Diabetic macular edema treated with intravitreal aflibercept injection after treatment with other anti-VEGF agents (SWAP-TWO study): 6-month interim analysis

Aflibercept or ranibizumab for diabetic macular edema

Background

Vascular endothelial growth factor (VEGF) is the primary substance involved in retinal barrier breach. VEGF overexpression may cause diabetic macular edema (DME). Laser photocoagulation of the macula is the standard treatment for DME; however, recently, intravitreal anti-VEGF injections have surpassed laser treatment. Our aim was to evaluate the efficacy of intravitreal injections of aflibercept or ranibizumab for managing treatment-naive DME.

Methods

This single-center, retrospective, interventional, comparative study included eyes with visual impairment due to treatment-naive DME that underwent intravitreal injection of either aflibercept 2 mg/0.05 mL or ranibizumab 0.5 mg/0.05 mL at Al-Azhar University Hospitals, Egypt between March 2023 and January 2024. Demographic data and full ophthalmological examination results at baseline and 1, 3, and 6 months post-injection were collected, including the best-corrected distance visual acuity (BCDVA) in logarithm of the minimum angle of resolution (logMAR) notation, slit-lamp biomicroscopy, dilated fundoscopy, and central subfield thickness (CST) measured using spectral-domain optical coherence tomography.

Results

Overall, the 96 eyes of 96 patients with a median (interquartile range [IQR]) age of 57 (10) (range: 20-74) years and a male-to-female ratio of 1:2.7 were allocated to one of two groups with comparable age, sex, diabetes mellitus duration, and presence of other comorbidities (all P >0.05). There was no statistically significant difference in baseline diabetic retinopathy status or DME type between groups (both P >0.05). In both groups, the median (IQR) BCDVA significantly improved from 0.7 (0.8) logMAR at baseline to 0.4 (0.1) logMAR at 6 months post-injection (both P = 0.001), with no statistically significant difference between groups at all follow-up visits (all P >0.05). The median (IQR) CST significantly decreased in the aflibercept group from 347 (166) µm at baseline to 180 (233) µm at 6 months post-injection, and it decreased in the ranibizumab group from 360 (180) µm at baseline to 190 (224) µm at 6 months post-injection (both P = 0.001), with no statistically significant differences between groups at all follow-up visits (all P >0.05). No serious adverse effects were documented in either group.

Conclusions

Ranibizumab and aflibercept were equally effective in achieving the desired anatomical and functional results in patients with treatment-naïve DME in short-term follow-up without significant differences in injection counts between both drugs. Larger prospective, randomized, double-blinded trials with longer follow-up periods are needed to confirm our preliminary results.

Two different initial treatment regimens of Conbercept in diabetic macular edema: 12-month results from a multicenter randomized controlled study

BACKGROUND

The optimal treatment regimen for diabetic macular edema (DME) and predictors for its treatment`s outcome need emerging evidence but currently poorly studied.

METHODS

A prospective, multicenter, open label randomized controlled study among adult patients with DME was conducted. Eyes were randomized to three or six doses initial Conbercept treatments. Additional injections were suggested pro re nata (PRN) over 12 months. Optical coherence tomography angiography (OCTA) was adopted to quantify the macular vessel density. Visual acuity gain and anatomical improvement and their associated factors were evaluated by multivariable linear regression.

RESULTS

41 patients with 59 eyes participated in current study. Patients in both 3 + PRN (n = 32 eyes) or 6 + PRN (n = 27 eyes) treatments experienced similar best-corrected visual acuity (BCVA) gain and anatomical improvement, including the central macular thickness, foveal avascular aone (FAZ) and the retinal vessel density. Over 12 months, eyes in the 6 + PRN group received better changes of the deep capillary plexus (2.53 ± 5.45%). In multivariate linear regression, the age significantly affected visual outcome in 3 + PRN group (β = -0.014, P = 0.028), while the initial CMT (β = -0.001, P = 0.022) and FAZ area (β = -0.946, P = 0.007) associated with visual outcome in 6 + PRN group. Furthermore, the duration of diabetes exhibited significant results on CMT among 3 + PRN group (β= -7.516, P = 0.04).

CONCLUSIONS

Both 3 + and 6 + initial treatment regimens of Conbercept loading dose achieved parallel anatomical and functional visual improvement, while 6 + group had a trend of better treatment outcome. Older age, higher initial CMT and longer duration of diabetes might influence the clinical outcomes over 12 months from baseline.

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.

Peripheral and central capillary non-perfusion in diabetic retinopathy: An updated overview

Capillary non-perfusion (CNP) is one of the key hallmarks of diabetic retinopathy (DR), which may develop both in the periphery and at the posterior pole. Our perspectives on CNP have extended with the introduction of optical coherence tomography angiography (OCTA) and ultra-widefield imaging, and the clinical consequences of peripheral and macular CNP have been well characterized. Fluorescein angiography (FA) continues to be the gold standard for detecting and measuring CNP, particularly when ultra-widefield imaging is available. OCTA, on the other hand, is a quicker, non-invasive approach that allows for a three-dimensional examination of CNP and may soon be regarded as an useful alternative to FA. In this review, we provide an updated scenario regarding the characteristics, clinical impact, and management of central and peripheral CNP in DR.

Effect of age on response to anti-VEGF agents in patients with center involving diabetic macular edema in a tertiary hospital

PURPOSE

The aim of the current study is to evaluate the effect of age as an independent factor for the response to two anti-VEGF agents, intravitreal ranibizumab and intravitreal aflibercept, among patients presented with central-involving DME in one tertiary care center in Riyadh, Saudi Arabia.

METHODS

Retrospective cohort study.

RESULTS

A total of 210 eyes of 121 patients were included in the study. The mean age was 61.2 ± 11.40 years, 50.4% were males. On characterizing groups based on age, the group of patients 60 years or younger are 48 patients (mean age 51.5 ± 9.92) and 52.1% of them are females. On the other hand, the group of patients older than 60 years are 73 patients (mean age 67.6 ± 6.85) and 52.1% of them are males. The two anti-VEGF agents used were aflibercept (88.1%) and ranibizumab (11.9%). The mean BCVA using ETDRS letter score improved after treatment (5.55238095 ± 15.9538695) and the mean change in CST decreased after treatment (- 106.91 ± 117.385 μm). Regarding age, we found that there is no significant difference in mean improvement of BCVA in patients according to their age (p = 0.5429), patients younger than 60 years old gained 5.64 ETDRS letter score and those older than 60 years old gained 5.49 improvement. Similarly, mean improvement in CST was different between patients younger than 60 years old (- 125.1 μm) and those who were older than 60 years old (- 94 μm) with a trend favoring younger patients but this difference was not statistically significant (p = 0.08).

CONCLUSION

Age is a clinically significant factor affecting the outcome of anti-VEGF injections. Patients' CST had a difference of > 30 μm on average between the two age groups favoring younger patients. However, it was not statistically significant, maybe a bigger sample size is needed to prove statistical significance.

Switching between anti-VEGF agents in the management of refractory diabetic macular edema: A systematic review

Refractory diabetic macular edema (DME) to monthly intravitreal anti-vascular endothelial growth factor (VEGF) monotherapy has a prevalence of approximately 40% in landmark clinical trials. Options for these patients include use of intravitreal steroids, focal laser, or switching to an alternative anti-VEGF agent. We summarize the key conclusions from studies analyzing the efficacy of switching anti-VEGF agents for refractory DME. Twenty-four studies were included in analysis. The most common definitions of refractory in the included studies were a central retinal thickness (CRT) greater than 300μm or a reduction in CRT less than 10% after at least 3-6 prior anti-VEGF injections. Switching to intravitreal aflibercept (IVA) from either intravitreal ranibizumab (IVR) or bevacizumab (IVB) is associated with moderate to significant improvement in central subfield thickness and may be an appropriate choice for patients with refractory DME. The improvement in retinal thickness and edema is typically seen after the first 3 injections of IVA post-switch. Switching to IVR has also demonstrated improvement in CRT at 3-6 months post-switch in large sample population studies. Future studies are required to elucidate the ideal time point for a switch in anti-VEGF agent or which patients would benefit from this change.

Disentangling the association between retinal non-perfusion and anti-VEGF agents in diabetic retinopathy

Diabetic retinopathy (DR) is the most common microvascular complication of diabetes mellitus (DM) and the leading cause of blindness in patients with DM. In the pathogenesis of DR, chronic hyperglycemia leads to biochemical and structural alterations in retinal blood vessels' wall, resulting in hyperpermeability and non-perfusion. Since vascular endothelial growth factor (VEGF) has been found to play a significant role in the pathogenesis of DR, this review sheds light on the effect of intravitreal anti-VEGF agents on retinal non-perfusion in patients with DR. Based on the existing literature, anti-VEGF agents have been shown to improve DR severity, although they cannot reverse retinal ischemia. The results of the published studies are controversial and differ based on the location of retinal non-perfusion, as well as the imaging modality used to assess retinal non-perfusion. In cases of macular non-perfusion, most of studies showed no change in both fundus fluorescein angiography (FFA) and optical coherence tomography (OCTA) in patients with DR treated with intravitreal anti-VEGF agents, while few studies reported worsening of non-perfusion with enlargement of foveal avascular zone (FAZ). Regarding peripheral ischemia, studies using wide-field-FFA demonstrated an improvement or stability in non-perfusion areas after anti-VEGF treatment. However, the use of wide-field-OCTA revealed no signs of re-perfusion of retinal vessels post anti-VEGF treatment. Further prospective studies with long follow-up and large sample size are still needed to draw solid conclusions.

Twenty-Four-Month OCTA Assessment in Diabetic Patients Undergoing Fixed-Interval Intravitreal Aflibercept Therapy

BACKGROUND AND OBJECTIVE

Evaluate capillary perfusion density (CPD) in patients with diabetic macular edema (DME) undergoing fixed intravit-real aflibercept injections (IAI) through 24 months.

PATIENTS AND METHODS

Prospective, interventional, single-arm study enrolling 20 patients with persistent DME. Patients received IAI every 4 weeks until DME resolution followed by extension to every 8 weeks. Optical coherence tomography angiography was obtained at baseline, 6, 12, and 24 months.

RESULTS

Sixteen of 20 eyes completed the study. Baseline mean central subfield thickness was 420 µm, which improved to 251 µm (P < .001). The mean best-corrected visual acuity (BCVA) improved by 5.5 letters (P = .042). The whole superficial CPD decreased by 5.3% (P = .001) and the deep CPD decreased by 4.4% (P = .009). Better BCVA correlated with less CPD loss within the superficial parafovea (r = +0.66 [0.23, 0.88]; P = .006) and whole (r = +0.60 [0.12, 0.85]; P = .017) areas.

CONCLUSION

Superficial and deep CPD decreased despite fixed IAI through 24 months. [Ophthalmic Surg Lasers Imaging Retina. 2020;51:448-455.].

Optical Coherence Tomography Angiography of Macular Perfusion Changes after Anti-VEGF Therapy for Diabetic Macular Edema: A Systematic Review

BACKGROUND

Diabetic macular edema (DME) is a major cause of vision loss in diabetics that is currently mainly treated by antivascular endothelial growth factor (VEGF) agents. The effect of these agents on macular perfusion (MP) is a current concern. Optical coherence tomography angiography (OCTA) is an imaging modality that allows noninvasive high-resolution retinal microvasculature imaging. Several recent studies evaluated the effect of anti-VEGF agents on the MP of DME patients using OCTA. Our aim is to provide a systematic review of these studies.

METHODS

Multiple databases were searched including PubMed, Ovid Medline, EMBASE, and Google Scholar for relevant studies published between January 2016 and November 2020 which were included in this review. Studies were compared regarding their design, the number of included patients, the machine and scanning protocol used, the inclusion and exclusion criteria, the number of injections given, the type of anti-VEGF agent used, the outcome measures assessed, and the effect of injections on different MP parameters.

RESULTS

A total of 16 studies were included. The studies assessed various OCTA parameters that define MP including the foveal avascular zone area and superficial and deep vascular density and yielded conflicting results. Seven studies showed stable or improved MP following treatment, while 7 studies showed worsening MP following treatment, and 2 studies showed inconclusive results. This could have been due to differences in study design, inclusion criteria, type of anti-VEGF agents used, treatment duration, and methods of image analysis and vascular density quantification. All identified studies were noncomparative case series, and 14 of them (87.5%) used the RTVue XR Avanti OCTA machine. Only one study compared OCTA to fluorescein angiography findings.

CONCLUSION

Analysis of MP changes following VEGF inhibition for DME could benefit from a unified scanning protocol and analysis approach that uses similar study designs to eliminate potential sources of bias. This may provide more definitive conclusions regarding the effect of treatment on MP.

Hyperreflective foci in predicting the treatment outcomes of diabetic macular oedema after anti-vascular endothelial growth factor therapy

This retrospective study evaluated the association of hyperreflective foci (HRF) with treatment response in diabetic macular oedema (DME) after anti-vascular endothelial growth factor (VEGF) therapy. The medical records, including of ophthalmologic examinations and optical coherence tomography (OCT) images, of 106 patients with DME treated with either intravitreal ranibizumab or aflibercept were reviewed. The correlations between best-corrected visual acuity (BCVA) changes and HRF along with other OCT biomarkers were analysed. The mean logMAR BCVA improved from 0.696 to 0.461 after an average of 6.2 injections in 1 year under real-world conditions. Greater visual-acuity gain was noted in patients with a greater number of HRF in the outer retina at baseline (p = 0.037), along with other factors such as poor baseline vision (p < 0.001), absence of epiretinal membrane (p = 0.048), and presence of subretinal fluid at baseline (p = 0.001). The number of HRF after treatment was correlated with the presence of hard exudate (p < 0.001) and baseline haemoglobin A1C (p = 0.001). Patients with proliferative diabetic retinopathy had greater HRF reduction after treatment (p = 0.018). The number of HRF in the outer retina, in addition to other baseline OCT biomarkers, could be used to predict the treatment response in DME after anti-VEGF treatment.

Prediction of response to anti-vascular endothelial growth factor treatment in diabetic macular oedema using an optical coherence tomography-based machine learning method

PURPOSE

To predict the anti-vascular endothelial growth factor (VEGF) therapeutic response of diabetic macular oedema (DME) patients from optical coherence tomography (OCT) at the initiation stage of treatment using a machine learning-based self-explainable system.

METHODS

A total of 712 DME patients were included and classified into poor and good responder groups according to central macular thickness decrease after three consecutive injections. Machine learning models were constructed to make predictions based on related features extracted automatically using deep learning algorithms from OCT scans at baseline. Five-fold cross-validation was applied to optimize and evaluate the models. The model with the best performance was then compared with two ophthalmologists. Feature importance was further investigated, and a Wilcoxon rank-sum test was performed to assess the difference of a single feature between two groups.

RESULTS

Of 712 patients, 294 were poor responders and 418 were good responders. The best performance for the prediction task was achieved by random forest (RF), with sensitivity, specificity and area under the receiver operating characteristic curve of 0.900, 0.851 and 0.923. Ophthalmologist 1 and ophthalmologist 2 reached sensitivity of 0.775 and 0.750, and specificity of 0.716 and 0.821, respectively. The sum of hyperreflective dots was found to be the most relevant feature for prediction.

CONCLUSION

An RF classifier was constructed to predict the treatment response of anti-VEGF from OCT images of DME patients with high accuracy. The algorithm contributes to predicting treatment requirements in advance and provides an optimal individualized therapeutic regimen.

Diabetic Macular Edema Treated With Intravitreal Aflibercept Injection After Treatment With Other Anti-VEGF Agents (SWAP-TWO Study)—12-Month Analysis

Purpose:

This article reports 12-month outcomes of patients with diabetic macular edema previously treated with other antivascular endothelial growth factor agents and transitioned to fixed dosing of intravitreal aflibercept (IAI).

Methods:

This prospective, single-arm study enrolled patients to receive IAI 2 mg (0.05 mL) every 4 weeks until optical coherence tomography demonstrated no fluid. Patients then received fixed dosing of IAI 2 mg once every 8 weeks through 12 months. Primary outcome was mean absolute change from baseline central subfield thickness (CST) at 12 months measured by optical coherence tomography.

Results:

Twenty eyes were enrolled. At baseline, best-corrected visual acuity was 70.0 letters, mean CST was 419.7 µm ± 92.0, superficial capillary perfusion density (CPD) was 46.0 ± 4.2%, and deep CPD was 50.8 ± 4.3%. At 12 months, the mean CST improved to 287.2 µm ± 80.2 ( P < .001), superficial CPD decreased to 43.6 ± 4.8% ( P = .04), and deep CPD decreased to 47.6 ± 4.8% ( P = .05).

Conclusions:

Patients who switched to fixed dosing of IAI demonstrated significant anatomic improvements in CST at 12 months. CPD values decreased significantly both in superficial and deep layers without significant changes in vision.

Persistent or Recurrent Diabetic Macular Edema After Fluocinolone Acetonide 0.19 mg Implant: Risk Factors and Management

PURPOSE

To investigate baseline characteristics of patients undergoing additional antivascular endothelial growth factor (VEGF) injections for residual or recurrent diabetic macular edema (DME) in the first year after 0.19-mg fluocinolone acetonide (FAc) implant.

DESIGN

Prospective cohort study.

METHODS

Ninety-four eyes of 66 patients received an FAc implant. Eyes with persistent or recurrent DME were managed with pro re nata anti-VEGF agents. Demographic data and medical history were collected at baseline. Best-corrected visual acuity and central macular thickness were measured every 2 months. The 3 outcomes explored were 1) the risk factors for administration of additional anti-VEGF agents, 2) the interval from FAc to first anti-VEGF injection; and 3) the number of anti-VEGF doses required to maintain regression of DME.

RESULTS

Eighteen eyes (19.1%) of 13 patients received 1.3 ± 0.6 anti-VEGF injections. These eyes had significantly thicker central macular thickness at baseline and over the entire follow-up period (P < .001); best-corrected visual acuity was similar at every time point to eyes that were not receiving extra DME treatments. Eyes without preexistent panretinal photocoagulation (PRP) had a higher risk to undergo supplemental treatments (hazard ratio 1.5 [95% confidence interval 1.1-2.5, P = .03). The interval between FAc implant and the first anti-VEGF had a significant linear positive relationship with the number of dexamethasone implants before FAc implant (P = .002, R² = 0.47). No association was found between baseline factors and the number of injections given.

CONCLUSION

Anti-VEGF agents are efficient treatment to maintain visual acuity in residual/recurrent DME after FAc. Patients with higher baseline central macular thickness and with no previous central macular thickness are more likely to require additional treatments to control DME.

Choroidal Thickness After Dexamethasone Implant or Aflibercept in Patients with Diabetic Macular Edema Persistent to Ranibizumab

Purpose: This study aims to compare subfoveal choroidal thicknesses (SFCTs) after intravitreal dexamethasone (IVD) or intravitreal aflibercept (IVA) treatment in patients with persistent diabetic macular edema (DME) unresponsive to intravitreal ranibizumab (IVR). Methods: The study consisted of patients with DME unresponsive to IVR treatment in which 37 were administered 1 dose IVD (group A) and 34 patients who were administered 3 doses of IVA (group B), as well as 35 healthy individuals (group C). Detailed ophthalmological examination and optical coherence tomography parameters of group A and group B, including central retinal thickness and SFCT, were retrospectively evaluated before and after treatment. Results from preinjection, and 1, 2, and 3 months after injection were analyzed. Results of group A and group B were compared within themselves and also compared with group C. Results: SFCT measurements were compared within group A and group B (1 = preinjection; 2 = 1 month postinjection; 3 = 2 months postinjection; 4 = 3 months postinjection). There was significant thinning in SFCT between 1-2, 1-3, 1-4, 2-3, 2-4, and 3-4 time intervals within both group A and group B (both P < 0.001). Comparison of SFCT measurements showed preinjection, 1-, and 2-month values of group A were significantly thicker than those of group C (P < 0.001), whereas there was no significant difference between 3-month values (P = 0.09). Preinjection, 1-, and 2-month values of group B were significantly thicker than those of group C (P < 0.001), whereas there was no significant difference between 3-month values (P = 0.06). Conclusions: Three month follow-up showed thinning in SFCT measurements in patients with persistent DME unresponsive to IVR who were applied IVD or IVA treatment.

Changes in retinal and choriocapillaris density in diabetic patients receiving anti-vascular endothelial growth factor treatment using optical coherence tomography angiography

Background

Optical coherence tomography angiography (OCTA) enables detailed, non-invasive assessment of ocular vasculature. This study uses OCTA imaging to evaluate choriocapillaris and retinal capillary perfusion density (CPD) changes in diabetic retinopathy following anti-vascular endothelial growth factor (VEGF) treatment.

Methods

Records of 38 eyes at a single institution were reviewed, grouped as non-diabetic controls (19 eyes), diabetes mellitus patients with diabetic retinopathy (DR, 19 eyes) and macular edema (DME). DR eyes were imaged at baseline, 6-months and 12-months after anti-VEGF treatment. Quantitative analyses assessed CPD of the choriocapillaris and retinal plexus.

Results

DR eyes showed decreased choriocapillaris whole-image CPD (62.6 ± 6.1 vs. 68.4 ± 5.1, p < 0.003), foveal CPD (61.2 ± 7.4 vs. 66.3 ± 9.8, p < 0.014), and parafoveal CPD (61.9 ± 6.6 vs. 68.2 ± 4.8, p < 0.002) at baseline. DR eyes also showed decreased retinal density, including whole-image CPD (46.9 ± 5.1 vs. 50.7 ± 5.6, p < 0.04), foveal CPD (27.6 ± 5.9 vs. 34.1 ± 6.1, p < 0.002), and parafoveal CPD (49.0 ± 5.6 vs. 53.1 ± 6.0, p < 0.011). Following 12 months of anti-VEGF treatment, no changes to retinal or choriocapillaris or CPD were observed. Retinal central subfield thickness decreased (397.1 ± 93.2 µm vs. 294.2 ± 71.5 µm, p < 0.005). Lastly, FAZ area (0.307 ± 0.133 mm² vs. 0.184 ± 0.058 mm², p = 0.008) and perimeter (2.415 ± 0.692 mm² vs. 1.753 ± 0.408 mm², p = 0.002) were increased in DR eyes at baseline. No changes to FAZ area or perimeter were seen with anti-VEGF treatment in DR eyes.

Conclusions

Compared to control, choriocapillaris and retinal CPD are reduced in DR, while FAZ area and perimeter are increased. No retinal capillary or choriocapillaris CPD changes were observed in DR eyes following anti-VEGF treatment.

Emerging Concepts in the Treatment of Diabetic Retinopathy

PURPOSE OF REVIEW

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

RECENT FINDINGS

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