Twenty-one eyes received conbercept, and 17 eyes received ranibizumab. Twenty eyes were classified as NPDR and 18 eyes as PDR. No significant differences were found between the groups receiving conbercept and ranibizumab in the increase in BCVA nor in the increase of CCT at 1 day and 7 days after injection. As compared with NPDR eyes, PDR eyes demonstrated a significantly greater increase in CCT (-5.3 ± 3.7 vs. 6.5 ± 2.9 μm, P = 0.02 < 0.05) but not in BCVA (P = 0.33) at 1 day after injection. At 7 days after injection, no significant differences were found in the increase in BCVA nor in the increase of CCT between NPDR eyes and PDR eyes.

CONCLUSION

Intravitreal administration of anti-VEGF agents could cause a small but significant greater increase in CCT in PDR than in NPDR eyes in the early period. In patients with DR, no significant difference was found between conbercept and ranibizumab in the early effects on the visual acuity nor in the cornea.

Transcriptional Comparison of Human and Murine Retinal Neovascularization

Purpose

Retinal neovascularization (RNV) is the leading cause of vision loss in diseases like proliferative diabetic retinopathy (PDR). A significant failure rate of current treatments indicates the need for novel treatment targets. Animal models are crucial in this process, but current diabetic retinopathy models do not develop RNV. Although the nondiabetic oxygen-induced retinopathy (OIR) mouse model is used to study RNV development, it is largely unknown how closely it resembles human PDR.

Methods

We therefore performed RNA sequencing on murine (C57BL/6J) OIR retinas (n = 14) and human PDR RNV membranes (n = 7) extracted during vitrectomy, each with reference to control tissue (n=13/10). Differentially expressed genes (DEG) and associated biological processes were analyzed and compared between human and murine RNV to assess molecular overlap and identify phylogenetically conserved factors.

Results

In total, 213 murine- and 1223 human-specific factors were upregulated with a small overlap of 94 DEG (7% of human DEG), although similar biological processes such as angiogenesis, regulation of immune response, and extracellular matrix organization were activated in both species. Phylogenetically conserved mediators included ANGPT2, S100A8, MCAM, EDNRA, and CCR7.

Conclusions

Even though few individual genes were upregulated simultaneously in both species, similar biological processes appeared to be activated. These findings demonstrate the potential and limitations of the OIR model to study human PDR and identify phylogenetically conserved potential treatment targets for PDR.

Optical Coherence Tomography Angiography Changes in Macular Area in Patients with Proliferative Diabetic Retinopathy Treated with Panretinal Photocoagulation

BACKGROUND

The purpose of this study was to investigate the changes in macular microvasculature using optical coherence tomography angiography (OCTA) in association with functional changes in patients with proliferative diabetic retinopathy (PDR) treated with panretinal photocoagulation (PRP) with a follow up of 12 months.

METHODS

The participants in this study were 28 patients with PDR and no macular oedema, who were eligible for PRP. All participants underwent best-corrected visual acuity (BCVA) measurement, optical coherence tomography (OCT), and OCT angiography (OCTA) at baseline (before treatment) and at months 1, 6, and 12 after the completion of PRP treatment. The comparison of OCTA parameters and BCVA between baseline and months 1, 6, and 12 after PRP was performed.

RESULTS

There was a statistically significant decrease in foveal avascular zone (FAZ) area at months 6 and 12 of the follow-up period compared to baseline (p = 0.014 and p = 0.011 for month 6 and 12, respectively). Of note is that FAZ became significantly more circular 6 months after PRP (p = 0.009), and remained so at month 12 (p = 0.015). There was a significant increase in the mean foveal and parafoveal vessel density (VD) at all quadrants at the superficial capillary plexus (SCP) at month 6 and month 12 after PRP compared to baseline. No difference was noticed in VD at the deep capillary plexus (DCP) at any time-point of the follow up. BCVA remained the same throughout the follow-up period.

CONCLUSIONS

At months 6 and 12 after PRP, foveal and parafoveal VD at SCP significantly increased compared to baseline, while the FAZ area significantly decreased and FAZ became more circular.

Correlation between diabetic retinopathy and diabetic nephropathy: a two-sample Mendelian randomization study

Rationale & objective

A causal relationship concerning diabetic retinopathy (DR) and diabetic nephropathy (DN) has been studied in many epidemiological observational studies. We conducted a two-sample mendelian randomization study from the perspective of genetics to assess these associations.

Methods

20 independent single nucleotide polymorphisms (SNPs) associated with diabetic retinopathy were selected from the FinnGen consortium. Summary-level data for diabetic nephropathy were obtained from the publicly available genome-wide association studies (GWAS) database, FinnGen and CKDGen consortium. Inverse variance weighted (IVW) was selected as the primary analysis. MR-Egger, weighted median (WM), simple mode and weighted mode were used as complementary methods to examine causality. Additionally, sensitivity analyses including Cochran's Q test, MR-Egger, MR-Pleiotropy Residual Sum and Outlier (MR-PRESSO), and leave-one-out analyses were conducted to guarantee the accuracy and robustness of our MR analysis.

Results

Our current study demonstrated positive associations of genetically predicted diabetic retinopathy with diabetic nephropathy (OR=1.32; P=3.72E-11), type 1 diabetes with renal complications (OR=1.96; P= 7.11E-11), and type 2 diabetes with renal complications (OR=1.26, P=3.58E-04). Further subtype analysis and multivariate mendelian randomization (MVMR) also reached the same conclusion. A significant casualty with DN was demonstrated both in non-proliferative DR (OR=1.07, P=0.000396) and proliferative DR (OR=1.67, P=3.699068E-14). All the findings were robust across several sensitivity analyses.

Conclusion

Consistent with previous clinical studies, our findings revealed a positive correlation between DR and DN, providing genetic evidence for the non-invasive nature of DR in predicting DN.

Advances and Perspectives in Relation to the Molecular Basis of Diabetic Retinopathy-A Review

Diabetes mellitus (DM) is a growing problem nowadays, and diabetic retinopathy (DR) is its predominant complication. Currently, DR diagnosis primarily relies on fundoscopic examination; however, novel biomarkers may facilitate that process and make it widely available. In this current review, we delve into the intricate roles of various factors and mechanisms in DR development, progression, prediction, and their association with therapeutic approaches linked to the underlying pathogenic pathways. Specifically, we focus on advanced glycation end products, vascular endothelial growth factor (VEGF), asymmetric dimethylarginine, endothelin-1, and the epigenetic regulation mediated by microRNAs (miRNAs) in the context of DR.

CD40 Ligand-CD40 Interaction Is an Intermediary between Inflammation and Angiogenesis in Proliferative Diabetic Retinopathy

We aimed to investigate the role of the CD40-CD40 ligand (CD40L) pathway in inflammation-mediated angiogenesis in proliferative diabetic retinopathy (PDR). We analyzed vitreous fluids and epiretinal fibrovascular membranes from PDR and nondiabetic patients, cultures of human retinal microvascular endothelial cells (HRMECs) and Müller glial cells and rat retinas with ELISA, immunohistochemistry, flow cytometry and Western blot analysis. Functional tests included measurement of blood-retinal barrier breakdown, in vitro angiogenesis and assessment of monocyte-HRMEC adherence. CD40L and CD40 levels were significantly increased in PDR vitreous samples. We demonstrated CD40L and CD40 expression in vascular endothelial cells, leukocytes and myofibroblasts in epiretinal membranes. Intravitreal administration of soluble (s)CD40L in normal rats significantly increased retinal vascular permeability and induced significant upregulation of phospho-ERK1/2, VEGF, intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1). sCD40L induced upregulation of VEGF, MMP-9, MCP-1 and HMGB1 in cultured Müller cells and phospo-ERK1/2, p65 subunit of NF-ĸB, VCAM-1 and VEGF in cultured HRMECS. TNF-α induced significant upregulation of CD40 in HRMECs and Müller cells and VEGF induced significant upregulation of CD40 in HRMECs. sCD40L induced proliferation and migration of HRMECs. We provide experimental evidence supporting the involvement of the CD40L-CD40 pathway and how it regulates inflammatory angiogenesis in PDR.

Early versus Late Pars Plana Vitrectomy in Vitreous Hemorrhage: A Systematic Review

Background: Vitreous hemorrhage (VH) is a common vitreoretinal condition causing impairment of vision due to various etiologies. No consensus exists on the best timing for performing pars plana vitrectomy (PPV) in fundus-obscuring VH. Materials and Methods: Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) standards, we conducted a systematic review of the timing of PPV in VH. We assessed the strength of the evidence using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach for all the included publications, in accordance with the 2011 Oxford Centre for Evidence-Based Medicine (OCEBM) recommendations. Results: A total of 1731 articles were identified. Following the removal of duplicates and screening of abstracts, 1203 articles remained. Subsequently, a comprehensive full-text review of 30 articles was conducted. Ultimately, 18 articles met the predefined inclusion criteria. Conclusions: Despite the small number of studies on the timing of treatment for VH, the advantage of early over late PPV seems to be a reasonable approach in selected cases, and it might be considered modern standard care.

Retinal main vessel calibers and systemic markers for long-term development of proliferative diabetic retinopathy

PURPOSE

To evaluate if retinal vascular calibers and systemic risk factors in patients with no or minimal diabetic retinopathy (DR) can predict risk of long-term progression to proliferative diabetic retinopathy (PDR).

METHODS

This was a matched case-control study of patients with diabetes having no or minimal DR at baseline with (cases) or without (controls) subsequent development of PDR. We collected six-field, 45-degree retinal images, demographic and clinical data from the Funen Diabetes Database.

RESULTS

We included 52 eyes from 39 cases and 107 eyes from 89 controls matched on sex, age, type of diabetes, time from first to last screening episode and baseline DR level. Cases had higher HbA1c (73 vs. 55 mmoL/moL; p < 0.001), triglycerides (1.32 vs. 1.16 mmoL/L; p = 0.02) and longer duration of diabetes (19 vs. 14 years; p = 0.01), but the groups did not differ in calibers of retinal arterioles (229 vs. 227 μm; p = 0.49), venules (289 vs. 290 μm; p = 0.83) or the arterio-to-venule ratio (0.78 vs. 0.77; p = 0.86).In a multivariable logistic regression model with cluster robust standard error, HbA1c (OR 1.54 per 10 mmoL/moL; 95%-CI: 1.15-2.07; p = 0.004), triglyceride (OR 1.39 per 1 mmoL/L; 95%-CI: 1.03-1.86; p = 0.03) and duration of diabetes (OR 1.09 per year; 95%-CI: 1.03-1.16; p = 0.003) were independent risk factors for PDR.

CONCLUSION

Retinal vascular calibers did not predict long-term development of PDR in contrast to well-established risk factors like HbA1c, triglyceride and duration of diabetes.

25‑gauge vitrectomy in the management of proliferative diabetic retinopathy with preoperative intravitreal injection of conbercept

Small-gauge vitrectomy has become popular due to its notable advantages, including less trauma, shortened convalescence and improved manoeuvrability. The aim of the present study was to compare the surgical outcomes of 27-gauge (27-G) vitrectomy with those of 25-gauge (25-G) vitrectomy in the management of proliferative diabetic retinopathy (PDR) with preoperative intravitreal injection of conbercept. The data of 48 consecutive patients with PDR (48 eyes) were retrospectively collected. The patients underwent conbercept intravitreal injection and pars plana vitrectomy with a 27-G group (23 eyes) or 25-G group (25 eyes) vitrectomy system. The operating time, suturing rate, endodiathermy rate, postoperative best-corrected visual acuity (BCVA), intraocular pressure (IOP) and complications were recorded. The mean postoperative BCVA at final follow-up was significantly improved compared with that at the baseline in both groups (P<0.001 for both). The differences in the mean BCVA changes between the two groups were not significant (P>0.99), and no differences were observed in the final central foveal thickness (P=0.51) between the two groups. The final IOP remained stable compared with that at the baseline in the 27-G group (P=0.36) and the 25-G group (P=0.05). The suturing rate was significantly decreased in the 27-G group compared with the 25-G group (P=0.04). There were no significant differences between the two groups in terms of the operating time (P=0.18), rate of endodiathermy use (P>0.99), iatrogenic retinal breaks (P=0.42) or postoperative recurrent vitreous haemorrhage (P>0.99). In addition, no case of ocular hypotony was observed in either group. In conclusion, 27-G vitrectomy was as efficient and safe as 25-G vitrectomy in the management of PDR in terms of operating time and complications. With reference to the literature, preoperative conbercept injection appears to assist in decreasing the incidence of intraoperative and postoperative complications.

Tractional Retinal Detachment: Prevalence and Causes in Nigerians

Aim

To determine the causes of tractional retinal detachment (TRD) in Nigerians.

Materials and Methods

A prospective, multicentre study evaluating eyes diagnosed to have TRD. History, clinical examination (including visual acuity, intraocular pressure measurement, anterior segment examination and dilated fundoscopy) and systemic evaluation (including previous diagnosis of diabetes, hypertension, sickle-cell disease and others) were performed in TRD eyes out of a cohort of retinal detachment eyes.

Results

The prevalence of TRD of the 237 patients diagnosed with RD within a one-year study period was 25.7% (61 patients). Eighty eyes were diagnosed with TRD. Thirty-eight eyes of nineteen patients (31%) were bilateral, and 42 (69%) were unilateral. There were 38 male patients (62.3%) and 23 female patients (37.7%). The mean age was 52.3 ± 12.7 years (11-69 years). 88.5% of all TRD patients had an associated systemic disease, diabetes being the most common disease in 88.8% of them. Proliferative diabetic retinopathy was the most common cause of TRD (77.5%) and the most common cause of bilateral TRD. Both trauma and proliferative sickle-cell retinopathy occurred in 3.8% of the eyes. 68.8% of TRD eyes were blind at the presentation. However, the causes of TRD did not show any significant association with blindness (P = 0.819).

Conclusion

Proliferative diabetic retinopathy poses a significant threat to vision, being the most common cause of TRD. Early detection and treatment of proliferative retinopathy in diabetes and sickle-cell disease, and trauma prevention will significantly reduce the burden of blindness due to TRD.

Analysis of Risk Factors for Revitrectomy in Eyes with Diabetic Vitreous Hemorrhage

Purpose

We aimed to investigate the risk factors associated with revitrectomy in eyes with diabetic vitreous hemorrhage and to determine the prognosis of these patients at least one year postoperatively.

Patients and Methods

This retrospective case-control study had a minimum follow-up period of one year. Patients were divided into single vitrectomy group (control group, n=202) and revitrectomy group (case group, n=36) for analysis. The indications, number, and timing of revitrectomies were documented. And the revitrectomy group was further divided into two vitrectomies group (n=30) and three or more vitrectomies group (n=6). The best-corrected visual acuity (BCVA) at the last follow-up and the occurrence of neovascular glaucoma (NVG) were compared among the single vitrectomy, two vitrectomies and three or more vitrectomies groups. We conducted a thorough collection of patient data and used univariate and binary logistic regression analyses to identify the risk factors associated with revitrectomy.

Results

A total of 197 patients (238 eyes) were included. Thirty-six eyes (15.1%) required revitrectomy with six eyes (2.5%) undergoing three or more vitrectomies during the follow-up period. The median duration of the second vitrectomy was 3 (2-6) months. The indications for a second vitrectomy included 28 eyes (77.8%) of postoperative vitreous hemorrhage and 7 eyes (22.2%) combined with tractional retinal detachment. Patients undergoing three or more vitrectomies had significantly worse postoperative BCVA and a higher incidence of NVG (P<0.01). Fibrinogen> 4 g/L (P<0.001) and preoperative anti-vascular endothelial growth factor intravitreal injection (P=0.015) were independent risk factors for revitrectomy, and glycated hemoglobin A1c (HbA1c)>10% (P=0.049) showed significant difference only in univariate analysis.

Conclusion

Patients requiring revitrectomy tended to have higher fibrinogen levels, tightly adhered fibrovascular membranes, higher HbA1c levels, and worse prognoses.

Effect of ILM Peeling on Anatomical and Visual Outcomes in Diabetic Tractional Retinal Detachment

Objectives

The objcetive is to compare the anatomic and functional outcomes of vitrectomy between internal limiting membrane (ILM) peeling and non-ILM peeling in diabetic tractional retinal detachment (TRD).

Methods

Twenty-three eyes with diabetic TRD with ILM peeling were compared with twenty-four eyes with non-ILM peeling. Best-corrected visual acuity (BCVA) was recorded at baseline and 3, 6, 9, 12 months, and end of follow-up. The mean retinal thickness across nine different regions that defined in the Early Treatment Diabetic Retinopathy Study (ETDRS) were obtained. The ETDRS grid was used to determine the extent of macular involvement.

Results

In the 1st month postoperatively, the mean BCVA of eyes with ILM peeling (1.08±0.63 LogMAR) was significantly better than eyes with ILM non-peeling (1.69±0.75 LogMAR, p=0.003). There was also a significant difference at 9 and 12 months between groups in BCVA, in favor of ILM peeling (p=0.012 and p=0.047, respectively). Seven patients (29.2%) developed epiretinal membrane (ERM), and one patient (4.1%) had ERM with the lamellar macular hole in the ILM non-peeling group, while only one patient developed ERM in ILM peeling group during the follow-up.

Conclusion

ILM removal may be considered in diabetic TRD surgery, as it can provide rapid visual recovery. Moreover, post-operative ERM formation was less frequent in ILM peeled eyes within 1 year after surgery.

Transient Intraocular Pressure Fluctuations After Intravitreal Bevacizumab Injection in Proliferative Diabetic Retinopathy Patients: A Prospective Study

INTRODUCTION

The clinical use of intravitreal bevacizumab (IVB), a recombinant humanized monoclonal antibody that functions as an anti-vascular endothelial growth factor (anti-VEGF), has recently increased in patients with retinal ischemic diseases such as proliferative diabetic retinopathy (PDR). The short-term and long-term complications associated with this procedure have not been well established. We aimed to study the possible short-term complication of intraocular pressure (IOP) fluctuations shortly after IVB injection in patients with PDR.

MATERIALS AND METHODS

A prospective case series of diabetic patients with PDR who underwent IVB injection was performed in the Department of Ophthalmology, Medical Teaching Institution, Khyber Teaching Hospital, Peshawar, Pakistan, from November 1, 2020, to May 1, 2021. The total number of PDR patients of both sexes included in the study was 101. A slit lamp examination was performed, and IOP readings were recorded before and 30 min after IVB injection using Goldmann applanation tonometry (GAT). IBM Statistical Package for the Social Sciences version 22 for Windows was used to analyze the data. Safety of the procedure, defined as IOP ≤20 mmHg 30 min after IVB injection, was determined and stratified according to sex, age, duration of diabetes, and baseline IOP. A post-stratification chi-square test was applied, and a p-value <0.05 was taken as statistically significant.

RESULTS

In this study, 60.4% of the participants were male and 39.6% were female. The age of the patients ranged from 30 to 75 years, with a mean age of 55.66±6.37 years. The mean duration of diabetes among the participants was 7.73±2.94 years and the mean baseline IOP was 15.40±1.77 mmHg. Safety (IOP ≤20 mmHg 30 min after IVB injection) was observed in 90.1% of the patients.

CONCLUSION

IVB injections are safe for use in patients with PDR in terms of immediate IOP changes. However, patients with higher baseline IOP (>15 mmHg) are more likely to develop increased IOP post-procedure and prophylaxis may be prudent in such cases.

Update on current pharmacologic therapies for diabetic retinopathy

INTRODUCTION

Diabetic retinopathy is a major cause of visual loss worldwide. The most important clinical findings include diabetic macular edema (DME) and proliferative diabetic retinopathy (PDR).

AREAS COVERED

PubMed was used for our literature review. Articles from 1995 to 2023 were included. Pharmacologic treatment of diabetic retinopathy generally involves the use of intravitreal anti-vascular endothelial growth factor (VEGF) therapy for DME and PDR. Corticosteroids remain important second-line therapies for patients with DME. Most emerging therapies focus on newly identified inflammatory mediators and biochemical signaling pathways involved in disease pathogenesis.

EXPERT OPINION

Emerging anti-VEGF modalities, integrin antagonists, and anti-inflammatory agents have the potential to improve outcomes with reduced treatment burdens.

Macrophage-Myofibroblast Transition Contributes to Myofibroblast Formation in Proliferative Vitreoretinal Disorders

Inflammation and fibrosis are key features of proliferative vitreoretinal disorders. We aimed to define the macrophage phenotype and investigate the role of macrophage-myofibroblast transition (MMT) in the contribution to myofibroblast populations present in epiretinal membranes. Vitreous samples from proliferative diabetic retinopathy (PDR), proliferative vitreoretinopathy (PVR) and nondiabetic control patients, epiretinal fibrovascular membranes from PDR patients and fibrocellular membranes from PVR patients, human retinal Müller glial cells and human retinal microvascular endothelial cells (HRMECs) were studied by ELISA, immunohistochemistry and flow cytometry analysis. Myofibroblasts expressing α-SMA, fibroblast activation protein-α (FAP-α) and fibroblast-specific protein-1 (FSP-1) were present in all membranes. The majority of CD68+ monocytes/macrophages co-expressed the M2 macrophage marker CD206. In epiretinal membranes, cells undergoing MMT were identified by co-expression of the macrophage marker CD68 and myofibroblast markers α-SMA and FSP-1. Further analysis revealed that CD206+ M2 macrophages co-expressed α-SMA, FSP-1, FAP-α and ß-catenin. Soluble (s) CD206 and sFAP-α levels were significantly higher in vitreous samples from PDR and PVR patients than in nondiabetic control patients. The proinflammatory cytokine TNF-α and the hypoxia mimetic agent cobalt chloride induced upregulation of sFAP-α in culture media of Müller cells but not of HRMECs. The NF-ĸß inhibitor BAY11-7085 significantly attenuated TNF-α-induced upregulation of sFAP-α in Müller cells. Our findings suggest that the process of MMT might contribute to myofibroblast formation in epiretinal membranes, and this transition involved macrophages with a predominant M2 phenotype. In addition, sFAP-α as a vitreous biomarker may be derived from M2 macrophages transitioned to myofibroblasts and from Müller cells.

Establishment and validation of a prognostic nomogram for long-term low vision after diabetic vitrectomy

Purpose

We aimed to evaluate the risk factors and develop a prognostic nomogram of long-term low vision after diabetic vitrectomy.

Methods

This retrospective study included 186 patients (250 eyes) that underwent primary vitrectomy for proliferative diabetic retinopathy with a minimum follow-up period of one year. Patients were assigned to the training cohort (200 eyes) or validation cohort (50 eyes) at a 4:1 ratio randomly. Based on a cutoff value of 0.3 in best-corrected visual acuity (BCVA) measurement, the training cohort was separated into groups with or without low vision. Univariate and multivariate logistic regression analyses were performed on preoperative systemic and ocular characteristics to develop a risk prediction model and nomogram. The calibration curve and the area under the receiver operating characteristic curves (AUC) were used to evaluate the calibration and discrimination of the model. The nomogram was internally validated using the bootstrapping method, and it was further verified in an external cohort.

Results

Four independent risk factors were selected by stepwise forward regression, including tractional retinal detachment (β=1.443, OR=4.235, P<0.001), symptom duration ≥6 months (β=0.954, OR=2.595, P=0.004), preoperative BCVA measurement (β=0.540, OR=1.716, P=0.033), and hypertension (β=0.645, OR=1.905, P=0.044). AUC values of 0.764 (95% CI: 0.699-0.829) in the training cohort and 0.755 (95% CI: 0.619-0.891) in the validation cohort indicated the good predictive ability of the model.

Conclusion

The prognostic nomogram established in this study is useful for predicting long-term low vision after diabetic vitrectomy.

The Association Between Lipid Profile and Subfoveal Choroidal Thickness in Chinese Patients with Proliferative Diabetic Retinopathy Secondary to Type 2 Diabetes

Introduction

Extensive studies have studied the factors associated with subfoveal choroidal thickness (SFCT). However, studies of the association between lipid profile and SFCT in patients with proliferative diabetic retinopathy (PDR) in type 2 diabetes remain limited. Thus, we aimed to investigate the relationship between lipid profile and SFCT in patients with PDR.

Materials and Methods

This was a retrospective cross-sectional study. The included participants were inpatients who underwent vitrectomy for PDR with type 2 diabetes and contralateral eyes of PDR patients meeting the criteria. Multivariate linear regression analysis was used to determine the independent association between lipid profile and SFCT.

Results

A total of 131 participants with PDR were enrolled in the final analysis. The average age of the participants was 55.76 ± 9.88 years, and the average SFCT was 276.10 ± 92.92 μm. Multivariate linear regression model results showed that in the fully adjusted model, total cholesterol, high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) had a negative association with SFCT (β = -16.51, 95% CI: -29.57, -3.46; P = 0.0148; β = -42.65, 95% CI: -82.60, -2.70; P = 0.0390; β = -17.89, 95% CI: -33.24, -2.54; P = 0.0245, respectively), while triglyceride was not significantly associated with SFCT (β = 5.23, 95% CI: -18.57, 29.02; P = 0.6678). Furthermore, the results of stratified analysis showed that except for triglyceride, the trends of total cholesterol, HDL-C, LDL-C, and SFCT were consistent among different stratifications in participants.

Conclusion

The cholesterol profile had a significant negative association with SFCT in Chinese PDR patients, but triglyceride was not significantly associated with SFCT. This suggests that these systemic imbalances contribute to choroidal changes, and often coexist in diabetic patients.

Determining the Superiority of Vitrectomy vs Aflibercept for Treating Dense Diabetic Vitreous Hemorrhage: A Systematic Review and Meta-Analysis of Randomized Clinical Trials

This review aimed to systematically compare the efficacy and safety of intravitreal aflibercept (IVA) and vitrectomy for treating severe vitreous hemorrhage (VH) secondary to proliferative diabetic retinopathy (PDR). The review was conducted in accordance with PRISMA guidelines. A search strategy, including the MEDLINE, Embase, Cochrane Central Register of Controlled Trials, and US National Library of Medicine databases, was developed to identify randomized controlled trials (RCTs) that compared vitrectomy and IVA for managing VH due to PDR (participant age ≥ 18 years). The primary outcome measure was the difference in the mean visual acuity between the two treatment groups at 1, 6, and 24 months. Outcome measures included clearance of VH (in weeks), the incidence of recurrent VH, and the rate of complications. The studies were evaluated using the Cochrane Bias (ROB) tool. We identified 774 articles; six articles met the inclusion criteria, and two were ultimately included (n = 239 eyes). With or without PRP, IVA injections and vitrectomy were performed in 117 and 122 eyes, respectively. The mean BCVA at one month was significantly better in the vitrectomy group (MD=0.22, CI:0.10-0.34, p=0.0003), but no difference was found at six months (MD=0.04, CI: -0.04-0.12, p=0.356). The incidence of recurrent VH was significantly higher in the IVA group (OR=5.05, CI:2.71-9.42, p<0.0001). The probability of recurrent VH was five times greater in the IVA group than that in the vitrectomy group. There were no significant differences in the overall proportions of intra- or postoperative complications (OR=0.64, CI: 0.09-4.85, p=0.669). None of the studies had a low ROB in any of the seven domains. We conclude that IVA can be considered a viable treatment modality for diabetic VH in patients with a good follow-up. Vitrectomy initially provides better visual effect, faster VH recovery, and lower VH recurrence than IVA injections.

Comparative proteomics of proliferative diabetic retinopathy in people with Type 2 diabetes highlights the role of inflammation, visual transduction, and extracellular matrix pathways

Purpose

To explore the vitreous humor proteome from type 2 diabetes subjects with proliferative diabetic retinopathy (PDR) in the Indian population.

Methods

We performed mass spectrometry-based label-free quantitative analysis of vitreous proteome of PDR (n = 13) and idiopathic macular hole (IMH; control) subjects (n = 14). Nine samples of PDR and 10 samples of IMH were pooled as case and control, respectively, and compared. Four samples each of PDR and IMH were analyzed individually without pooling to validate the results of the pooled analysis. Comparative quantification was performed using Scaffold software which calculated the fold changes of differential expression. Bioinformatics analysis was performed using DAVID and STRING software.

Results

We identified 469 proteins in PDR and 517 proteins in IMH vitreous, with an overlap of 172 proteins. Also, 297 unique proteins were identified in PDR and 345 in IMH. In PDR vitreous, 37 proteins were upregulated (P < 0.05) and 19 proteins were downregulated compared to IMH. Protein distribution analysis clearly demonstrated a separation of protein expression in PDR and IMH. Significantly upregulated proteins included fibrinogen gamma chain, fibrinogen beta chain, and carbonic anhydrase 1 and downregulated proteins included alpha-1-antitrypsin, retinol-binding protein 3, neuroserpin, cystatin C, carboxypeptidase E and cathepsin-D.

Conclusion

Diabetic retinopathy pathogenesis involves proteins which belong to inflammation, visual transduction, and extracellular matrix pathways. Validation-based experiments using enzyme-linked immunosorbent assay (ELISA) or western blotting are needed to establish cause and effect relationships of these proteins to the disease state, to develop them as biomarkers or drug molecules.

Topographic distribution of retinal neovascularization in proliferative diabetic retinopathy using ultra-wide field angiography

Purpose

To analyze the topographic distribution of neovascularization (NV) and capillary nonperfusion (CNP) using ultra-wide field fluorescein angiography (UWFFA) in patients with proliferative diabetic retinopathy (PDR).

Methods

This was a prospective, single-center, observational study in which all patients who presented between March 2019 and December 2020 and satisfied the inclusion criteria were recruited. In our study, patients with treatment-naïve PDR without any fibrovascular proliferation underwent UWFFA. The images were analyzed qualitatively for the topographic distribution of NV and the CNP area was quantified. The number of lesions picked by UWFFA was compared with 7 standard field (7SF) image using overlay of 7SF. The main outcome measure was characteristics of neovascularization, such as the number, location, and area of CNP, measured using UWFFA, which was considered with 95% confidence intervals (CI).

Results

Two hundred and fifty-three eyes of 187 patients with a mean age of 56.03 ± 8 years were included. Mean neovascularization elsewhere (NVE) was 2.91 ± 3.43. Maximum NVEs were seen in the superotemporal (ST; 0.9 ± 1.13) quadrant, followed by the inferotemporal (IT; 0.7 ± 1.08), inferonasal (IN; 0.66 ± 1.02) and superonasal (SN; 0.66 ± 1.01) quadrants. Maximum CNP area was seen in the SN (13.75 ± 8.83 disc diameter square [DD2]) quadrant, followed by the IN (13.48 ± 8.59 DD2), IT (11.34 ± 8.37 DD2), and ST (11.3 ± 8.34 DD2) quadrants. Mean CNP area was maximum in patients with only neovascularization of disc (NVD; 64.99 ± 41.47 DD2), followed by both NVD and NVE (61.37 ± 35.61 DD2), and was minimum in patients with only NVE (36.44 ± 22.03 DD2). Eighty-one (32%) eyes out of 253 had NVE and 189 (75%) out of 253 had CNP area outside 7SF (overlay) of Early Treatment Diabetic Retinopathy Study (ETDRS).

Conclusion

Diabetic NV lesions and CNP areas are distributed asymmetrically throughout the retina and are not restricted to the posterior pole. Compared to conventional 7SF imaging, UWFFA reveals significantly more retinal vascular pathology in patients with PDR.

The correlation between peripheral complete blood count parameters and diabetic macular edema in proliferative diabetic retinopathy patients: a cross-sectional study

Background

Numerous studies have demonstrated that retinal chronic inflammation plays a critical role in the pathogenesis of diabetic macular edema (DME). However, studies about the association between peripheral complete blood count, an inexpensive and easily measurable laboratory index, and DME are limited.

Research design and methods

The current study was a hospital-based, cross-sectional study. The participants were inpatients with type 2 diabetes who underwent vitrectomy for PDR, and the contralateral eyes in these PDR patients meeting the criteria were included in the study. Central macular thickness (CMT) was measured automatically and the DME was characterized as CMT ≥ 300 μm.

Results

A total of 239 PDR participants were enrolled. The average age was 55.46 ± 10.08 years old, and the average CMT was 284.23 ± 122.09 μm. In the fully adjusted model, for CMT, the results revealed a significantly negative association between CMT and both white blood cell (WBC) count and neutrophil count (β = -11.95, 95% CI: -22.08, -1.82; p = 0.0218; β = -14.96, 95% CI: -28.02, -1.90; p = 0.0259, respectively); for DME, the results showed an inverse association between DME and WBC count, monocyte count, and eosinophil count (OR = 0.75, 95% CI: 0.59, 0.95; p = 0.0153; OR = 0.07, 95% CI: 0.00, 0.92; p = 0.0431; OR = 0.03, 95% CI: 0.00, 0.88; p = 0.0420, respectively).

Conclusions

In conclusion, our results suggest that WBC and its subtypes in circulation may play an important role in the pathogenesis of DME in PDR patients.

Erythropoiesis-Stimulating Agents and the Risk of Vision-Threatening Diabetic Retinopathy

PURPOSE

Animal studies have suggested that Erythropoiesis-Stimulating Agents (ESAs) may increase vascular endothelial growth factor (VEGF)-related retinopathies, but this effect is unclear in humans. This study evaluates the risk of vision-threatening diabetic retinopathy (VTDR), defined as either diabetic macular edema (DME) or proliferative diabetic retinopathy (PDR), in patients exposed to an ESA.

METHODS

Two analyses were performed. First, a retrospective matched-cohort study was designed using a de-identified commercial and Medicare Advantage medical claims database. The ESA cohort of non-proliferative diabetic retinopathy patients who were new users of an ESA from 2000 to 2022 was matched to controls up to a 3:1 ratio. Exclusion criteria included less than 2 years in the plan, history of VTDR or history of other retinopathy. Multivariable Cox proportional hazards regression with inverse proportional treatment weighting (IPTW) was used to assess the hazard of developing VTDR, DME, and PDR. The second analysis was a self-controlled case series (SCCS) evaluating the incidence rate ratios (IRR) of VTDR during 30-day periods before and after initiating an ESA.

RESULTS

After inclusion of 1502 ESA-exposed patients compared with 2656 controls, IPTW-adjusted hazard ratios found the ESA cohort had an increased hazard of progressing to VTDR (HR = 3.0 95%CI:2.3-3.8;p < .001) and DME (HR = 3.4,95%CI:2.6-4.4,p < .001), but not PDR (HR = 1.0,95%CI:0.5-2.3,p = .95). Similar results were found within the SCCS which demonstrated higher IRRs for VTDR (IRRs = 1.09-1.18;p < .001) and DME (IRRs = 1.16-1.18;p < .001), but not increased IRRs in PDR (IRR = 0.92-0.97,p = .02-0.39).

CONCLUSION

ESAs are associated with higher risks for VTDR and DME, but not PDR. Those studying ESAs as adjunctive therapy for DR should be cautious of possible unintended effects.

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.

Retinal laser - Protocols and practical tips

Background

Many a young doctors in training find retinal laser photocoagulation a daunting task. However, if correct protocols are followed and checklists are observed, then it is not difficult to have a successful laser sitting with a happy patient. Most of the complications can be avoided with correct settings and techniques.

Purpose

To enumerate the basic protocols of retinal laser photocoagulation and provide practical tips including laser settings and checklists for hassle-free laser experience.

Synopsis

Laser settings for a pan-retinal photocoagulation (PRP) for proliferative diabetic retinopathy differ from those for a focal laser for macular edema. A fill in PRP is indicated when an active Proliferative diabetic retinopathy (PDR) is seen after the initial PRP is completed. The settings and protocols for laser photocoagulation for lattice degeneration are different, and various techniques of barrage laser are discussed. Practical tips and checklists are given, which will not be found in any textbooks.

Highlights

Animated illustrations and fundus photos are used to explain the correct techniques of performing laser photocoagulation in different indications and scenarios. Detailed instructions and checklists are provided, which can be very useful to avoid complications and medicolegal problems. The practical tips and guidelines in an easy-to-understand manner make this video highly educational for the novice retinal surgeons who want to perfect their technique of retinal laser photocoagulation.

Video Link

https://youtu.be/saQ4s49ciXI.

Comparison of the adjuvant effect of conbercept intravitreal injection at different times before vitrectomy for proliferative diabetic retinopathy

Purpose

To assess the optimal time of intravitreal conbercept (IVC) treatment prior to pars plana vitrectomy (PPV) in patients with severe proliferative diabetic retinopathy (PDR).

Method

This study was exploratory in nature. Forty-eight consecutive patients (48 eyes) with PDR were divided into four groups according to different IVC times (0.5 mg/0.05 mL) before PPV: group A (3 days), group B (7 days), group C (14 days), and group D (non-IVC). Intraoperative and postoperative effectiveness were assessed, and vitreous VEGF concentrations were detected.

Result

For intraoperative effectiveness, groups A and D had a higher incidence of intraoperative bleeding than groups B and C (P = 0.041). Furthermore, groups A-C required less surgical time than group D (P < 0.05). For postoperative effectiveness, group B had a significantly higher proportion of visual acuity that improved or remained unchanged than group D (P = 0.014), and groups A-C had lower proportions of postoperative bleeding than group D. The vitreous VEGF concentration of group B (67.04 ± 47.24 pg/mL) was significantly lower than that of group D (178.29 ± 110.50 pg/mL) (P = 0.005).

Conclusion

IVC treatment that was administered 7 days preoperatively was associated with better effectiveness and a lower vitreous VEGF concentration than its administration at other time points.

Systematic evaluation of combined herbal adjuvant therapy for proliferative diabetic retinopathy

Objective

To evaluate the efficacy and safety of combined traditional Chinese medicine in the adjuvant treatment of proliferative diabetic retinopathy (PDR) by Meta-analysis.

Methods

PubMed, Embase, Web of Science, Cochrane Library, China National Knowledge Infrastructure (CNKI), Wanfang databases were searched by computer. Random controlled clinical trials (RCTS) using traditional Chinese medicine as adjuvant therapy for proliferative diabetic retinopathy were screened, and Stata16.0 software was used to perform meta-analysis on the final included literatures.

Results

A total of 18 studies involving 1392 patients were included. Meta-analysis showed that the clinical effective rate OR=2.99 (CI: 2.18-4.10, I² = 42.7%, P<0.05); Visual acuity MD=0.10(CI: 0.06-0.13, I² = 0%, P<0.05); Fundus efficacy OR=5.47 (CI: 1.33-22.51, I² = 71.4%, P<0.05); Neovascularisation regression rate OR=8 (CI: 3.83-16.71, I² = 30.1%, P<0.05); Macular foveal thickness MD=-44.24 (CI: -84.55-3.93, I² = 95.6%, P<0.05); Absorption of vitreous hemorrhage OR=4.7 (CI: 2.26-9.77, I² = 0%, P<0.05); Fasting blood glucose MD=-0.23, (CI: -0.38-0.07, I² = 0%, P<0.05); 2h postprandial blood glucose MD=-0.19 (CI: -0.52-0.14, I² = 0%, P=0.25). From the results, the combined Chinese medicine adjuvant therapy showed better efficacy than the control group. A total of 69 kinds of traditional Chinese medicine were involved in 18 studies, among which the top four applied frequencies were Panax notoginseng, Rehmannia rehmannii, Astragalus membranaceus and Poria cocos. Most of the medicines were sweet and bitter in taste, the qi tended to be slight cold and cold, and the meridian tropism belongs to the liver meridian.

Conclusion

The combination of traditional Chinese medicine adjuvant therapy has a good curative effect on PDR patients. However, the relevant clinical trials are few and more high-quality clinical trials are still needed, what's more the attention should be paid to the exploration of its safety.

Aflibercept for long-term treatment of diabetic macular edema and proliferative diabetic retinopathy: a meta-analysis

Purpose

This meta-analysis compared the long-term (12 months or 24 months) efficacy and safety of intravitreal aflibercept injection (IAI) for diabetic macular edema (DME) and proliferative diabetic retinopathy (PDR).

Methods

We selected 16 randomized controlled trials (RCTs) performed after 2015 that had a minimum of 12 months and up to 24 months of treatment and conducted a meta-analysis with Review Manager version 5.3. Visual acuity (VA), central subfield thickness (CST) and adverse events were the outcomes selected for evaluation from the eligible studies.

Results

Based on 16 RCTs, we evaluated a total of 7125 patients. For PDR and severe DME with poor baseline vision, after a minimum of 12 months and up to 24 months of treatment, the aflibercept treatment group obtained better VA improvement than the focal/grid laser photocoagulation treatment group (MD=13.30; 95%CI: 13.01~13.58; P<0.001) or other treatments (ranibizumab, focal/grid laser photocoagulation, PRP, et al.) group (MD=1.10; 95%CI: 1.05~1.16; P<0.001). In addition, the aflibercept treatment group got higher CST reduction than the focal/grid laser photocoagulation treatment (MD=-33.76; 95%CI: -45.53 ~ -21.99; P<0.001) or other treatments (ranibizumab, focal/grid laser photocoagulation, et al.) group (MD=-33.76; 95%CI: -45.53 ~ -21.99; P<0.001). There was no significant difference in the overall incidence of ocular and non-ocular adverse events in each treatment group.

Conclusions

This meta-analysis showed that the advantages of IAI are obvious in the management of DME and PDR with poor baseline vision for long-term observation (a minimum of 12 months and up to 24 months) with both VA improvement and CST reduction. Applied IAI separately trended to be more effective than panretinal photocoagulation separately in VA improvement for PDR. More parameters should be required to assess functional and anatomic outcomes.

Oxidative Stress, Inflammatory, Angiogenic, and Apoptotic molecules in Proliferative Diabetic Retinopathy and Diabetic Macular Edema Patients

The aim of this study is to evaluate molecules involved in oxidative stress (OS), inflammation, angiogenesis, and apoptosis, and discern which of these are more likely to be implicated in proliferative diabetic retinopathy (PDR) and diabetic macular edema (DME) by investigating the correlation between them in the plasma (PLS) and vitreous body (VIT), as well as examining data obtained from ophthalmological examinations. Type 2 diabetic (T2DM) patients with PDR/DME (PDRG/DMEG; n = 112) and non-DM subjects as the surrogate controls (SCG n = 48) were selected according to the inclusion/exclusion criteria and programming for vitrectomy, either due to having PDR/DME or macular hole (MH)/epiretinal membrane (ERM)/rhegmatogenous retinal detachment. Blood samples were collected and processed to determine the glycemic profile, total cholesterol, and C reactive protein, as well as the malondialdehyde (MDA), 4-hydroxynonenal (4HNE), superoxide dismutase (SOD), and catalase (CAT) levels and total antioxidant capacity (TAC). In addition, interleukin 6 (IL6), vascular endothelial growth factor (VEGF), and caspase 3 (CAS3) were assayed. The VITs were collected and processed to measure the expression levels of all the abovementioned molecules. Statistical analyses were conducted using the R Core Team (2022) program, including group comparisons and correlation analyses. Compared with the SCG, our findings support the presence of molecules involved in OS, inflammation, angiogenesis, and apoptosis in the PLS and VIT samples from T2DM. In PLS from PDRG, there was a decrease in the antioxidant load (p < 0.001) and an increase in pro-angiogenic molecules (p < 0.001), but an increase in pro-oxidants (p < 0.001) and a decline in antioxidants (p < 0.001) intravitreally. In PLS from DMEG, pro-oxidants and pro-inflammatory molecules were augmented (p < 0.001) and the antioxidant capacity diminished (p < 0.001), but the pro-oxidants increased (p < 0.001) and antioxidants decreased (p < 0.001) intravitreally. Furthermore, we found a positive correlation between the PLS-CAT and the VIT-SOD levels (rho = 0.5; p < 0.01) in PDRG, and a negative correlation between the PSD-4HNE and the VIT-TAC levels (rho = 0.5; p < 0.01) in DMEG. Integrative data of retinal imaging variables showed a positive correlation between the central subfield foveal thickness (CSFT) and the VIT-SOD levels (rho = 0.5; p < 0.01), and a negative correlation between the CSFT and the VIT-4HNE levels (rho = 0.4; p < 0.01) in PDRG. In DMEG, the CSFT displayed a negative correlation with the VIT-CAT (rho = 0.5; p < 0.01). Exploring the relationship of the abovementioned potential biomarkers between PLS and VIT may help detecting early molecular changes in PDR/DME, which can be used to identify patients at high risk of progression, as well as to monitor therapeutic outcomes in the diabetic retina.

Effect of Lens Status on Diabetic Vitreous Hemorrhage Resolution

Purpose: To determine the effect of lens status (pseudophakic vs phakic) on diabetic vitreous hemorrhage (VH) resolution time. Methods: Medical records were reviewed retrospectively for each case of diabetic VH until resolution, pars plana vitrectomy (PPV), or loss to follow-up. Univariate and multivariate Cox regression models were used to determine predictors of diabetic VH resolution time through estimated hazard ratios (HRs). Kaplan-Meier survival analysis compared differences in the resolution rate by lens status and other significant factors. Results: Overall, 243 eyes were included. Pseudophakia (HR, 1.76; 95% CI, 1.07-2.90; P = .03) and prior PPV (HR, 3.28; 95% CI, 1.77-6.07; P < .001) were significant factors for faster resolution. Pseudophakic eyes resolved in 5.5 months (median, 25.1 weeks; 95% CI, 19.3-31.0) and phakic eyes in 10 months (median, 43.0 weeks; 95% CI, 36.0-50.0) (P = .001). More pseudophakic eyes than phakic eyes resolved without PPV (44.2% vs 24.8%) (P = .001). Eyes without prior PPV resolved in 9.5 months (median, 41.0 weeks; 95% CI, 35.7-46.3) compared with 5 months (median, 22.3 weeks; 95% CI, 9.8-34.8) in vitrectomized eyes (P < .001). Age, treatment with antivascular endothelial growth factor injections or panretinal photocoagulation, intraocular pressure medications, and glaucoma history were not significant predictors. Conclusions: Diabetic VH resolved almost twice as fast in pseudophakic eyes than in phakic eyes. Eyes with a history of PPV resolved 3 times quicker than those without PPV. A better understanding of VH resolution can help personalize the decision on when to proceed with PPV.

The Association of Neovascularization With Optical Coherence Tomography Angiography Parameters in Proliferative Diabetic Retinopathy

AIM

We aim to find an association between neovascularization (NVn) and optical coherence tomography angiography (OCTA) parameters in proliferative diabetic retinopathy (PDR).

METHODS

In a prospective study, 41 subjects including 28 (68%) males and 13 (32%) females having PDR were examined for neovascularization disc (NVD) and neovascularization elsewhere (NVE) clinically and with fundus fluorescein angiography (FFA). A total of 79 eyes were found to be involved. We examined OCTA parameters including foveal avascular zone (FAZ) size, perimeter and circularity, and vessel density (VD) in the superficial capillary plexus (SCP), deep capillary plexus (DCP), outer retina (OR), outer retinal chorio-capillaries (ORCC), chorio-capillaries (CC), and choroid (C) in these subjects.

RESULTS

 In eyes with NVD, the central foveal thickness (CFT) (p=0.83) and sub-foveal choroidal thickness (SFCT) (p=0.08) were higher, the FAZ area was significantly larger (p=0.005), and the VD was lower in all retino-choroidal layers. However, it was significantly lower in SCP foveal (p=0.005) and ORCC foveal (p=0.05) than in eyes not having NVD. For NVE, the CFT (p=0.03) and SFCT (p=0.01) were more in affected eyes. The eyes without NVE had a better circularity index (p=0.07) and the highest VD in OR slab (p=0.02) than those eyes that had NVE < ½ disc area (DA) and NVE > ½ DA. On comparing eyes without NVE, NVE < ½ DA, and NVE > ½ DA, the latest had the highest VD in SCP (p=0.59) and lowest VD in DCP (p=0.43) and OR (p=0.02). The VD in ORCC, CC, and choroid was highest in the no NVE group, followed by the NVE > ½ DA and NVE < ½ DA groups in that order. The subjects having vitreous hemorrhage (VH) and intra-retinal microvascular abnormalities (IRMA) had higher values for CFT and SFCT than eyes without these.

CONCLUSIONS

 An increased CFT and SFCT are associated with the appearance of NVD, NVE, VH, and IRMA. The presence of NVD, VH, and IRMA is associated with a larger FAZ area, while that of IRMA and NVE is associated with reduced FAZ circularity. Eyes with NVD, VH, and IRMA had lesser VD in all the retino-choroidal layers. Eyes with NVE > ½ DA had the highest VD in SCP and lowest in DCP and OR; this pattern of VD foretells severer affection in NVE. IRMA was associated with a larger FAZ area, larger FAZ perimeter, and lesser circularity, indicating the presence of central ischemia.

Risk Factors for Recurrent Vitreous Hemorrhage in Type 2 Diabetes Mellitus Patients after Posterior Vitrectomy

(Background) The aim of this study was to determine the factors related to recurrent vitreous hemorrhage (RVH) in a sample of proliferative diabetic retinopathy (PDR) patients. (Methods) This was a retrospective, review-based study. We studied 183 eyes from 121 type 2 diabetes patients with PDR. We recorded the duration of diabetes, history of hypertension, retinal photocoagulation status, posterior vitreous status, mean HbA1c and hemoglobin levels, renal function, and systemic complications associated with diabetes. We also recorded surgical variables-the presence of tractional retinal detachment, the application of segmentation and diathermy on fibrovascular proliferative tissue, and the use of silicone oil-to study which independent variables were significantly related to the presence of RVH. (Results) The duration of diabetes (p = 0.028), hemoglobin level (p = 0.02), status of the posterior vitreous (p = 0.03), retinal photocoagulation status (p = 0.002), and the presence of tractional retinal detachment (p = 0.03) were significantly associated with the presence of RVH. On the other hand, the use of diathermy was associated with fewer RVH events (p < 0.005). In addition, patients with diabetic polyneuropathy, myocardial infarction, and ischemia in the lower limbs exhibited more vitreous hemorrhage events (p < 0.001). (Conclusions) Patients with PDR and a longer diabetes duration, anemia, attached posterior vitreous, deficient retinal photocoagulation, and prior cardiovascular events were more prone to RVH.

Spontaneous Resolution of Tractional Retinal Detachment in a Type II Diabetic Patient

A 43 years old male with diabetes type II was under treatment for diabetic retinopathy with extramacular tractional retinal detachment (TRD) in the left eye OS. During the follow-up visit, the patient had a drop in vision from 20/25 to 20/60. The TRD was found to have progressed to involve the macula and was threatening the fovea; therefore, vitrectomy was thought to be inevitable. Meanwhile, the patient adopted exercise and tight glycemic control, and during the preoperative evaluation of three months duration, we observed resolution of traction and return of visual acuity to baseline (20/20). In conclusion, spontaneous resolution of TRD is extremely rare. If it occurs, the patient may be spared from undergoing a vitrectomy.

In a Large Healthcare System in the Bronx, Teleretinal Triaging Was Found to Increase Screening and Healthcare Access for an Underserved Population with a High Incidence of T2DM and Retinopathy

The early treatment of diabetic retinopathy (DR) prevents vision-threatening proliferative retinopathy (PDR) and macular edema (DME). Our study evaluates telemedicine (teleretinal) screening for DR in an inner-city healthcare network with a high ethnic diversity and disease burden. Fundus photographs were obtained and graded in a centralized reading center between 2014 and 2016. Patients with positive screenings were referred to a retina specialist. An analysis of sensitivity and specificity and a subgroup analysis of prevalence, disease severity, and follow-up adherence were conducted. In 2251 patients, the '1-year' and 'Overall' follow-ups were 35.1% and 54.8%, respectively. Severe grading, male gender, and age were associated with better follow-up compliance. The DR, PDR, and DME prevalence was 24.9%, 4.1%, and 5.9%, respectively, and was significantly associated with HbA1c. The sensitivity and specificity for DR, PDR, and DME were 70% and 87%, 87% and 75%, and 37% and 95%, respectively. No prevalence differences were noted between ethnicities. Annual diabetic eye exam adherence increased from 55% to 85% during the study period. Teleretinal triaging is sensitive and specific for DR and improved diabetic eye exam compliance for underserved populations when integrated into large healthcare networks. The adherence to follow-up recommendations was better among older patients and among those with more severe retinopathy.

Effect of Intravitreal Conbercept Injection on Complications of Pars Plana Vitrectomy in Patients with Proliferative Diabetic Retinopathy

BACKGROUND

The effect of intravitreal conbercept (IVC) before pars plana vitrectomy (PPV) on surgical complications in patients with proliferative diabetic retinopathy (PDR) was observed.

METHODS

A total of 152 patients with PDR operated on in Jiangsu Provincial People's Hospital from November 2019 to November 2020 were divided into two groups: 124 patients in the preoperative intravitreal conbercept injection + PPV group (IVC group) and 28 patients in the PPV only group (No-IVC group). Vitreous samples were collected in all eyes of patients who underwent vitrectomy, and the content of VEGF-A was measured by Luminex. The effect of conbercept on intraoperative and postoperative complications of PDR was assessed.

RESULTS

The content of VEGF in the vitreous of the IVC group was significantly lower than that in the No-IVC group (64.50 ± 58.40 pg/mL vs. 805.17 ± 417.60 pg/mL, p < 0.001). During postoperative follow-up, early postoperative vitreous hemorrhage (VH) occurred in 13 of 142 eyes (9.15%). Compared with the No-IVC group, PDR patients with VH and fibrovascular membrane (FVM) or high complexity in the IVC group had lower intraoperative bleeding rates (p < 0.05). The early postoperative hemorrhage rate in the IVC group was lower than in the No-IVC group (6.03% vs. 23.08%, p < 0.05). The number of intraoperative electrocoagulation and iatrogenic retinal holes in the IVC group was significantly lower than in the No-IVC group (p < 0.05). There were no significant differences in intraocular hypertension and NVG numbers between the two groups. Visual acuity in both groups improved after PPV surgery, reaching the highest level in the 3rd month after the operation.

CONCLUSIONS

IVC before PPV can reduce the level of VEGF-A in the vitreous body and reduce surgical complications.