Significance of monitoring vascular endothelial growth factor, monocyte chemoattractant protein-1 and Interleukin-8 in diabetic macular edema towards early identification of nonresponders to ranibizumab therapy

Effect of Anti-VEGF drugs on diabetic Retinopathy-Microaneurysms: A correlation study

Objective

To investigate the efficacy of anti-vascular endothelial growth factor (VEGF) drugs in diabetic retinopathy (DR)-retinal microaneurysms, and its prognosis.

Method

This was a retrospectively study in which total of 120 patients with DR in Baoding No.1 Central Hospital from June 2020 to June 2022 were retrospectively analyzed. According to different treatment methods based on macular edema, they were divided into an injection group and a control group. The control group was treated routinely, while the injection group was additionally intravitreally injected with an anti-VEGF drug. The patients were followed up for one year, and the changes in the number of retinal microaneurysms, best corrected visual acuity (BCVA) and central retinal thickness (CRT) were compared between the two groups. The effect on retinal microaneurysms was analyzed.

Result

After treatment for 12 months, the total efficacy of the injection group was 95.00%, which was higher than 80.00% of the control group (p< 0.05). After one, three, six and twelve months of treatment, both CRT and the number of retinal microaneurysms reduced in the injection group compared with those before treatment. After treatment for one, three, six and twelve months, BCVA showed increases in the injection group, but no obvious changes in the control group compared with that before treatment.

Conclusion

For patients with DR complicated with macular edema, early use of anti-VEGF drugs can significantly improve the fundus lesions, reduce the CRT and number of retinal microaneurysms, and improve the BCVA of the patients, with high clinical efficacy.

Dexamethasone implant in naive versus refractory patients with diabetic macular edema: a Meta-analysis

AIM

To evaluate the efficacy and safety of the intravitreal dexamethasone implant in naive and refractory patients with diabetic macular edema (DME).

METHODS

PubMed, Embase, Web of Science, and Medline databases were searched. The main outcomes were best-corrected visual acuity (BCVA) and central retinal thickness (CRT). The secondary outcomes included mean number of injections, intraoperative or postoperative complications including intraocular pressure (IOP) elevation and cataract.

RESULTS

Ten comparative studies involving a total of 1000 DME eyes including 402 naive eyes and 598 refractory eyes were selected. The postoperative BCVA in the naive group was significantly better than in the refractory group [mean difference (MD) -0.11, 95% confidence interval (CI) -0.17 to -0.05, P=0.0003; MD 8.69, 95%CI 5.08 to 12.30, P<0.00001)]. Additionally, the naive group got greater improvement of BCVA change as well as more gains of BCVA letters than the refractory group [MD 7.71, 95%CI 2.02 to 13.40, P=0.008; odds ratio (OR) 2.99, 95%CI 2.05 to 4.37, P<0.00001]. The subgroup analysis revealed that the naive group had significantly higher BCVA gains of ≥5, ≥10, and ≥15 letters compared to the refractory group (P=0.002, 0.0001, 0.003, respectively). No significant difference was detected between the two groups in either postoperative CRT (MD -22.36, 95%CI -46.39 to 1.66, P=0.07) or the overall mean number of injections (MD -0.08, 95%CI -0.38 to 0.22, P=0.61). Intraoperative and postoperative complications including the elevation of IOP (OR 0.47, 95%CI 0.20 to 1.13, P=0.09) and cataract (OR 1.78, 95%CI 0.97 to 3.24, P=0.06) showed no significant differences between the two groups during the follow-up time.

CONCLUSION

Intravitreal dexamethasone implants for DME can improve anatomical and functional outcomes in both naive and refractory eyes and have a well-acceptable safety profile. Moreover, naive eyes maintain better visual outcomes than refractory eyes. It provides further evidence of better visual response when used for naive eyes as first-line therapy.

Switching to an Intravitreal Dexamethasone Implant after Intravitreal Anti-VEGF Therapy for Diabetic Macular Edema: A Review

Among working-age people, diabetic retinopathy and diabetic macular edema are currently considered the main causes of blindness. Nowadays, intravitreal injections are widely acknowledged as a significant milestone in ophthalmology, especially for the treatment of several retinal diseases, including diabetic macular edema. In particular, anti-vascular endothelial growth factor (VEGF) agents are typically the first line of treatment; however, monthly injections are required, at least, during the loading dosage. Notably, an intravitreal 0.7 mg dexamethasone (DEX) implant (Ozurdex®, AbbVie Inc., North Chicago, IL, USA) is considered a legitimate substitute treatment for diabetic eyes that have not responded to anti-VEGF treatment. In fact, clinical trials and real-life studies have demonstrated the effectiveness and safety of an intravitreal DEX implant in treating such conditions over a period of three to six months. For this reason, wisely selecting diabetic patients might be crucial to decreasing the load of injections in clinics and hospitals. The purpose of this review is to analyze the available scientific literature to highlight the benefits, efficacy, and clinical criteria for choosing whether to switch from intravitreal anti-VEGF therapy to an intravitreal DEX implant in diabetic macular edema.

Vitreous protein networks around ANG2 and VEGF in proliferative diabetic retinopathy and the differential effects of aflibercept versus bevacizumab pre-treatment

Extracellular signalling proteins interact in networks rather than in isolation. In this context we investigated vitreous protein levels, including placental growth factor (PlGF), angiopoietin-2 (ANG2) and vascular endothelial growth factor (VEGF), in patients with proliferative diabetic retinopathy (PDR) with variable disease severities, and after anti-VEGF pre-treatment. Vitreous samples of 112 consecutive patients undergoing vitrectomy for PDR and of 52 non-diabetic patients with macular holes as controls were studied. A subset of the PDR patients were treated with either aflibercept (AFB, n = 25) or bevacizumab (BVZ)/ranibizumab (RZB) (n = 13), before surgery. Antibody-based analysis of 35 proteins (growth factors and cytokines) showed a significant increase in expression levels of 27 proteins in PDR patients as compared to controls. In network analysis of co-regulated proteins, a strong correlation in expression levels between VEGF, PlGF, MCP1 and ANG2 was found, mostly clustered around ANG2. In the AFB treatment group, concentrations of several proteins were decreased, including VEGFR1, whereas interleukin 6 and 8 were increased as compared to untreated PDR patients. The observed differences in vitreous protein levels between the different treatments and untreated PDR patients may underlie differences in clinical outcomes in patients with PDR.

The Role of Intravitreal Corticosteroids in the Treatment of DME: Predictive OCT Biomarkers

This work aims to summarize predictive biomarkers to guide treatment choice in DME. Intravitreal anti-VEGF is considered the gold standard treatment for centers involving DME, while intravitreal steroid treatment has been established as a second-line treatment in DME. However, more than 1/3 of the patients do not adequately respond to anti-VEGF treatment despite up to 4-weekly injections. Not surprisingly, insufficient response to anti-VEGF therapy has been linked to low-normal VEGF levels in the serum and aqueous humor. These patients may well benefit from an early switch to intravitreal steroid treatment. In these patients, morphological biomarkers visible in OCT may predict treatment response and guide treatment decisions. Namely, the presence of a large amount of retinal and choroidal hyperreflective foci, disruption of the outer retinal layers and other signs of chronicity such as intraretinal cysts extending into the outer retina and a lower choroidal vascular index are all signs suggestive of a favorable treatment response of steroids compared to anti-VEGF. This paper summarizes predictive biomarkers in DME in order to assist individual treatment decisions in DME. These markers will help to identify DME patients who may benefit from primary dexamethasone treatment or an early switch.

Vitreous Inflammatory Cytokines and Chemokines, Not Altered After Preoperative Adjunctive Conbercept Injection, but Associated With Early Postoperative Macular Edema in Patients With Proliferative Diabetic Retinopathy

Purpose

To investigate the influence of preoperative adjunctive anti-VEGF drug (Conbercept) on vitreous inflammatory cytokines and chemokines profiles and whether those cytokines were associated with early macular edema (ME) after surgery for patients with proliferative diabetic retinopathy (PDR).

Methods

In this post hoc analysis of the CONCEPT clinical trial, subjects with PDR underwent vitrectomy were included and vitreous samples were collected at the start of vitrectomy. Levels of vitreous VEGF, 17 inflammatory cytokines, and 11 chemokines were measured using Luminex multiplex technology. Subjects were then divided into groups based on with (Pre-IV) or without (No-Pre-IV) preoperative intravitreous injection of Conbercept; with or without early ME after surgery.

Results

There was no difference between Pre-IV (13/30) and No-Pre-IV (7/29) concerning the ratio of patients with early ME (p = 0.17). After preoperative intravitreous injection of Conbercept, VEGF level dramatically decreased (p = 0.001), TNF-α (p = 0.002), and IP-10 (p = 0.018) increased in Pre-IV group. In patients with early ME after surgery, however, a number of cytokines increased, including IL-1β (p = 0.008), IL-2 (p = 0.023), IL-4 (p = 0.030), IL-9 (p = 0.02), IL-10 (p = 0.002), IL-12 (p = 0.001), IL-13 (p = 0.031), IL-17A (p = 0.008), TNF-α (p = 0.012), CXCL9 (p = 0.023), G-CSF (p = 0.019), MCP-1 (p = 0.048), and RANTES (p = 0.016).

Conclusion

We found the preoperative adjunctive Conbercept injection has limited influence on the levels of vitreous inflammatory cytokines and chemokines in PDR. The elevated levels of a series of cytokines might be associated with early inflammation after vitrectomy, which may lead to postoperative ME.