Diabetic macular edema: Current management 2013

Critical roles of miR-21 in promotions angiogenesis: friend or foe?

MiRNAs are small RNA strands that are managed following transcription and are of substantial importance in blood vessel formation. It is essential to oversee the growth, differentiation, death, movement and construction of tubes by angiogenesis-affiliated cells. If miRNAs are not correctly regulated in regard to angiogenesis, it can deteriorate the health and lead to various illnesses, which include cancer, cardiovascular disorder, critical limb ischemia, Crohn's disease, ocular diseases, diabetic microvascular complications, and more. Consequently, it is vital to understand the crucial part that miRNAs play in the development of blood vessels, so we can develop reliable treatment plans for vascular diseases. This write-up will assess the critical role of miR-21/exosomal miR-21 in managing angiogenesis associated with bone growth, wound recovery, and other pathological conditions like tumor growth, ocular illnesses, diabetes, and other diseases connected to formation of blood vessels. Previous investigations have demonstrated that miR-21 is present at higher amounts in certain cancerous cells, and it influences a multitude of genes that moderate the increased creation of blood vessels. Furthermore, studies demonstrated that exosomal miR-21 has the capacity to interact with endothelial cells to foster tumor angiogenesis. For that reason, this review explains the critical importance of miR-21/exosomal miR-21 in managing both healthy and diseased states of angiogenesis.

Subfoveal neurosensory detachment flattening and observe (SNF-Ob) approach for the management of Ci-DMO - a multicentric study

PURPOSE

To understand subfoveal neurosensory detachment flattening and observe (SNF-Ob) strategy and its relationship with visual acuity in the management of centre-involved diabetic macular oedema (Ci-DMO).

METHODS

This was a multicentric retrospective observational study. We reviewed data of 188 eyes of 130 patients who presented with Ci-DMO with subfoveal neurosensory detachment (NSD) and treated with intravitreal anti-vascular endothelial growth factor (anti-VEGF) agents or steroids. The primary outcome was best corrected visual acuity (BCVA) measured at the time of the first subfoveal neurosensory detachment flattening (SNF) and at the end of follow-up.

RESULTS

Eyes that achieved 20/50 (LogMAR = 0.40) or better at first SNF had mean LogMAR BCVA 0.38 ± 0.21, 0.24 ± 0.11 and 0.21 ± 0.15 at baseline, at the time of first SNF, and at the end of the last follow-up respectively. Mean LogMAR BCVA significantly improved from baseline to first SNF (p < 0.0001; 95% CI 0.115-0.183) and at the end of the last follow-up (p < 0.0001; 95% CI 0.126-0.213) with a change of Early Treatment Diabetic Retinopathy Study (ETDRS) 10 letters. There was no significant difference in improvement in BCVA from the first SNF and at the end of the last follow-up (p = 0.0781; 95% CI -0.002 to 0.046).

CONCLUSIONS

Eyes presenting with Ci-DMO and subfoveal NSD are unlikely to improve at SNF with BCVA > 20/50 (LogMAR = 0.40). Further evidence is needed before the combination of good BCVA and SNF may be considered as endpoint of pharmacological therapy for DMO.

Visual Outcome after Anti-Vascular Epithelial Growth Factor Therapy Using New Classification of Diabetic Macular Edema by Optical Coherence Tomography

INTRODUCTION

The aim of the study was to examine alterations in visual acuity in patients with diabetic macular edema (DME), classified according to the TCED-HFV optical coherence tomography (OCT) system, following anti-vascular epithelial growth factor (VEGF) therapy.

METHODS

The medical records of patients with DME receiving anti-VEGF therapy were retrospectively reviewed. Patients were divided into four groups according to the TCED-HFV OCT classification. Patient demographic and clinical characteristics and best-corrected visual acuity (BCVA) before and after treatment were compared among the groups.

RESULTS

The BCVA before treatment was 0.49 ± 0.18, 0.81 ± 0.41, 0.83 ± 0.41, and 0.82 ± 0.49 in the early DME, advanced DME, severe DME, and atrophic maculopathy groups, respectively. The BCVA in the early DME group was therefore significantly lower than that in the other three groups (p = 0.042). After treatment, the BCVA improved to 0.15 ± 0.17, 0.52 ± 0.31, 0.62 ± 0.32, and 0.69 ± 0.47 in the early DME, advanced DME, severe DME, and atrophic maculopathy groups, respectively (p < 0.005). There were some differences among patients in the four groups in terms of the duration of diabetes, percentage of hemoglobin A1c, and duration of hypertension.

CONCLUSION

The TCED-HFV OCT classification of patients with DME is exact and functional and can allow the severity of DME, and its response to anti-VEGF therapy, to be estimated.

Impact of Injection Protocol Selection by Retina Specialists on Clinical Outcomes in Patients with Diabetic Macular Edema

Intravitreal anti-VEGF injections are the current gold standard for treating diabetic macular edema (DME). However, injection practice patterns of retina specialists have varied markedly based on physician discretion. This retrospective study analyzes the impact of injection protocol selection on change in best-corrected visual acuity (BCVA) and central macular thickness (CMT) in 170 eyes treated by 4 retina specialists practicing a pro re nata (PRN) strategy between 2010 and 2020. DME patients received an average of 7.25 injections every 6.24 weeks over 56.6 weeks. There were significant differences between retina specialists in mean number of injections (p = 0.0001) and mean length of treatment (p = 0.0007) but not in mean interval between injections. Over the treatment period, average change in BCVA was −0.053 logMAR, and average change in CMT was −51.1 µm, neither of which had significant differences between retina specialists. BCVA and CMT at initial visit were found to be significantly associated with improved BCVA and CMT over the treatment period (p < 0.001). Number of injections administered and interval between injections were not found to be significant factors affecting change in BCVA or CMT. Despite significant differences in injection dosing regimen, retina specialists achieved similar outcomes in change in BCVA and CMT over the treatment period.

Salidroside alleviates high-glucose-induced injury in retinal pigment epithelial cell line ARPE-19 by down-regulation of miR-138

Diabetic retinopathy (DR) is a complication of diabetes leading cause of blindness in adults. Salidroside (SAL) is a main ingredient from Rhodiola rosea L., has been reported to have a beneficial protection on vascular function. However, whether SAL is a suitable treatment for DR remains unreported. The study aimed to investigate the effect of SAL on high-glucose (HG)-induced injury in ARPE-19 cells. ARPE-19 cells were managed with diverse concentrations of glucose, and constructed a model of HG-induced ARPE-19 cells injury. Then, SAL was employed to stimulate ARPE-19 cells, and cell viability, apoptosis, apoptosis-associated factors, the pro-inflammatory cytokines, and ROS levels were determined. The correlation between miR-138 and SIRT1 was predicated by bioinformatics software of TargetScan (http://www.targetscan.org/) and Dual luciferase reporter assay. MiR-138 mimic, inhibitor and NCs were transfected into ARPE-19 cells, and the impacts of miR-138 on HG-induced cell injury were investigated. PI3K/AKT and AMPK signalling pathways were examined to explore the underlying mechanism. The results disclosed that HG inhibited cell viability, promoted apoptosis, up-regulated IL-6 and TNF-α, as well as increased ROS level in ARPE-19 cells. But, SAL obviously alleviated HG-induced ARPE-19 cells injury. Repressed miR-138 was triggered by SAL, and SIRT1 was predicated as a direct target of miR-138. Overexpressed miR-138 declined the protective effect of SAL on HG-injured ARPE-19 cells. Besides, SAL activated PI3K/AKT and AMPK pathways by adjusting miR-138. In conclusions, SAL flattened HG-induced injury in ARPE-19 cells by repression of miR-138 and activating PI3K/AKT and AMPK pathways.

Real-World Assessment of Dexamethasone Intravitreal Implant in DME: Findings of the Prospective, Multicenter REINFORCE Study

BACKGROUND AND OBJECTIVE

Dexamethasone intravitreal implant (DEX) (Ozurdex; Allergan plc, Dublin, Ireland) is approved for the treatment of diabetic macular edema (DME). This study assessed the real-world effectiveness, safety, and reinjection interval of DEX in adult patients with DME.

PATIENTS AND METHODS

This was a phase 4, prospective, multicenter (18 U.S. sites), observational study.

RESULTS

The study population comprised 177 patients (180 eyes; 93.8% previously treated). Baseline mean best-corrected visual acuity (BCVA) and central retinal thickness (CRT) were 54.4 letters and 424.6 μm, respectively. DEX was administered as monotherapy or with other DME therapy (55%/45%). The mean reinjection interval was 5.0 months. Mean maximum BCVA change from baseline after the first three DEX injections was +9.1 letters, +7.7 letters, and +7.0 letters, respectively (P < .001); 36.0% of eyes achieved 15-letter or greater BCVA improvement. Mean maximum CRT change from baseline was -137.7 μm (P < .001).

CONCLUSION

DEX used alone or with other DME therapy improved visual and anatomic outcomes in DME patients in clinical practice, with no new safety concerns. [Ophthalmic Surg Lasers Imaging Retina. 2018;49:425-435.].

When and How to Incorporate Steroids for Persistent Diabetic Macular Edema: A Discussion of Real-World Treatment Optimization Strategies

In the United States, diabetic macular edema (DME) is the leading cause of vision loss among people with diabetic retinopathy. Despite the availability of different therapies for DME, up to half of patients with DME show some persistent edema after anti-vascular endothelial growth factor (VEGF) treatment alone, leaving these patients at high risk for vision loss. However, dosing in a similar fashion to that of pivotal anti-VEGF trials is difficult because of real-life challenges faced in clinical practice. This is particularly true for DME, in that the frequency and burden of anti-VEGF injections are a major challenge to patient care. Research evaluating anti-VEGF therapies has shaped the treatment paradigms for patients with DME, and similar benefits have also been noted in clinical trials evaluating the use of intravitreal steroids. Treatment with a long-term intravitreal corticosteroid, which requires fewer injections than treatment with most short-acting therapies, has been found to reduce inflammation and improve vision in a percentage of patients. This roundtable discussion, which took place during the 2018 annual meeting of the Vit-Buckle Society, reviews the current treatment paradigms for DME and evaluates how to customize and optimize treatment strategies geared toward individualized patient care. [Ophthalmic Surg Lasers Imaging Retina. 2018;49:S5-S15.].

Correlations of blood lipids with early changes in macular thickness in patients with diabetes

PURPOSE

This study aimed to investigate the correlations of blood lipids with changes in macular volume and thickness in patients with diabetes.

METHODS

Central subfield macular thickness (CSMT) and central subfield macular volume (CSMV) were measured in 85 patients with type 2 diabetes (DM2) using spectral-domain optical coherence tomography (SD-OCT). In addition, serum creatinine (Cr), total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDLC), low-density lipoprotein cholesterol (LDLC), glycated hemoglobin (HbA1c), and proteinuria were measured in all patients.

RESULTS

The mean CSMT of the 85 patients was 272.8±16.9μm, and CSMV was 215.1±14.6×10^-3mm³. TC, LDLC, HbA1c, and proteinuria were closely correlated to CSMT, and HDLC, HbA1c, and proteinuria were correlated to CSMV. After adjustment for sex, age, DM2 course, proteinuria, and HbA1c, LDLC was significantly correlated to CSMT (95% confidence interval (CI), 1.93-11.05, P=0.008) and CSMV (95% CI, 0.92-8.41, P=0.021); however, HDLC, TC, and TG showed no significant correlation with CSMT or CSMV.

CONCLUSIONS

Increased LDLC was closely correlated to changes in CSMT and CSMV in early diabetic patients, and increased CSMT was also accompanied by increased LDLC; therefore, this type of patient would be more likely to develop macular edema.

COMBINED INTRAVITREAL RANIBIZUMAB AND ORAL SUPPLEMENTATION WITH DOCOSAHEXAENOIC ACID AND ANTIOXIDANTS FOR DIABETIC MACULAR EDEMA: Two-Year Randomized Single-Blind Controlled Trial Results

PURPOSE

To assess the 2-year effectiveness of intravitreal ranibizumab combined with a dietary supplement rich in docosahexaenoic acid (DHA) plus antioxidants in 62 patients with diabetic macular edema.

METHODS

In a randomized single-blind controlled study, 33 subjects (42 eyes) received intravitreal ranibizumab alone and 29 (34 eyes) combined with DHA (1,050 mg/day). Monthly ranibizumab (0.5 mg) was given for the first 4 months followed by on as-needed treatment.

RESULTS

At 24 months, the difference between groups in the decrease of central subfield macular thickness was significant in favor of the DHA supplementation group (95% confidence interval of the difference 7.20-97.656; P = 0.024), although improvement in best-corrected visual acuity measured in the Early Treatment Diabetic Retinopathy Study letters did not reach statistical significance (95% confidence interval 5.4-11.2, P < 0.66). At 24 months, gains of >5 and >10 letters were significantly higher in the DHA supplementation group as compared with controls when the worse and better seeing eyes were considered but other differences at 12 months and 24 months were not found.

CONCLUSION

Intravitreal ranibizumab combined with DHA supplementation reduced central subfield macular thickness after 2 years of follow-up as compared with ranibizumab alone in patients with diabetic macular edema. This anatomical improvement was accompanied by a trend for an amelioration of vision.

Anti-VEGF treatment of diabetic macular edema in clinical practice: effectiveness and patterns of use (ECHO Study Report 1)

Purpose

To evaluate the efficacy, safety, and injection frequency of vascular endothelial growth factor (VEGF) inhibitors as used in clinical practice for the treatment of diabetic macular edema.

Methods

Multicenter (10 sites), retrospective chart review in patients (n=156) who received ≥3 anti-VEGF injections. Data collected for ≥6 months after the first injection included Snellen best-corrected visual acuity (BCVA) and central retinal thickness (CRT) by time-domain or spectral-domain optical coherence tomography (TD-OCT or SD-OCT).

Results

Mean number of anti-VEGF injections (627 bevacizumab, 594 ranibizumab, 1 aflibercept) was 5.8 (year 1), 5.0 (year 2), and 3.4 (year 3). Percentage of patients with BCVA of 20/40 or better and CRT ≤250 μm on TD-OCT or ≤300 μm on SD-OCT at the same visit (primary endpoint) ranged from 16.4% to 38.9% after the first 10 injections; 51.9%–62.3% achieved ≥20/40 BCVA and 26.2%–48.0% met CRT criteria. Therapy was well tolerated with 19 treatment-related adverse events (all ocular) reported.

Conclusion

Anti-VEGF injections were administered less frequently and were less effective than those in the ranibizumab registration trials. After each of the first 9 injections, <25% of patients achieved both BCVA of 20/40 or better and a dry macula. A substantial proportion of patients are suboptimal responders to anti-VEGF therapy; these patients may be candidates for other therapies, including intravitreal corticosteroid and laser therapy.

Comparison of Intravitreal Bevacizumab and Intravitreal Diclofenac in the Treatment of Diabetic Macular Edema: a 6-month Follow-up

The aim of this study was to compare the effect of intravitreal diclofenac, a non-steroidal anti-inflammatory drug (NSAID), with that of bevacizumab, a well-known anti-vascular endothelial growth factor (VEGF) drug, in the treatment of diabetic macular edema (DME). Diclofenac was chosen in this study because it has both features of NSAIDs and corticosteroids by inhibiting the cyclooxygenase (COX) and lipoxygenase pathways, respectively. In this non-randomized comparative interventional case series, 64 eyes from 32 patients with bilateral naïve DME were selected and every eye was randomly assigned to intravitreal injection of bevacizumab (IVB) or diclofenac (IVD). After exclusion of some patients because of short follow-up duration or less than two intravitreal injections, finally, 52 eyes from 26 patients were analyzed. Of those, 26 eyes received 500 µg/0.1 mL IVD and 26 eyes received 1.25 mg IVB. After 6 months of follow-up, the results indicated that visual acuity was significantly improved from 0.50 ± 0.13 in IVB and 0.52 ± 0.12 LogMAR in IVD at baseline to 0.2 ± 0.1 and 0.29 ± 0.07, respectively. Central macular thickness (CMT) and macular volume were measured based on spectral-domain optical coherence tomography (OCT) at month 1, 3, and 6. Both groups showed a significant reduction in CMT and macular volume from baseline but there was no significant difference between the IVB and IVD groups. Interestingly, IVD, but not IVB, decreased intraocular pressure (IOP), which is a desirable effect. There was no serious complication due to injections. This study sheds light into the long-term effects of NSAIDs and may support the idea that inflammation suppression by NSAIDs may have the same results as anti-VEGF administration.

Intravitreal Diclofenac plus Bevacizumab versus Bevacizumab alone in treatment-naive diabetic macular edema: a randomized double-blind clinical trial

The aim of this study is to evaluate the short-term effects of a single intravitreal injection of 1.25 mg Bevacizumab combined with 300 lg/0.1 mL Diclofenac (IVB/D) versus 1.25 mg intravitreal Bevacizumab (IVB) alone in the treatment of naive diabetic macular edema (DME). In this prospective, randomized clinical trial, 80 eyes were included in the final analysis; 42 and 38 of which in the IVB and IVB/D groups, respectively. The primary outcome measure was a change in best-corrected visual acuity (BCVA) in logMAR at week 4. The secondary outcomes included changes in central macular thickness (CMT), macular volume, and potential injection-related complications. Significant improvement of BCVA was demonstrated in both study arms (mean reductions in LogMAR: -0.088 ± 0.278, -0.228 ± 0.330 for IVB and IVB/D, respectively). The difference in BCVA changes was in favor of IVB/D; however, not to a statistically significant level (P = 0.160). Significant reduction of CMT was documented in both study arms (mean reductions: 82.43 ± 160.09 and 153.26 ± 163.85 for IVB and IVB + IVD, respectively). Comparison of CMT changes between groups showed that IVB/D reduced CMT more than that of IVB (P = 0.04). Effects on macular volume corresponded to those of CMT. No injection-related complications or significant alterations in intraocular pressure were observed in any of the study arms. In treatment-naive DME, superiority of IVB/D combination therapy over IVB monotherapy may exist; especially as regards anatomical features. In our therapeutic arsenal for DME, IVD can be added as an adjunct to Bevacizumab.

The Characteristics and Short-term Refractive Error Outcomes of Cystoid Macular Edema in Premature Neonates as Detected by Spectral-Domain Optical Coherence Tomography

BACKGROUND AND OBJECTIVE

To explore characteristics associated with cystoid macular edema (CME) in neonates screened for retinopathy of prematurity (ROP).

PATIENTS AND METHODS

In this institutional review board-approved, prospective, observational study, premature neonates underwent imaging with handheld spectral-domain optical coherence tomography.

RESULTS

Of 73 included infants (median gestational age [GA]: 28 weeks, range 23-33 weeks; birth weight: 966 g, range 506 g-1695 g), 28 (38%) had CME and 17/28 (61%) had ROP. CME was associated with ROP (P=.03) and younger GA (P=.04), but not associated with sex, race, birth weight, postmenstrual age at imaging, ROP severity, or myopia at median 6 months corrected age. CME resolved in three cases after bevacizumab treatment for type 1 ROP and in five cases without treatment. CME appeared in two cases several weeks following injections.

CONCLUSION

CME was associated with ROP and younger GA, but not with myopia. Intravitreal bevacizumab for type 1 ROP has inconclusive effects on CME.

Novel strategies for the treatment of diabetic macular edema

Macular edema such as diabetic macular edema (DME) and diabetic retinopathy are devastating back-of-the-eye retinal diseases leading to loss of vision. This area is receiving considerable medical attention. Posterior ocular diseases are challenging to treat due to complex ocular physiology and barrier properties. Major ocular barriers are static (corneal epithelium, corneal stroma, and blood-aqueous barrier) and dynamic barriers (blood-retinal barrier, conjunctival blood flow, lymph flow, and tear drainage). Moreover, metabolic barriers impede posterior ocular drug delivery and treatment. To overcome such barriers and treat back-of-the-eye diseases, several strategies have been recently developed which include vitreal drainage, laser photocoagulation and treatment with biologics and/or small molecule drugs. In this article, we have provided an overview of several emerging novel strategies including nanotechnology based drug delivery approach for posterior ocular drug delivery and treatment with an emphasis on DME.

Novel Therapies in Development for Diabetic Macular Edema

Diabetic macular edema (DME) secondary to diabetic retinopathy (DR) is a major cause for functional visual loss in the developed world. Laser photocoagulation has been used for decades in the treatment of DME. However, the advent of anti-vascular endothelial growth factor (anti-VEGF) has revolutionized the treatment of DME. Three important anti-VEGF agents whose efficacy has been well established via phase III clinical trials include ranibizumab, bevacizumab, and aflibercept. However, even in the era of anti-VEGF therapies, there are some challenges that retina specialists have to confront in managing patients with DME. These include the need for frequent treatment and an unpredictable response to therapy. There is evidence to suggest that pathways other than the VEGF pathway may be playing a role in the development of DME. Thus, extensive research is focused on development of novel agents that target these pathways. This review focuses on novel therapeutic agents in development, which may be used as a monotherapy or in combination with anti-VEGF agents, for the management of DME in the future.

Anti-VEGFs hinder bone healing and implant osseointegration in rat tibiae

AIM

To assess the effect of anti-vascular endothelial growth factors (VEGF) on bone healing (defect volume) and implant osseointegration (bone-implant contact per cent) in rat tibia.

MATERIALS AND METHODS

In Sprague-Dawley rats (n = 36), a unicortical defect was created in the right tibia and a titanium implant was placed in the left tibia of each rat. Rats were assigned into three groups and received either anti-vascular endothelial growth factor neutralizing antibody, Ranibizumab or saline (control). Two weeks following surgery, rats were euthanized and bone samples were retrieved. Bone healing and osseointegration were assessed using micro-CT and histomorphometry. One-way anova followed by the Tukey's test was used for data analyses.

RESULTS

The volume of the bone defects in the anti-VEGF group (2.48 ± 0.33 mm(3) ) was larger (p = 0.026) than in the controls (2.11 ± 0.36 mm(3) ) as measured by μ-CT. Bone-implant contact percent in the anti-VEGF (19.9 ± 9.4%) and Ranibizumab (21.7 ± 9.2%) groups were lower (p < 0.00) than in the control group (41.8 ± 12.4%).

CONCLUSIONS

The results of this study suggest that drugs that inhibit the activity of vascular endothelial growth factor (i.e. anti-VEGF) may hinder bone healing and implant osseointegration in rat tibiae.

Diabetic Retinopathy Clinical Research Network, Friedman SM, Almukhtar TH, Baker CW, Glassman AR, Elman MJ, Bressler NM, Maker MP, Jampol LM, Melia M. Topical nepafenec in eyes with noncentral diabetic macular edema

PURPOSE

To evaluate the effect of a topical, nonsteroidal antiinflammatory drug, nepafenac 0.1%, in eyes with noncentral diabetic macular edema.

METHODS

Multicenter, double-masked randomized trial. Individuals with good visual acuity and noncentral-involved diabetic macular edema were randomly assigned to nepafenac 0.1% (N = 61) or placebo (nepafenac vehicle, N = 64) 3 times a day for 12 months. The primary outcome was mean change in optical coherence tomography retinal volume at 12 months.

RESULTS

Mean baseline retinal volume was 7.8 mm. At 12 months, in the nepafenac and placebo groups respectively, mean change in retinal volume was -0.03 mm and -0.02 mm (treatment group difference: -0.02, 95% confidence interval: -0.27 to 0.23, P = 0.89). Central-involved diabetic macular edema was present in 7 eyes (11%) and 9 eyes (14%) at the 12-month visit (P = 0.79), respectively. No differences in visual acuity outcomes were identified. One study participant developed a corneal melt after using nepafenac in the nonstudy eye, which had a history of severe dry eye. No additional safety concerns were evident.

CONCLUSION

In eyes with noncentral diabetic macular edema and good visual acuity, topical nepafenac 0.1% 3 times daily for 1 year likely does not have a meaningful effect on optical coherence tomography-measured retinal thickness.