Exploratory analysis of the effect of intravitreal ranibizumab or triamcinolone on worsening of diabetic retinopathy in a randomized clinical trial

Requirement of Site-Specific Tyrosine Phosphorylation of Cortactin in Retinal Neovascularization and Vascular Leakage

BACKGROUND

Retinal neovascularization is a major cause of vision impairment. Therefore, the purpose of this study is to investigate the mechanisms by which hypoxia triggers the development of abnormal and leaky blood vessels.

METHODS

A variety of cellular and molecular approaches as well as tissue-specific knockout mice were used to investigate the role of Cttn (cortactin) in retinal neovascularization and vascular leakage.

RESULTS

We found that VEGFA (vascular endothelial growth factor A) stimulates Cttn phosphorylation at Y421, Y453, and Y470 residues in human retinal microvascular endothelial cells. In addition, we observed that while blockade of Cttn phosphorylation at Y470 inhibited VEGFA-induced human retinal microvascular endothelial cell angiogenic events, suppression of Y421 phosphorylation protected endothelial barrier integrity from disruption by VEGFA. In line with these observations, while blockade of Cttn phosphorylation at Y470 negated oxygen-induced retinopathy-induced retinal neovascularization, interference with Y421 phosphorylation prevented VEGFA/oxygen-induced retinopathy-induced vascular leakage. Mechanistically, while phosphorylation at Y470 was required for its interaction with Arp2/3 and CDC6 facilitating actin polymerization and DNA synthesis, respectively, Cttn phosphorylation at Y421 leads to its dissociation from VE-cadherin, resulting in adherens junction disruption. Furthermore, whereas Cttn phosphorylation at Y470 residue was dependent on Lyn, its phosphorylation at Y421 residue required Syk activation. Accordingly, lentivirus-mediated expression of shRNA targeting Lyn or Syk levels inhibited oxygen-induced retinopathy-induced retinal neovascularization and vascular leakage, respectively.

CONCLUSIONS

The above observations show for the first time that phosphorylation of Cttn is involved in a site-specific manner in the regulation of retinal neovascularization and vascular leakage. In view of these findings, Cttn could be a novel target for the development of therapeutics against vascular diseases such as retinal neovascularization and vascular leakage.

Perspectives of diabetic retinopathy-challenges and opportunities

Diabetic retinopathy (DR) may lead to vision-threatening complications in people living with diabetes mellitus. Decades of research have contributed to our understanding of the pathogenesis of diabetic retinopathy from non-proliferative to proliferative (PDR) stages, the occurrence of diabetic macular oedema (DMO) and response to various treatment options. Multimodal imaging has paved the way to predict the impact of peripheral lesions and optical coherence tomography-angiography is starting to provide new knowledge on diabetic macular ischaemia. Moreover, the availability of intravitreal anti-vascular endothelial growth factors has changed the treatment paradigm of DMO and PDR. Areas of research have explored mechanisms of breakdown of the blood-retinal barrier, damage to pericytes, the extent of capillary non-perfusion, leakage and progression to neovascularisation. However, knowledge gaps remain. From this perspective, we highlight the challenges and future directions of research in this field.

Anti-vascular endothelial growth factor for diabetic macular oedema: a network meta-analysis

Background

Diabetic macular oedema (DMO) is a common complication of diabetic retinopathy. Antiangiogenic therapy with anti-vascular endothelial growth factor (anti-VEGF) can reduce oedema, improve vision, and prevent further visual loss. These drugs have replaced laser photocoagulation as the standard of care for people with DMO. In the previous update of this review, we found moderate-quality evidence that, at 12 months, aflibercept was slightly more effective than ranibizumab and bevacizumab for improving vision in people with DMO, although the difference may have been clinically insignificant (less than 0.1 logarithm of the minimum angle of resolution (logMAR), or five Early Treatment Diabetic Retinopathy Study (ETDRS) letters, or one ETDRS line).

Objectives

The objective of this updated review was to compare the effectiveness and safety of the different anti-VEGF drugs in RCTs at longer followup (24 months).

Search methods

We searched various electronic databases on 8 July 2022.

Selection criteria

We included randomised controlled trials (RCTs) that compared any anti-angiogenic drug with an anti-VEGF mechanism of action versus another anti-VEGF drug, another treatment, sham, or no treatment in people with DMO.

Data collection and analysis

We used standard Cochrane methods for pairwise meta-analysis and we augmented this evidence using network meta-analysis (NMA) methods. We used the Stata 'network' meta-analysis package for all analyses. We used the CINeMA (Confidence in Network Meta-Analysis) web application to grade the certainty of the evidence.

Main results

We included 23 studies (13 with industry funding) that enrolled 3513 people with DMO (median central retinal thickness (CRT) 460 microns, interquartile range (IQR) 424 to 482) and moderate vision loss (median best-corrected visual acuity (BCVA) 0.48 logMAR, IQR 0.42 to 0.55. One study that investigated ranibizumab versus sham and one study that mainly enrolled people with subclinical DMO and normal BCVA were not suitable for inclusion in the efficacy NMA. Consistent with the previous update of this review, we used ranibizumab as the reference drug for efficacy, and control (including laser, observation, and sham) as the reference for systemic safety. Eight trials provided data on the primary outcome (change in BCVA at 24 months, in logMAR: lower is better). We found no evidence of a difference between the following interventions and ranibizumab alone: aflibercept (mean difference (MD) -0.05 logMAR, 95% confidence interval (CI) -0.12 to 0.02; moderate certainty); bevacizumab (MD -0.01 logMAR, 95% CI -0.13 to 0.10; low certainty), brolucizumab (MD 0.00 logMAR, 95% CI -0.08 to 0.07; low certainty), ranibizumab plus deferred laser (MD 0.00 logMAR, 95% CI -0.11 to 0.10; low certainty), and ranibizumab plus prompt laser (MD 0.03 logMAR, 95% CI -0.04 to 0.09; very low certainty). We also analysed BCVA change at 12 months, finding moderate-certainty evidence of increased efficacy with brolucizumab (MD -0.07 logMAR, 95%CI -0.10 to -0.03 logMAR), faricimab (MD -0.08 logMAR, 95% CI -0.12 to -0.05), and aflibercept (MD -0.07 logMAR, 95 % CI -0.10 to -0.04) compared to ranibizumab alone, but the difference could be clinically insignificant. Compared to ranibizumab alone, NMA of six trials showed no evidence of a difference with aflibercept (moderate certainty), bevacizumab (low certainty), or ranibizumab with prompt (very low certainty) or deferred laser (low certainty) regarding improvement by three or more ETDRS lines at 24 months. There was moderate-certainty evidence of greater CRT reduction at 24 months with brolucizumab (MD -23 microns, 95% CI -65 to -1 9) and aflibercept (MD -26 microns, 95% CI -53 to 0.9) compared to ranibizumab. There was moderate-certainty evidence of lesser CRT reduction with bevacizumab (MD 28 microns, 95% CI 0 to 56), ranibizumab plus deferred laser (MD 63 microns, 95% CI 18 to 109), and ranibizumab plus prompt laser (MD 72 microns, 95% CI 25 to 119) compared with ranibizumab alone. Regarding all-cause mortality at the longest available follow-up (20 trials), we found no evidence of increased risk of death for any drug compared to control, although effects were in the direction of an increase, and clinically relevant increases could not be ruled out. The certainty of this evidence was low for bevacizumab (risk ratio (RR) 2.10, 95% CI 0.75 to 5.88), brolucizumab (RR 2.92, 95% CI 0.68 to 12.58), faricimab (RR 1.91, 95% CI 0.45 to 8.00), ranibizumab (RR 1.26, 95% CI 0.68 to 2.34), and very low for conbercept (RR 0.33, 95% CI 0.01 to 8.81) and aflibercept (RR 1.48, 95% CI 0.79 to 2.77). Estimates for Antiplatelet Trialists Collaboration arterial thromboembolic events at 24 months did not suggest an increase with any drug compared to control, but the NMA was overall incoherent and the evidence was of low or very low certainty. Ocular adverse events were rare and poorly reported and could not be assessed in NMAs.

Authors' conclusions

There is limited evidence of the comparative efficacy and safety of anti-VEGF drugs beyond one year of follow-up. We found no clinically important differences in visual outcomes at 24 months in people with DMO, although there were differences in CRT change. We found no evidence that any drug increases all-cause mortality compared to control, but estimates were very imprecise. Evidence from RCTs may not apply to real-world practice, where people in need of antiangiogenic treatment are often under-treated, and the individuals exposed to these drugs may be less healthy than trial participants.

Network meta-analysis of intravitreal conbercept as an adjuvant to vitrectomy for proliferative diabetic retinopathy

Purpose

Intravitreal Conbercept (IVC) has been shown to be effective in treating proliferative diabetic retinopathy (PDR) as an adjuvant in pars plana vitrectomy (PPV); however, the best timing of IVC injection remains unknown. This network meta-analysis (NMA) sought to ascertain the comparative efficacy of different timings of IVC injection as an adjuvant to PPV on PDR.

Methods

A comprehensive literature search was conducted in PubMed, EMBASE, and the Cochrane Library to identify relevant studies published before August 11, 2022. According to the mean time of IVC injection before PPV, the strategy was defined as very long interval if it was > 7 days but ≤ 9 days, long interval if it was > 5 days but ≤ 7 days, mid interval if it was > 3 days but ≤ 5 days, and short interval if it was ≤ 3 days, respectively. The strategy was defined as perioperative IVC if IVC was injected both before and at the end of PPV, and the strategy was intraoperative IVC if injected immediately at the end of PPV. The mean difference (MD) and odds ratio (OR) with corresponding 95% confidence interval (CI) for continuous and binary variables, respectively, were computed through network meta-analysis using Stata 14.0 MP.

Results

Eighteen studies involving 1149 patients were included. There was no statistical difference between intraoperative IVC and control in treating PDR. Except for a very long interval, preoperative IVC significantly shortened operation time, and reduced intraoperative bleeding and iatrogenic retinal breaks. Long and short intervals reduced endodiathermy application, and mid and short intervals reduced postoperative vitreous hemorrhage. Moreover, long and mid intervals improved BCVA and central macular thickness. However, very long interval was associated with an increased risk of postoperative vitreous hemorrhage (RR: 3.27, 95%CI: 1.84 to 5.83). Moreover, mid interval was better than intraoperative IVC in shortening operation time (MD: -19.74, 95%CI: -33.31 to -6.17).

Conclusions

There are no discernible effects of intraoperative IVC on PDR, but preoperative IVC, except for very long interval, is an effective adjuvant to PPV for treating PDR.

Clinical study of Chinese medicine holographic scraping combined with hot ironing in improving early diabetic retinopathy

OBJECTIVES

To investigate the clinical effect of holographic scraping combined with Chinese medicine hot ironing on the improvement of early diabetic retinopathy (DR).

METHODS

The clinical data of 120 inpatients with diabetes mellitus were retrospectively analyzed. All patients had early retinopathy. According to different treatment methods, the patients were segmented into a scraping group (accepted holographic scrapping), an ironing group (accepted Chinese medicine hot ironing), and a combined treatment group (accepted holographic scraping combined with Chinese medicine hot ironing). The traditional Chinese medicine (TCM) symptom scores, efficacy in TCM symptom relief and fundus symptom relief, quality of life, blood glucose index level, and safety were compared among the three groups.

RESULTS

Compared with the scraping group and the ironing group, the TCM symptom scores of the combined treatment group on the 3rd day, 7th day, and 14th day of treatment were decreased; The total effective rates in TCM symptom relief and fundus symptom relief were increased; The scores of four dimensions in QoL of patients increased (all P<0.05); and Fasting blood glucose (FBG), 2 h postprandial blood glucose, and glycosylated hemoglobin were decreased (all P<0.05). There was no significant difference in the distribution of DR grade (I, II, and III) in the combined treatment group compared with the scraping group and ironing group (all P>0.05). The resistance index of the combined group after treatment was lower than that before treatment and lower than that of the hot ironing group and scraping group (all P<0.05).

CONCLUSIONS

The application of holographic scraping combined with Chinese medicine hot ironing in the treatment of early DR could alleviate the symptoms of blurred vision and dry eyes. Early intervention for retinopathy with both methods can reduce the disability rate and improve the quality of life of patients, which has a better effect than simple therapy.

Comparison of efficacy and safety of intravitreal ranibizumab and conbercept before vitrectomy in Chinese proliferative diabetic retinopathy patients: a prospective randomized controlled trial

BACKGROUND

To compare the efficacy and safety of preoperative intravitreal injections of ranibizumab and conbercept in Chinese proliferative diabetic retinopathy (PDR) patients.

METHODS

This prospective randomized controlled trial enrolled 90 eyes of 80 patients with PDR. Forty-four eyes of 40 patients that received intravitreal ranibizumab (IVR) injections (0.5 mg/0.05 mL) before vitreous surgeries were assigned to the IVR group. Forty-six eyes of 40 patients that received intravitreal conbercept (IVC) injections (0.5 mg/0.05 mL) before vitreous surgeries were assigned to the IVC group. Intraoperative and postoperative indices were assessed for further comparison between the two groups.

RESULTS

There were no statistically significant differences in all surgery indices, including intraoperative indices (surgery time, P = 0.225; intraoperative bleeding, P = 0.808; endodiathermy use, P = 0.693; incidence of iatrogenic retinal breaks, P = 0.740; relaxing retinotomy, P = 0.682; retinal reattachment, P = 0.682 and silicone oil tamponade, P = 0.814) and postoperative indices (postoperative vitreous hemorrhage (VH), P = 0.808; neovascular glaucoma (NVG), P = 0.964; recurrent retinal detachment, P = 0.531; postoperative fibrovascular proliferation progression, P = 0.682 and reoperation, P = 0.955) between the two groups. There were no statistically significant differences in best-corrected visual acuity (BCVA) at each follow-up visit (P = 0.939, 0.669, 0.741 and 0.717, respectively) or in central retinal thickness (CRT) (P = 0.976, 0.699, 0.551 and 0.686, respectively). As for safety profile, both groups had no ocular or system adverse events during the observation period.

CONCLUSIONS

IVR and IVC as a pretreatment of vitrectomy had similar efficacy and safety profile for Chinese PDR patients.

TRIAL REGISTRATION

Registered at ClinicalTrials.gov ( NCT05414149 ).

Combined phacoemulsification surgery and intravitreal triamcinolone injection versus stand-alone surgery in patients with type 2 diabetes: a prospective randomized trial

Background

We would assess the efficacy of intravitreal injection of triamcinolone acetonide IVTA combined with standard phacoemulsification on the central subfield macular thickness (CSMT), the progression of diabetic retinopathy (DR), and the corrected distant visual acuity (CDVA) in type 2 diabetic patients.

Methods

In this prospective single-blinded randomized clinical trial we recruited patients with type 2 diabetes who were eligible for cataract surgery. The patients were randomly assigned to two groups. The case group received an intravitreal IVTA at the end of phacoemulsification, and the control group had routine surgery. CSMT, progression of DR, CDVA, IOP, and adverse events including endophthalmitis were compared between the groups preoperatively and at 1, 3, and 6 months postoperatively.

Results

Among a total of 66 patients that were treated within the study period, 50 patients were included in the final analysis. The case group comprised 21 eyes, and the control group included 29 eyes. Regression models and corrected ANOVA test for repeated measures showed a significant reduction in CSMT at 3 and 6 months postoperatively, which was most significant when the preoperative CSMT was ≥300 μm, with a cut-off value of 347.3 μm in the case group (p < 0.000). DR progression was halted in the case group at 6 months with 52.38% of patients having their DR classified as moderate (P = 0.012). CDVA was significantly improved from baseline 6/60 (logMAR 1.0) pre-op to 6/6 (logMAR 0.00) at 6 months post-op in the case group, and from baseline 6/120 (logMAR 1.3) pre-op to 6/12 (logMAR 0.3) at 6 months post-op in the control group. The gain in visual acuity was significantly higher in the case group at all study points (p < 0.001). No significant rise in IOP was observed at any study point in both groups (p = 0.23 > 0.05). No endophthalmitis was recorded.

Conclusions

Diabetic patients benefit significantly from cataract surgery. This study supports IVTA injection at the end of phacoemulsification in diabetic patients. Triamcinolone is an affordable (which is of particular importance in low-income countries as per our setting), and relatively safe “phaco-enhancer”.

Trial registration

NCT05413330. Initial release 10/06/2022. Unique Protocol ID: UDMS-Opthal-01-2022.

Prospective Comparison of Surgery Outcome Between Preoperative and Intraoperative Intravitreal Injection of Ranibizumab for Vitrectomy in Proliferative Diabetic Retinopathy Patients

INTRODUCTION

To compare the efficacy and safety of intravitreal injections of ranibizumab (IVR) before and at the end of vitrectomy in proliferative diabetic retinopathy (PDR) patients.

METHODS

A prospective comparative study was performed on 60 eyes of 52 PDR patients who received ranibizumab injection (0.5 mg/0.05 ml) 3-5 days before vitrectomy (preoperative group) and 55 eyes of 50 PDR patients who received ranibizumab injection (0.5 mg/0.05 ml) at the end of vitrectomy (intraoperative group). Intra- and postoperative indices were collected for further comparison.

RESULTS

Postoperative best-corrected visual acuity (BCVA) in preoperative group was better than in intraoperative group at 1 week after surgery (P < 0.05) but comparable at 1- and 3-month follow-up (P = 0.20 and P = 0.37, respectively). Central retinal thickness (CRT) in preoperative group was lower than in intraoperative group at 1 week postoperatively (P < 0.05), but comparable at 1- and 3-month follow-up (P = 0.39 and P = 0.77, respectively). The average surgery time was significantly shorter in preoperative group than in intraoperative group (61.50 ± 11.44 min vs. 74.49 ± 12.01 min, P < 0.01). The incidence of intraoperative bleeding was significant lower in preoperative group than in intraoperative group (21.7% vs. 40.0%, P < 0.05). Moreover, the incidence of intraocular electrocoagulation use, iatrogenic retinal breaks, relaxing retinotomy and silicone oil tamponade were all significantly lower in preoperative group than that in intraoperative group (P < 0.05, respectively). The incidences of postoperative vitreous hemorrhage (VH), neovascular glaucoma (NVG), recurrent retinal detachment, postoperative fibrovascular proliferation progression and reoperation showed no statistical differences between the two groups (P > 0.05, respectively). Both groups had no ocular or system adverse events during observation period.

CONCLUSION

In vitrectomy for PDR, preoperative IVR can significantly reduce surgery time and lower the incidence of intraoperative bleeding, intraocular electrocoagulation use, iatrogenic retinal breaks, relaxing retinotomy and silicone oil tamponade during surgery and gain short-term better postoperative BCVA and thinner CRT.

TRIAL REGISTRATION

ClinicalTrials.gov (identifier, NCT05408416).

PAI-1 is a vascular cell-specific HIF-2-dependent angiogenic factor that promotes retinal neovascularization in diabetic patients

For patients with proliferative diabetic retinopathy (PDR) who do not respond adequately to pan-retinal laser photocoagulation (PRP) or anti-vascular endothelial growth factor (VEGF) therapies, we hypothesized that vascular cells within neovascular tissue secrete autocrine/paracrine angiogenic factors that promote disease progression. To identify these factors, we performed multiplex ELISA angiogenesis arrays on aqueous fluid from PDR patients who responded inadequately to anti-VEGF therapy and/or PRP and identified plasminogen activator inhibitor-1 (PAI-1). PAI-1 expression was increased in vitreous biopsies and neovascular tissue from PDR eyes, limited to retinal vascular cells, regulated by the transcription factor hypoxia-inducible factor (HIF)-2α, and necessary and sufficient to stimulate angiogenesis. Using a pharmacologic inhibitor of HIF-2α (PT-2385) or nanoparticle-mediated RNA interference targeting Pai1, we demonstrate that the HIF-2α/PAI-1 axis is necessary for the development of retinal neovascularization in mice. These results suggest that targeting HIF-2α/PAI-1 will be an effective adjunct therapy for the treatment of PDR patients.

Diabetic retinopathy and diabetic macular oedema pathways and management: UK Consensus Working Group

The management of diabetic retinopathy (DR) has evolved considerably over the past decade, with the availability of new technologies (diagnostic and therapeutic). As such, the existing Royal College of Ophthalmologists DR Guidelines (2013) are outdated, and to the best of our knowledge are not under revision at present. Furthermore, there are no other UK guidelines covering all available treatments, and there seems to be significant variation around the UK in the management of diabetic macular oedema (DMO). This manuscript provides a summary of reviews the pathogenesis of DR and DMO, including role of vascular endothelial growth factor (VEGF) and non-VEGF cytokines, clinical grading/classification of DMO vis a vis current terminology (of centre-involving [CI-DMO], or non-centre involving [nCI-DMO], systemic risks and their management). The excellent UK DR Screening (DRS) service has continued to evolve and remains world-leading. However, challenges remain, as there are significant variations in equipment used, and reproducible standards of DMO screening nationally. The interphase between DRS and the hospital eye service can only be strengthened with further improvements. The role of modern technology including optical coherence tomography (OCT) and wide-field imaging, and working practices including virtual clinics and their potential in increasing clinic capacity and improving patient experiences and outcomes are discussed. Similarly, potential roles of home monitoring in diabetic eyes in the future are explored. The role of pharmacological (intravitreal injections [IVT] of anti-VEGFs and steroids) and laser therapies are summarised. Generally, IVT anti-VEGF are offered as first line pharmacologic therapy. As requirements of diabetic patients in particular patient groups may vary, including pregnant women, children, and persons with learning difficulties, it is important that DR management is personalised in such particular patient groups. First choice therapy needs to be individualised in these cases and may be intravitreal steroids rather than the standard choice of anti-VEGF agents. Some of these, but not all, are discussed in this document.

HIF-1α and HIF-2α redundantly promote retinal neovascularization in patients with ischemic retinal disease

Therapies targeting VEGF have proven only modestly effective for the treatment of proliferative sickle cell retinopathy (PSR), the leading cause of blindness in patients with sickle cell disease. Here, we shift our attention upstream from the genes that promote retinal neovascularization (NV) to the transcription factors that regulate their expression. We demonstrated increased expression of HIF-1α and HIF-2α in the ischemic inner retina of PSR eyes. Although both HIFs participated in promoting VEGF expression by hypoxic retinal Müller cells, HIF-1 alone was sufficient to promote retinal NV in mice, suggesting that therapies targeting only HIF-2 would not be adequate to prevent PSR. Nonetheless, administration of a HIF-2-specific inhibitor currently in clinical trials (PT2385) inhibited NV in the oxygen-induced retinopathy (OIR) mouse model. To unravel these discordant observations, we examined the expression of HIFs in OIR mice and demonstrated rapid but transient accumulation of HIF-1α but delayed and sustained accumulation of HIF-2α; simultaneous expression of HIF-1α and HIF-2α was not observed. Staggered HIF expression was corroborated in hypoxic adult mouse retinal explants but not in human retinal organoids, suggesting that this phenomenon may be unique to mice. Using pharmacological inhibition or an in vivo nanoparticle-mediated RNAi approach, we demonstrated that inhibiting either HIF was effective for preventing NV in OIR mice. Collectively, these results explain why inhibition of either HIF-1α or HIF-2α is equally effective for preventing retinal NV in mice but suggest that therapies targeting both HIFs will be necessary to prevent NV in patients with PSR.

Amine oxidase copper-containing 3 (AOC3) inhibition: a potential novel target for the management of diabetic retinopathy

Background

Diabetic retinopathy (DR), a microvascular complication of diabetes, is the leading cause of visual impairment in people aged 20–65 years and can go undetected until vision is irreversibly lost. There is a need for treatments for non-proliferative diabetic retinopathy (NPDR) which, in comparison with current intravitreal (IVT) injections, offer an improved risk–benefit ratio and are suitable for the treatment of early stages of disease, during which there is no major visual impairment. Efficacious systemic therapy for NPDR, including oral treatment, would be an important and convenient therapeutic approach for patients and physicians and would reduce treatment burden. In this article, we review the rationale for the investigation of amine oxidase copper-containing 3 (AOC3), also known as semicarbazide-sensitive amine oxidase and vascular adhesion protein 1 (VAP1), as a novel target for the early treatment of moderate to severe NPDR. AOC3 is a membrane-bound adhesion protein that facilitates the binding of leukocytes to the retinal endothelium. Adherent leukocytes reduce blood flow and in turn rupture blood vessels, leading to ischemia and edema. AOC3 inhibition reduces leukocyte recruitment and is predicted to decrease the production of reactive oxygen species, thereby correcting the underlying hypoxia, ischemia, and edema seen in DR, as well as improving vascular function.

Conclusion

There is substantial unmet need for convenient, non-invasive treatments targeting moderately severe and severe NPDR to reduce progression and preserve vision. The existing pharmacotherapies (IVT corticosteroids and IVT anti-vascular endothelial growth factor-A) target inflammation and angiogenesis, respectively. Unlike these treatments, AOC3 inhibition is predicted to address the underlying hypoxia and ischemia seen in DR. AOC3 inhibitors represent a promising therapeutic strategy for treating patients with DR and could offer greater choice and reduce treatment burden, with the potential to improve patient compliance.

Involvement of Cytokines in the Pathogenesis of Diabetic Macular Edema

Diabetic macular edema (DME) is a critical complication of diabetic retinopathy, a condition that arises from the breakdown of the blood–retinal barrier and the consequent increase in vascular permeability. Over the years, attempts have been made to treat DME by various approaches, including laser photocoagulation, steroid triamcinolone acetonide, and vitrectomy. However, treatment was unsatisfactory until research identified vascular endothelial growth factor (VEGF) as a factor in the pathogenesis of DME. Intraocular anti-VEGF agents show good efficacy in DME. Nevertheless, in some patients the condition recurs or becomes resistant to treatment, suggesting that other factors may be involved. Because inflammation and retinal hypoxia are seen in DME, research has examined the potential role of cytokines and other inflammatory mediators. In this review, we provide an overview of this research and describe feedback mechanisms that may represent a target for novel treatments.

Sustained suppression of VEGF for treatment of retinal/choroidal vascular diseases

Neovascular age-related macular degeneration (NVAMD) is the most prevalent choroidal vascular disease, and diabetic retinopathy (DR) and retinal vein occlusion (RVO) are the most prevalent retinal vascular diseases. In each of these, hypoxia plays a central role by stabilizing hypoxia-inducible factor-1 which increases production of vascular endothelial growth factor (VEGF) and other hypoxia-regulated gene products. High VEGF causes excessive vascular permeability, neovascularization, and in DR and RVO, promotes closure of retinal vessels exacerbating hypoxia and creating a positive feedback loop. Hence once VEGF expression is elevated it tends to remain elevated and drives disease progression. While other hypoxia-regulated gene products also contribute to pathology in these disease processes, it is remarkable how much pathology is reversed by selective inhibition of VEGF. Clinical trials have demonstrated outstanding visual outcomes in patients with NVAMD, DR, or RVO from frequent intraocular injections of VEGF-neutralizing proteins, but for a variety of reasons injection frequency has been substantially less in clinical practice and visual outcomes are disappointing. Herein we discuss the rationale, preclinical, and early clinical results of new approaches that provide sustained suppression of VEGF. These approaches will revolutionize the management of these prevalent retinal/choroidal vascular diseases.

Reproducibility of Fixed-luminance and Multi-luminance Flicker Electroretinography in Patients With Diabetic Retinopathy Using an Office-based Testing Paradigm

BACKGROUND

We evaluated the reproducibility of office-based flicker electroretinography (ERG) in patients with nonproliferative diabetic retinopathy (NPDR).

METHODS

An observational study was conducted in which ultra-widefield fluorescein angiography (UWF-FA) was performed on 20 patients with mild-to-moderate NPDR; images were graded by the Fundus Photography Reading Center (Department of Ophthalmology and Visual Sciences, University of Wisconsin, Madison, WI, USA). Fixed- and multi-luminance flicker ERG was repeated four times (greater than or equal to seven days apart). Recording consistency was assessed using intra-class correlation coefficients (ICCs), coefficients of variation, and Pearson correlations.

RESULTS

82.5% and 17.5% of eyes had mild and moderate NPDR using UWF-FA; 90% of the angiograms were given a high confidence grade. Fixed-luminance phase values were highly reproducible (ICC: 0.949; P < .001). There was a significant negative correlation between fixed-luminance phase and log-corrected ischemic index values (-0.426; P = .015).

CONCLUSIONS

Office-based, fixed-luminance phase values are highly reproducible and negatively correlate with retinal ischemia in NPDR, suggesting that global retinal dysfunction may be reliably quantified early in patients with diabetes.

<p>Predictors of Early Diabetic Retinopathy Regression with Ranibizumab in the RIDE and RISE Clinical Trials</p>

Purpose

To investigate the predictors of early diabetic retinopathy (DR) improvement in the RIDE/RISE (NCT00473382/NCT00473330) clinical trials.

Patients and Methods

In RIDE/RISE, adult patients with vision loss due to diabetic macular edema (DME) were randomized to monthly intravitreal ranibizumab 0.3 or 0.5 mg (n=502 total) or sham (n=257). DR severity was graded (using the Early Treatment Diabetic Retinopathy Study Diabetic Retinopathy Severity Scale). In this post hoc analysis of RIDE/RISE, eyes with baseline DR score ≥35 were evaluated for ≥2-step improvements, and eyes with baseline DR score ≥43 were evaluated for ≥3-step improvements. The characteristics associated with ≥2- or ≥3-step DR improvement at months 3 or 6 were assessed using univariate and/or multivariable analyses.

Results

The percentage of eyes with a ≥2- or ≥3-step DR improvement was 20.1% and 3.7% at month 3 and 31.2% and 5.8% at month 6. Odds of ≥2-step DR improvement at months 3 or 6 were significantly greater in eyes with moderately severe to severe nonproliferative DR (NPDR) at baseline versus less severe or more severe DR (both P<0.0001). At month 6, odds of ≥2-step DR improvement were significantly greater in eyes with no DME at month 3 (P=0.008). Most patients with ≥3-step DR improvement at months 3 or 6 had proliferative DR (PDR) at baseline (83.3% and 66.7%).

Conclusion

The strongest predictors of DR response to ranibizumab at month 6 were baseline DR severity and DME quiescence at month 3. Eyes with the most robust early improvements had moderately severe or severe NPDR or PDR at baseline.

Diabetic Population-Based Model to Estimate Impact of Ranibizumab on Diabetic Retinopathy Severity in Patients with Diabetic Macular Edema

PURPOSE

Estimate effects of ranibizumab on diabetic retinopathy (DR) severity in US Hispanic and non-Hispanic white persons with center-involved diabetic macular edema (DME) causing vision impairment for whom ranibizumab treatment would be considered.

PATIENTS AND METHODS

This model simulated DR severity outcomes over 2 years in the better-seeing eye using US census, National Health and Nutrition Examination Survey, Wisconsin Epidemiologic Study of Diabetic Retinopathy, and Los Angeles Latino Eye Study data. Baseline DR severity estimated from Diabetic Retinopathy Clinical Research Network trial data. Changes in DR severity after 2 years, with/without monthly ranibizumab (0.3 or 0.5 mg), were estimated from Phase III clinical trial data (RIDE/RISE) using a 2-dimensional Monte Carlo simulation model. Number of patients over a 2-year period for whom 1) DR severity worsening was avoided, 2) DR severity improved, and 3) selected clinical events related to proliferative DR (PDR) occurred, was estimated.

RESULTS

An estimated 37,274 US Hispanic and non-Hispanic white persons were projected to have DR with center-involved DME and be eligible for ranibizumab treatment. The number of persons with moderately severe non-proliferative DR (NPDR) or less severe DR at baseline who would worsen to PDR and experience a PDR complication over 2 years would be reduced from 437 with no ranibizumab to 19 with ranibizumab (95% reduction; 95% simulation interval [SI], 79-100%). The number of persons with severe NPDR or less severe DR at baseline who would be expected to improve by ≥2 DR severity levels over 2 years would increase from 1706 with no ranibizumab to 13,042 with ranibizumab (682% increase; 95% SI, 478-967%).

CONCLUSION

This model estimates that ranibizumab treatment in US Hispanic and non-Hispanic white patients with center-involved DME causing vision impairment would potentially reduce the number of patients with worsening DR and potentially increase the number with DR improvements.

Intravitreal conbercept improves outcome in patients undergoing vitrectomy for proliferative diabetic retinopathy: A systematic review and meta-analysis

OBJECTIVES

To evaluate the latest evidence concerning the efficacy of conbercept on vitrectomy for proliferative diabetic retinopathy (PDR) and its efficacy compared to control and other antivascular endothelial growth factor.

METHODS

We performed a systematic literature search on topics that assess the role of conbercept in patients undergoing vitrectomy for PDR from inception to November 2019, using PubMed, EuropePMC, Cochrane Central Database, ProQuest, ScienceDirect, and Clinicaltrials.gov. Two researchers independently searched literature, extracted data, and evaluated the risk of bias. RevMan 5.3 and StataMP 16 software were used to perform data analysis.

RESULTS

There were 699 cases (eyes) from eight studies. Baseline best-corrected visual acuity (BCVA) was better in the control group compared to conbercept group (mean difference [MD] = 0.13, I²   = 0%). A greater BCVA improvement was observed in the conbercept group after 1-month (MD = -0.27, I²   = 1%), 3-month (MD = -0.28, I²   = 0%), and 6-month (MD = -0.20, I²   = 78%) follow-up. The need for endodiathermy (odds ratio [OR] = 0.20, I²   = 0%) and silicone oil tamponade use (OR = 0.59, I²   = 72%) and intraoperative bleeding (OR = 0.11, I²   = 33%) was lower in conbercept group. Postoperative early (OR = 0.22, I²   = 0%) and late (OR = 0.47, I²   = 0%) vitreous hemorrhage was lower in conbercept group. There was no significant difference in BCVA improvement and intraoperative outcome between conbercept and ranibizumab.

CONCLUSIONS

Intravitreal conbercept was associated with a more significant BCVA improvement, better intraoperative outcome, and less postoperative vitreous hemorrhage compared to no conbercept.

The Evolving Treatment of Diabetic Retinopathy

Purpose

To review the current therapeutic options for the management of diabetic retinopathy (DR) and diabetic macular edema (DME) and examine the evidence for integration of laser and pharmacotherapy.

Methods

A review of the PubMed database was performed using the search terms diabetic retinopathy, diabetic macular edema, neovascularization, laser photocoagulation, intravitreal injection, vascular endothelial growth factor (VEGF), vitrectomy, pars plana vitreous surgery, antiangiogenic therapy. With additional cross-referencing, this yielded 835 publications of which 301 were selected based on content and relevance.

Results

Many recent studies have evaluated the pharmacological, laser and surgical therapeutic strategies for the treatment and prevention of DR and DME. Several newer diagnostic systems such as optical coherence tomography (OCT), microperimetry, and multifocal electroretinography (mfERG) are also assisting in further refinements in the staging and classification of DR and DME. Pharmacological therapies for both DR and DME include both systemic and ocular agents. Systemic agents that promote intensive glycemic control, control of dyslipidemia and antagonists of the renin-angiotensin system demonstrate beneficial effects for both DR and DME. Ocular therapies include anti-VEGF agents, corticosteroids and nonsteroidal anti-inflammatory drugs. Laser therapy, both as panretinal and focal or grid applications continue to be employed in management of DR and DME. Refinements in laser devices have yielded more tissue-sparing (subthreshold) modes in which many of the benefits of conventional continuous wave (CW) lasers can be obtained without the adverse side effects. Recent attempts to lessen the burden of anti-VEGF injections by integrating laser therapy have met with mixed results. Increasingly, vitreoretinal surgical techniques are employed for less advanced stages of DR and DME. The development and use of smaller gauge instrumentation and advanced anesthesia agents have been associated with a trend toward earlier surgical intervention for diabetic retinopathy. Several novel drug delivery strategies are currently being examined with the goal of decreasing the therapeutic burden of monthly intravitreal injections. These fall into one of the five categories: non-biodegradable polymeric drug delivery systems, biodegradable polymeric drug delivery systems, nanoparticle-based drug delivery systems, ocular injection devices and with sustained release refillable devices. At present, there remains no one single strategy for the management of the particular stages of DR and DME as there are many options that have not been rigorously tested through large, randomized, controlled clinical trials.

Conclusion

Pharmacotherapy, both ocular and systemic, will be the primary mode of intervention in the management of DR and DME in many cases when cost and treatment burden are less constrained. Conventional laser therapy has become a secondary intervention in these instances, but remains a first-line option when cost and treatment burden are more constrained. Results with subthreshold laser appear promising but will require more rigorous study to establish its role as adjunctive therapy. Evidence to support an optimal integration of the various treatment options is lacking. Central to the widespread adoption of any therapeutic regimen for DR and DME is substantiation of safety, efficacy, and cost-effectiveness by a body of sound clinical trials.

Emerging Concepts in the Treatment of Diabetic Retinopathy

PURPOSE OF REVIEW

Diabetic retinopathy (DR) is the leading cause of vision loss in working-age adults in the developed world. This review discusses the current approach to managing the disease, such as glycemic and blood pressure control, as well as laser photocoagulation, as well as emerging concepts and controversies on novel therapies.

RECENT FINDINGS

In recent years, the rise of intraocular anti-angiogenesis treatments is changing the paradigm of classic laser photocoagulation in the management of DR, but its long-term benefits remain an area of controversy. We also discuss new targets including anti-inflammation, neuroprotection, and novel laser technologies. Finally, we discuss new advances in retinal imaging that has vastly improved the diagnosis and management of DR. Diagnosis and management of diabetic retinopathy is a rapidly progressing field. Emerging concepts in ophthalmic imaging, medical treatments, and surgical approaches provide insights into how DR management will evolve in the near future.

OMICs approaches-assisted identification of macrophages-derived MIP-1γ as the therapeutic target of botanical products TNTL in diabetic retinopathy

Background

Inflammatory reaction in the dysfunction of retinal endotheliocytes has been considered to play a vital role in diabetic retinopathy (DR). Anti-inflammatory therapy so far gains poor outcome as DR treatment. This study aims to identify a novel therapeutic target of DR from the OMICs studies of a traditional anti-DR botanical products TNTL.

Methods

Hyperglycemic mice were treated with TNTL. The anti-hyperglycemic effect of TNTL was validated to confirm the biological consistency of the herbal products from batches. Improvement of DR by TNTL was examined by various assays on the retina. Next-generation transcriptome sequencing and cytokine array was used to identify the therapeutic targets. In vitro study was performed to validate the target.

Results

We observed that TNTL at its high doses possessed anti-hyperglycemic effect in murine type I diabetic model, while at its doses without reducing blood glucose, it suppressed DR incidence. TNTL restored the blood-retina barrier integrity, suppressed retinal neovascularization, and attenuated the retinal ganglion cell degeneration. Transcriptomic analysis on the retina tissue of hyperglycemic mice with or without TNTL revealed that the inflammatory retina microenvironment was significantly repressed. TNTL treatment suppressed pro-inflammatory macrophages in the retina, which resulted in the inactivation of endothelial cell migration, restoration of endothelial cell monolayer integrity, and prevention of leakage. Cytokine array analysis suggested that TNTL could significantly inhibit the secretion of MIP1γ from pro-inflammatory macrophages. Prevention of endothelial dysfunction by TNTL may be mediated by the inhibition of MIP1γ/CCR1 axis. More specifically, TNTL suppressed MIP1γ release from pro-inflammatory macrophages, which in turn inhibited the activation of CCR1-associated signaling pathways in endothelial cells.

Conclusion

Our findings demonstrated that TNTL might be an alternative treatment to DR, and the primary source of potential drug candidates against DR targeting MIP1γ/CCR1 axis in the retinal microenvironment.

Fluocinolone acetonide 0.19 mg intravitreal implant improves foveal thickness and reduces treatment burden for up to 1 year in eyes with persistent diabetic macular edema

Objective: To assess the effectiveness, safety, and treatment burden in eyes with persistent diabetic macular edema (DME) for up to 1 year after administration of 0.19 mg fluocinolone acetonide (FAc) implant (Iluvien^®).

Methods: This retrospective study at one private practice in the US included 40 eyes from 33 patients treated with an FAc implant. Eyes had previously been treated with VEGF antagonists, dexamethasone, or focal laser. The primary outcome was change in central foveal thickness from baseline. Data were also collected on demographics, visual acuity, intraocular pressure (IOP), use of IOP-lowering drugs for elevated IOP, lens clarity, and treatment burden before and after the implant.

Results: Average duration of diabetes and DME at baseline was 19 and 5 years, respectively, and average glycated hemoglobin was 7.21%. Severity of diabetic retinopathy before the implant had a slight bimodal distribution: moderate nonproliferative diabetic retinopathy (35%) and proliferative diabetic retinopathy (40%). Improvements in central foveal thickness from baseline were evident at 3 months (mean change –74.2 µm, P<0.001) and sustained through 12 months (–55.3 µm; P=0.005) for most eyes. Mean visual acuity remained stable (66.2 letters at baseline versus 67.2 letters at 12 months, roughly equivalent to 20/50 vision; P=0.855). On average, eyes required one anti-VEGF injection every 1.9 months before and one every 6.6 months after the implant, while 60% of eyes did not require additional anti-VEGF injections. Small but significant increases in IOP at months 3, 6, and 9 were not sustained to month 12, and mean IOP was normal throughout follow-up.

Conclusion: In patients with DME previously treated with a steroid, and treated according to licensed indications in the US, an FAc implant not only reduces the burden of disease in the real-world setting, but also the burden of injections and office visits for patients.

Therapeutic implications of nanomedicine for ocular drug delivery

Delivering therapeutics to the eye is challenging on multiple levels: rapid clearance of eyedrops from the ocular surface requires frequent instillation, which is difficult for patients; transport of drugs across the blood-retinal barrier when drugs are administered systemically, and the cornea when drugs are administered topically, is difficult to achieve; limited drug penetration to the back of the eye owing to the cornea, conjunctiva, sclera and vitreous barriers. Nanomedicine offers many advantages over conventional ophthalmic medications for effective ocular drug delivery because nanomedicine can increase the therapeutic index by overcoming ocular barriers, improving drug-release profiles and reducing potential drug toxicity. In this review, we highlight the therapeutic implications of nanomedicine for ocular drug delivery.

Efficacy of ranibizumab for the treatment of diabetic retinopathy: A protocol for systematic review of randomized controlled trial

BACKGROUND

Previous clinical trials have reported that ranibizumab can be used to treat diabetic retinopathy (DR) effectively. However, no study has been conducted to evaluate its efficacy for patients with DR systematically. Thus, this study will specifically and systematically assess the efficacy and safety of ranibizumab for DR.

METHODS

Cochrane Library, EMBASE, PUBMED, Web of Science, Google Scholar, Cumulative Index to Nursing and Allied Health Literature, China National Knowledge Infrastructure, and Chinese Biomedical Literature Database will be searched from inceptions to the March 20, 2019 for studies related to the topic. This study will only consider publicly released randomized controlled trials for evaluating the effect and safety of ranibizumab for DR. No language restrictions will be imposed for all databases search. Methodological quality of each included trial will be assessed by Cochrane risk of bias tool. Statistical analysis will be performed by Stata 12.0 software.

RESULTS

This study will provide recent summary evidence of ranibizumab for DR. Primary outcomes include percentages with retinopathy improvement, and cumulative probabilities for retinopathy worsening. Secondary outcome consist of visual function, best-corrected visual acuities, central subfield thickness, total macular volume, peripheral visual field loss, retinal neovascularization, and adverse events.

CONCLUSION

The findings of this study may provide theoretical basis for clinical practice refer and may benefit more patients with DR.

Current and Future Pharmacologic Therapies for Diabetic Retinopathy

Background:

Currently, diabetic retinopathy is the leading cause of permanent visual loss in workingage adults in industrialized nations. The chronic microangiopathic changes associated with diabetic retinopathy lead to the most common causes of severe permanent visual loss: diabetic macular edema (DME) and proliferative diabetic retinopathy (PDR). Multiple studies have evaluated different pharmacotherapies for different levels of retinopathy.

Methods:

A review of the pathophysiology of diabetic retinopathy and current and emerging pharmacotherapies for diabetic retinopathy.

Results:

Historically, DME has been the primary focus of treatment in patients with nonproliferative diabetic retinopathy (NPDR). Due to the rapidly increasing number of agents and treatment options, management algorithms for DME have become increasingly complex. Furthermore, spectral domain optical coherence tomography (OCT) has allowed unparalleled sensitivity and specificity for detecting macular edema. All available intravitreal vascular endothelial growth factor (VEGF) inhibitors have demonstrated efficacy in the treatment of patients with DME and PDR. Intravitreal triamcinolone acetonide has also proven beneficial in diabetic retinopathy. Most recently, various corticosteroids have been designed as sustained-release intraocular implants in order to reduce the burden and risks associated with retreatment. Current research is focused on providing new agents that target alternate pathways and signaling molecules to provide patients with additional therapeutic tools, especially in patients who have an incomplete response to the current medications.

Conclusion:

Anti-VEGF therapy has revolutionized the medical management of diabetic retinopathy. The most important existing challenges in the treatment of diabetic retinopathy are improving visual outcomes and decreasing the treatment burden associated with repeated intravitreal injections. Combination therapy with anti-VEGF and corticosteroids with other previously available treatments, such as panretinal photocoagulation, may be a reasonable clinical strategy to reduce the intravitreal injections burden. Many exciting novel drugs that target newly discovered pathways hold clinical promise. The results of ongoing randomized clinical trials will answer the important concerns surrounding new drugs and delivery devices: safety and visual outcomes.

Bioactive lipids and pathological retinal angiogenesis

Angiogenesis, disruption of the retinal barrier, leukocyte-adhesion and oedema are cardinal signs of proliferative retinopathies that are associated with vision loss. Therefore, identifying factors that regulate these vascular dysfunctions is critical to target pathological angiogenesis. Given the conflicting role of bioactive lipids reported in the current literature, the goal of this review is to provide the reader a clear road map of what has been accomplished so far in the field with specific focus on the role of polyunsaturated fatty acids (PUFAs)-derived metabolites in proliferative retinopathies. This necessarily entails a description of the different retina cells, blood retina barriers and the role of (PUFAs)-derived metabolites in diabetic retinopathy, retinopathy of prematurity and age-related macular degeneration as the most common types of proliferative retinopathies.

A Novel Machine Learning Algorithm to Automatically Predict Visual Outcomes in Intravitreal Ranibizumab-Treated Patients with Diabetic Macular Edema

Purpose: Artificial neural networks (ANNs) are one type of artificial intelligence. Here, we use an ANN-based machine learning algorithm to automatically predict visual outcomes after ranibizumab treatment in diabetic macular edema. Methods: Patient data were used to optimize ANNs for regression calculation. The target was established as the final visual acuity at 52, 78, or 104 weeks. The input baseline variables were sex, age, diabetes type or condition, systemic diseases, eye status and treatment time tables. Three groups were randomly devised to build, test and demonstrate the accuracy of the algorithms. Results: At 52, 78 and 104 weeks, 512, 483 and 464 eyes were included, respectively. For the training group, testing group and validation group, the respective correlation coefficients were 0.75, 0.77 and 0.70 (52 weeks); 0.79, 0.80 and 0.55 (78 weeks); and 0.83, 0.47 and 0.81 (104 weeks), while the mean standard errors of final visual acuity were 6.50, 6.11 and 6.40 (52 weeks); 5.91, 5.83 and 7.59; (78 weeks); and 5.39, 8.70 and 6.81 (104 weeks). Conclusions: Machine learning had good correlation coefficients for predicating prognosis with ranibizumab with just baseline characteristics. These models could be the useful clinical tools for prediction of success of the treatments.

Durability of Diabetic Retinopathy Improvement with As-Needed Ranibizumab: Open-Label Extension of RIDE and RISE Studies

PURPOSE

To evaluate the durability of diabetic retinopathy (DR) improvements after a change in ranibizumab dosing from monthly to individualized pro re nata (PRN) therapy.

DESIGN

Pooled analysis of the open-label extension (OLE) of RIDE and RISE (clinicaltrials.gov identifiers, NCT00473382 and NCT00473330) patients with DR and diabetic macular edema (DME).

PARTICIPANTS

Patients who completed 36-month participation in RIDE and RISE and entered the OLE.

METHODS

In RIDE and RISE, patients (n = 759) were randomized 1:1:1 to ranibizumab 0.3 mg monthly, 0.5 mg monthly, or monthly sham injections with rescue macular laser available after 6 months, per protocol-specified criteria. After 24 months, sham patients crossed over to ranibizumab 0.5 mg monthly. After 36 months in the core studies, patients in the OLE (n = 500) could receive ranibizumab 0.5 mg PRN based on predefined DME re-treatment criteria. Diabetic retinopathy severity was evaluated photographically using the Early Treatment Diabetic Retinopathy Study DR severity scale.

MAIN OUTCOME MEASURES

Change in DR severity from months 36 to 48 by re-treatment status.

RESULTS

Among patients who entered the OLE, 121 of 500 (24%) did not require additional ranibizumab injections. Overall, 367 patients had evaluable DR at months 36 and 48. Among patients not requiring ranibizumab re-treatment from months 36 to 48 (88/367), 57% to 78%, 0% to 7%, and 22% to 36% experienced DR severity stability, 2-step or more improvement, and 2-step or more worsening, respectively. Among patients requiring ranibizumab re-treatment (279/367), 84% to 94%, 2%, and 3% to 14% experienced DR severity stability, 2-step or more improvement, and 2-step or more worsening, respectively. On average, vision improvements were maintained during the OLE regardless of change in DR severity.

CONCLUSIONS

Diabetic retinopathy severity improvements with ranibizumab were maintained in over 70% of OLE patients after switching from ranibizumab monthly to an individualized ranibizumab 0.5 mg PRN dosing regimen. Because approximately one third of OLE patients experienced DR worsening, careful monitoring should be part of the long-term management of patients with DR.

Anti-vascular endothelial growth factor for diabetic macular oedema: a network meta-analysis

BACKGROUND

Diabetic macular oedema (DMO) is a common complication of diabetic retinopathy. Antiangiogenic therapy with anti-vascular endothelial growth factor (anti-VEGF) can reduce oedema, improve vision and prevent further visual loss. These drugs have replaced laser photocoagulation as the standard of care for people with DMO.

OBJECTIVES

The 2014 update of this review found high-quality evidence of benefit with anti-VEGF modalities, compared to laser photocoagulation, for the treatment of DMO. The objective of this updated review is to compare the effectiveness and safety of the different anti-VEGF drugs using network meta-analysis methods.

SEARCH METHODS

We searched various electronic databases on 26 April 2017.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared any anti-angiogenic drug with an anti-VEGF mechanism of action versus another anti-VEGF drug, another treatment, sham or no treatment in people with DMO.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods for pair-wise meta-analysis and we augmented this evidence using network meta-analysis methods. We focused on the relative efficacy and safety of the three most commonly used drugs as interventions of direct interest for practice: aflibercept and ranibizumab, used on-label; and off-label bevacizumab.We collected data on three efficacy outcomes (gain of 15 or more Early Treatment Diabetic Retinopathy Study (ETDRS) letters; mean change in best-corrected visual acuity (BCVA); mean change in central retinal thickness (CRT)), three safety outcomes (all severe systemic adverse events (SSAEs); all-cause death; arterial thromboembolic events) and quality of life.We used Stata 'network' meta-analysis package for all analyses. We investigated the risk of bias of mixed comparisons based on the variance contribution of each study, having assigned an overall risk of bias to each study.

MAIN RESULTS

Twenty-four studies included 6007 participants with DMO and moderate vision loss, of which two studies randomised 265 eyes of 230 participants and one was a cross-over study on 56 participants (62 eyes) that was treated as a parallel-arm trial. Data were collected on drugs of direct interest from three studies on aflibercept (975 eyes), eight studies on bevacizumab (515 eyes), and 14 studies on ranibizumab (1518 eyes). As treatments of indirect interest or legacy treatment we included three studies on pegaptanib (541 eyes), five studies on ranibizumab plus prompt laser (557 eyes), one study on ranibizumab plus deferred laser (188 eyes), 13 studies on laser photocoagulation (936 eyes) and six studies on sham treatment (793 eyes).Aflibercept, bevacizumab and ranibizumab were all more effective than laser for improving vision by 3 or more lines after one year (high-certainty evidence). Approximately one in 10 people improve vision with laser, and about three in 10 people improve with anti-VEGF treatment: risk ratio (RR) versus laser 3.66 (95% confidence interval (CI) 2.79 to 4.79) for aflibercept; RR 2.47 (95% CI 1.81 to 3.37) for bevacizumab; RR 2.76 (95% CI 2.12 to 3.59) for ranibizumab. On average there was no change in visual acuity (VA) with laser after one year, compared with a gain of 1 or 2 lines with anti-VEGF treatment: laser versus aflibercept mean difference (MD) -0.20 (95% CI -0.22 to -0.17) logMAR; versus bevacizumab MD -0.12 (95% CI -0.15 to -0.09) logMAR; versus ranibizumab MD -0.12 (95% CI -0.14 to -0.10) logMAR. The certainty of the evidence was high for the comparison of aflibercept and ranibizumab with laser and moderate for bevacizumab comparison with laser due to inconsistency between the indirect and direct evidence.People receiving ranibizumab were less likely to gain 3 or more lines of VA at one year compared with aflibercept: RR 0.75 (95% CI 0.60 to 0.94), moderate-certainty evidence. For every 1000 people treated with aflibercept, 92 fewer would gain 3 or more lines of VA at one year if treated with ranibizumab (22 to 148 fewer). On average people receiving ranibizumab had worse VA at one year (MD 0.08 logMAR units, 95% CI 0.05 to 0.11), moderate-certainty evidence; and higher CRT (MD 39 µm, 95% CI 2 µm to 76 µm; low-certainty evidence). Ranibizumab and bevacizumab were comparable with respect to aflibercept and did not differ in terms of VA: RR of gain of 3 or more lines of VA at one year 1.11 (95% CI 0.87 to 1.43), moderate-certainty evidence, and difference in change in VA was 0.00 (95% CI -0.02 to 0.03) logMAR, moderate-certainty evidence. CRT reduction favoured ranibizumab by -29 µm (95% CI -58 µm to -1 µm, low-certainty evidence). There was no evidence of overall statistical inconsistency in our analyses.The previous version of this review found moderate-certainty evidence of good safety of antiangiogenic drugs versus control. This update used data at the longest available follow-up (one or two years) and found that aflibercept, ranibizumab and bevacizumab do not differ regarding systemic serious adverse events (SSAEs) (moderate- or high-certainty evidence). However, risk of bias was variable, loop inconsistency could be found and estimates were not precise enough on relative safety regarding less frequent events such as arterial thromboembolic events or death (low- or very low-certainty evidence).Two-year data were available and reported in only four RCTs in this review. Most industry-sponsored studies were open-label after one year. One large publicly-funded study compared the three drugs at two years and found no difference.

AUTHORS' CONCLUSIONS

Anti-VEGF drugs are effective at improving vision in people with DMO with three to four in every 10 people likely to experience an improvement of 3 or more lines VA at one year. Aflibercept may confer some advantage over ranibizumab and bevacizumab in people with DMO at one year in visual and anatomic terms but it is unclear whether this applies to the long-term. There is a need for more evidence on the long-term (greater than two years) comparative effects of these anti-VEGF agents. Evidence from RCTs may not apply to real-world practice, where people in need of antiangiogenic treatment are often under-treated and under-monitored.We found no signals of differences in overall safety between the three antiangiogenic drugs that are currently available to treat DMO, but our estimates are imprecise for cardiovascular events and death.

Rationale and Application of the Protocol S Anti-Vascular Endothelial Growth Factor Algorithm for Proliferative Diabetic Retinopathy

PURPOSE

To present the rationale, guidelines, and results of ranibizumab treatment for proliferative diabetic retinopathy (PDR) in Diabetic Retinopathy Clinical Research Network (DRCR.net) Protocol S.

DESIGN

Post hoc analyses from a randomized clinical trial.

PARTICIPANTS

Three hundred five participants (394 study eyes) having PDR without prior panretinal photocoagulation (PRP).

METHODS

Intravitreous ranibizumab (0.5 mg) versus PRP for PDR. Ranbizumab-assigned eyes (n = 191) received monthly injections for 6 months unless resolution was achieved after 4 injections. After 6 months, injections could be deferred if neovascularization was stable over 3 consecutive visits (sustained stability). If neovascularization worsened, monthly treatment resumed. Panretinal photocoagulation could be initiated for failure or futility criteria.

MAIN OUTCOME MEASURES

Neovascularization status through 2 years.

RESULTS

At 1 month, 19% (35 of 188) of ranibizumab-assigned eyes showed complete neovascularization resolution and an additional 60% (113) showed improvement. At 6 months, 52% (80 of 153) showed neovascularization resolution, 3% (4) were improved, 37% (56) were stable, and 8% (13) had worsened since the last visit. Among eyes with versus without resolved neovascularization at 6 months, the median (interquartile range) number of injections between 6 months and 2 years was 4 (1-7; n = 73) versus 7 (4-11; n = 67; P < 0.001). Injections were deferred in 68 of 73 eyes (93%) meeting sustained stability at least once during the study; 62% (42 of 68) resumed injections within 16 weeks after deferral. At 2 years, 43% (66 of 154) showed neovascularization resolution, 5% (7) showed improvement, 23% (36) were stable, and 27% (42) had worsened since the last visit. Only 3 eyes met criteria for failure or futility through 2 years.

CONCLUSIONS

The DRCR.net treatment algorithm for PDR can provide excellent clinical outcomes through 2 years for patients initiating anti-vascular endothelial growth factor (VEGF) therapy for PDR. When choosing between anti-VEGF and PRP as first-line therapy for PDR, treatment decisions should be guided by consideration of the relative advantages of each therapeutic method and anticipated patient compliance with follow-up and treatment recommendations.

Agent-based computational model of retinal angiogenesis simulates microvascular network morphology as a function of pericyte coverage

OBJECTIVE

Define a role for perivascular cells during developmental retinal angiogenesis in the context of EC Notch1-DLL4 signaling at the multicellular network level.

METHODS

The retinal vasculature is highly sensitive to growth factor-mediated intercellular signaling. Although EC signaling has been explored in detail, it remains unclear how PC function to modulate these signals that lead to a diverse set of vascular network patterns in health and disease. We have developed an ABM of retinal angiogenesis that incorporates both ECs and PCs to investigate the formation of vascular network patterns as a function of pericyte coverage. We use our model to test the hypothesis that PC modulate Notch1-DLL4 signaling in endothelial cell-endothelial cell interactions.

RESULTS

Agent-based model (ABM) simulations that include PCs more accurately predict experimentally observed vascular network morphologies than simulations that lack PCs, suggesting that PCs may influence sprouting behaviors through physical blockade of endothelial intercellular connections.

CONCLUSIONS

This study supports a role for PCs as a physical buffer to signal propagation during vascular network formation-a barrier that may be important for generating healthy microvascular network patterns.

Panretinal Photocoagulation Versus Ranibizumab for Proliferative Diabetic Retinopathy: Factors Associated with Vision and Edema Outcomes

PURPOSE

To identify baseline factors associated with change in visual acuity or development of vision-impairing central-involved diabetic macular edema (DME) over 2 years when treating proliferative diabetic retinopathy (PDR) with ranibizumab or panretinal photocoagulation (PRP).

DESIGN

Post hoc analyses of randomized, multicenter clinical trial data.

PARTICIPANTS

Eyes completing the 2-year visit (n = 328) or without vision-impairing central-involved DME at baseline (n = 302) in Diabetic Retinopathy Clinical Research Network Protocol S.

METHODS

Intravitreous ranibizumab (0.5 mg/0.05 ml) or PRP.

MAIN OUTCOME MEASURES

Change in visual acuity (area under the curve) and development of vision-impairing (20/32 or worse) central-involved DME over 2 years.

RESULTS

After multivariable model selection with adjustment for baseline visual acuity and central subfield thickness, no factors were identified as associated with change in visual acuity or development of vision-impairing central-involved DME within the ranibizumab group. In the PRP group, worse change in visual acuity was more likely with higher hemoglobin A_1c level (-0.6 letters per 1% increase; 95% confidence interval [CI], -1.2 to -0.1 letters; continuous P = 0.03), more severe diabetic retinopathy (difference between high-risk PDR or worse vs. moderate PDR or better, -2.8 letters [95% CI, -5.5 to -0.2 letters]; continuous P = 0.003), and higher mean arterial pressure (difference between ≥100 mmHg vs. <100 mmHg, -2.0 letters [95% CI, -4.6 to 0.5 letters]; continuous P = 0.009). Development of vision-impairing central-involved DME was more likely with higher hemoglobin A_1c level (hazard ratio [HR] per 1% increase, 1.31 [95% CI, 1.13-1.52]; continuous P < 0.001), more severe diabetic retinopathy (HR for high-risk PDR or worse vs. moderate PDR or better, 1.46 [95% CI, 0.73-2.92]; continuous P = 0.03), and the presence of cystoid abnormalities within 500 μm of the macula center (HR, 2.90 [95% CI, 1.35-6.24]; P = 0.006).

CONCLUSIONS

For eyes managed with PRP, higher hemoglobin A_1c level and more severe diabetic retinopathy were associated with less vision improvement and an increased risk of vision-impairing central-involved DME developing. When managing PDR with ranibizumab, eyes gained vision, on average, with no baseline characteristics identified as associated with visual acuity or central-involved DME outcomes.

Efficacy and Safety of Intravitreal Conbercept, Ranibizumab, and Triamcinolone on 23-Gauge Vitrectomy for Patients with Proliferative Diabetic Retinopathy

Introduction

To compare the effect and safety of intravitreal conbercept (IVC), intravitreal ranibizumab (IVR), or intravitreal triamcinolone acetonide (IVTA) injection on 23-gauge (23-G) pars plana vitrectomy (PPV) for proliferative diabetic retinopathy (PDR).

Methods

Fifty patients (60 eyes) of varying degrees of PDR were randomly grouped into 3 groups (1 : 1 : 1) (n = 20 in each group). The 23-G PPV was performed with intravitreal conbercept or ranibizumab injection 3–7 days before surgery or intravitreal TA injection during surgery. The experiment was randomized controlled, with a noninferiority limit of five letters. Main outcome measures included BCVA, operation time, incidence of iatrogenic retinal breaks, endodiathermy rate, and silicone oil tamponade.

Results

At 6 months after surgery, there were no significant differences of BCVA improvements, operation time, incidence of iatrogenic retinal breaks, endodiathermy rate, silicone oil tamponade, vitreous clear-up time, and the incidence of intraoperative bleeding between the IVC and IVR groups (all P values ≥ 0.05), but they were significantly different from the IVTA group (all P values < 0.05). IOP increases did not show significant differences between the IVC and IVR groups, but both were significantly different with the IVTA group. More patients had higher postoperative IOP in the IVTA group.

Conclusions

The intravitreal injection of conbercept, ranibizumab, or TA for PDR had a significant different effect on outcomes of 23-G PPV surgery. Conbercept and ranibizumab can reduce difficulty of the operation, improve the success rate of PPV surgery, and decrease the incidence of postoperative complications.

Management of diabetic macular edema with intravitreal dexamethasone implants: Expert recommendations using a Delphi-based approach

OBJECTIVES:

Despite being approved and effective, steroids, and especially dexamethasone intravitreal implants, still have a poorly-defined role in management of diabetic macular edema. In order to overcome some of the limitations in current recommendations, a group of experts met to define consensus on some of the most controversial issues on the use of dexamethasone intravitreal implants in daily management of diabetic macular edema.

METHODS:

A Delphi-based approach was utilized to develop clinically relevant statements applicable to routine treatment settings. A Steering Committee composed of four experts formulated 30 relevant statements, which were voted upon by a panel of 40 ophthalmologists/retinal specialists from across Italy.

RESULTS:

Dexamethasone intravitreal implants were considered to be a valid first-line alternative to treatment with an anti-vascular endothelial growth factor agent and should be the first choice in pseudophakic and vitrectomized patients. A Pro Re Nata regimen was felt to be appropriate for retreatment with dexamethasone intravitreal implants while a 6-month waiting period was not considered suitable. Among steroid treatments, dexamethasone intravitreal implants were considered to have the best ocular tolerability. In patients with persistent macular edema after the loading-phase treatment with an anti-vascular endothelial growth factor, consensus was reached that clinicians should consider switching therapy to dexamethasone intravitreal implants. Moreover, dexamethasone intravitreal implants can reduce the treatment burden for individuals who are not able to cope with the more intensive treatment regimen required by anti-vascular endothelial growth factor therapy.

CONCLUSIONS:

While further studies are needed, this survey provides some key recommendations for clinicians treating diabetic macular edema that may be useful when choosing dexamethasone intravitreal implants in daily practice.

Progression of diabetic retinopathy severity after treatment with dexamethasone implant: a 24-month cohort study the 'DR-Pro-DEX Study'

PURPOSE

Intravitreal anti-vascular endothelial growth factor agents have been shown to reduce diabetic retinopathy (DR) progression; data on the effects of intravitreal corticosteroids on modifying disease severity are limited. This study evaluates the long-term effect of intravitreal dexamethasone implant (DEX) on the severity and progression of non-proliferative DR (NPDR).

METHODS

This was a retrospective cohort study. Sixty eyes from 60 consecutive patients with NPDR and diabetic macular edema (DME) treated with dexamethasone implant (DEX group) and 49 eyes from consecutive 49 patients without DME requiring observation only. Fundus angiography images from baseline and after 24 months were graded by two masked assessors into mild, moderate and severe NPDR and PDR, according to the ETDRS classification. Patients were followed up 1-3 and 4-6 months after each DEX implant. Re-treatment with DEX implant was on a pro re nata basis. Records were reviewed for performance of panretinal photocoagulation. Main outcome was as follows: change of DR ≥ 1 grade and progression to proliferative diabetic retinopathy (PDR).

RESULTS

Three eyes (5%) in the DEX group and 43 (87.8%) eyes in the control group progressed to PDR (P < 0.0001). Twenty-five eyes (41.7%) in the DEX group but none in the control group demonstrated an improvement in DR severity (P < 0.0001).

CONCLUSION

This study provides the first long-term evidence that DEX implant has the potential to not only delay progression of DR and PDR development, but may also improve DR severity over 24 months. Better understanding of the effects of corticosteroids will help guide its use in the treatment pathway of DR.

Cost Evaluation of Early Vitrectomy versus Panretinal Photocoagulation and Intravitreal Ranibizumab for Proliferative Diabetic Retinopathy

PURPOSE

To evaluate costs and cost-utility of early vitrectomy (pars plana vitrectomy [PPV]) compared with panretinal photocoagulation (PRP) and intravitreal ranibizumab (IVR) for proliferative diabetic retinopathy (PDR) without diabetic macular edema.

DESIGN

A decision analysis model of cost-utility.

PARTICIPANTS

There were no participants.

METHODS

A decision analysis was based on results from the Diabetic Retinopathy Clinical Research Network Protocol S comparing treatment of PRP with IVR (0.3 mg) in PDR without incident macular edema to model the total 2-year costs and outcomes for each treatment scenario. These values were compared with the 2-year hypothetical costs of early PPV for PDR. Centers for Medicare and Medicaid Services data were used to calculate associated modeled costs in a hospital/facility-based and nonfacility setting. Cost-utility was calculated on the basis of the preserved visual utility and estimated life years remaining. In addition, costs for lifetime treatment were modeled for all scenarios and used to calculate lifetime quality-adjusted life years (QALY) costs for each scenario. Sensitivity analyses were performed to evaluate the impact of the model's assumptions.

MAIN OUTCOME MEASURES

Cost of treatment, utility, and cost per QALY.

RESULTS

The modeled cost per QALY of treatment for PDR for 2 years of utility in the facility (nonfacility) setting was $163 988 ($102 559) in the PRP group, $436 992 ($326 424) in the IVR group, and $181 144 ($107 965) in the PPV group. Sensitivity analysis showed that both IVR and PPV groups would have equivalent costs per QALY over the first 2 years if 78% (facility) and 80% (nonfacility) of patients in the PPV group required additional treatment with IVR (at the dose of 10.1 injections as in Protocol S). Beyond 2 years, the cost per QALY in the facility (nonfacility) setting was calculated as $61 695 ($21 752) in the PRP group, $338 348 ($239 741) in the IVR group, and $63 942 ($22 261) in the PPV group.

CONCLUSIONS

Early PPV as a strategy for treatment of PDR without macular edema demonstrates cost-utility similar to management with PRP and more favorable cost-utility compared with IVR in the short term. This advantage over IVR continues when lifetime costs are factored.

Propranolol for Proliferative Diabetic Retinopathy

BACKGROUND AND OBJECTIVE

To determine the effect of propranolol on retinal neovascularization due to proliferative diabetic retinopathy (PDR).

PATIENTS AND METHODS

For this prospective pilot, interventional, case series, patients with diabetes with PDR (n = 10 subjects; 12 eyes) were recruited at the ophthalmology clinic of the University of Wisconsin - Madison. Subjects were administered oral propranolol for 12 weeks and retinopathy and area of retinal neovascularization were monitored with fundus photography and fluorescein angiography (FA). The study's main outcome measures were photographic area of retinal neovascularization and degree of leakage on FA.

RESULTS

All eyes demonstrated stable degrees of retinal neovascularization by the end of 12 weeks.

CONCLUSION

This dose of oral propranolol during a period of 12 weeks did not demonstrate significant effect on retinal neovascularization due to PDR. [Ophthalmic Surg Lasers Imaging Retina. 2018;49:35-40.].

Management of diabetic macular edema in Japan: a review and expert opinion

Diabetic retinopathy is a frequent cause of visual impairment in working-age adults (≥ 30 years) and in Japan is most commonly observed in those aged 50-69 years. Diabetic macular edema (DME) is one of the main causes of vision disturbance in diabetic retinopathy, which is a clinically significant microvascular complication of diabetes. Anti-vascular endothelial growth factor (VEGF) therapy is becoming the mainstay of treatment for DME. However, to achieve sustained long-term improvement in visual acuity, conventional laser photocoagulation, vitrectomy and steroid therapy are also expected to play a role in the treatment of DME. This review summarizes the epidemiology and pathology of diabetic retinopathy and DME, evaluates the findings regarding the diagnosis and treatment of DME, and underscores the importance of systemic management of the disease in the context of the current health care situation in Japan. Finally, the unmet needs of patients with DME and prospects for research are discussed. The weight of evidence suggests that it is important to establish a multipronged treatment strategy centered on anti-VEGF therapy.

Recent advances in the management and understanding of diabetic retinopathy

Despite recent advances in the diagnosis and treatment of diabetic retinopathy, this complication remains a steadfast challenge to patients and physicians. This review summarizes recent progress in the diagnosis and management of diabetic retinopathy, including automated screening, optical coherence tomography, control of systemic risk factors, surgical techniques, laser treatment, and pharmaceutical treatment, including vascular endothelial growth factor inhibitors. Recent advances in pharmaceutical treatments, in particular, hold strong promise of halting and sometimes reversing the disease process. Clinicians nevertheless must remain vigilant in their efforts to diagnose and treat this disease early in its course.

Vision-Related Functional Burden of Diabetic Retinopathy Across Severity Levels in the United States

Importance

Among adults with diabetes in the United States, severe forms of diabetic retinopathy (DR) are significantly associated with a greater vision-related functional burden.

Objective

To assess the functional burden of DR across severity levels in the United States.

Design, Setting, and Participants

This cross-sectional study was based on 1004 participants 40 years or older with diabetes and valid ocular and sociodemographic outcomes in the National Health and Nutrition Examination Surveys (NHANES) (2005-2006 and 2007-2008). Diabetic retinopathy was based on fundus photograph grading, using the Early Treatment Diabetic Retinopathy Study severity scale. The analysis was performed from October 15, 2016, to June 15, 2017.

Main Outcomes and Measures

Functional difficulties secondary to vision were assessed during a household questionnaire in which participants self-reported difficulty with reading, visuospatial tasks (ie, close-up work or finding things on a crowded shelf), mobility (ie, walking down steps, stairs, or curbs), and driving. The main outcome measure was vision-related functional burden, which was defined as present for individuals reporting moderate or greater difficulty in any of the aforementioned tasks.

Results

Of the 1004 persons with diabetes analyzed for this study (mean age, 65.7 years [95% CI, 64.0-67.3 years]; 51.1% male [95% CI, 47.1-55.2] and 48.9% female [95% CI, 44.8-52.9]), the prevalence was 72.3% for no retinopathy, 25.4% for mild and moderate nonproliferative diabetic retinopathy (NPDR), and 2.3% for severe NPDR or proliferative diabetic retinopathy (PDR). The prevalence of vision-related functional burden was 20.2% (95% CI, 16.3%-24.1%) for those with no retinopathy, 20.4% (95% CI, 15.3%-27.8%) for those with mild and moderate NPDR, and 48.5% (95% CI, 25.6%-71.5%) for those with severe NPDR or PDR (P = .02). In multivariable analysis, the odds of vision-related functional burden were significantly greater among those with severe NPDR or PDR relative to those with no retinopathy (adjusted odds ratio [aOR], 3.59; 95% CI, 1.29-10.05; P = .02). Those with severe NPDR or PDR did not have a statistically significant greater odds of vision-related functional burden than did those with mild or moderate NPDR (aOR, 2.70; 95% CI, 0.93-7.78; P = .07).

Conclusions and Relevance

Among US adults with diabetes, approximately half of those with severe NPDR or PDR had difficulty with at least one visual function task. Moreover, vision-related functional burden was significantly greater among those with severe NPDR or PDR than among those with no retinopathy. These data suggest the importance of preventing severe forms of DR to mitigate the vision-related functional burden among US adults with diabetes. Future studies should complement our study by assessing the association of worsening retinopathy with objectively measured functional outcomes.

Expression of the angiogenic mediator, angiopoietin-like 4, in the eyes of patients with proliferative sickle retinopathy

The recent success of therapies directly targeting the angiogenic mediator, vascular endothelial growth factor (VEGF), for the treatment of proliferative diabetic retinopathy has encouraged clinicians to extend the use of anti-VEGF therapies for the treatment of another ischemic retinal vascular disease, proliferative sickle cell retinopathy (PSR), the most common cause of irreversible blindness in patients with sickle cell disease. However, results from case reports evaluating anti-VEGF therapies for PSR have been mixed. This highlights the need to identify alternative therapeutic targets for the treatment of retinal neovascularization in sickle cell patients. In this regard, angiopoietin-like 4 (ANGPTL4) is a novel angiogenic factor regulated by the transcription factor, hypoxia-inducible factor 1, the master regulator of angiogenic mediators (including VEGF) in ischemic retinal disease. In an effort to identify alternative targets for the treatment of sickle cell retinopathy, we have explored the expression of ANGPTL4 in the eyes of patients with PSR. To this end, we examined expression and localization of ANGPTL4 by immunohistochemistry in autopsy eyes from patients with known PSR (n = 5 patients). Complementary studies were performed using enzyme-linked immunosorbent assays in aqueous (n = 8; 7 patients, 2 samples from one eye of same patient) and vitreous (n = 3 patients) samples from a second group of patients with active PSR. We detected expression of ANGPTL4 in neovascular tissue and in the ischemic inner retina in PSR, but not control, eyes. We further observed elevated expression of ANGPTL4 in the aqueous and vitreous of PSR patients compared to controls. These results suggest that ANGPTL4 could contribute to the development of retinal neovascularization in sickle cell patients and could therefore be a therapeutic target for the treatment of PSR.

Effect of Topical Nepafenac on Central Foveal Thickness following Panretinal Photocoagulation in Diabetic Patients

Purpose

To evaluate effectiveness of topical nepafenac in reducing macular edema following panretinal photocoagulation (PRP).

Design

Prospective randomized double-blinded controlled study.

Methods

Sixty eyes of 60 patients having proliferative or severe nonproliferative diabetic retinopathy had PRP. Patients were then divided into two groups: nepafenac group (30 eyes) receiving 1% topical nepafenac eye drops for 6 months and control group (30 eyes) receiving carboxymethylcellulose eye drops for 6 months. Best-corrected visual acuity (BCVA) and macular optical coherence tomography were followed up at 1, 2, 4, and 6 months after PRP.

Results

BCVA was significantly better in nepafenac group than in control group at all follow-ups (P < 0.01). At 6 months post-PRP, logMAR BCVA was 0.11 ± 0.04 (equivalent to 20/26 Snellen acuity) in the nepafenac group and 0.18 ± 0.08 (equivalent to 20/30 Snellen acuity) in the control group (P < 0.01). Central foveal thickness (CFT) increased in both groups from the first month after PRP. Increase in CFT was higher in control group than in nepafenac group throughout follow-up, but the difference became statistically significant only after 4 months. No significant ocular adverse events were reported with topical nepafenac.

Conclusion

Topical nepafenac can minimize macular edema and stabilize visual acuity following PRP for diabetic patients.

Change in Diabetic Retinopathy Through 2 Years: Secondary Analysis of a Randomized Clinical Trial Comparing Aflibercept, Bevacizumab, and Ranibizumab

Importance

Anti-vascular endothelial growth factor (anti-VEGF) therapy for diabetic macular edema (DME) favorably affects diabetic retinopathy (DR) improvement and worsening. It is unknown whether these effects differ across anti-VEGF agents.

Objective

To compare changes in DR severity during aflibercept, bevacizumab, or ranibizumab treatment for DME.

Design, Setting, and Participants

Preplanned secondary analysis of data from a comparative effectiveness trial for center-involved DME was conducted in 650 participants receiving aflibercept, bevacizumab, or ranibizumab. Retinopathy improvement and worsening were determined during 2 years of treatment. Participants were randomized in 2012 through 2013, and the trial concluded on September 23, 2015.

Interventions

Random assignment to aflibercept, 2.0 mg; bevacizumab, 1.25 mg; ranibizumab, 0.3 mg, up to every 4 weeks through 2 years following a retreatment protocol.

Main Outcomes and Measures

Percentages with retinopathy improvement at 1 and 2 years and cumulative probabilities for retinopathy worsening through 2-year without adjustment for multiple outcomes.

Results

A total of 650 participants (495 [76.2%] nonproliferative DR [NPDR], 155 proliferative DR [PDR]) were analyzed; 302 (46.5%) were women and mean (SD) age was 61 (10) years; 425 (65.4%) were white. At 1 year, among 423 NPDR eyes, 44 of 141 (31.2%) treated with aflibercept, 29 of 131 (22.1%) with bevacizumab, and 57 of 151 (37.7%) with ranibizumab had improvement of DR severity (adjusted difference: 11.7%; 95% CI, 2.9% to 20.6%; P = .004 for aflibercept vs bevacizumab; 8.9%; 95% CI, 1.7% to 16.1%; P = .01 for ranibizumab vs bevacizumab; and 2.9%; 95% CI, -5.7% to 11.4%; P = .51 for aflibercept vs ranibizumab). At 2 years, 33 eyes (24.8%) in the aflibercept group, 25 eyes (22.1%) in the bevacizumab group, and 40 eyes (31.0%) in the ranibizumab group had DR improvement; no treatment group differences were identified. For 93 eyes with PDR at baseline, 1-year improvement rates were 75.9% for aflibercept, 31.4% for bevacizumab, and 55.2% for ranibizumab (adjusted difference: 50.4%; 95% CI, 26.8% to 74.0%; P < .001 for aflibercept vs bevacizumab; 20.4%; 95% CI, -3.1% to 44.0%; P = .09 for ranibizumab vs bevacizumab; and 30.0%; 95% CI, 4.4% to 55.6%; P = .02 for aflibercept vs ranibizumab). These rates and treatment group differences appeared to be maintained at 2 years. Despite the reduced numbers of injections in the second year, 66 (59.5%) of NPDR and 28 (70.0%) of PDR eyes that manifested improvement at 1 year maintained improvement at 2 years. Two-year cumulative rates for retinopathy worsening ranged from 7.1% to 10.2% and 17.2% to 26.4% among anti-VEGF groups for NPDR and PDR eyes, respectively. No statistically significant treatment differences were noted.

Conclusions and Relevance

At 1 and 2 years, eyes with NPDR receiving anti-VEGF treatment for DME may experience improvement in DR severity. Less improvement was demonstrated with bevacizumab at 1 year than with aflibercept or ranibizumab. Aflibercept was associated with more improvement at 1 and 2 years in the smaller subgroup of participants with PDR at baseline. All 3 anti-VEGF treatments were associated with low rates of DR worsening. These data provide additional outcomes that might be considered when choosing an anti-VEGF agent to treat DME.