Intravitreal bevacizumab (Avastin) for proliferative diabetic retinopathy: 6-months follow-up

Factors Affecting Compliance and Visual Outcomes in Patients Receiving Intravitreal Bevacizumab Injections

Background Vascular endothelial growth factor (VEGF) is a powerful mitogen for endothelial cells that promotes migration, proliferation, and tube formation necessary for the angiogenic development of new blood vessels. When VEGF increases significantly, it causes pathological angiogenesis and increased vascular permeability in eye conditions such as diabetic retinopathy (DR), age-related macular degeneration (AMD), and retinal vein occlusion (RVO). These disorders have become important global sources of morbidity and have a substantial financial impact not only on the medical community but also on the patients. Therefore, this study aims to determine the success rates of intravitreal bevacizumab therapy and the visual outcomes which may be increased by determining the factors affecting patient compliance and raising awareness about DR, neovascular AMD, and RVO among patients and studying the factors responsible for non-compliance to treatment. Methodology This experimental pre-post study was conducted in the ophthalmology department at a tertiary care hospital and research center in western Maharashtra from September 2022 to June 2024. A total of 150 eyes of 150 patients who were diagnosed cases of DR, neovascular AMD, and non-ischemic RVO were included in the study. Written informed consent was obtained from each patient. Data were entered in Microsoft Excel (Microsoft Corp., Redmond, WA, USA) and statistical analysis was done using SPSS 27.0 software (IBM Corp., Armonk, NY, USA). The chi-square test was employed to check the association between categorical variables. Pearson's correlation test was used, and p-values <0.05 were considered significant. Results The compliance rate in our study was 79.3% (113 individuals). In our study, 58% (87 individuals) were male while 42% (63 individuals) were females. Most patients were from urban areas 74.7% (112 individuals). Among the study participants, DR patients constituted 48.6% (73 individuals), while neovascular AMD and RVO were seen in 32% (48 individuals) and 19.4% (29 individuals), with 62% (93 individuals) being diabetic and 64.7% (97 individuals) being hypertensive. In our study, 92% (138 individuals) were willing to take treatment, with 88.7% (133 individuals) worried about their visual outcomes and 66% (99 individuals) afraid of getting injected. Appointments posed a financial burden to 30.7% (46 individuals) of patients, with 55.3% (83 individuals) having transportation issues. Overall, 18.7% (28 individuals) of patients had missed appointments between 14 and 90 days while 30.7% (46 individuals) had missed their appointments by 90 and 365 days. Younger patients with a shorter duration of diabetes had higher compliance rates. Post-injection, there was an overall significant improvement in vision as well as a reduction in the central subfield macular thickness, volume cube, and thickness average cube. Conclusions In the present study, four-fifths of the patients were compliant with treatment, and visual improvement was significant. In addition, there was a significant reduction in the macular thickness after the treatment. One of the factors for non-compliance included in our study was the need for follow-up. Younger patients and those with a shorter duration of diabetes had significantly higher compliance. We recommend further studies should be conducted to compare the effectiveness with the control group in randomized control trials.

Retrospective Study of Diabetic Retinopathy and Macular Edema in Southern Part of Bangladesh

Background

Diabetic mellitus is a vision-threatening disease because it causes diabetic retinopathy worldwide. The main focus of this research is to determine the prevalence and assess the visual outcome in diabetic retinopathy and macular edema patients by injecting Bevacizumab clinically.

Methods

This hospital-based trial case was conducted in Khulna BNSB Eye Hospital, Bangladesh. This study is based on a prospective cohort with a population of macular edema in 41 eyes of 25 diabetic patients, of whom 94 were diagnosed with diabetic retinopathy in 320 type 2 diabetes mellitus patients. The treating physician inserts 1.25 mg (0.05 ml) into the patient's eye. We have used optical coherence tomography (OCT) and colour fundus photography (CFP) for an eye check performed on all patients before and after the injection of Bevacizumab. The method results analyze the effects of the technique using IBM SPSS 25.

Results

The study population selected 25 patients with 41 eyes for clinical investigation by injection of Bevacizumab. The net effects of this study on five eyes with macular edema were entirely resolved. It was BCVA from 6/6 to 6/9. The 29 eyes were partially resolved, which is called improved visual acuity, and BCVA was 6/12 to 6/60. In the case of seven eyes, we found that the vision did not change before or after the Avastin injection. No change was seen in seven eyes of macular edema due to the effects of the Avastin injection before and after.

Conclusions

In clinical trial-based research, Bevacizumab (Avastin) is best effective for diabetic retinopathy (DR) and diabetic macular edema (DME) patients.

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.

Efficacy of ranibizumab combined with photocoagulation for diabetic retinopathy: A meta-analysis study

BACKGROUND

Ranibizumab addition may benefit to improve the efficacy in patients with diabetic retinopathy than only photocoagulation, and this meta-analysis aims to explore the impact of ranibizumab addition on efficacy for diabetic retinopathy.

METHODS

PubMed, EMbase, Web of science, EBSCO, and Cochrane library databases were systematically searched, and we included randomized controlled trials assessing the effect of ranibizumab addition on patients with diabetic retinopathy for this meta-analysis.

RESULTS

Six randomized controlled trials were finally included in the meta-analysis. Overall, compared with control intervention for diabetic retinopathy, ranibizumab addition showed significantly increased number of neovascularization area reduction (OR = 4.20; 95% CI = 1.47-12.02; P = .007) and reduced fluorescein leakage (MD = -2.53; 95% CI = -3.31 to -1.75; P < .00001), but showed no obvious impact on neovascularization area (MD = -1.80; 95% CI = -3.68 to 0.08; P = .06), photocoagulation retreatment (OR = 1.03; 95% CI = 0.47-2.27; P = .94) or adverse events (OR = 1.45; 95% CI = 0.49-4.29; P = .50).

CONCLUSIONS

Ranibizumab combined with photocoagulation is effective to improve efficacy for diabetic retinopathy.

Prophylactic intravitreal injection of aflibercept for preventing postvitrectomy hemorrhage in proliferative diabetic retinopathy: A randomized controlled trial

Introduction

The aim of this study was to assess the effects of preoperative intravitreal aflibercept (IVA) injection on the incidence of postoperative vitreous hemorrhage (VH) after vitrectomy for proliferative diabetic retinopathy (PDR).

Methods

This study involved a prospective, randomized clinical trial. One hundred twenty-eight eyes of 128 patients of PDR who underwent pars plana vitrectomy (PPV) were enrolled. Sixty-four eyes were assigned randomly to either the IVA group (IVA injection 1 to 5 days before PPV) or the control group (no IVA injection). The primary outcome was the incidence of VH at 1 month after PPV. Secondary outcome measures were best-corrected visual acuity (BCVA) changes from baseline to at 1 week, 1 month, 2 months, and 3 months after surgery.

Results

The VH incidences in the IVA group and the control group were 14.8 and 39.3% at week 1, 8.6 and 31.7% at month 1, 11.7 and 30.5% at month 2, and 8.6 and 30.5% at month 3, respectively. Intergroup differences showed a significantly decreased VH rate in the IVA group compared with that in the control group at week 1, month 1, and month 3 (p = 0.021, 0.006, and 0.047, respectively). Compared to the baseline, neither the mean BCVA nor the BCVA change in the Logarithm of the Minimum Angle of Resolution (logMAR) scale did differ significantly between the two groups at each visit point. There are a greater number of eyes with BCVA improvement of more than 2 logMAR in the IVA group than in the control group at week 1 (8 vs. 2, p = 0.048).

Conclusions

This study found that the adjunctive use of preoperative IVA reduces early and late postoperative VH in vitrectomy for PDR.

Resveratrol, an Inhibitor Binding to VEGF, Restores the Pathology of Abnormal Angiogenesis in Retinopathy of Prematurity (ROP) in Mice: Application by Intravitreal and Topical Instillation

Retinopathy of prematurity (ROP) is a severe eye disease leading to blindness. Abnormal vessel formation is the pathological hallmark of neovascular ROP. In forming vessels, vascular endothelial growth factor (VEGF) is an important stimulator. The current anti-ROP therapy has focused on bevacizumab, a monoclonal antibody against VEGF, and pazopanib, a tyrosine kinase inhibitor on the VEGF receptor (VEGFR). Several lines of evidence have proposed that natural compounds may be more effective and safer for anti-VEGF function. Resveratrol, a common natural compound, binds to VEGF and blocks its interaction with VEGFR, thereafter suppressing angiogenesis. Here, we evaluate the efficacy of intravitreal injection, or topical instillation (eye drops), of resveratrol into the eyes of mice suffering from oxygen-induced retinopathy, i.e., developing ROP. The treatment of resveratrol significantly relieved the degree of vascular distortion, permeability and hyperplasia; the efficacy could be revealed by both methods of resveratrol application. In parallel, the treatments of resveratrol inhibited the retinal expressions of VEGF, VEGFR and CD31. Moreover, the applied resveratrol significantly relieved the damage caused by oxygen radicals through upregulating the level of superoxide dismutase (SOD) and downregulating the level of malondialdehyde (MDA) in the retina. Taken together, the potential therapeutic benefit of resveratrol in pro-angiogenic diseases, including retinopathy, can be considered.

Recent trends in drug-delivery systems for the treatment of diabetic retinopathy and associated fibrosis

Diabetic retinopathy is a frequent microvascular complication of diabetes and a major cause of visual impairment. In advanced stages, the abnormal neovascularization can lead to fibrosis and subsequent tractional retinal detachment and blindness. The low bioavailability of the drugs at the target site imposed by the anatomic and physiologic barriers within the eye, requires long term treatments with frequent injections that often compromise patient's compliance and increase the risk of developing more complications. In recent years, much effort has been put towards the development of new drug delivery platforms aiming to enhance their permeation, to prolong their retention time at the target site and to provide a sustained release with reduced toxicity and improved efficacy. This review provides an overview of the etiology and pathophysiology of diabetic retinopathy and current treatments. It addresses the specific challenges associated to the different ocular delivery routes and provides a critical review of the most recent developments made in the drug delivery field.

A 60% Edible Ethanolic Extract of Ulmus davidiana Inhibits Vascular Endothelial Growth Factor-Induced Angiogenesis

As abnormal angiogenesis is associated with exacerbation of various diseases, precise control over angiogenesis is imperative. Vascular endothelial growth factor (VEGF), the most well-known angiogenic factor, binds to VEGF receptor (VEGFR), activates various signaling pathways, and mediates angiogenesis. Therefore, blocking the VEGF-induced angiogenic response-related signaling pathways may alleviate various disease symptoms through inhibition of angiogenesis. Ulmus davidiana is a safe natural product that has been traditionally consumed, but its effects on endothelial cells (ECs) and the underlying mechanism of action are unclear. In the present study, we focused on the effect of a 60% edible ethanolic extract of U. davidiana (U60E) on angiogenesis. U60E inhibited the VEGF-mediated proliferation, tube formation, and migration ability of ECs. Mechanistically, U60E inhibited endothelial nitric oxide synthase activation and nitric oxide production by blocking the protein kinase B signaling pathway activated by VEGF and consequently inhibiting proliferation, tube formation, and migration of ECs. These results suggest that U60E could be a potential and safe therapeutic agent capable of suppressing proangiogenic diseases by inhibiting VEGF-induced angiogenesis.

Comparison of efficacy of combination therapy of an Intravitreal injection of bevacizumab and photocoagulation versus Pan Retinal Photocoagulation alone in High risk Proliferative Diabetic Retinopathy

Objective:

To compare efficacy of intravitreal bevacizumab augmented with Panretinal photocoagulation versus Panretinal photocoagulation alone in high risk proliferative diabetic retinopathy.

Methods:

This is Randomized clinical control trial study conducted at ISRA University Hospital, Hyderabad from July 2018 to December 2018. A total of 76 eyes were randomized into two groups, 38 eyes undergone PRP plus intravitreal bevacizumab, while 38 eyes had PRP alone. Status of neovessels was assessed before and after treatment with the help of fundus fluorescein angiography. Neovessels at disc (NVD’s) and neovessels elsewhere (NVE’s) were assessed with the disc surface diameter.

Results:

Seventy-six eyes were enrolled in this randomized clinical trial into two groups consecutively, that all completed the six months follow-up. In the PRP group mean BCVA (logMAR) worsened significantly from mean 0.30±0.07 to mean 0.40±0.04 at a 30^th day and mean 0.40±0.04 at day 90. While BCVA become improved from 0.30±0.05 to 0.1±0.03 at week four and 0.1±0.02 at week 12 in PRP-Plus group. There was significant change in regression of NVES in PRP only group at week 4 is 2.25±0.75 (p=0.00004) and at 12 weeks 2.00±0.50 (p=0.00002), while in PRP + intravitreal bevacizumab group at 4^th week was 1±0.5 (p =0.0001) and at 12^th week was 0.75±0.25 (p=0.0001).

Conclusion:

Intravitreal Bevacizumab augmented with PRP is more effective in early regression of neovessels in high risk PDR patients.

Intravitreal ranibizumab for persistent diabetic vitreous haemorrhage: a randomised, double-masked, placebo-controlled feasibility study

PURPOSE

To determine the feasibility of a definitive study of intravitreal ranibizumab to promote the clearance of persistent diabetic vitreous haemorrhage and thereby avoid vitrectomy.

METHODS

This randomised, double-masked, placebo-controlled feasibility study recruited 24 participants with persistent diabetic vitreous haemorrhage listed for pars plana vitrectomy. Participants were randomised to a single 0.5-mg intravitreal ranibizumab injection or a single subconjunctival saline injection. The primary outcome measure was the number of participants requiring pars plana vitrectomy at week 7.

RESULTS

Eight of 12 participants (66.7%) in the ranibizumab group required vitrectomy at week 7 versus 12 of 12 (100%) in the placebo group (absolute risk reduction 33.3%, 95% confidence interval 2.1-70.7%; p = 0.09). One additional eye in the ranibizumab group required vitrectomy by 12 months. Mean visual acuity letter score at 12 months was 72.7 ± 12.3 in the ranibizumab group and 75.1 ± 10.1 in the placebo group. Safety was similar across groups.

CONCLUSION

Intravitreal ranibizumab may reduce the likelihood of proceeding to vitrectomy in patients with persistent, dense diabetic vitreous haemorrhage. Further studies appear feasible and justified.

TIME COURSE OF CHANGES IN OPTIC DISK NEOVASCULARIZATION AFTER A SINGLE INTRAVITREAL BEVACIZUMAB INJECTION

PURPOSE

To evaluate the longitudinal changes in optic disk neovascularization (NVD) after intravitreal bevacizumab injection using optical coherence tomography angiography.

METHODS

In this prospective, interventional, case series, eyes with NVD secondary to diabetic retinopathy were enrolled. En face optical coherence tomography angiographic images were obtained from the optic disks before and 3 hours, 6 hours, 24 hours, 7 days, and 30 days after intravitreal bevacizumab injection. The size and flow area of the neovascularization were measured by two graders.

RESULTS

Eleven eyes of 9 patients with a mean age of 52.11 ± 9.48 years were included. The reduction in the NVD size and flow area was statistically significant at 24 hours, 7 days, and 30 days after injections compared with the baseline measurements (all P < 0.05). The decremental regression in the NVD size and flow area continued during the study course. The changes were not statistically significant in 3-hour and 6-hour measurements (all P > 0.05).

CONCLUSION

In this study, statistically significant regression in the NVD size and flow area was observed as early as 24 hours after a single intravitreal bevacizumab injection, with a continued decreasing trend for at least a 1-month period.

Anti-Vascular Endothelial Growth Factor Therapy as an Alternative or Adjunct to Pan-Retinal Photocoagulation in Treating Proliferative Diabetic Retinopathy: Meta-Analysis of Randomized Trials

Aim

To compare anti-vascular growth factor (anti-VEGF) pharmacotherapy with pan-retinal photocoagulation (PRP) for proliferative diabetic retinopathy (PDR).

Method

PubMed, Embase, Medline, the ClinicalTrials.gov and the Cochrane Central Register of Controlled Trials were reviewed systemically. Randomized controlled trials (RCT) on anti-VEGF therapy versus PRP or anti-VEGF agent combined with PRP versus PRP for PDR are eligible to be included. Outcome measures were regression and recurrence of neovascularization, change in best corrected vision acuity, development of vitreous hemorrhage, and need for vitrectomy. A meta-analysis was conducted using RevMan (Cochrane Collaboration, Oxford, United Kingdom).

Results

Twelve RCTs with a total of 1026 eyes were identified. The meta-analysis results showed that regression of neovascularization did not vary significantly among different treatment regimens (P=0.06), whereas the recurrence of new vessels was significantly lower in PRP monotherapy (P < 0.00001). The best corrected visual acuity was significantly improved with anti-VEGF monotherapy or in the combined group than in the PRP groups (P < 0.00001, P=0.04, respectively). Odds ratio for post-treatment vitreous hemorrhage and vitrectomy rate between anti-VEGF therapy and PRP were 0.65 (95% confidence interval, 0.45–0.95; P = 0.03), and 0.24 (95% confidence interval, 0.12–0.48; P < 0.0001).

Conclusion

Our meta-analysis indicates that anti-VEGF pharmacotherapy is associated with superior visual acuity outcomes and less PDR-related complications. However, there is insufficient evidence to suggest anti-VEGF therapy as an alternative to PRP.

Ghost cell glaucoma after intravitreous injection of ranibizumab in proliferative diabetic retinopathy

Background

The development of ghost cell glaucoma in patients with proliferative diabetic retinopathy (PDR) after intravitreous injection (IV) was rare. Here we reported a series of patients with PDR who received Intravitreous Ranibizumab (IVR) and developed ghost cell glaucoma and analyzed the potential factors that might be related to the development of ghost cell glaucoma.

Methods

Retrospective case series study. The medical records of 71 consecutive eyes of 68 PDR patients who received vitrectomy after IVR from January 2015 to January 2017 were reviewed. The development of ghost cell glaucoma after IVR was recorded. Characteristics of enrolled patients were retrieved from their medical charts. Factors associated with ghost cell glaucoma were compared between eyes with the development of ghost cell glaucoma and eyes without the development of ghost cell glaucoma. Variables were further enrolled in a binary backward stepwise logistic regression model, and the model that had the lowest AIC was chosen.

Results

There were 8 out of 71 eyes of the PDR patients developed ghost cell glaucoma after they received IVR. The interval between detection of elevation of intraocular pressure (IOP) and IV ranged from 0 to 2 days. Among them, after IVR, there were two eyes had IOP greater than 30 mmHg within 30 min, four eyes showed normal IOP at 30 min, and then developed ghost cell glaucoma within 1 day, two eyes developed ghost cell glaucoma between 24 and 48 h. The mean IOP was 46.5 ± 8.0 mmHg. All patients gained normal IOP after vitrectomy without medicine for lowering IOP. The presence of ghost cell glaucoma was associated with tractional retinal detachment (RR = 4.60 [2.02 ~ 8.48], p = 0.004) and fibrovascular membrane involving disk (RR = -3.57 [− 7.59 ~ − 0.92], p = 0.03) (AIC = 39.23, AUC = 0.88) in a logistic regression model.

Conclusion

Attention to postoperative IOP should be paid to patients with PDR undergoing vitrectomy who receive a preoperative IV of anti-VEGF agents. PDR patients with tractional retinal detachment or fibrovasucular membrane involving optic disc are more likely to develop ghost cell glaucoma after IV.

Vascular endothelial growth factor inhibition and proliferative diabetic retinopathy, a changing treatment paradigm?

Prior to the development of panretinal photocoagulation (PRP) in the 1970s, proliferative diabetic retinopathy (PDR) was the most common cause of blindness in diabetic patients. The diabetic retinopathy study demonstrated that PRP could decrease severe visual loss from PDR by 50%. Since then and for the past four decades, PRP has been the treatment of choice for eyes with PDR. In the past decade, vascular endothelial growth factor (VEGF) inhibition has become the treatment of choice for diabetic macular edema (DME). When treated intensively with anti-VEGF drugs, about one-third of eyes with DME experience an improvement in their diabetic retinopathy severity scale. Randomized clinical trials comparing ranibizumab to PRP and aflibercept to PRP have shown that VEGF inhibitors cause regression of intraocular neovascularization but need to be given on a fairly regular basis. Despite these promising results, concerns about treatment adherence have surfaced. Patients with PDR that are treated solely with anti-VEGF drugs and somehow interrupt their treatment are at a high risk of developing irreversible blindness. Combination treatment of PRP plus an anti-VEGF drug may be the treatment of choice for PDR.

Spermine oxidase: A promising therapeutic target for neurodegeneration in diabetic retinopathy

Diabetic Retinopathy (DR), is a significant public health issue and the leading cause of blindness in working-aged adults worldwide. The vision loss associated with DR affects patients' quality of life and has negative social and psychological effects. In the past, diabetic retinopathy was considered as a vascular disease; however, it is now recognized to be a neuro-vascular disease of the retina. Current therapies for DR, such as laser photocoagulation and anti-VEGF therapy, treat advanced stages of the disease, particularly the vasculopathy and have adverse side effects. Unavailability of effective treatments to prevent the incidence or progression of DR is a major clinical problem. There is a great need for therapeutic interventions capable of preventing retinal damage in DR patients. A growing body of evidence shows that neurodegeneration is an early event in DR pathogenesis. Therefore, studies of the underlying mechanisms that lead to neurodegeneration are essential for identifying new therapeutic targets in the early stages of DR. Deregulation of the polyamine metabolism is implicated in various neurodegenerative diseases, cancer, renal failure, and diabetes. Spermine Oxidase (SMOX) is a highly inducible enzyme, and its dysregulation can alter polyamine homeostasis. The oxidative products of polyamine metabolism are capable of inducing cell damage and death. The current review provides insight into the SMOX-regulated molecular mechanisms of cellular damage and dysfunction, and its potential as a therapeutic target for diabetic retinopathy. Structural and functional changes in the diabetic retina and the mechanisms leading to neuronal damage (excitotoxicity, loss of neurotrophic factors, oxidative stress, mitochondrial dysfunction etc.) are also summarized in this review. Furthermore, existing therapies and new approaches to neuroprotection are discussed.

Retinopathy among Chinese subjects with type 2 diabetes mellitus in Shanghai: A community-based follow-up study

OBJECTIVE

To determine the incidence, progression, and regression rates of diabetic retinopathy (DR), as well as their associated factors, in Chinese type 2 diabetic patients.

METHODS

Diabetic patients who participated in a previous survey were recruited for a 1-year follow-up study. Nonmydriatic fundus photographs were acquired to assess the severity of DR as per the International Clinical Diabetic Retinopathy Disease Severity Scale (2002). Factors that potentially influence DR outcomes, including its incidence, progression, and regression, were identified via statistical analyses.

RESULTS

We initially recruited 2453 subjects, among whom 2331 were followed and included in the final analysis. The incidences of new and progressed (ie, ≥2 scale steps) DR were 10.6% and 6.1%, respectively. Moreover, 7.3% of patients with established DR at baseline experienced complete regression. Multivariate logistic regression analysis revealed that high glycosylated haemoglobin (HbA1c) (odds ratio [OR] = 1.50, P = .021) and hyperlipidaemia (OR = 1.46, P = .025) were independent predictors of DR development, high HbA1c (OR = 4.16, P = .027) and macroalbuminuria (OR = 5.60, P = .010) predicted DR progression, and low HbA1c (OR = 0.20, P = .001) and low triglyceride levels (OR = 0.34, P = .026) were associated with DR regression.

CONCLUSIONS

Albumin and HbA1c levels should be closely monitored as signs of progressive retinal damage in diabetic subjects. Optimized control of glucose and triglyceride levels is vital for reducing the incidence of DR or promoting its regression in afflicted patients.

Role of oxidative stress, inflammation, hypoxia and angiogenesis in the development of diabetic retinopathy

Diabetic retinopathy (DR) is a retinal disease which is one of the most severe complications occuring due to diabetes mellitus and is a major cause of blindness. Patients who have diabetes mellitus for number of years develop characteristic group of lesions in the retina which leads to Diabetic retinopathy. It is a multifactorial condition occuring due to complex cellular interactions between biochemical and metabolic abnormalities taking place in all retinal cells. Considerable research efforts in the past 20 years have suggested that the microvasculature of the retina responds to hyperglycemia through a number of biochemical changes, which includes polyol pathway, protein kinase C activation, upregulation of advanced glycation end products formation and renin angiotensin system activation. Various previous studies had suggest that interaction of these biochemical changes may cause a cascade of events, such as apoptosis, oxidative stress, inflammation and angiogenesis which can lead to the damage of a diabetic retina, causing DR. This highlights that oxidative stress, inflammation, angiogenesis-related factors triggers the occurrence of retinal complication in diabetes are highlighted.

Oleanolic Acids Inhibit Vascular Endothelial Growth Factor Receptor 2 Signaling in Endothelial Cells: Implication for Anti-Angiogenic Therapy

Angiogenesis must be precisely controlled because uncontrolled angiogenesis is involved in aggravation of disease symptoms. Vascular endothelial growth factor (VEGF)/VEGF receptor 2 (VEGFR-2) signaling is a key pathway leading to angiogenic responses in vascular endothelial cells (ECs). Therefore, targeting VEGF/VEGFR-2 signaling may be effective at modulating angiogenesis to alleviate various disease symptoms. Oleanolic acid was verified as a VEGFR-2 binding chemical from anticancer herbs with similar binding affinity as a reference drug in the Protein Data Bank (PDB) entry 3CJG of model A coordination. Oleanolic acid effectively inhibited VEGF-induced VEGFR-2 activation and angiogenesis in HU-VECs without cytotoxicity. We also verified that oleanolic acid inhibits in vivo angiogenesis during the development and the course of the retinopathy of prematurity (ROP) model in the mouse retina. Taken together, our results suggest a potential therapeutic benefit of oleanolic acid for inhibiting angiogenesis in proangiogenic diseases, including retinopathy.

Observation of optic disc neovascularization using OCT angiography in proliferative diabetic retinopathy after intravitreal conbercept injections

This study reports the short-term efficacy and safety of intravitreal conbercept injections for neovascularization at the disc (NVD) in patients with proliferative diabetic retinopathy (PDR). Conbercept is a recombinant fusion protein with a high affinity for all isoforms of vascular endothelial growth factor (VEGF)-A, placental growth factor and VEGF-B. A prospective case series study was conducted in 15 patients (15 eyes). Patients had complete ocular examinations and received a 0.5 mg intravitreal conbercept injection followed by supplemental pan-retinal photocoagulation (PRP). Optical coherence tomography angiography (OCTA) was performed before and after treatment. Before treatment, the mean NVD area was 1.05 ± 0.33 mm², and it decreased to 0.56 ± 0.17 mm² after an interval of 7.5 d (p = 0.000). One eye required vitrectomy during follow-up. Recurrent NVD was observed in 2 eyes, which resolved after repeated injections. The remaining 12 eyes were stable over a mean follow-up period of 8.3 months. The mean area of the NVD in 14 patients without vitrectomy was 0.22 ± 0.11 mm² (p = 0.000) at the last visit. Intravitreal conbercept injections combined with intensive PRP are an effective and safe treatment for PDR with NVD. Quantitative information on NVD can be obtained with OCTA, which may be clinically useful in evaluating the therapeutic effect.

Ranibizumab Plus Panretinal Photocoagulation versus Panretinal Photocoagulation Alone for High-Risk Proliferative Diabetic Retinopathy (PROTEUS Study)

PURPOSE

Comparison of the efficacy of ranibizumab (RBZ) 0.5 mg intravitreal injections plus panretinal photocoagulation (PRP) versus PRP alone in the regression of the neovascularization (NV) area in subjects with high-risk proliferative diabetic retinopathy (HR-PDR) over a 12-month period.

DESIGN

Prospective, randomized, multicenter, open-label, phase II/III study.

PARTICIPANTS

Eighty-seven participants (aged ≥18 years) with type 1/2 diabetes and HR-PDR (mean age, 55.2 years; 37% were female).

METHODS

Participants were randomized (1:1) to receive RBZ+PRP (n = 41) or PRP monotherapy (n = 46). The RBZ+PRP group received 3 monthly RBZ injections along with standard PRP. The PRP monotherapy group received standard PRP between day 1 and month 2; thereafter, re-treatments in both groups were at the investigators' discretion.

MAIN OUTCOME MEASURES

The primary outcome was regression of NV total, on the disc (NVD) plus elsewhere (NVE), defined as any decrease in the area of NV from the baseline to month 12. Secondary outcomes included best-corrected visual acuity (BCVA) changes from baseline to month 12, time to complete NV regression, recurrence of NV, macular retinal thickness changes from baseline to month 12, need for treatment for diabetic macular edema, need for vitrectomy because of occurrence of vitreous hemorrhage, tractional retinal detachment or other complications of DR, and adverse events (AEs) related to treatments.

RESULTS

Seventy-seven participants (88.5%) completed the study. Overall baseline demographics were similar for both groups, except for age. At month 12, 92.7% of participants in the RBZ+PRP group presented NV total reduction versus 70.5% of the PRP monotherapy participants (P = 0.009). The number of participants with NVD and NVE reductions was higher with RBZ+PRP (93.3% and 91.4%, respectively) versus PRP (68.8% and 73.7%, respectively), significant only for NVE (P = 0.048). Complete NV total regression was observed in 43.9% in the RBZ+PRP group versus 25.0% in the PRP monotherapy group (P = 0.066). At month 12, the mean BCVA was 75.2 letters (20/32) in the RBZ+PRP group versus 69.2 letters (20/40) in the PRP monotherapy group (P = 0.104). In the RBZ+PRP group, the mean number of PRP treatments over month 12 was 3.5±1.3, whereas in the PRP monotherapy group, it was 4.6±1.5 (P = 0.001). No deaths or unexpected AEs were reported.

CONCLUSIONS

Treatment with RBZ+PRP was more effective than PRP monotherapy for NV regression in HR-PDR participants over 12 months.

Experience with Intravitreal Bevacizumab as a Preoperative Adjunct in 23-G Vitrectomy for Advanced Proliferative Diabetic Retinopathy

Purpose

To evaluate the safety and efficacy of intravitreal injection of bevacizumab before vitrectomy in advanced proliferative diabetic retinopathy.

Methods

A randomized clinical trial was performed on 40 eyes of 40 patients. Inclusion criteria were advanced proliferative diabetic retinopathy with fractional retinal detachment and HbA1c <7%. Patients were randomly assigned into 2 groups. Patients in one group had an intravitreal injection (1.25 mg) of bevacizumab 48 hours before 23-G pars plana vitrectomy surgery was performed, whereas the other group did not. Best-corrected visual acuity, intraocular pressure, and fundus photographs were taken prior to surgery 1 week and 3 and 6 months postoperatively.

Results

Effective vitrectomy time was 8.05 minutes in the bevacizumab group vs 16.8 minutes in the non-bevacizumab group. Statistically significant differences were observed in visual acuity at 1 week and 3 and 6 months follow-up between the 2 groups (p<0.05 for each visit). Also, there was less bleeding intraoperatively in the bevacizumab group. Mean final visual acuity in the bevacizumab group was 0.82 logMAR and 2.01 logMAR in the non-bevacizumab group.

Conclusions

Adjuvant intravitreal injection of bevacizumab prior to vitrectomy in diabetic retinopathy with fractional retinal detachment significantly eases the procedure, diminishing intraoperative complications, and leads to a better visual outcome.

Intravitreal Bevacizumab Injection Attenuates Diabetic Retinopathy in Adult Rats with Experimentally Induced Diabetes in the Early Stage

Diabetic retinopathy is the leading cause of blindness, yet its treatment is very limited. Anti-VEGF drug has been widely applied in ocular disease, but its effects on diabetic retinopathy and the underlying mechanism have remained to be fully explored. To elucidate the role of anti-VEGF treatment, we sought to determine the effects of bevacizumab on diabetic neurovascular changes extending from the 3rd to 9th week with induced diabetes in adult rats. The retinal neurovascular changes included increased expression of VEGF, nNOS, iNOS, eNOS, and NO in the course of diabetes progression. In diabetic rats given bevacizumab injection, the ganglion cell loss and alterations of retinal thickness were ameliorated. In this connection, the immunofluorescence labeling of the above biomarkers was noticeably decreased. Along with this, Western blotting confirmed that bevacizumab treatment was associated with a decrease of VEGF, Flk-1, and cAMP response element binding and protein kinase C protein expression. The present results suggest that bevacizumab treatment in the early stage of the retinopathy may ameliorate the lesions of retinopathy, in which VEGF/Flk-1 signaling has been shown here to play an important role.

INTRAVITREAL BEVACIZUMAB FOR PROLIFERATIVE DIABETIC RETINOPATHY: Results From the Pan-American Collaborative Retina Study Group (PACORES) at 24 Months of Follow-up

PURPOSE

To evaluate the effects of intravitreal bevacizumab (IVB) on retinal neovascularization in patients with proliferative diabetic retinopathy (PDR).

METHODS

Retrospective multicenter interventional case series. A chart review was performed of 81 consecutive patients (97 eyes) with retinal neovascularization due to PDR, who received at least 1 IVB injection.

RESULTS

The mean age of the patients was 55.6 ± 11.6 years. The mean number of IVB injections was 4 ± 2.5 injections (range, 1-8 injections) per eye. The mean interval between IVB applications was 3 ± 7 months. The mean duration of follow-up was 29.6 ± 2 months (range, 24-30 months). Best-corrected visual acuity and optical coherence tomography improved statistically significantly (P < 0.0001, both comparisons). Three eyes without previous panretinal photocoagulation ("naive" eyes) and with vitreous hemorrhage did not require vitreoretinal surgery. Five (5.2%) eyes with PDR progressed to tractional retinal detachment requiring vitrectomy. No systemic adverse events were noted.

CONCLUSION

Intravitreal bevacizumab resulted in marked regression of retinal neovascularization in patients with PDR and previous panretinal photocoagulation. Intravitreal bevacizumab in naive eyes resulted in control or regression of 42.1% of eyes without adjunctive laser or vitrectomy during 24 months of follow-up. There were no safety concerns during the 2 years of follow-up of IVB for PDR.

Retinal pigment epithelium-secretome: A diabetic retinopathy perspective

Diabetic retinopathy is a major complication of diabetes mellitus that can lead to retinal vascular abnormalities and visual impairment. While retinal endothelial pathology is well studied, retinal pigment epithelium (RPE) layer modifications and the patho-physiological regulations are not widely understood. The RPE is a highly specialized pigmented layer regulating not only physiological functions such as transport of nutrients, ions, absorption of light, phagocytosis of photoreceptor membranes, but also secretion of a number of cytokines, chemokines, angiogenic and anti-angiogenic factors. The RPE secretome, though crucial in health and disease, remains elusive in diabetic retinopathy. A knowledge of these secreted factors would help explain and correlate the clinical phase of the disease aiding in improved disease management. A comprehensive knowledge of the secreted factors of the RPE is a potential tool for understanding the differential treatment regime of early diabetic retinopathy, diabetic proliferative retinopathy and diabetic macular edema. In this review, we have delineated the importance of factors secreted by the retinal pigment epithelium and its regulation in the pathogenesis of diabetic retinopathy.

Efficacy of intravitreal bevacizumab combined with pan retinal photocoagulation versus panretinal photocoagulation alone in treatment of proliferative diabetic retinopathy

Objective:

To compare effectiveness of pan-retinal photocoagulation alone versus panretinal photocoagulation combined with intravitreal bevacizumab on visual acuity and central macular thickness in patients presenting with proliferative diabetic retinopathy.

Methods:

This Randomized controlled trial was carried out at Armed Forces Institute of ophthalmology, Pakistan from Jan 2016 to Aug 2016. Seventy six eyes of 50 patients having proliferative diabetic retinopathy and diabetic macular edema were included in the study. All the patients were subjected to detailed clinical examination that included Uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), slit lamp examination of anterior and posterior segments. Optical coherence tomography (OCT) and fundus fluorescein angiography (FFA) were carried out and patients were divided in two groups (GP and GI). Three monthly sessions of Pan retinal photocoagulation (PRP) using Pattern Scan Laser (PASCAL) alone was performed in group GP while PRP along with three monthly intravitreal bevacizumab (IVB) was performed in group GI. BCVA and CMT was recorded 04 weeks after the third PRP session in both the groups.

Results:

Seventy six eyes of 50 patients (38 in each group) were treated with three sessions of PRP alone and PRP with IVB in Group GP and GI respectively. Mean age of the patient in group GP was 57.47± 6.08 years while that in group GI was 55.69 ±6.58. The magnitude of induced change in BCVA was 0.09 ± 0.15 in GP while 0.22 + 0.04 in GI groups while mean induced change in CMT after treatment was 77.44 ± 92.30 um and 117.50 ± 93.82 um in group GP and GI.

Conclusion:

Laser PRP combined with IVB has superior visual and anatomical outcome than PRP alone in patients with combined presentation of PDR and DME.

The Efficacy of Intravitreal Bevacizumab in Vitreous Hemorrhage of Diabetic Subjects

Objectives:

To evaluate the efficacy of intravitreal bevacizumab (IVB) in the resolution of vitreous hemorrhage (VH) secondary to proliferative diabetic retinopathy (PDR).

Materials and Methods:

Seventy eyes of 70 patients (43 male, mean age 55.6±12.2 years) diagnosed with VH secondary to PDR were evaluated retrospectively. Demographic characteristics of the patients, baseline and final clinical results, and the interventions the patients were subject to were recorded. The patients who received IVB injections (group 1, n=29) were compared to those who did not receive injections (group 2, n=41) in terms of VH clearance time and surgery rates.

Results:

The mean follow-up time was 14.5±6.1 months in group 1 and 18.4±9.6 months in group 2 (p=0.185). The mean visual acuity was similar between the groups at baseline and at the last visit (for all p>0.05). Panretinal photocoagulation could be applied in 86% of subjects in group 1 and in 58% in group 2 2 within the first month (p=0.016). VH clearance time was not different between the groups (2.3±2.1 months in group 1 and 3.4±2.6 months in group 2, p=0.146). The number of subjects requiring surgery was 7 (24%) in group 1 and 20 (48.8%) in group 2 (p=0.048).

Conclusion:

IVB was found effective in cases with VH secondary to PDR in terms of reducing the need for surgery and increasing the rate of subjects to whom panretinal photocoagulation could be applied in the early period, although there was no impact on final visual acuity.

Evidence-Based Treatment of Diabetic Retinopathy

Diabetic retinopathy (DR) is the most frequent microvascular complication from diabetes and requires annual screening and at least annual follow-up. A systemic approach to optimize blood glucose and blood pressure may halt progression to severe stages of DR and obviate the need for ocular treatment. Although there is evidence of benefit from fenofibrate or intravitreous antiVEGF treatment for eyes with nonproliferative DR (NPDR), these therapies are not standard care for NPDR at this time. Some patients with severe NPDR, especially those with type 2 diabetes, benefit from early panretinal photocoagulation (PRP). Once DR progresses to proliferative DR (PDR), treatment is often necessary to prevent visual loss. PRP remains mainstay treatment for PDR with high-risk characteristics. However, intravitreous antiVEGF injections appear to be a safe and effective treatment alternative for PDR through at least two years. Vitreoretinal surgery is indicated for PDR cases with non-clearing vitreous hemorrhage and/or tractional retinal detachment.

New Therapeutic Approaches in Diabetic Retinopathy

Diabetic retinopathy is a common microvascular complication of diabetes mellitus. It affects a substantial proportion of US adults over age 40. The condition is a leading cause of visual loss. Much attention has been given to expanding the role of current treatments along with investigating various novel therapies and drug delivery methods. In the treatment of diabetic macular edema (DME), intravitreal pharmacotherapies, especially anti-vascular endothelial growth factor (anti-VEGF) agents, have gained popularity. Currently, anti-VEGF agents are often used as first-line agents in center-involved DME, with recent data suggesting that among these agents, aflibercept leads to better visual outcomes in patients with worse baseline visual acuities. While photocoagulation remains the standard treatment for proliferative diabetic retinopathy (PDR), recent FDA approvals of ranibizumab and aflibercept in the management of diabetic retinopathy associated with DME may suggest a potential for pharmacologic treatments of PDR as well. Novel therapies, including small interfering RNAs, chemokines, kallikrein-kinin inhibitors, and various anti-angiogenic agents, are currently being evaluated for the management of diabetic retinopathy and DME. In addition to these strategies, novel drug delivery methods such as sustained-release implants and refillable reservoir implants are either under active evaluation or have recently gained FDA approval. This review provides an update on the novel developments in the treatment of diabetic retinopathy.

Neuroinflammatory responses in diabetic retinopathy

Diabetic retinopathy (DR) is a common complication of diabetes and has been recognized as a vascular dysfunction leading to blindness in working-age adults. It becomes increasingly clear that neural cells in retina play an important role in the pathogenesis of DR. Neural retina located at the back of the eye is part of the brain and a representative of the central nervous system. The neurosensory deficits seen in DR are related to inflammation and occur prior to the clinically identifiable vascular complications. The neural deficits are associated with abnormal reactions of retina glial cells and neurons in response to hyperglycemia. Improper activation of the innate immune system may also be an important contributor to the pathophysiology of DR. Therefore, DR manifests characteristics of both vasculopathy and chronic neuroinflammatory diseases. In this article, we attempt to provide an overview of the current understanding of inflammation in neural retina abnormalities in diabetes. Inhibition of neuroinflammation may represent a novel therapeutic strategy to the prevention of the progression of DR.

Intravitreal injection of Bevacizumab in diabetic macular edema

OBJECTIVE

To assess the effectiveness of intravitreal injection of Bevacizumab in the treatment of diabetic macular edema.

METHODS

This case series was conducted at Department of Ophthalmology, Jinnah Post Graduate Medical Centre (JPMC), Karachi. The duration of study was six months from May 26, 2011 to November 25, 2011. The study group comprised of 54 patients of the Diabetic Macular Edema (DME). Intravitreal injection of 1.25 mg of bevacizumab (Avastin) was injected 3.5 mm from the limbus under topical anaesthetic drops. Post procedure follow up was scheduled on 1(st) post procedure day and after one month. Post procedure Optical Coherence tomography (OCT) was performed in all patients 1 week before and 1(st) month after 1(st) injection. The results were statistically analyzed through SPSS 17.

RESULTS

Out of the 54 Eyes of 54 Patients who were given the Intravitreal injection of Avastin (Bevacizumab), 43 Eyes (79.6%) showed more than ten percent decrease in macular thickness from pre-injection thickness, 10 Eyes (18.5%) showed less than ten percent decrease and 1 Eye (1.9%) showed increase in macular thickness post operatively after one month.

CONCLUSIONS

Intravitreal injection of Bevacizumab (Avastin) is effective in the treatment of diabetic macular edema.

The 5-year onset and regression of diabetic retinopathy in Chinese type 2 diabetes patients

PURPOSE

To determine the rate and risk factors of diabetic retinopathy (DR) onset and regression in Chinese type 2 diabetes mellitus patients.

METHODS

This is a 5-year community-based prospective study. The demographic information, systemic examination results and ophthalmological test results of each participant were collected. The study outcomes were DR incidence, defined as the onset of DR in at least one eye, and DR regression, defined as full regression from existing DR to no retinopathy without invasive treatments. The associations between each potential risk factor and the outcomes were studied.

RESULTS

In total, 778 participants were enrolled. There were 322 patients without DR at baseline, of which 151 participants developed DR during follow-up (DR incidence rate = 46.89%). Baseline hyperglycemia and high blood pressure were two independent risk factors associated with DR incidence. Among the 456 participants with existing DR at entry, 110 fully recovered after 5 years (DR regression rate = 24.12%). Low baseline glucose and low serum triglyceride were two independent factors associated with DR regression.

CONCLUSIONS

DR incidence occurred more frequently in patients with hyperglycemia and high blood pressure. DR regression occurred mostly in patients with lower glucose and lower serum triglyceride levels among Chinese type 2 diabetes patients.

Angiogenic potential of vitreous from Proliferative Diabetic Retinopathy and Eales' Disease patients

PURPOSE

Proliferative Diabetic Retinopathy (PDR) and Eales' Disease (ED) have different aetiologies although they share certain common clinical symptoms including pre-retinal neovascularization. Since there is a need to understand if the shared end-stage angiogenic pathology of PDR and ED is driven by common stimulating factors, we have studied the cytokines contained in vitreous from both patient groups and analyzed the angiogenic potential of these samples in vitro.

MATERIAL AND METHODS

Vitreous samples from patients with PDR (n = 13) and ED (n = 5) were quantified for various cytokines using a cytokine biochip array and sandwich ELISA. An additional group of patients (n = 5) with macular hole (MH) was also studied for comparison. To determine the angiogenic potential of these vitreous samples, they were analyzed for their ability to induce tubulogenesis in human microvascular endothelial cells. Further, the effect of anti-VEGF (Ranibizumab) and anti-IL-6 antibodies were studied on vitreous-mediated vascular tube formation.

RESULTS

Elevated levels of IL-6, IL-8, MCP-1 and VEGF were observed in vitreous of both PDR and ED when compared to MH. PDR and ED vitreous induced greater levels of endothelial cell tube formation compared to controls without vitreous (P<0.05). When VEGF in vitreous was neutralized by clinically-relevant concentrations of Ranibizumab, tube length was reduced significantly in 5 of 6 PDR and 3 of 5 ED samples. Moreover, when treated with IL-6 neutralizing antibody, apparent reduction (71.4%) was observed in PDR vitreous samples.

CONCLUSIONS

We have demonstrated that vitreous specimens from PDR and ED patients share common elevations of pro-inflammatory and pro-angiogenic cytokines. This suggests that common cytokine profiles link these two conditions.

Combined Tractional and Rhegmatogenous Retinal Detachment in Proliferative Diabetic Retinopathy in the Anti-VEGF Era

Purpose. To investigate the clinical features, surgical outcomes, and prognostic factors of combined rhegmatogenous and tractional detachment (combined RD) in proliferative diabetic retinopathy (PDR) in recent years. Methods. Medical records of PDR and combined RD treated with vitrectomy from 2008 to 2013 were retrospectively reviewed. Results. A total of 57 eyes from 49 patients were included. Nine eyes had received panretinal photocoagulation (PRP) and 7 eyes had intravitreal bevacizumab (IVB) within 3 months before RD developed. Thirty-eight eyes (66.7%) had ≧3 sites of broad adhesion of fibrovascular proliferation (FVP). Thirty-three eyes (57.9%) showed active FVP. Thirty-four eyes (59.6%) had extent of RD involving 3 or 4 quadrants. The primary reattachment rate was 93.0%, and the final visual acuity (VA) improved by more than 3 lines in 80.7% of eyes. Neovascular glaucoma occurred in 4 eyes postoperatively. Poor preoperative VA, severe vitreoretinal adhesion, and broad extent of RD had significant correlation with poor visual outcomes. Conclusion. PRP or IVB might play a role in provoking combined RD. The anatomical and functional success rates of surgery were high. Poor preoperative VA and severe proliferations predicted poor visual outcomes.

Evolving strategies in the management of diabetic retinopathy

Diabetic retinopathy (DR), the most common long-term complication of diabetes mellitus, remains one of the leading causes of blindness worldwide. Tight glycemic and blood pressure control has been shown to significantly decrease the risk of development as well as the progression of retinopathy and represents the cornerstone of medical management of DR. The two most threatening complications of DR are diabetic macular edema (DME) and proliferative diabetic retinopathy (PDR). Focal/grid photocoagulation and panretinal photocoagulation are standard treatments for both DME and PDR, respectively. Focal/grid photocoagulation is a better treatment than intravitreal triamcinolone acetonide in eyes with DME. Currently, most experts consider combination focal/grid laser therapy and pharmacotherapy with intravitreal antivascular endothelial growth factor agents in patients with center-involving DME. Combination therapy reduces the frequency of injections needed to control edema. Vitrectomy with removal of the posterior hyaloid seems to be effective in eyes with persistent diffuse DME, particularly in eyes with associated vitreomacular traction. Emerging therapies include fenofibrate, ruboxistaurin, renin-angiotensin system blockers, peroxisome proliferator-activated receptor gamma agonists, pharmacologic vitreolysis, and islet cell transplantation.

Intravitreal bevacizumab in the treatment of diabetic ocular neovascularization

PURPOSE

To evaluate the efficacy of intravitreal bevacizumab for treating diabetic retinal and/or iris neovascularization.

METHODS

Consecutive, prospective, interventional case series study of 60 eyes with diabetic retinal and/or iris neovascularization. Patients had a complete ocular examination before receiving 1.25 mg (0.05 mL) of intravitreal bevacizumab. Abnormal new vessels elsewhere in the retina, optic disk, or iris were graded by size and associated hemorrhage or glaucoma. Patients had complete postinjection ophthalmic evaluations with regrading of the abnormal new vessels at 3 months and 6 months. The main outcome measures included clinical partial or total regression of abnormal new vessels, changes in visual acuity, and complications related to the intravitreal injections.

RESULTS

Twenty-six patients (47.3%) were men (mean age, 59 years). Abnormal new vessel regression at 6 months occurred in 65% of new vessels of the iris (P = 0.001), 45% of new vessels of the optic disk (P = 0.009), and 43% of new vessels elsewhere (P = 0.008). The visual acuity improved in 20% of eyes, which was not significant (P = 0.235); the visual acuity deteriorated in 23% of eyes (P = 0.163). No systemic or ocular side effects developed except for postinjection hypotony in one eye.

CONCLUSION

Intravitreal bevacizumab is a well-tolerated medication that causes regression of abnormal diabetic neovascularization. New vessels of the iris responded more than new vessels of the optic disk and new vessels elsewhere.

Sustained delivery of a HIF-1 antagonist for ocular neovascularization

Doxorubicin (DXR) and daunorubicin (DNR) inhibit hypoxia-inducible factor-1 (HIF-1) transcriptional activity by blocking its binding to DNA. Intraocular injections of DXR or DNR suppressed choroidal and retinal neovascularization (NV), but also perturbed retinal function as demonstrated by electroretinograms (ERGs). DXR was conjugated to novel copolymers of branched polyethylene glycol and poly(sebacic acid) (DXR-PSA-PEG3) and formulated into nanoparticles that when placed in aqueous buffer, slowly released small DXR-conjugates. Intraocular injection of DXR-PSA-PEG3 nanoparticles (1 or 10 μg DXR content) reduced HIF-1-responsive gene products, strongly suppressed choroidal and retinal NV, and did not cause retinal toxicity. In transgenic mice that express VEGF in photoreceptors, intraocular injection of DXR-PSA-PEG3 nanoparticles (10 μg DXR content) suppressed NV for at least 35 days. Intraocular injection of DXR-PSA-PEG3 nanoparticles (2.7 mg DXR content) in rabbits resulted in sustained DXR-conjugate release with detectable levels in aqueous humor and vitreous for at least 105 days. This study demonstrates a novel HIF-1-inhibitor-polymer conjugate formulated into controlled-release particles that maximizes efficacy and duration of activity, minimizes toxicity, and provides a promising new chemical entity for treatment of ocular NV.

Intravitreal bevacizumab for proliferative diabetic retinopathy with new dense vitreous hemorrhage after full panretinal photocoagulation

PURPOSE

To evaluate the efficacy and safety of intravitreal bevacizumab (IVB) injections for the treatment of proliferative diabetic retinopathy (PDR) with new dense vitreous hemorrhage (VH) after previous full panretinal photocoagulation (PRP).

METHODS

Prospective study of consecutive PDR with prior complete PRP patients, who presented with new dense VH, were treated with IVB injection. Complete ophthalmic examination and/or ocular ultrasonography were performed at baseline and 1, 6, and 12 weeks and 6, 9, and 12 months after the first injection. Reinjection was done in non-clearing and recurrent VH.

RESULTS

Eighteen eyes of 18 patients, mean age 47.7 ± 12.69 years were included. In all, 14 (77.78%) patients had type 2 diabetes mellitus. Systemic hypertension and dyslipidemia were the most common systemic diseases. All cases were phakic eye with previous complete PRP. Patients received 1.6 ± 0.42 intravitreal injections over a 12-month period. VH cleared completely in 7 (38.89%), 9 (50%), and 13 (72.22%) eyes after 6 weeks, 6 months, and 12 months, respectively. Re-bleeding, however, occurred in 10 (56%) eyes during the follow-up period, and 5 (28%) eyes still had residual VH at the last visit. Statistically significant visual gain was observed in 9 (50%) eyes. Unfortunately, 2 (11%) eyes had severe visual loss because of the tractional retinal detachment (TRD). Mild ocular complication was detected in one patient.

CONCLUSION

IVB injection had good efficacy and safety for treatment of new VH in patients with PDR and prior complete PRP. This procedure may be especially relevant for diabetic patients at high-risk for surgical intervention.

Intravitreal bevacizumab (Avastin) and panretinal photocoagulation in the treatment of high-risk proliferative diabetic retinopathy

PURPOSE

To report the short-term efficacy and safety of intravitreal bevacizumab (Avastin) injection with panretinal laser photocoagulation (PRP) in patients with high-risk proliferative diabetic retinopathy (PDR) according to the Early Treatment Diabetic Retinopathy Study criteria.

METHODS

A prospective, interventional case series study was conducted in 17 patients (20 eyes) with high-risk PDR, who were treated with intravitreal bevacizumab (2.5 mg) followed by PRP when the peripheral vitreous became clear or 2 weeks after injection. Patients underwent complete ophthalmic evaluation, including Snellen visual acuity and fluorescein angiography at baseline, 1, 3, and 6 months after bevacizumab injection. Main outcome measures included the serial changes in visual acuity, vitreous clear-up time, and neovascularization on the disc (NVD) regression time.

RESULTS

All patients had obvious reduction in angiographic leakage and involution of retinal neovascularization (NV) at the 1- and 3-month follow-up. The mean follow-up time was 7.5 months. The vitreous hemorrhage (VH) showed a partial resolution as early as 1 week, and complete regression at 3 months. The mean vitreous clear-up time after intravitreal Avastin was 8.5±2.2 weeks. The mean time interval from intravitreal Avastin to NVD regression was 10.8±3.4 weeks. Mean logarithm of the minimum angle resolution visual acuity improved from 1.03 at baseline to 0.36 at 1-month, 0.38 at 3-month, and 0.48 at the 6-month follow-up (P<0.01). Three eyes (18%) required vitrectomy surgery during follow-up. The indication for vitrectomy was dense, persistent VH in 2 eyes, and focal tractional retinal detachment (TRD) in 1 eye. Recurrent retinal NV with minor preretinal hemorrhage was observed in 6 eyes (30%) 3 months after the first injection, and resolved after repeated bevacizumab injections. Patients received an average of 1.4 injections (range: 1-2). Seven eyes (35%) underwent 2 injections. One eye (5%) had ocular complication of PDR progression to TRD. No systemic adverse events were observed following injections.

CONCLUSIONS

Short-term results suggest combined intravitreal bevacizumab and PRP achieved rapid clearance of VH, regression of retinal NV, and visual improvement in the treatment of high-risk PDR. Long-term study is warranted to assess the long-term efficacy and safety.