Comparative therapy evaluation of intravitreal bevacizumab and triamcinolone acetonide on persistent diffuse diabetic macular edema

Bilateral effect following off label unilateral intravitreal brolucizumab injection in patient with pseudophakic cystoid macular edema

PURPOSE

To report a bilateral reduction in pseudophakic cystoid macular edema (PCME) after unilateral intravitreal injection (IVI) of brolucizumab.

OBSERVATIONS

A 64-year-old female with bilateral recalcitrant PCME was treated with one dose of intravitreal ozurdex implant and triamcinolone acetonide each in both the eyes, with an equivocal response. On switching to IVI brolucizumab in the right eye (OD), the patient showed significant improvement in the best-corrected visual acuity (BCVA) with a notable reduction in the intraretinal fluid (IRF) and central subfield thickness (CST) in both the eyes at one month.

CONCLUSIONS AND IMPORTANCE

In conclusion, IVI brolucizumab is effective for the management of recalcitrant PCME with good visual and anatomical outcomes at one month. However, this molecule can also have therapeutic efficacy in the uninjected eye possibly due to systemic escape. More research into the pharmacokinetic properties of this novel molecule is needed to validate our findings.

Persistent diabetic macular edema: Definition, incidence, biomarkers, and treatment methods

Intravitreal antivascular endothelial growth factor (anti-VEGF) treatment has drastically improved the visual and anatomical outcomes in patients with diabetic macular edema (DME); however, success is not always guaranteed, and a proportion of these eyes demonstrate persistent DME (pDME) despite intensive treatment. While standardized criteria to define these treatment-resistant eyes have not yet been established, many studies refer to eyes with no clinical response or an unsatisfactory partial response as having pDME. A patient is considered to have pDME if the retinal thickness improves less than 10-25% after 6 months of treatment. A range of treatment options have been recommended for eyes with pDME, including switching anti-VEGF agents, using corticosteroids and/or antioxidant drugs in adjunct with anti-VEGF therapy, and vitrectomy. In addition, multimodal imaging of DME eyes may be advantageous in predicting the responsiveness to treatment; this is beneficial when initiating alternative therapies. We explore the literature on persistent DME regarding its defining criteria, incidence, the baseline biological markers that may be useful in anticipating the response to treatment, and the available treatment options.

Contralateral Effect following Intravitreal Brolucizumab Injection in Diabetic Macular Edema

The authors describe a novel case of a 48-year-old male with bilateral diabetic macular edema (DME) who underwent intravitreal injection (IVI) of brolucizumab in the left eye. At four weeks, the patient demonstrated a bilateral response by way of improvement in the best-corrected visual acuity (BCVA) and reduction in the central macular thickness (CMT) in both eyes. Further studies on the ocular and systemic assays of the brolucizumab molecule are warranted to evaluate its systemic escape and to better understand the pharmacokinetics behind the bilateral effect.

Systemic dendrimer nanotherapies for targeted suppression of choroidal inflammation and neovascularization in age-related macular degeneration

Inflammation and neovascularization are key pathological events in human age-related macular degeneration (AMD). Activated microglia/macrophages (mi/ma) and retinal pigmented epithelium (RPE) play an active role in every stage of disease progression. Systemic therapies that can target these cells and address both inflammation and neovascularization will broaden the impact of existing therapies and potentially open new avenues for early AMD where there are no viable therapies. Utilizing a clinically relevant rat model of AMD that mirrors many aspects that of human AMD pathological events, we show that systemic hydroxyl-terminated polyamidoamine dendrimer-triamcinolone acetonide conjugate (D-TA) is selectively taken up by the injured mi/ma and RPE (without the need for targeting ligands). D-TA suppresses choroidal neovascularization significantly (by >80%, >50-fold better than free drug), attenuates inflammation in the choroid and retina, by limiting macrophage infiltration in the pathological area, significantly suppressing pro-inflammatory cytokines and pro-angiogenic factors, with minimal side effects to healthy ocular tissue and other organs. In ex vivo studies on human postmortem diabetic eyes, the dendrimer is also taken up into choroidal macrophages. These results suggest that the systemic hydroxyl dendrimer-drugs can offer new avenues for therapies in treating early/dry AMD and late/neovascular AMD alone, or in combination with current anti-VEGF therapies. This hydroxyl dendrimer platform but conjugated to a different drug is undergoing clinical trials for severe COVID-19, potentially paving the way for faster clinical translation of similar compounds for ocular and retinal disorders.

Prevention of Macular Edema in Patients With Diabetic Retinopathy Undergoing Cataract Surgery: The PROMISE Trial

BACKGROUND AND OBJECTIVE

To determine the safety and efficacy of intravitreal aflibercept injection (IAI) in patients with diabetic retinopathy (DR) in the prevention of macular edema (ME) following cataract surgery.

PATIENTS AND METHODS

This phase 2, prospective, interventional, single-masked, randomized trial at a single academic center included 30 patients who were 18 years of age or older with nonproliferative DR and undergoing cataract surgery with phacoemulsification. Patients received 2 mg intravitreal aflibercept (0.05 mL) or sham injection during cataract surgery. Main outcome measures included treatment adverse events (AEs), best-corrected visual acuity (BCVA), and incidence of ME (defined as presence of cystoid abnormalities as detected by optical coherence tomography at any follow-up visit), a 30% or greater increase from preoperative baseline in central subfield macular thickness, or a BCVA decrease of more than 5 ETDRS letters from Day 7 due to retinal thickening.

RESULTS

There were similar incidences of AEs between the two groups and no clinically serious ocular AEs in either group. The IAI group had fewer ME events at Day 14 (13% vs. 53%; P = .022), but there was no significant difference in ME events at Day 30 (27% vs. 60%; P = .057), Day 60 (27% vs. 60%; P = .057), or Day 90 (40% vs. 67%; P = .161). Compared to the study group, the control group had a significantly greater increase in central subfield thickness (CST) at Day 30 (50.05 μm vs. 7.95 μm; P = .040) and Day 60 (56.45 μm vs. 3.02 μm; P = .010). However, the difference in CST between groups was no longer significant at Day 90 (50.31 μm vs. 18.48 μm; P = .12). There were no significant differences in BCVA gains between the IAI and sham group at the end of the follow-up period (Day 90, ETDRS letters: 9.88 vs. 8.52; P = .66).

CONCLUSIONS

Use of IAI in patients with DR for prevention of ME following cataract surgery showed no significant AEs. Although there were significant differences in ME incidence and retinal thickness at periods of time, there was no clinically meaningful benefit in terms of VA. Further larger trials are needed to validate these findings. [Ophthalmic Surg Lasers Imaging Retina. 2020;51:170-178.].

Alone laser versus bevacizumab plus laser for diffuse diabetic macular edema (ALBA randomized trial)

Purpose:

To report the 12-month results of laser (treatment G1) versus intravitreal bevacizumab combined with laser (treatment G2) in patients with diffuse diabetic macular edema (DME).

Methods:

In this single-center randomized independent controlled trial, 32 patients were randomized to G1 (n = 15) or G2 (n = 17). In G1, laser was given at baseline and then pro re nata (PRN). In G2, three intravitreal bevacizumab (1.25 mg) injections were given once every 6 weeks, then laser and then PRN. Analysis was performed by treatment as administered. This study was registered in clinicaltrials.gov as NCT01572350 and EU Clinical Trial Registry as 2009-014654-15.

Results:

G2 was superior to G1 improving best corrected visual acuity (BCVA) with respect baseline (+8.0 vs + 3.0; p < 0.01). At month 12, a significantly greater proportion of patients had a BCVA letter score >15 and >73 in G2 (3 of 15 (20%) and 8 of 15 (53%), respectively) versus G1 (1 of 17 (6%) and 4 of 18 (23%), respectively). Health-related quality of life, assessed through National Eye Institute Visual Function Questionnaire, at 12 months was statistically indistinguishable between both groups.

Conclusion:

G2 provided superior visual acuity gains over G1 in patients with visual impairment due to center-involving diffuse DME, associated with significant gains in VFQ-25 scores.

Intravitreal bevacizumab versus intravitreal triamcinolone for diabetic macular edema-Systematic review, meta-analysis and meta-regression

Background

The most frequent cause of vision loss from diabetic retinopathy is diabetic macular edema (DME). Earlier clinical trials tried to examine the role of intravitreal triamcinolone (IVT) and intravitreal bevacizumab (IVB) in DME; they either qualified IVT over IVB or IVB over IVT or did not exhibit a significant difference.

Objective

This paper aims to compare the efficacy and safety of IVB versus IVT alone or combined IVB+IVT in the treatment of DME.

Methods

We systematically searched PubMed, CENTRAL, Scopus, Embase, Science Direct, OVID, and Web of Science for randomized controlled trials of IVB versus IVT alone or combined IVB+IVT and IVT versus the combined IVB+IVT in DME patients.

Results

A total of 1243 eyes of 17 trials were included in our meta-analysis and regression. Repeated injections of IVB were superior at improving VA comparing with those of IVT at 12, 24, 48-weeks, and IVB+IVT at 12, 24, 48-weeks. Single injections were comparable across the three arms regarding BCVA improvement. CMT reductions were also comparable across the three arms. Meanwhile, the overall safety regarding intraocular pressure and intraocular hypertension significantly favored the IVB group. Improvement in VA was best modified with CMT reduction from 480 um to 320um. This association was significant at 12-weeks in the three arms and persisted till 24-weeks and 48-weeks exclusively in the IVB group.

Conclusions and relevance

Our analysis reveals that repeated successive injections associate with better BCVA compared to single injection. Current evidence affirms that IVB is superior to IVT and IVB+IVT at improving BCVA, comparable at reducing CMT, and presents a better safety profile in the treatment of DME.

Intravitreal steroids for macular edema in diabetes

BACKGROUND

Diabetic macular edema (DME) is secondary to leakage from diseased retinal capillaries with thickening of central retina, and is an important cause of poor central visual acuity in people with diabetic retinopathy. Intravitreal steroids have been used to reduce retinal thickness and improve vision in people with DME.

OBJECTIVES

To assess the effectiveness and safety of intravitreal steroid therapy compared with other treatments for DME.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, and Embase on 15 May, 2019. We also searched reference lists, Science Citation Index, conference proceedings, and relevant trial registers. We conducted a top up search on 21 October, 2020.

SELECTION CRITERIA

We included randomized controlled trials that evaluated any type of intravitreal steroids as monotherapy against any other intervention (e.g. observation, laser photocoagulation, anti-vascular endothelial growth factor (antiVEGF) for DME.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study eligibility and risk of bias and extracted data. Where appropriate, we performed meta-analyses.

MAIN RESULTS

We included 10 trials (4348 participants, 4505 eyes). These trials compared intravitreal steroid therapies versus other treatments, including intravitreal antiVEGF therapy, laser photocoagulation, and sham injection. Most trials had an overall unclear or high risk of bias. One trial (701 eyes ) compared intravitreal dexamethasone implant 0.7mg with sham. We found moderate-certainty evidence that dexamethasone leads to slightly more improvement of visual acuity than sham at 12 months (mean difference [MD] -0.08 logMAR, 95% confidence interval [CI] -0.12 to -0.05 logMAR). Regarding improvement of three or more lines of visual acuity, there was moderate-certainty evidence in favor of dexamethasone at 12 months, but the CI covered the null value (risk ratio (RR) 1.39, 95% CI 0.91 to 2.12). Regarding adverse events, dexamethasone increased by about four times the risk of cataract progression and the risk of using intraocular pressure (IOP)-lowering medications compared to sham (RR 3.89, 95% CI 2.75 to 5.50 and RR 4.54, 95% CI 3.19 to 6.46, respectively; moderate-certainty evidence); about 4 in 10 participants treated with dexamethasone needed IOP-lowering medications. Two trials (451 eyes) compared intravitreal dexamethasone implant 0.7mg with intravitreal antiVEGF (bevacizumab and ranibizumab). There was moderate-certainty evidence that visual acuity improved slightly less with dexamethasone compared with antiVEGF at 12 months (MD 0.07 logMAR, 95% CI 0.04 to 0.09 logMAR; 2 trials; 451 participants/eyes; I² = 0%). The RR of gain of three or more lines of visual acuity was inconsistent between trials, with one trial finding no evidence of a difference between dexamethasone and bevacizumab at 12 months (RR 0.99, 95% CI 0.70 to 1.40; 1 trial; 88 eyes), and the other, larger trial finding the chances of vision gain were half with dexamethasone compared with ranibizumab (RR 0.50, 95% CI 0.32 to 0.79; 1 trial; 432 participants). The certainty of evidence was low. Cataract progression and the need for IOP-lowering medications increased more than 4 times with dexamethasone implant compared to antiVEGF (moderate-certainty evidence). One trial (560 eyes) compared intravitreal fluocinolone implant 0.19mg with sham. There was moderate-certainty evidence that visual acuity improved slightly more with fluocinolone at 12 months (MD -0.04 logMAR, 95% CI -0.06 to -0.01 logMAR). There was moderate-certainty evidence that an improvement in visual acuity of three or more lines was more common with fluocinolone than with sham at 12 months (RR 1.79, 95% CI 1.16 to 2.78). Fluocinolone also increased the risk of cataract progression (RR 1.63, 95% CI 1.35 to 1.97; participants = 335; moderate-certainty evidence), which occurred in about 8 in 10 participants, and the use of IOP-lowering medications (RR 2.72, 95% CI 1.87 to 3.98; participants = 558; moderate-certainty evidence), which were needed in 2 to 3 out of 10 participants. One small trial with 43 participants (69 eyes) compared intravitreal triamcinolone acetonide injection 4 mg with sham. There may be a benefit in visual acuity at 24 months (MD -0.11 logMAR, 95% CI -0.20 to -0.03 logMAR), but the certainty of evidence is low. Differences in adverse effects were poorly reported in this trial. Two trials (615 eyes) compared intravitreal triamcinolone acetonide injection 4mg with laser photocoagulation and reached discordant results. The smaller trial (31 eyes followed up to 9 months) found more visual acuity improvement with triamcinolone (MD -0.18 logMAR, 95% CI -0.29 to -0.07 logMAR), but a larger, multicenter trial (584 eyes, 12-month follow-up) found no evidence of a difference regarding change in visual acuity (MD 0.02 logMAR, 95% CI -0.03 to 0.07 logMAR) or gain of three or more lines of visual acuity (RR 0.85, 95% CI 0.55 to 1.30) (overall low-certainty evidence). Cataract progression was about three times more likely (RR 2.68, 95% CI 2.21 to 3.24; moderate-certainty evidence) and the use of IOP-lowering medications was about four times more likely (RR 3.92, 95% CI 2.59 to 5.96; participants = 627; studies = 2; I² = 0%; moderate-certainty evidence) with triamcinolone. About 1 in 3 participants needed IOP-lowering medication. One small trial (30 eyes) compared intravitreal triamcinolone acetonide injection 4mg with intravitreal antiVEGF (bevacizumab or ranibizumab). Visual acuity may be worse with triamcinolone at 12 months (MD 0.18 logMAR, 95% CI 0.10 to 0.26 logMAR); the certainty of evidence is low. Adverse effects were poorly reported in this trial. Four trials reported data on pseudophakic participants, for whom cataract is not a concern. These trials found no decrease in visual acuity in the second treatment year due to cataract progression.

AUTHORS' CONCLUSIONS

Intravitreal steroids may improve vision in people with DME compared to sham or control. Effects were small, about one line of vision or less in most comparisons. More evidence is available for dexamethasone or fluocinolone implants when compared to sham, and the evidence is limited and inconsistent for the comparison of dexamethasone with antiVEGF treatment. Any benefits should be weighed against IOP elevation, the use of IOP-lowering medication and, in phakic patients, the progression of cataract. The need for glaucoma surgery is also increased, but remains rare.

Glucocorticoid-transactivated TSC22D3 attenuates hypoxia- and diabetes-induced Müller glial galectin-1 expression via HIF-1α destabilization

Galectin‐1/LGALS1, a newly recognized angiogenic factor, contributes to the pathogenesis of diabetic retinopathy (DR). Recently, we demonstrated that glucocorticoids suppressed an interleukin‐1β‐driven inflammatory pathway for galectin‐1 expression in vitro and in vivo. Here, we show glucocorticoid‐mediated inhibitory mechanism against hypoxia‐inducible factor (HIF)‐1α‐involved galectin‐1 expression in human Müller glial cells and the retina of diabetic mice. Hypoxia‐induced increases in galectin‐1/LGALS1 expression and promoter activity were attenuated by dexamethasone and triamcinolone acetonide in vitro. Glucocorticoid application to hypoxia‐stimulated cells decreased HIF‐1α protein, but not mRNA, together with its DNA‐binding activity, while transactivating TSC22 domain family member (TSC22D)3 mRNA and protein expression. Co‐immunoprecipitation revealed that glucocorticoid‐transactivated TSC22D3 interacted with HIF‐1α, leading to degradation of hypoxia‐stabilized HIF‐1α via the ubiquitin‐proteasome pathway. Silencing TSC22D3 reversed glucocorticoid‐mediated ubiquitination of HIF‐1α and subsequent down‐regulation of HIF‐1α and galectin‐1/LGALS1 levels. Glucocorticoid treatment to mice significantly alleviated diabetes‐induced retinal HIF‐1α and galectin‐1/Lgals1 levels, while increasing TSC22D3 expression. Fibrovascular tissues from patients with proliferative DR demonstrated co‐localization of galectin‐1 and HIF‐1α in glial cells partially positive for TSC22D3. These results indicate that glucocorticoid‐transactivated TSC22D3 attenuates hypoxia‐ and diabetes‐induced retinal glial galectin‐1/LGALS1 expression via HIF‐1α destabilization, highlighting therapeutic implications for DR in the era of anti‐vascular endothelial growth factor treatment.

Effect of Intravitreal Anti-Vascular Growth Factor Agents With or Without Macular Photocoagulation on Diabetic Macular Edema: A Systematic Review and Meta-Analysis

INTRODUCTION

Diabetes is a common cause of new sight loss in populations world-wide, and diabetic macular edema (DME) is a major cause of visual deficits in the diabetic populations of developed countries. We have performed a meta-analysis to evaluate whether combined treatment with anti-vascular endothelial growth factor (VEGF) injections and macular photocoagulation (MPC) is more efficacious than primary monotherapy with anti-VEGF injections in patients with DME.

METHODS

We systematically searched the PubMed and Web of Science databases for studies providing sufficient information for a comparison of pre- and post-treatment of central macular thickness (CMT) and best-corrected visual acuity (BCVA) between two groups of patients with DME given interventional therapies (monotherapy with an anti-VEGF agent vs. combination therapy with an anti-VEGF agent and MPC) before January 2019. A meta-analysis was performed to summarize the results of the studies included in the systematic review.

RESULTS

The results of our meta-analysis indicated that post-treatment CMT was significantly lower at 3 months in DME patients receiving combination therapy with bevacizumab, a humanized anti-VEGF antibody, and MPC than in those receiving monotherapy with bevacizumab. The results also showed that post-treatment CMT was lower in DME patients given ranibizumab, an anti-VEGF agent, in combination with MPC at 6, 9 and 12 months than in those treated with ranibizumab alone. However, no significant differences were found in post-treatment BCVA at 1, 3, 6, 9 and 12 months between DME patients receiving combination therapy with an anti-VEGF agent (bevacizumab or ranibizumab) and MPC and those receiving monotherapy with an anti-VEGF agent.

CONCLUSION

In conclusion, the results of our meta-analysis demonstrate a transiently synergistic effect of MPC on CMT when this treatment is combined with anti-VEGF agents, whereas no similar synergistic effect could be detected on the BCVA. A relatively longer follow-up was essential to be able to evaluate the long-term existence of this synergistic effect.

Efficacy of vitrectomy combined with an intraoperative dexamethasone implant in refractory diabetic macular edema

AIMS

To evaluate the safety and efficacy of vitrectomy combined with an intraoperative dexamethasone (Ozurdex^®) implant in refractory diabetic macular edema (DME).

METHODS

Patients who were diagnosed at our institution as having DME refractory to more than 6 months of non-surgical treatment and underwent intravitreal dexamethasone implantation combined with vitrectomy. All patients were followed up for more than 12 months. Best-corrected visual acuity (BCVA, logMAR), central macular thickness (CMT), and intraocular pressure at the initial visit and 1, 3, 4, 6, and 12 months after treatment were recorded.

RESULTS

Twenty-two eyes (22 patients) were included in this study. The mean preoperative BCVA was 0.68 and the mean CMT was 470.80 µm. The total number of the previous injections was 5.1 ± 1.6. The mean BCVA was significantly improved at all visits, and the mean CMT was also significantly reduced (p < 0.05). Sixteen eyes (73%) did not need additional implantations during follow-up.

CONCLUSIONS

Vitrectomy combined with an intraoperative dexamethasone (Ozurdex) implant was an effective and safe treatment option in patients with refractory DME.

The Relationship between Carotid Intima-Media Thickness and Ocular Circulation in Type-2 Diabetes

Purpose

To compare clinical findings, including ocular blood flow and intima-media thickness (IMT) of the carotid artery, in mild nonproliferative diabetic retinopathy (NPDR) and no diabetic retinopathy (NDR) patients, and to determine risk factors contributing to mild NPDR.

Methods

In 129 subjects (129 eyes) with type-2 diabetes patients and mild NPDR or NDR, standard statistical techniques were used to determine associations between clinical findings, including diabetes duration, blood levels of creatinine and hemoglobin A1c (HbA1c), central macular thickness (CMT; measured with optical coherence tomography), mean blur rate (MBR; measured with laser speckle flowgraphy), and ultrasound-measured carotid IMT.

Results

Diabetes duration, IMT, and CMT were significantly higher in the mild NPDR patients than the NDR patients (P=0.004, P=0.004, and P=0.003, respectively), while conversely, MBR in the overall optic nerve head (MBR-A) was lower in the mild NPDR patients. Furthermore, a logistic regression analysis showed that diabetes duration (OR, 1.11; P=0.006), diastolic blood pressure (OR, 0.93; P=0.025), heart rate (OR, 1.07; P=0.004), IMT (OR, 8.65; P=0.005), and CMT (OR, 1.03; P=0.007) were independent contributing factors to mild NPDR. Spearman's rank correlation test also showed that IMT was negatively correlated with MBR-A (P=0.011).

Conclusions

Increased IMT showed a close association with ocular ischemia in patients with type-2 diabetes and contributed to the presence of mild NPDR. These findings suggest that IMT may be an early biomarker of mild NPDR.

Effect of Intravitreal Bevacizumab with or without Macular Photocoagulation for Diabetic Macular Edema: A Meta-Analysis

INTRODUCTION

In this meta-analysis, we aimed to assess the possible benefits of macular photocoagulation (MPC) as an additional treatment with intravitreal bevacizumab (IVB) in patients with diabetic macular edema.

METHODS

The studies were identified from three databases: PubMed, Web of Science, and the Cochrane Library. The main outcome measures included change in best-corrected visual acuity (BCVA), differences in central macular thickness (CMT), and adverse events within the follow-up period. The results were pooled using weight mean difference with their corresponding 95% confidence intervals. A fixed or random effects model was employed, depending on the heterogeneity of the inclusion trials.

RESULTS

Finally, three randomized controlled trial and two high-quality retrospective studies were identified and included. Changes in CMT at 1, 3, and 6 months did not vary significantly between the IVB-alone group and the IVB with MPC group (P = 0.26, 0.06, and 0.65, respectively). Similarly, changes in BCVA at 1, 3, and 6 months also did not vary significantly between the two groups (P = 0.20, 0.91, and 0.70, respectively). Whereas substantial heterogeneity was detected in the CMT results among these studies, the sensitivity analyses showed Solaiman's study was probably the source of the heterogeneity. No publication bias was detected by funnel plots in this study.

CONCLUSION

Results of this meta-analysis showed that the treatments with IVB alone and combined IVB and MPC were similarly effective in improving BCVA and reducing CMT. However, more evidence is needed to evaluate their effects in the long-term periods.

INTRAVITREAL DEXAMETHASONE IMPLANTATION IN PATIENTS WITH DIFFERENT MORPHOLOGICAL DIABETIC MACULAR EDEMA HAVING INSUFFICIENT RESPONSE TO RANIBIZUMAB

PURPOSE

To evaluate the effectiveness of a single intravitreal injection of dexamethasone implant in resistant diabetic macular edema that have different morphological types.

METHODS

In this retrospective study, 31 patients (35 eyes) with persistent diabetic macular edema, who underwent a single injection of dexamethasone implant, were evaluated. Diabetic macular edema was classified into three types: diffuse retinal thickening (n = 10), cystoid macular edema (n = 13), and serous retinal detachment (n = 12). Primary outcome measures were best corrected visual acuity, and central macular thickness.

RESULTS

The three subgroups were similar in terms of age and gender (P > 0.05). Total duration of diabetes was significantly less in the serous retinal detachment subgroup (P = 0.01). There were no differences in the best corrected visual acuity between the three subgroups until the sixth month. However, the best corrected visual acuity was significantly better in the diffuse retinal thickness subgroup at the sixth month (P = 0.008). Regarding the central macular thickness values, it was statistically better in serous retinal detachment than in diffuse retinal thickening and cystoid macular edema subgroups till the sixth month (P = 0.001). However, at the sixth month, there was not any statistical difference between subgroups regarding central macular thickness values. Antiglaucomatous agents were required in 4 (11.4%) patients throughout the study.

CONCLUSION

Treatment algorithms should differ according to the morphology of diabetic macular edema; however, more data is needed to give specific recommendations.

Potential Interplay between Hyperosmolarity and Inflammation on Retinal Pigmented Epithelium in Pathogenesis of Diabetic Retinopathy

Diabetic retinopathy is a frequent eyesight threatening complication of type 1 and type 2 diabetes. Under physiological conditions, the inner and the outer blood-retinal barriers protect the retina by regulating ion, protein, and water flux into and out of the retina. During diabetic retinopathy, many factors, including inflammation, contribute to the rupture of the inner and/or the outer blood-retinal barrier. This rupture leads the development of macular edema, a foremost cause of sight loss among diabetic patients. Under these conditions, it has been speculated that retinal pigmented epithelial cells, that constitute the outer blood-retinal barrier, may be subjected to hyperosmolar stress resulting from different mechanisms. Herein, we review the possible origins and consequences of hyperosmolar stress on retinal pigmented epithelial cells during diabetic retinopathy, with a special focus on the intimate interplay between inflammation and hyperosmolar stress, as well as the current and forthcoming new pharmacotherapies for the treatment of such condition.

The Relationship between Peripheral Nerve Conduction Velocity and Ophthalmological Findings in Type 2 Diabetes Patients with Early Diabetic Retinopathy

PURPOSE

Nerve conduction velocity (NCV) is an indicator of neuronal damage in the distal segment of the peripheral nerves. Here, we determined the association between NCV and other systemic and ocular clinical findings, in type 2 diabetes patients with early diabetic retinopathy (DR).

METHODS

This study included 42 eyes of 42 type 2 diabetes patients (median age: 54 years) with no DR or with mild nonproliferative DR. Standard statistical techniques were used to determine associations between clinical findings.

RESULTS

Sural sensory conduction velocity (SCV) and tibial motor conduction velocity (MCV) were significantly lower in mild nonproliferative DR patients than patients with no DR (P = 0.008 and P = 0.01, resp.). Furthermore, logistic regression analyses revealed that sural SCV and tibial MCV were independent factors contributing to the presence of mild nonproliferative DR (OR 0.83, P = 0.012 and OR 0.69 P = 0.02, resp.). Tibial MCV was correlated with choroidal thickness (CT) (P = 0.01), and a multiple regression analysis revealed that age, tibial MCV, and carotid intima-media thickness were independent associating factors with CT (P = 0.035, P = 0.015, and P = 0.008, resp.).

CONCLUSIONS

Our findings suggest that reduced NCV may be closely associated with early DR in type 2 diabetes patients. Thus, reduced nerve conduction is a potential early biomarker of DR.

Intravitreal bevacizumab alone or combined with 1 mg triamcinolone in diabetic macular edema: a randomized clinical trial

PURPOSE

To compare the results of intravitreal bevacizumab (IVB) injection alone or in combination with intravitreal 1 mg triamcinolone acetonide (IVT) in center-involved diabetic macular edema.

METHODS

In this randomized clinical trial study, ninety-two eyes of 46 patients with bilateral center-involved diabetic macular edema and no previous treatment were included in the study. One eye of each patient was randomly assigned to 1.25 mg of IVB injection or combination of 1.25 IVB and 1 mg IVT. Evaluation of best-corrected visual acuity (BCVA), central macular thickness (CMT), intraocular pressure (IOP) and grading of lens opacity was conducted at baseline, and weeks 2, 4, 6, 8, 12 and 24 after treatment. Retreatment was performed at a 6-week interval whenever indicated based on CMT.

RESULTS

Between the groups, BCVA changes were not statistically different until 24-week follow-up (P > 0.05), but at 24 weeks after treatment, BCVA improvement was significantly better in IVB group (P = 0.049). Significant CMT reduction was observed in each group along the follow-up period (P = 0.001). The mean CMT reduction was more significant in combination (IVB + IVT) group at 2 weeks of follow-up (P < 0.001), but CMT changes were not significant between the groups at weeks 12th and 24th after injection. Overall, retreatment was applied for 59 eyes up to 24 weeks (33 in the IVB group, 26 in the IVB + IVT group). Among patients with 2 or more injections, number of injections was significantly lower in IVB + IVT group (P = 0.043). Three eyes within IVB + IVT group developed IOP rise beyond 21 mmHg, which were controlled with topical anti-glaucoma medications within 1 week. Changes in lens opacity were not significant between two groups.

CONCLUSION

Eyes treated with IVB plus 1 mg IVT injections had more significant reduction in CMT in early post-injection, but this effect was transient. Although after 24 weeks visual acuity improvement was better in IVB group, combination therapy may decrease the number of injections. Combining 1 mg of intravitreal triamcinolone with bevacizumab was not accompanied with significant side effects.

Aqueous cytokine levels are associated with reduced macular thickness after intravitreal ranibizumab for diabetic macular edema

Purpose

It is controversial whether the administration of anti-vascular endothelial growth factor drugs for diabetic macular edema (DME) affects intraocular inflammatory cytokines. In this study, we measured cytokine concentration in aqueous humor before and after intravitreal injection of ranibizumab (IVR). The aim was to determine changes in cytokine concentration and their effects on DME reduction.

Methods

Twelve patients (13 eyes) with DME received two IVR (0.5 mg) with a 1 month interval, and a total of 26 aqueous humor samples were obtained. Macular thickness was measured with an optical coherence tomography (OCT) using thickness-map mode with an Early Treatment Diabetic Retinopathy Study (ETDRS) 9-zone grid that was divided into two zones: a central circle with a diameter of 1 mm (zone1); and an outer circle with a diameter of 6 mm (zone2).

Results

The concentration of eotaxin-1 in aqueous humor samples decreased significantly after IVR. Baseline cytokine concentration was associated with IVR-induced DME reduction. In zone1, higher baseline concentration of interferon-induced protein (IP)-10, and in zone 2, higher baseline concentration of granulocyte-macrophage colony-stimulating factor, IP-10, and tumor necrosis factor (TNF) α; and lower baseline concentration of eotaxin-1, interleukin (IL)-5, and IL-8 were associated with improved DME. Cytokine changes were associated with IVR-induced DME reduction. In zone1, lower concentration of IP-10 compared to baseline or higher concentration of macrophage inflammatory protein (MIP) -α, and in zone 2, lower concentration of IL-5 compared to baseline, IL-8, and IP-10 or higher concentration of eotaxin-1 and MIP-1β were associated with improved DME.

Conclusions

These findings suggest that ranibizumab affects the concentration of cytokines in aqueous humor. Various cytokines contribute to a decrease in retinal thickness, both in the center of the macula and in a larger area of the retina.

Vessel diameter study: intravitreal vs posterior subtenon triamcinolone acetonide injection for diabetic macular edema

PurposeTo detect and compare the vessel diameter effect of intravitreal vs subtenon injection of triamcinolone for diabetic macular edema (DME).MethodsSixty patients with DME who underwent triamcinolone injection either intravitreally (N=30) or under the tenon capsule (N=30) were included. Non-injected fellow eyes served as control. The main outcome measures were central retinal artery equivalent (CRAE), central retinal vein equivalent (CRVE), and artery-vein ratio (AVR).ResultsIn the intravitreal group, pre-injection mean CRAE (147.07 μ) decreased to 141.03 μ at 1 week and to 139.43 μ at 1 month (P<0.001) while baseline CRVE (209.61 μ) decreased initially to 198.85 μ at 1 week then to 198.49 μ at 1 month (P<0.001). In the subtenon group, pre-injection CRAE (152.18 μ) decreased to 149.49 μ at 1 week and to 147.47 μ at 1 month (P=0.017), while baseline CRVE (215.60 μ) decreased initially to 208.69 μ at 1 week then to 207.25 μ at 1 month (P=0.003). Pre-injection AVR values did not change at 1 week and at 1 month in both injection groups (P=0.66 and P=0.196, respectively). In the control group, none of the 3 parameters changed throughout the study period compared to the baseline (P>0.28).ConclusionIn eyes with DME, both intravitreal and subtenon triamcinolone injection led to a significant constriction of retinal arteries and veins.

CHARACTERIZATION OF MACULAR CHOROIDAL THICKNESS IN ISCHEMIC AND NONISCHEMIC DIABETIC MACULOPATHY

PURPOSE

To evaluate changes in macular choroidal thickness in eyes with ischemic and nonischemic diabetic maculopathy.

METHODS

Cross-sectional study of enhanced depth imaging optical coherence tomography of patients with diabetes. The diabetic eyes were divided into 3 groups: 1) eyes with no diabetic retinopathy (NDR); 2) those with diabetic retinopathy without macular ischemia (DR/MI-); and 3) those with diabetic retinopathy and macular ischemia (DR/MI+).

RESULTS

This analysis included 261 eyes of 160 patients. Eighty-eight eyes belonged to the NDR, 90 to the DR/MI-, and 83 to the DR/MI+ group. The choroidal thickness was significantly reduced in the DR/MI+ group as compared with the other 2 groups in the subfoveal region (NDR: 285.94 ± 80.38 μm, DR/MI-: 311.22 ± 94.55 μm, DR/MI+: 216.06 ± 58.41 μm; P < 0.001), nasally and temporally (P < 0.01). Between the NDR and DR/MI- groups, the choroidal thickness was significantly reduced nasally (P = 0.02) in the NDR group, but not subfoveally (P = 0.1) and temporally (P = 0.2). Notably, no statistically significant difference in central macular thickness was found between the DR/MI- (328.68 ± 103.28 μm) and DR/MI+ (341.99 ± 130.63 μm) groups (P = 1), although it was found to significantly increase in both these groups as compared with the NDR group (264.03 ± 27.74 μm; P < 0.001).

CONCLUSION

In diabetic maculopathy, an overall significant reduction was observed in macular choroidal thickness in eyes in ischemic stage as compared with nonischemic stage. In vivo evaluation of choroidal structural changes in the form of choroidal thickness may possibly be intuitive in understanding the pathogenesis of progression of diabetic maculopathy from nonischemic to ischemic stage, and associated functional damage.

Metabolomic profiling of reactive persulfides and polysulfides in the aqueous and vitreous humors

We investigate the metabolomic profile of reactive persulfides and polysulfides in the aqueous and vitreous humors. Eighteen eyes of 18 consecutive patients with diabetes mellitus (DM) and diabetic retinopathy underwent microincision vitrectomy combined with cataract surgery. Samples of the aqueous and vitreous humors were collected and underwent mass spectrometry-based metabolomic profiling of reactive persulfides and polysulfides (polysulfidomics). The effect of reactive polysulfide species on the viability of immortalized retinal cells (the RGC-5 cell line) under oxidative stress (induced with H₂O₂) was also evaluated with an Alamar Blue assay. The experiments showed that cysteine persulfides (CysSSH), oxidized glutathione trisulfide (GSSSG) and cystine were elevated in the aqueous humor, and CysSSH, Cys, and cystine were elevated in the vitreous. Furthermore, GSSSG, cystine, and CysSSH levels were correlated in the aqueous and vitreous humors. A comparison, in DM and control subjects, of plasma levels of reactive persulfides and polysulfides showed that they did not differ. In vitro findings revealed that reactive polysulfide species increased cell viability under oxidative stress. Thus, various reactive persulfides and polysulfides appear to be present in the eye, and some reactive sulfide species, which have a protective effect against oxidative stress, are upregulated in the aqueous and vitreous humors of DM eyes.

Comparison of aqueous concentrations of angiogenic and inflammatory cytokines based on optical coherence tomography patterns of diabetic macular edema

Purpose:

The purpose was to compare aqueous inflammatory and angiogenic cytokine levels in diabetic macular edema (DME).

Materials and Methods:

Aqueous samples were obtained from 50 eyes with DME and 12 normal eyes (control group). DME was classified according to the morphologic pattern based on optical coherence tomography: Diffuse retinal thickening (DRT; n = 19), cystoid macular edema (CME; n = 17), or serous retinal detachment (SRD; n = 14). Aqueous samples were collected just before intravitreal injection and at the beginning of cataract surgery in the control group. Interleukin (IL)-6, IL-8, interferon-induced protein (IP)-10, monocyte chemotactic protein (MCP)-1, platelet-derived growth factor (PDGF)-AA, and vascular endothelial growth factor (VEGF) levels were measured by multiplex bead assay.

Results:

The IL-6, IL-8, IP-10, and PDGF-AA levels differed significantly among the three groups of DME (P = 0.014, P = 0.038, P = 0.021, and P = 0.041, respectively). However, there were no differences between groups in aqueous concentration levels of MCP-1 and VEGF (P = 0.205 and P = 0.062, respectively). IL-6 (P = 0.026) and IL-8 (P = 0.023) correlated positively with central foveal thickness (CFT) in the CME group. None of the cytokine levels correlated significantly with CFT in any of the DRT and SRD groups.

Conclusions:

Aqueous concentrations of cytokines varied according to the morphologic pattern of DME, which might explain the variable response to treatments such as intravitreal bevacizumab or triamcinolone injection.

The relationship between advanced glycation end products and ocular circulation in type 2 diabetes

AIMS

To determine whether skin autofluorescence (SAF) and serum pentosidine, biomarkers of advanced glycation end products (AGEs), were associated with ocular microcirculation in type 2 diabetes patients with early diabetic retinopathy (DR).

METHODS

This study included 46 eyes of 46 type 2 diabetes patients with no DR or non-proliferative DR. SAF was measured with an autofluorescence reader. Optic nerve head (ONH) microcirculation, represented by mean blur rate (MBR), was measured with laser speckle flowgraphy. Overall MBR, vascular MBR, and tissue MBR were calculated in software. MBR, SAF, pentosidine levels, and clinical findings, including central macular thickness (CMT), were then compared.

RESULTS

SAF in the diabetes patients was correlated with age (P=0.018). Serum pentosidine was correlated with age, vascular MBR and tissue MBR (P=0.046, P=0.035, and P=0.01, respectively). CMT was correlated with tissue MBR (P=0.016), but not with vascular MBR or overall MBR. Separate multiple regression analyses of independent contributing factors revealed that age, SAF, serum pentosidine, duration of diabetes, and pulse rate contributed to tissue MBR (P=0.041, P=0.046, P=0.022, P=0.011 and P=0.036, respectively), while SAF, HbA1c, pulse rate, tissue MBR, diastolic blood pressure, and creatinine contributed to CMT (P=0.005, P=0.039, P<0.001, P<0.001, P=0.022 and P=0.001, respectively).

CONCLUSIONS

Tissue MBR may be closely related to AGE levels and CMT in type 2 diabetes patients with early DR, suggesting that ocular circulation might be potential early biomarkers of DR.

Reduction in the frequency of intravitreal bevacizumab administrations achieved by posterior subtenon injection of triamcinolone acetonide in patients with diffuse diabetic macular edema

PURPOSE

To evaluate the effectiveness of posterior subtenon injections of triamcinolone acetonide (STTA) during treatment with intravitreal injections of bevacizumab (IVB) in eyes with diffuse diabetic macular edema (DDME).

METHODS

Forty eyes of 20 patients with bilateral DDME with foveal thickness (FT) greater than 400 μm were studied. Initially, both eyes of each patient received 1.25 mg/0.05 ml of IVB. One eye then received 20 mg/0.5 ml of STTA at the onset and at 16, 32, and 48 weeks. For the control, the other eye was not treated with STTA. Patients were treated with additional IVB when DDME recurred during the study to maintain the FT at <350 μm. The FT, logMAR visual acuity (VA), and intraocular pressure (IOP) were monitored monthly for 56 weeks. The total number of IVB injections during the 1-year follow-up was also calculated.

RESULTS

STTA-treated eyes had significantly more regression of FT and improvement of VA at several time points during the study than did the controls. The mean (SD) required number of IVB injections in the STTA-treated eyes during the study was 5.00 ± 1.75, which was significantly less than the 7.95 ± 1.57 in the control eyes.

CONCLUSIONS

Adjunctive STTA therapy to IVB for the treatment of DDME not only improved the morphological and functional regressions but also reduced the frequency of IVB treatments.

Macular laser photocoagulation with or without intravitreal triamcinolone pretreatment for diabetic macular edema: a result from five randomized controlled trials

AIM

To assess possible benefits of intravitreal triamcinolone acetonide (IVTA) injection as pretreatment for macular laser photocoagulation (MLP) in patients with diabetic macular edema (DME).

METHODS

Published randomized controlled trials (RCTs) concerning MLP with or without IVTA pretreatment for DME were retrieved from databases CNKI, Medline, EMbase, Web of Science, and the Cochrane Library. A Meta-analysis on eligible studies was conducted using RevMan 5.0 software. Two investigators independently assessed the quality of the trials and extracted data. Main outcome measures included the change in best corrected visual acuity (BCVA), difference in central macular thickness (CMT) and adverse events reporting in particular elevated intraocular pressure within the follow-up period. The results were pooled using weight mean difference (WMD) or odds risk (OR) with their corresponding 95% confidence intervals (CI). A fixed- or random-effect model was employed depending on the heterogeneity of the inclusion trials.

RESULTS

Finally, five independent RCTs were identified and used for comparing MLP with IVTA pretreatment (131 eyes) with MLP alone (133 eyes, control group). The overall study quality was relatively higher according to the modified Jadad scale. The Meta-analysis showed that MLP with IVTA pretreatment significantly reduced CMT at one, three and six months (P=0.002, 0.0003 and 0.04, respectively), compared with MLP alone. The IVTA pretreatment group showed statistically significant improvements in BCVA at the one-month follow up as compared with the control group (P=0.03). At three- and six-month follow up, there was a beneficial trend towards improving visual acuity in the IVTA pretreatment group without statistical significance between groups (P=0.06 and 0.20, respectively). The incidence of elevation of intraocular pressure was significantly higher in the IVTA pretreatment group than in the control group (P<0.0001). No evidence of publication bias was present according to Begg's test and Egger's test. There was a low level of heterogeneity in the included studies.

CONCLUSION

This Meta-analysis indicates that MLP with IVTA pretreatment has a better therapeutic effect in terms of CMT reduction and earlier (1mo) visual improvement for patients with DME as compared with MLP alone. Further confirmation with rigorously well-designed multi-center trials is needed.

Comparison of intravitreal triamcinolone acetonide versus intravitreal bevacizumab as the primary treatment of clinically significant macular edema

OBJECTIVES

To evaluate the short-term efficacy of triamcinolone acetonide versus bevacizumab for the treatment of diabetic, clinically significant, macular edema with different optical coherence tomography findings.

METHODS

Fifty eyes of 45 consecutive patients with diabetic, clinically significant, macular edema were incorporated in this prospective interventional case series. Patients were divided into 3 groups according to findings on optical coherence tomography: 1) macular edema combined with serous retinal detachment (Group 1), 2) diffused macular thickening (Group 2), and 3) cystoid macular edema (Group 3). Patients from each group were treated with a single intravitreal injection of triamcinolone (IVTA) or 2 intravitreal injections of bevacizumab (IVB) with an interval of 6 weeks. Patients were observed at 6, 12, and 24 weeks after IVTA or the first IVB injection. Best-corrected visual acuity (BCVA) and central retinal thickness (CRT) were examined at each visit. Repeated-measures analysis of variance was used to compare the efficacy of the treatment groups.

RESULTS

In Group 1, IVTA showed more favorable effects on CRT reduction and BCVA improvement compared with IVB at 6, 12, and 24 weeks (P = 0.002, 0.001, 0.027 and P = 0.036, 0.001, 0.027), respectively. In Group 2, IVB had more CRT reduction than IVTA at 6 and 12 weeks (P = 0.013 and 0.036), although there was no significant difference in BCVA improvement between the 2 groups (P > 0.05). In Group 3, IVTA and IVB did not have significant effects on CRT reduction and BCVA improvement (P > 0.05).

CONCLUSION

The short-term efficacy of IVTA and IVB on treating clinically significant macular edema varied with different optical coherence tomography findings. In clinically significant macular edema combined with serous retinal detachment, IVTA may be more favorable than IVB in CRT reduction and BCVA improvement. In patients with diffused macular thickening, IVB may be better than IVTA in macular thickness reduction, although this does not translate to a significant improvement in BCVA.

Comparison of intravitreal bevacizumab and triamcinolone acetonide theraphies for diffuse diabetic macular edema

AIM

To compare therapeutic effects of intravitreal triamcinolone acetonide (IVTA) versus intravitreal bevacizumab (IVB) injections for bilateral diffuse diabetic macular edema (DDME).

METHODS

Forty eyes of 20 patients with bilateral DDME participated in this study. For each patient, 4 mg/0.1 mL IVTA was injected to one eye and 2.5 mg/0.1 mL IVB was injected to the other eye. The effects of injection for diabetic macular edema (DME) were evaluated using best-corrected visual acuity (BCVA), central macular thickness (CMT) by optical coherence tomography (OCT) and intraocular pressure (IOP) by applanation tonometer. Patients underwent eye examinations, including BCVA, CMT, and IOP at pre-injection, 1, 4, 8, 12 and 24wk after injection. During the follow-up, second injections were performed to eyes which have CMT greater than 400 µm at 12wk for salvage therapy.

RESULTS

BCVA (logarithm of the minimum angle of resolution) at pre-injection, 1, 4, 8, 12 and 24wk after injection was 0.71±0.19, 0.62±0.23, 0.63±0.12, 0.63±0.13, 0.63±0.14 and 0.61±0.24 in the IVTA group and 0.68±0.25, 0.61±0.22, 0.60±0.24, 0.62±0.25, 0.65±0.26 and 0.59±0.25 in the IVB group, respectively. CMT (µm) at pre-injection, 1, 4, 8, 12 and 24wk after injection was 544±125, 383±96, 335±87, 323±87, 333±92, 335±61 in the IVTA group and 514±100, 431±86, 428±107, 442±106, 478±112, 430±88 in the IVB group respectively. Reduction ratios of mean CMT were 29% at 1wk, 38% at 4wk, 40% at 8wk, 38% at 12wk, and 38% at 24wk in the IVTA group. Second IVTA injections were performed to the 6 eyes (30%) at 12wk. Reduction ratios of mean CMT were 16% at 1wk, 17% at 4wk, 14% at 8wk, 7% at 12wk, and 16% at 24wk in the IVB group. Second IVB injections were performed to the 15 eyes (75%) at 12wk.

CONCLUSION

This study showed earlier and more frequent macular edema recurrences in the eyes treated with bevacizumab compared with the ones treated with triamcinolone acetonide. Triamcinolone acetonide was found to provide more efficient and long-standing effect in terms of reducing CMT compared with the bevacizumab.

New treatments for diabetic macular edema

This work comprehensively reviews the latest treatment options for diabetic macular edema (DME) used in its management and presents further work on the topic. Diabetic retinopathy is an important and increasingly prevalent cause of preventable blindness worldwide. To meet this increasing burden there has recently been a proliferation of pharmacological therapies being used in clinical practice. A variety of medical treatment options now exist for DME. These include non-steroidal anti-inflammatory drugs such as nepafenac, as well as intravitreal steroids like triamcinolone (kenalog). Long-term results up to 7 years after commencing treatment are presented for triamcinolone. Studies are reviewed on the use of dexamethasone (ozurdex) and fluocinolone (Retisert and Iluvien implants) including the FAME studies. A variety of anti-vascular endothelial growth factor (anti-VEGF) agents used in DME are considered in detail including ranibizumab (lucentis) and the RESTORE, RIDE, RISE and Diabetic Retinopathy Clinical Research Network (DRCR.net) studies. Bevacizumab (avastin) and pegaptinib (macugen) are also considered. The use of aflibercept (eylea) is reviewed including the significance of the DA VINCI, VISTA-DME, VIVID-DME and the DRCR.net studies which have recently suggested potentially greater efficacy when treating DME for aflibercept in patients with more severely reduced visual acuity at baseline. Evidence for the anti-VEGF agent bevasiranib is also considered. Studies of anti-tumour necrosis factor agents like infliximab are reviewed. So are studies of other agents targeting inflammation including minocycline, rapamycin (sirolimus) and protein kinase C inhibitors such as midostaurin and ruboxistaurin. The protein kinase C β inhibitor Diabetic Macular Edema Study is considered. Other agents which have been suggested for DME are discussed including cyclo-oxygenase-2 inhibitors like celecoxib, phospholipase A2 inhibitors, recombinant erythropoietin, and monoclonal anti-interleukin antibodies such as canakinumab. The management of DME in a variety of clinical scenarios is also discussed - in newly diagnosed DME, refractory DME including after macular laser, and postoperatively after intraocular surgery. Results of long-term intravitreal triamcinolone for DME administered up to seven years after commencing treatment are considered in the context of the niche roles available for such agents in modern management of DME. This is alongside more widely used treatments available to the practitioner such as anti-VEGF agents like aflibercept (Eylea) and ranibizumab (Lucentis) which at present are the mainstay of pharmacological treatment of DME.

Increased vitreous concentrations of MCP-1 and IL-6 after vitrectomy in patients with proliferative diabetic retinopathy: possible association with postoperative macular oedema

PURPOSE

To determine whether vitreal concentrations of MCP-1, IL-6 and IL-8 are altered after vitrectomy in patients with proliferative diabetic retinopathy (PDR) and to investigate whether the altered levels of these cytokines are associated with postoperative macular oedema.

METHODS

Vitreous samples were collected from 36 eyes of 33 patients with PDR before pars plana vitrectomy without intraocular lens (IOL) implantation, and also from the same 36 eyes during IOL implantation surgery approximately 7 months after the initial vitrectomy. Levels of MCP-1, IL-6, IL-8 and vascular endothelial growth factor were measured by flow cytometry using cytometric bead array (CBA) technology.

RESULTS

The mean vitreous levels of MCP-1, IL-6 and IL-8 in the samples collected before vitrectomy were significantly higher in patients with PDR than in control patients (p<0.0001). The levels of MCP-1 and IL-6 in the samples collected at the time of IOL implantation were significantly higher than those collected before vitrectomy (p<0.05). In contrast, the level of IL-8 was significantly lower after vitrectomy (p<0.05). The levels of IL-6 and IL-8, but not MCP-1, in the vitreous from eyes with PDR were inversely correlated with the interval between the initial vitrectomy and the time of implantation surgery. Among the vitrectomised patients, the mean vitreous level of MCP-1 in eyes with diabetic macular oedema (DME) was significantly higher than in those without DME (p=0.028).

CONCLUSIONS

The elevated levels of MCP-1 and IL-6 may indicate prolonged inflammation even after successful vitrectomy, which can cause postoperative DME.

Short pulse laser induces less inflammatory cytokines in the murine retina after laser photocoagulation

AIMS

The purpose of this study was to evaluate the effect of pulse duration on the expression of inflammatory cytokines in the murine retina after laser photocoagulation treatment with a PASCAL(®) pattern scan laser photocoagulator and conventional laser treatment.

METHODS

Retinal scatter laser photocoagulation was performed on C57BL/6J mice using a short pulse (10 ms) with a PASCAL laser or conventional settings (100 ms) with a multicolor laser. Eyes were enucleated before treatment (control) and 1 day, 3 days and 7 days after treatment. The levels of inflammatory cytokines (i.e., VEGF, MCP-1, RANTES and IL-6) in the retina/choroid were quantified by an ELISA. The expression patterns of VEGF and macrophages (i.e., F4/80) in the retina/choroid were evaluated by immunohistochemistry.

RESULTS

The levels of RANTES, IL-6 and MCP-1 after PASCAL and conventional laser treatments were significantly elevated compared with controls (p < 0.05). Conventional laser treatment, but not PASCAL treatment, resulted in the up-regulation of VEGF. RANTES and IL-6 levels on day 1 and MCP-1 levels on day 3 in the sensory retina were also significantly up-regulated with conventional laser treatment compared with PASCAL treatment (p < 0.05). Immunohistochemical analysis showed that PASCAL treatment was associated with lower VEGF and F4/80 expression levels compared with conventional laser treatment.

CONCLUSIONS

Our data suggested that the short pulse duration induced fewer inflammatory cytokines in the sensory retina compared with the conventional pulse duration. Short pulse laser photocoagulation with the PASCAL may prevent macular edema after panretinal photocoagulation.

Effect of intravitreal dexamethasone implant on the contralateral eye: a case report

PURPOSE

To describe the effect of unilateral intravitreal injection of 0.7-mg dexamethasone implant on the other eye.

METHODS

Interventional case report and literature review.

RESULTS

A 54-year-old woman with bilateral, refractory, clinically significant macular edema was given an intravitreal injection of 0.7-mg dexamethasone sustained release implant in the right eye. The central foveal thickness improved in both the eyes with recurrence of edema after 16 weeks in both the eyes.

CONCLUSION

An intravitreal dexamethasone injection seems to have bilateral effect after unilateral injection.

Role of inflammation in diabetic macular edema

Vitreous fluid levels of vascular endothelial growth factor (VEGF), soluble VEGF receptor (sVEGFR)-2, soluble intercellular adhesion molecule (sICAM)-1, monocyte chemotactic protein (MCP)-1 and pentraxin 3 (PTX3) were measured by enzyme-linked immunosorbent assay in 36 patients with diabetic macular edema (DME) and 15 patients with macular hole (MH). Aqueous flare values were measured with a laser flare meter, and macular edema was examined by optical coherence tomography. Vitreous fluid levels of VEGF, sVEGFR-2, sICAM-1, MCP-1 and PTX3 were significantly higher in the patients with DME than in those with MH. There was a significant correlation between the vitreous fluid level of sVEGFR-2 and the levels of sICAM-1, MCP-1 and PTX3. The aqueous flare value was significantly correlated with the vitreous fluid levels of sVEGFR-2, sICAM-1, MCP-1 and PTX3. These findings suggest that inflammatory factors may induce an increase in vascular permeability and disrupt the blood-aqueous barrier in DME patients.

The role of inflammation in the pathogenesis of macular edema secondary to retinal vascular diseases

Macular edema (ME) is a nonspecific sign of numerous retinal vascular diseases. This paper is an updated overview about the role of inflammatory processes in the genesis of both diabetic macular edema (DME) and ME secondary to retinal vein occlusion (RVO). We focus on the inflammatory mediators implicated, the effect of the different intravitreal therapies, the recruitment of leukocytes mediated by adhesion molecules, and the role of retinal Müller glial (RMG) cells.

The effect of intravitreal bevacizumab on ocular blood flow in diabetic retinopathy and branch retinal vein occlusion as measured by laser speckle flowgraphy

Background

This study evaluated the effect of intravitreal injection of bevacizumab (IVB) on macular edema associated with diabetic retinopathy (DME) or branch retinal vein occlusion (BRVOME) using laser speckle flowgraphy.

Methods

A comparative interventional study of 25 eyes from 22 patients with macular edema (DME group: 12 eyes; BRVOME group: 13 eyes) who underwent IVB. Mean blur rate (MBR) was measured in the retinal artery, retinal vein, optic nerve head (ONH), and choroid before and after IVB.

Results

In the BRVOME group, there was no significant change in MBR in the retinal artery, retinal vein or ONH, but choroidal MBR decreased significantly (P=0.04). In the DME group, the MBR in the retinal artery, retinal vein, ONH, and choroid decreased significantly (P=0.02, P=0.04, P<0.001, and P=0.04, respectively). In the DME group, pre-IVB MBR in the ONH was significantly correlated with post-IVB foveal thickness (R= −0.71, P=0.002). There was no such correlation in the BRVOME group in the ONH.

Conclusion

IVB had a suppressive effect on circulation in eyes with DME but not in those with BRVOME. This suggests that this noninvasive and objective biomarker may be a useful part of pre-IVB evaluations and decision-making in DME.

Relationship of skin autofluorescence to severity of retinopathy in type 2 diabetes

PURPOSE

To evaluate the relationship between skin autofluorescence (SAF), which reflects the accumulation of advanced glycation end products (AGEs), and the severity of diabetic retinopathy (DR) in patients with type 2 diabetes.

METHODS

Sixty-seven eyes of 67 patients with type 2 diabetes were enrolled. Sixty-seven age-matched non-diabetic subjects served as controls. Diabetic patients were classified by the severity of their DR: no DR (NDR), non-proliferative DR (NPDR), and proliferative DR (PDR). SAF was measured with an autofluorescence reader.

RESULTS

SAF in the diabetes patients was significantly higher than in the controls (median 2.5 (interquartile range 2.3-2.7) and 1.8 (1.6-2.3) arbitrary unit (AU), respectively, p < 0.001). There was a statistically significant increase in SAF along with the increasing severity of DR (from NDR to NPDR: p = 0.034; NPDR to PDR: p < 0.01). Logistic regression analysis revealed that SAF (OR, 17.2; p < 0.05) was an independent factor indicating the presence of PDR.

CONCLUSIONS

SAF has an independent relationship with PDR in patients with type 2 diabetes. SAF measurement with an autofluorescence reader is a non-invasive way to assess the risk of DR. SAF may, therefore, be a surrogate marker candidate for the non-invasive evaluation of DR.

Effects of intravitreal injection of bevacizumab on inflammatory cytokines in the vitreous with proliferative diabetic retinopathy

BACKGROUND

To investigate the effects of preoperative intravitreal injection of bevacizumab (IVB) on the levels of 27 inflammatory cytokines, including interleukins (ILs) and vascular endothelial growth factor.

METHODS

From among 200 patients who had proliferative diabetic retinopathy and underwent vitrectomy in our department from September 2009 to October 2010, 8 study subjects met the enrollment criteria in which both eyes at nearly equivalent stages underwent vitrectomy. The first vitrectomy for each patient was performed without IVB (control group), whereas the second vitrectomy on the contralateral eye was performed with IVB treatment (1.25 mg/0.05 mL) 3 days before surgery (IVB group). Undiluted vitreous fluid was collected at the start of each vitrectomy. A multiplex assay was used to simultaneously determine the levels of 27 inflammatory cytokines and growth factors.

RESULTS

Mean vascular endothelial growth factor levels were significantly lower in the IVB group (519.69 pg/mL) than in the control group (11,807.44 pg/mL) (P = 0.012, Wilcoxon signed rank test). Moreover, the mean levels (IVB/control, pg/mL) of IL-1RA (38.50/62.31, P = 0.036), IL-5 (27.75/34.00, P = 0.018), IL-10 (433.63/1,995.94, P = 0.012), IL-12 (246.69/1,033.69, P = 0.012), IL-13 (707.50/1,450.38, P = 0.012), and interferon γ (71.13/84.69, P = 0.036) were significantly lower in the IVB group. No other significant differences were observed in the levels of the other 20 cytokines and growth factors between the 2 groups.

CONCLUSION

Preoperative IVB reduced not only the intravitreal vascular endothelial growth factor level but also the intravitreal levels of other inflammatory cytokines, including IL-1RA, IL-5, IL-10, IL-12, IL-13, and interferon γ. These results indicate the interaction of some cytokines in the vitreous fluid of proliferative diabetic retinopathy patients and suggest the possibility that preoperative IVB may not only reduce vascular proliferation by its direct antivascular endothelial growth factor effect but also modulate the inflammatory response through putative cytokine networks. None of the other cytokines examined were elevated after IVB.

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.

Repeated intravitreal bevacizumab injection with and without macular grid photocoagulation for treatment of diffuse diabetic macular edema

PURPOSE

To study whether the use of macular grid photocoagulation 3 weeks subsequent to the initial intravitreal bevacizumab (IVB) injection for the treatment of diffuse diabetic macular edema can provide a longer disease-free intervals and reduce the burden of more frequent injections.

METHODS

A prospective pilot study that included 22 patients with bilateral diffuse diabetic macular edema. In each patient, one eye was treated with repeated IVB injections alone (IVB group), while the other eye was treated with repeated IVB injections in addition to macular grid photocoagulation once only 3 weeks after the initial IVB injection (combined group). Before each IVB injection and during the follow-up visits, all patients received a complete ophthalmic examination. The central macular thickness was measured by optical coherence tomography at baseline and during the follow-up examinations. Fundus fluorescein angiography was performed at baseline and before each IVB injection, to detect and assess macular leakage. All patients were followed-up monthly for at least 12 months after the initial IVB injection and for 3 months after the last IVB injection.

RESULTS

By the end of the follow-up duration (14.2 ± 1.91 months), the mean number of injections was significantly lower (P < 0.05) in the combined group (2.36 per eye) than in the IVB group (3.27 per eye). The mean duration between the injections was significantly longer in the combined group than in the IVB group (P < 0.05). Within each group, the difference between the mean central macular thickness at the baseline and at the end of the follow-up duration was statistically significant (P < 0.05). The change in the mean best-corrected visual acuity between the baseline and the end of the follow-up period was not statistically significant in both the groups (P > 0.05). There was no statistically significant difference between the 2 groups of the study as regards the number of patients who gained, maintained, or lost vision (P > 0.05).

CONCLUSION

Repeated IVB injection could provide a long-term benefit for the treatment of diffuse diabetic macular edema. Performing macular grid photocoagulation once only 3 weeks subsequent to the initial IVB injection might provide a longer disease-free intervals and reduces the burden of more frequent injections.

Effect of ranirestat, a new aldose reductase inhibitor, on diabetic retinopathy in SDT rats

PURPOSE

To evaluate the effect of ranirestat, a new aldose reductase inhibitor (ARI), on diabetic retinopathy (DR) in Spontaneously Diabetic Torii (SDT) rats.

METHODS

The animals were divided into six groups, normal Sprague-Dawley rats (n = 8), untreated SDT rats (n = 9), ranirestat-treated SDT rats (0.1, 1.0, and 10 mg/kg/day, n = 7, 8, and 6, resp.), and epalrestat-treated SDT rats (100 mg/kg/day, n = 7). Treated rats received oral ranirestat or epalrestat once daily for 40 weeks after the onset of diabetes. After the eyes were enucleated, the retinal thickness and the area of stained glial fibrillary acidic protein (GFAP) were measured.

RESULTS

The retinas in the untreated group were significantly thicker than those in the normal and ranirestat-treated (0.1, 1.0, and 10 mg/kg/day) groups. The immunostained area of GFAP in the untreated group was significantly larger than that in the normal and ranirestat-treated (1.0 and 10 mg/kg/day) groups. There were no significant differences between the untreated group and epalrestat-treated group in the retinal thickness and the area of stained GFAP.

CONCLUSION

Ranirestat reduced the retinal thickness and the area of stained GFAP in SDT rats and might suppress DR and have a neuroprotective effect on diabetic retinas.

Intravitreal bevacizumab (Avastin) versus triamcinolone (Volon A) for treatment of diabetic macular edema: one-year results

PURPOSE

The objective was to compare retinal morphology and function following intravitreal injections of bevacizumab (Avastin) or triamcinolone (Volon A) in patients with early diabetic macular edema (DME).

PATIENTS AND METHODS

The study was planned as a randomized, prospective, interventional clinical trial. A total of 30 diabetic patients with treatment-naïve, clinically significant macular edema were included in this study and randomized to two equal groups. One group initially received three injections of 2.5 mg bevacizumab in monthly intervals. The second group received a single injection of 8 mg triamcinolone, followed by two sham interventions. Functional and anatomic results were evaluated monthly using ETDRS vision charts and spectral-domain optical coherence tomography. According to the study protocol, retreatment after 3 months was dependent on functional and anatomic outcome in a PRN regimen.

RESULTS

Baseline best corrected visual acuity (BCVA) was 0.30 logMAR and central retinal subfield thickness (CSRT) was 505 μm in the bevacizumab group and 0.32 logMAR and 490 μm CSRT in the triamcinolone group. After 3 months, BCVA improved to 0.23 logMAR (bevacizumab) and 358 μm CRST and 0.26 logMAR (triamcinolone) and 308 μm CSRT. After 12 months, BCVA further recovered in the bevacizumab group (0.18 logMAR) but slightly decreased in the triamcinolone group (0.36 logMAR).

CONCLUSION

Intravitreal bevacizumab and triamcinolone are both equally effective in reducing CSRT in early DME. After 6 months, rehabilitation of vision was comparable in both treatment arms, whereas at the final follow-up at month 12, BCVA was superior in the bevacizumab than in the triamcinolone sample. This may be related to cataract development following steroid treatment, as well as to substance-specific mechanisms within the angiogenic versus the inflammatory cascade.