Diabetic macular edema: pathogenesis and treatment

Deep Capillary Geometric Perfusion Deficits on OCT Angiography Detect Clinically Referable Eyes with Diabetic Retinopathy

PURPOSE

To evaluate the sensitivity (SN) and specificity (SP) of OCT angiography (OCTA) parameters for detecting clinically referable eyes with diabetic retinopathy (DR) in a cohort of patients with diabetes mellitus (DM).

DESIGN

Retrospective, cross-sectional study.

SUBJECTS

Patients with DM with various levels of DR.

METHODS

We measured vessel density, vessel length density (VLD), and geometric perfusion deficits (GPDs) in the full retina, superficial capillary plexus (SCP), and deep capillary plexus (DCP) on 3 × 3-mm OCTA images. Geometric perfusion deficit was recently described as retinal tissue located further than 30 μm from blood vessels, excluding the foveal avascular zone (FAZ). We modified the GPD metric by including the FAZ as an additional variable. Clinically referable eyes were defined as moderate nonproliferative DR (NPDR) or worse retinopathy, or diabetic macular edema (DME). One eye from each patient was selected for the analysis based on image quality. We used a binary logistic regression model to adjust for covariates.

MAIN OUTCOME MEASURES

Sensitivity, SP, and area under the curve (AUC).

RESULTS

Seventy-one of 150 included eyes from 150 patients (52 with DM without DR, 27 with mild NPDR, 16 with moderate NPDR, 10 with severe NPDR, 30 with proliferative DR, and 15 with DME) had clinically referable DR. Geometric perfusion deficit metric that included the FAZ performed better than GPD in detecting referable DR in the SCP (P = 0.025) but not the DCP or full retina (P > 0.05 for both). Deep capillary plexus GPD had the largest AUC for detecting clinically referable eyes (AUC = 0.965, SN = 97.2%, SP = 84.8%), which was significantly larger than the AUC for vessel density of any layer (P < 0.05 for all) but not DCP VLD (P = 0.166). The cutoff value of 2.5% for DCP GPD resulted in a highly sensitive test for detecting clinically referable eyes without adjusting for covariates (AUC = 0.955, SN = 97.2%, SP = 79.7%).

CONCLUSIONS

Vascular parameters in OCTA, especially in the DCP, have the potential to identify eyes that warrant further evaluation. Geometric perfusion deficits may better distinguish these clinically referable eyes with DR than standard vessel density parameters.

Relationship Between Macular Thickness and Visual Acuity in the Treatment of Diabetic Macular Edema With Anti-VEGF Therapy: Systematic Review

Purpose:

To examine the relationship between central macular thickness (CMT) measured by optical coherence tomography (OCT) and visual acuity (VA) in patients with center-involving diabetic macular edema (DME) receiving antivascular endothelial growth factor (anti-VEGF) treatment.

Methods:

Peer-reviewed articles from 2016 to 2020 reporting intravitreal injections of bevacizumab, ranibizumab, or aflibercept that provided data on pretreatment (baseline) and final retinal thickness (CMT) and visual acuity (VA) were identified. The relationship between relative changes was assessed via a linear random-effects regression model controlling for treatment group.

Results:

No significant association between the logarithm of the minimum angle of resolution (logMAR) VA and CMT was found in 41 eligible studies evaluating 2667 eyes. The observed effect estimate was a 0.12 increase (95% CI, −0.124 to 2.47) in logMAR VA per 100 µm reduction in CMT after treatment change. There were no significant differences in logMAR VA between the anti-VEGF treatment groups.

Conclusions:

There was no statistically significant relationship between the change in logMAR VA and change in CMT as well as no significant effect of the type of anti-VEGF treatment on the change in logMAR VA. Although OCT analysis, including measurements of CMT, will continue to be an integral part of the management of DME, further exploration is needed on additional anatomic factors that might contribute to visual outcomes.

Correlating the patterns of diabetic macular edema, optical coherence tomography biomarkers and grade of diabetic retinopathy with stage of renal disease

PURPOSE

To correlate optical coherence tomography (OCT)-based morphological patterns of diabetic macular edema (DME), biomarkers and grade of diabetic retinopathy (DR) in patients with various stages of chronic kidney disease (CKD) secondary to diabetes.

DESIGN

Multicentric retrospective cross-sectional study was conducted at seven centers across India.

METHODS

Data from medical records of patients with DME and CKD were entered in a common excel sheet across all seven centers. Staging of CKD was based on estimated glomerular filtration rate (eGFR).

RESULTS

The most common morphological pattern of DME was cystoid pattern (42%) followed by the mixed pattern (31%). The proportion of different morphological patterns did not significantly vary across various CKD stages (p = 0.836). The presence of external limiting membrane-ellipsoid zone (ELM-EZ) defects (p < 0.001) and foveal sub-field thickness (p = 0.024) showed a direct correlation with the stage of CKD which was statistically significant. The presence of hyperreflective dots (HRD) and disorganization of inner retinal layers (DRIL) showed no significant correlation with the stage of CKD. Sight threatening DR was found to increase from 70% in CKD stage 3 to 82% in stages 4 and 5 of CKD, and this was statistically significant (p = 0.03).

CONCLUSION

Cystoid morphological pattern followed by mixed type was the most common pattern of DME on OCT found in patients suffering from stage 3 to 5 of CKD. However, the morphological patterns of DME did not significantly vary across various CKD stages. ELM-EZ defects may be considered as an important OCT biomarker for advanced stage of CKD.

Direct Tie2 Agonists Stabilize Vasculature for the Treatment of Diabetic Macular Edema

Purpose

Diabetic macular edema (DME) is the leading cause of vision loss and blindness among working-age adults. Although current intravitreal anti-vascular endothelial growth factor (VEGF) therapies improve vision for many patients with DME, approximately half do not achieve the visual acuity required to drive. We therefore sought additional approaches to resolve edema and improve vision for these patients.

Methods

We explored direct agonists of Tie2, a receptor known to stabilize vasculature and prevent leakage. We identified a multivalent PEG–Fab conjugate, Tie2.1-hexamer, that oligomerizes Tie2 and drives receptor activation and characterized its activities in vitro and in vivo.

Results

Tie2.1-hexamer normalized and stabilized intercellular junctions of stressed endothelial cell monolayers in vitro, suppressed vascular leak in mice under conditions where anti-VEGF alone was ineffective, and demonstrated extended ocular exposure and robust pharmacodynamic responses in non-human primates.

Conclusions

Tie2.1-hexamer directly activates the Tie2 pathway, reduces vascular leak, and is persistent within the vitreal humor.

Translational Relevance

Our study presents a promising potential therapeutic for the treatment of DME.

The Role of Medical Image Modalities and AI in the Early Detection, Diagnosis and Grading of Retinal Diseases: A Survey

Traditional dilated ophthalmoscopy can reveal diseases, such as age-related macular degeneration (AMD), diabetic retinopathy (DR), diabetic macular edema (DME), retinal tear, epiretinal membrane, macular hole, retinal detachment, retinitis pigmentosa, retinal vein occlusion (RVO), and retinal artery occlusion (RAO). Among these diseases, AMD and DR are the major causes of progressive vision loss, while the latter is recognized as a world-wide epidemic. Advances in retinal imaging have improved the diagnosis and management of DR and AMD. In this review article, we focus on the variable imaging modalities for accurate diagnosis, early detection, and staging of both AMD and DR. In addition, the role of artificial intelligence (AI) in providing automated detection, diagnosis, and staging of these diseases will be surveyed. Furthermore, current works are summarized and discussed. Finally, projected future trends are outlined. The work done on this survey indicates the effective role of AI in the early detection, diagnosis, and staging of DR and/or AMD. In the future, more AI solutions will be presented that hold promise for clinical applications.

Current and Novel Therapeutic Approaches for Treatment of Diabetic Macular Edema

Diabetic macular edema (DME) is a major ocular complication of diabetes mellitus (DM), leading to significant visual impairment. DME's pathogenesis is multifactorial. Focal edema tends to occur when primary metabolic abnormalities lead to a persistent hyperglycemic state, causing the development of microaneurysms, often with extravascular lipoprotein in a circinate pattern around the focal leakage. On the other hand, diffusion edema is due to a generalized breakdown of the inner blood-retinal barrier, leading to profuse early leakage from the entire capillary bed of the posterior pole with the subsequent extravasation of fluid into the extracellular space. The pathogenesis of DME occurs through the interaction of multiple molecular mediators, including the overexpression of several growth factors, including vascular endothelial growth factor (VEGF), insulin-like growth factor-1, angiopoietin-1, and -2, stromal-derived factor-1, fibroblast growth factor-2, and tumor necrosis factor. Synergistically, these growth factors mediate angiogenesis, protease production, endothelial cell proliferation, and migration. Treatment for DME generally involves primary management of DM, laser photocoagulation, and pharmacotherapeutics targeting mediators, namely, the anti-VEGF pathway. The emergence of anti-VEGF therapies has resulted in significant clinical improvements compared to laser therapy alone. However, multiple factors influencing the visual outcome after anti-VEGF treatment and the presence of anti-VEGF non-responders have necessitated the development of new pharmacotherapies. In this review, we explore the pathophysiology of DME and current management strategies. In addition, we provide a comprehensive analysis of emerging therapeutic approaches to the treatment of DME.

The effect of pars plana vitrectomy with internal limiting membrane peeling on the durability of the intravitreal dexamethasone implant in the treatment of diabetic macular edema

Purpose

To evaluate the influence of pars plana vitrectomy with internal limiting membrane peeling on recurrence time of diabetic macular edema in eyes under treatment with dexamethasone intravitreal implant injections.

Material and methods

Twelve pseudophakic eyes of 12 patients with non-proliferative diabetic retinopathy and non-tractional diabetic macular edema were included. All eyes had already been treated with two or more dexamethasone intravitreal implant injections evidencing a recurrence time of three months or less (early recurrence). At baseline, they underwent pars plana vitrectomy with internal limiting membrane peeling, ending with dexamethasone intravitreal implant injection. Patients were then followed-up monthly, treated with a second injection at the first recurrence, and followed up to the second recurrence. Measurements of best corrected visual acuity, intraocular pressure, and central foveal thickness by spectral-domain optical coherence tomography were performed at each follow-up examination.

Results

Vitrectomized eyes showed a significant extension of recurrence time of diabetic macular edema, and specifically from 3.4 (3.2–3.7) to 6.5 (5.7–8.2) months after the first injection, and to 7.0 (5.7–8.2) months (p < 0.01) after the second injection (p < 0.01).

Conclusions and importance

Pars plana vitrectomy with internal limiting membrane peeling seems not to influence functional and anatomical results in eyes under treatment with dexamethasone intravitreal implant injections for diabetic macular edema, but appears to significantly extend the benefit of the drug.

Prediction of the Short-Term Therapeutic Effect of Anti-VEGF Therapy for Diabetic Macular Edema Using a Generative Adversarial Network with OCT Images

Purpose: To generate and evaluate individualized post-therapeutic optical coherence tomography (OCT) images that could predict the short-term response of anti-vascular endothelial growth factor (VEGF) therapy for diabetic macular edema (DME) based on pre-therapeutic images using generative adversarial network (GAN). Methods: Real-world imaging data were collected at the Department of Ophthalmology, Qilu Hospital. A total of 561 pairs of pre-therapeutic and post-therapeutic OCT images of patients with DME were retrospectively included in the training set, 71 pre-therapeutic OCT images were included in the validation set, and their corresponding post-therapeutic OCT images were used to evaluate the synthetic images. A pix2pixHD method was adopted to predict post-therapeutic OCT images in DME patients that received anti-VEGF therapy. The quality and similarity of synthetic OCT images were evaluated independently by a screening experiment and an evaluation experiment. Results: The post-therapeutic OCT images generated by the GAN model based on big data were comparable to the actual images, and the response of edema resorption was also close to the ground truth. Most synthetic images (65/71) were difficult to differentiate from the actual OCT images by retinal specialists. The mean absolute error (MAE) of the central macular thickness (CMT) between the synthetic OCT images and the actual images was 24.51 ± 18.56 μm. Conclusions: The application of GAN can objectively demonstrate the individual short-term response of anti-VEGF therapy one month in advance based on OCT images with high accuracy, which could potentially help to improve treatment compliance of DME patients, identify patients who are not responding well to treatment and optimize the treatment program.

Robust Fovea Detection in Retinal OCT Imaging using Deep Learning

The fovea centralis is an essential landmark in the retina where the photoreceptor layer is entirely composed of cones responsible for sharp, central vision. The localization of this anatomical landmark in optical coherence tomography (OCT) volumes is important for assessing visual function correlates and treatment guidance in macular disease. In this study, the "PRE U-net" is introduced as a novel approach for a fully automated fovea centralis detection, addressing the localization as a pixel-wise regression task. 2D B-scans are sampled from each image volume and are concatenated with spatial location information to train the deep network. A total of 5586 OCT volumes from 1,541 eyes was used to train, validate and test the deep learning method. The test data is comprised of healthy subjects and patients affected by neovascular age-related macular degeneration (nAMD), diabetic macula edema (DME) and macular edema from retinal vein occlusion (RVO), covering the three major retinal diseases responsible for blindness. Our experiments demonstrate that the PRE U-net significantly outperforms state-of-the-art methods and improves the robustness of automated localization, which is of value for clinical practice.

Optical coherence tomography patterns of diabetic macular edema and treatment response to bevacizumab: a short-term study

Background:

The purpose of this study was to evaluate the short-term response of intravitreal bevacizumab in diabetic macular edema (DME) and assess the variation in treatment outcomes in different morphology patterns using spectral domain–optical coherence tomography (SD-OCT).

Objective:

To study different morphological patterns of DME based on OCT and compare their treatment response to bevacizumab.

Methods:

Hundred and twelve eyes of 112 patients with DME were included and treated with intravitreal bevacizumab (1.25 mg/0.05 ml monthly for 3 months). The morphological patterns of DME were classified on the basis of OCT into three groups – diffuse retinal thickening (DRT), cystoid macular edema (CME), and serous retinal detachment (SRD) – and changes in central macular thickness (CMT) and best corrected visual acuity (BCVA) after treatment were compared.

Results:

A total of 112 eyes with DME were included and consisted of 40 DRT, 37 CME, and 35 SRD. Treatment with bevacizumab resulted in decrease in central macular thickness and improvement in BCVA in all three groups. The baseline visual acuity and CMT of DRT group was better than that of the other two groups. The treatment outcome was measured in terms of CMT and BCVA. Change in CMT was statistically significant among three groups and was found to be better in DRT group (p < 0.05, 95% confidence interval). However, there was statistically no significant variation between the three groups regarding the change in BCVA (p = 0.169, 95% confidence interval).

Conclusion:

Anatomic and visual improvement can be achieved by bevacizumab in all patterns of DME. However, individual pattern may respond differently. DRT, which appears to be the earliest form of DME, responds better than other types. Thus, the pattern of macular edema shown by OCT may provide an objective guideline in predicting the response of bevacizumab injection in DME.

Screening of telangiectatic capillaries in chronic macular edema based on multimodal imaging: a study of 101 eyes. LyoMAC1 study

PURPOSE

To estimate the prevalence of telangiectatic capillaries (TCs) in patients followed for chronic macular edema (CME) (diabetic ME [DME] and ME associated with retinal vein occlusion [RVO]).

METHODS

Real-life, prospective, bi-centric cohort study including all consecutive patients followed for a clinically significant CME secondary to diabetic retinopathy or RVO. Inclusion criteria were patients treated with intravitreal injection for their ME for at least 12 months who had to undergo follow-up angiography. Multimodal imaging with color retinophotography, spectral-domain optical coherence tomography (SD-OCT), OCT angiography, and en face OCT was performed in all patients.

RESULTS

A total of 101 eyes of 71 patients were included between November 2019 and June 2020. Of the 101 eyes analyzed, indocyanine green angiography found at least one TC in 67 eyes (66.3%). No significant differences were found between the groups with and without TC except for the distribution of DME and RVO (p < 0.008). In 83.6% of eyes with TCs, TCs contributed to the formation of the ME. SD-OCT sensitivity for TC detection was 94%.

CONCLUSION

In our study, the estimated prevalence of TCs in CME (DME and ME associated with RVO) was 66.3%, i.e., two-thirds of patients. SD-OCT was an excellent screening examination with a sensitivity of 94%.

LRG1 as a novel therapeutic target in eye disease

Retinal and choroidal diseases are major causes of blindness and visual impairment in the developed world and on the rise due to an ageing population and diabetes epidemic. Standard of care is centred around blockade of vascular endothelial growth factor (VEGF), but despite having halved the number of patients losing sight, a high rate of patient non-response and loss of efficacy over time are key challenges. Dysregulation of vascular homoeostasis, coupled with fibrosis and inflammation, are major culprits driving sight-threatening eye diseases. Improving our knowledge of these pathological processes should inform the development of new drugs to address the current clinical challenges for patients. Leucine-rich α-2 glycoprotein 1 (LRG1) is an emerging key player in vascular dysfunction, inflammation and fibrosis. Under physiological conditions, LRG1 is constitutively expressed by the liver and granulocytes, but little is known about its normal biological function. In pathological scenarios, such as diabetic retinopathy (DR) and neovascular age-related macular degeneration (nvAMD), its expression is ectopically upregulated and it acquires a much better understood pathogenic role. Context-dependent modulation of the transforming growth-factor β (TGFβ) pathway is one of the main activities of LRG1, but additional roles have recently been emerging. This review aims to highlight the clinical and pre-clinical evidence for the pathogenic contribution of LRG1 to vascular retinopathies, as well as extrapolate from other diseases, functions which may be relevant to eye disease. Finally, we will provide a current update on the development of anti-LRG1 therapies for the treatment of nvAMD.

Deep Learning Prediction of Response to Anti-VEGF among Diabetic Macular Edema Patients: Treatment Response Analyzer System (TRAS)

Diabetic macular edema (DME) is the most common cause of visual impairment among patients with diabetes mellitus. Anti-vascular endothelial growth factors (Anti-VEGFs) are considered the first line in its management. The aim of this research has been to develop a deep learning (DL) model for predicting response to intravitreal anti-VEGF injections among DME patients. The research included treatment naive DME patients who were treated with anti-VEGF. Patient’s pre-treatment and post-treatment clinical and macular optical coherence tomography (OCT) were assessed by retina specialists, who annotated pre-treatment images for five prognostic features. Patients were also classified based on their response to treatment in their post-treatment OCT into either good responder, defined as a reduction of thickness by >25% or 50 µm by 3 months, or poor responder. A novel modified U-net DL model for image segmentation, and another DL EfficientNet-B3 model for response classification were developed and implemented for predicting response to anti-VEGF injections among patients with DME. Finally, the classification DL model was compared with different levels of ophthalmology residents and specialists regarding response classification accuracy. The segmentation deep learning model resulted in segmentation accuracy of 95.9%, with a specificity of 98.9%, and a sensitivity of 87.9%. The classification accuracy of classifying patients’ images into good and poor responders reached 75%. Upon comparing the model’s performance with practicing ophthalmology residents, ophthalmologists and retina specialists, the model’s accuracy is comparable to ophthalmologist’s accuracy. The developed DL models can segment and predict response to anti-VEGF treatment among DME patients with comparable accuracy to general ophthalmologists. Further training on a larger dataset is nonetheless needed to yield more accurate response predictions.

Incidence of Pseudophakic Cystoid Macular Oedema Post-Cataract Surgery in Illawarra Shoalhaven Local Health District, Australia

BACKGROUND

Post-operatively, cataract surgery is associated with pseudophakic cystoid macular oedema (PCMO) causing vision disturbances. The presence of comorbidities may increase the incidence of PCMO post-cataract surgery.

OBJECTIVE

This observational study aimed to assess the incidence of PCMO in Australia (Illawarra region) and identify risk factors for developing PCMO.

METHODS

Retrospective analysis was performed on data from patients who underwent uncomplicated phacoemulsification and intraocular lens implantation between 1st March and June 30, 2016. Demographics, comorbidities, central subfield thickness (CST), visual acuity, and intraocular pressure (IOP) were collected preoperatively, day 1, and weeks 2, 4, and 6 post-operatively. Statistical analysis was performed using SPSS v.27.0 and GraphPad Prism v.9.0. The median and 95% confidence intervals were used to describe data. Logistic regression and χ2 tests were used to describe the associations. We followed the Declaration of Helsinki guidelines.

RESULTS

Fifty right and 35 left cataract eyes were operated on (58.8% were females; average age 72.8 ± 8.146 years). Total PCMO incidence was 10.6%, and true PCMO incidence (removing PCMO risk factors) was 4.2% at week 6 post-operatively. CST was slightly increased between pre- and post-cataract surgery at week 4 (p = 0.002) and week 6 (p < 0.0001; median = 259 μm, 264 μm, and 263 μm, respectively). IOP was found to be decreased (p < 0.0001) compared to day 1 (median = 17 mm Hg) and week 6 (median = 13 mm Hg). The probability of developing PCMO (odds ratio [OR] = 3) and vitreomacular traction (OR = 2.9) was higher in diabetic patients compared to non-diabetic patients and in patients >65 years old (OR = 1.5).

CONCLUSION

The true incidence of PCMO was found to be the greatest at 2-4 weeks post-operatively. Patients with diabetes or advanced age (>65 years) are at an elevated risk of developing PCMO after cataract surgery. The treatment regimens for the comorbid populations, especially diabetic patients, remain limited, and future efforts should target pharmaceutical management for these groups.

Hyperreflective Foci and Subretinal Fluid Are Potential Imaging Biomarkers to Evaluate Anti-VEGF Effect in Diabetic Macular Edema

Purpose: The aim was to investigate the effect and underlying mechanism of anti-vascular endothelial growth factor (anti-VEGF) in diabetic macular edema (DME) by optical coherence tomography angiography (OCTA). Methods: Twenty-five eyes in 18 treatment-naïve patients with DME were included. All eyes were imaged by OCTA at baseline and 1 week after monthly intravitreal aflibercept injection (IAI). Visual acuity was measured as best corrected visual acuity (BCVA). Additional parameters were evaluated by OCTA, including central macular thickness (CMT), the number of hyperreflective foci (HRF), foveal avascular zone (FAZ), vessel density (VD) in the deep capillary plexus (DCP), the en-face area of cystoid edema in DCP segmentation, and subretinal fluid (SRF) height. Results: The mean time between baseline and final follow-up by OCTA was 79.24 ± 38.15 (range, 28-163) days. Compared with baseline, BCVA was increased significantly after the 3rd IAI, while CMT was decreased significantly from the 1st IAI. SRF height and the area of cystoid edema in DCP segmentation were decreased significantly after the 2nd IAI compared with baseline. The number of HRF was decreased significantly after the 1st IAI (8.87 ± 9.38) compared with baseline (11.22 ± 10.63). However, FAZ's area and perimeter as well as VD in DCP showed no significant changes post-treatment. Conclusion: Anti-VEGF is effective in treating DME, improving visual acuity and decreasing macular edema. The decreased HRF indicates anti-inflammatory effects of aflibercept to deactivate retinal microglia/macrophages. The decreased cystoid edema and SRF height indicated improved drainage function of Müller glial cells and retinal pigment epithelium after IAI.

Clinical Outcome and Drug Expenses of Intravitreal Therapy for Diabetic Macular Edema: A Retrospective Study in Sardinia, Italy

Background: Diabetic macular edema (DME) is a leading cause of visual loss in working-age adults. The purpose of this retrospective study was to perform an epidemiological analysis on DME patients treated with intravitreal drugs in a tertiary hospital. The clinical outcome, adverse drug reactions (ADRs), and intravitreal drug expenses were assessed. Methods: All DME patients treated with Ranibizumab, Aflibercept, Dexamethasone implant, and Fluocinolone Acetonide implant at the Sassari University Hospital, Italy, between January 2017 and June 2020 were included. Central macular thickness (CMT) and best corrected visual acuity (BCVA) were measured. ADRs and drug expenses were analyzed. Results: Two-hundred thirty-one DME patients (mean age: 65 years) received intravitreal agents. Mean CMT and BCVA were 380 μm and 0.5 LogMAR at baseline, 298 μm and 0.44 logMAR after one year (p = 0.04), and 295 μm and 0.4 logMAR at the end of the follow-up period. A total of 1501 intravitreal injections were given; no major ADRs were reported. Treatment cost was €915,000 (€261,429/year). Twenty non-responders to Ranibizumab or Aflibercept were switched to a Dexamethasone implant. In these patients, mean CMT and BCVA were 468 µm and 0.5 LogMar at the time of switching and 362 µm and 0.3 LogMar at the end of the follow-up (p = 0.00014 and p = 0.08, respectively). Conclusion: Results confirm that Ranibizumab, Aflibercept, and Dexamethasone implant are effective and safe in DME treatment. A switch to Dexamethasone implant for patients receiving Aflibercept or Ranibizumab with minimal/no clinical benefit should be considered.

Severity of diabetic retinopathy and its relationship with age at onset of diabetes mellitus in India: A multicentric study

Purpose:

To present clinical profile and risk factors of sight-threatening diabetic retinopathy (STDR) among people with age of onset of diabetes (AOD) <25 versus ≥25 years.

Methods:

A retrospective chart analysis of consecutive patients with diabetic retinopathy (DR) n = 654) treated at 14 eye care centers across India between 2018 and 2019 was performed. Patients were divided into two groups, Group 1: AOD <25 years and Group 2: AOD ≥25 years. DR and diabetic macular edema (DME) were classified using the International Clinical Classification of DR severity scale. STDR included severe nonproliferative DR (NPDR), proliferative DR (PDR), and moderate to severe DME. A multilevel mixed-effects model was used for comparison between two groups: 1) Patients with DR and AOD <25 years and 2) Patients with DR and AOD ≥25 years. Bivariate and multivariate regression analyses were used to evaluate risk factors between the two groups.

Results:

A total of 654 patients were included, 161 (307 eyes) in AOD <25 and 493 (927 eyes) in AOD >25 group. There was a higher prevalence of PDR with high-risk characteristics in AOD <25 group (24% vs. 12%) at baseline and 12-month follow-up (25% vs. 6%); P < 0.001. Systolic hypertension and poor glycemic control were risk factors in both groups, with no difference in these modifiable risk factors between groups.

Conclusion:

People with youth-onset DM are likely to present with severer form of STDR despite similar modifiable risk factors. Therefore, strict control of systolic blood pressure, glycemic status, and regular screening for DR are recommended to reduce the risk of STDR irrespective of the age of onset of diabetes.

Impact of Different Clinical Baseline Characteristics on Intravitreal Dexamethasone Implant Ozurdex® Outcomes

Purpose

To determine the impact of different baseline clinical characteristics on the improvement in best corrected visual acuity (BCVA) in patients with diabetic macular edema (DME) who underwent the intravitreal dexamethasone implant (DEX) Ozurdex^®.

Methods

This was a single center retrospective study conducted on patients with DME, either naïve or previously treated, who were treated with one or more DEX and had a follow-up of at least 6 months. The main outcome measure was the proportion of DEX achieving an improvement ≥15 letters in BCVA.

Results

The study analyzed 192 DEX implants administered to 97 eyes (65 patients). Among the 192 DEX analyzed, 57 (29.7%) implants achieved a BCVA improvement ≥15 letters (ETDRS) from baseline, with a mean time for achieving such improvement of 89.2 (39.7) days. Eyes who received an additional DEX and those with a duration of DME < 6 months had a greater probability of achieving a BCVA improvement ≥15 letters (odds-ratio: 2.55, p = 0.0028 and odds-ratio: 1.93, p = 0.0434). The mean (standard deviation) change in BCVA from baseline was 7.5 (14.5) letters, p < 0.0001. The mean change in central macular thickness (CMT) from baseline was -128.0 (151.0) µm, p < 0.0001. The mean number of DEX implanted was 1.9 (0.8). Four (2.1%) DEX experienced an intraocular pressure increased ≥10 mm Hg; all the cases were successfully managed with topical antiglaucoma medication.

Conclusion

The results of this study confirmed previous evidence suggesting that DEX is effective for improving BCVA and CMT in patients with DME.

Choroidal Blood Flow After Intravitreal Ranibizumab in Vitrectomized and Non-Vitrectomized Eyes with Diabetic Macular Edema

Aim

Diabetic retinopathy staging system and progression predictors are soon to be considered insufficient for ophthalmologic practice. Given the growing evidence of the role of choroidal dysfunction, our purpose was to assess choroidal vascular changes with intravitreal ranibizumab (RBZ) treatment in diabetic macular edema (DME).

Methods

This was a prospective longitudinal cohort study. The study included DME eyes, grouped in vitrectomized (group 1) and non-vitrectomized (group 2) eyes, submitted to RBZ in a pro re nata regimen, with 24 weeks of follow-up. Main outcome measures such as central subfield foveal thickness (CFT), choroidal thickness (CT), and choroidal vascular index (CVI) were obtained from structural OCT, and choriocapillaris flow density (CCD) was obtained from OCT angiography and analyzed before and after treatment.

Results

Thirty-one patients were included, 10 eyes in group 1 and 24 eyes in group 2. The mean number of injections was 5.18 (range 2–6). Globally, there was an improvement in BCVA (+4.3 ETDRS letters, p=0.004) and CFT (−84.6 µm, p<0.001) with no changes in CT, CVI, or CCD (p>0.05). When considering only group 2, there was a significant decrease in CT (p=0.033) and a significant increase in CCD (p=0.010) 6 months after treatment, with no differences in CVI (p=0.111). Baseline CVI was correlated with visual acuity at week 24 both globally (r=0.406, p=0.029) and in group 2 (r=0.604, p=0.004).

Conclusion

In non-vitrectomized eyes, choriocapillaris blood flow improves with RBZ. Baseline CVI may correlate with visual function after RBZ. ClinicalTrials.gov NCT04387604.

Intravitreal corticosteroids for diabetic macular edema: a network meta-analysis of randomized controlled trials

BACKGROUND

To evaluate the efficacy and safety of different intravitreal corticosteroids for treating diabetic macular edema (DME).

METHODS

Four databases were systematically searched for randomized controlled trials comparing different intravitreal corticosteroids for treating DME. The primary outcome was the change in best-corrected visual acuity (BCVA) within 6 months after the first injection (short-term BCVA). Secondary outcomes were the change in BCVA over 1 year (long-term BCVA) and changes in central macular thickness (CMT) and intraocular pressure (IOP) within 6 months after the first injection. Network meta-analysis was performed to aggregate the results from the individual studies.

RESULTS

Nineteen trials involving 2839 eyes were included. Intravitreal triamcinolone acetonide (TA) injections (≥ 8 mg and 4-8 mg), fluocinolone acetonide (FA) implants (0.5 µg/day) and dexamethasone (DEX) implants (700 µg) improved short-term BCVA (mean changes in logMAR [95% confidence interval] - 0.27 [- 0.40, - 0.15]; - 0.12 [- 0.18, - 0.06]; - 0.10 [- 0.21, - 0.01]; and - 0.06 [- 0.11, - 0.01]). Intravitreal TA injections (4 mg, multiple times), FA implants (0.5 µg/day and 0.2 µg/day), and DEX implants (350 µg) improved long-term BCVA (mean changes in logMAR [95% confidence interval] - 0.11 [- 0.21, - 0.02]; - 0.09 [- 0.15, - 0.03]; - 0.09 [- 0.14, - 0.02]; and - 0.04 [- 0.07, - 0.01]). All intravitreal corticosteroids reduced CMT, and different dosages of TA did not show significant differences in increasing IOP.

CONCLUSIONS

Intravitreal corticosteroids effectively improved BCVA in DME patients, with higher dosages showing greater efficacies. TA was not inferior to FA or DEX and may be considered a low-cost alternative choice for DME patients. The long-term efficacy and safety of different corticosteroids deserve further investigation. Trial registration Prospectively registered: PROSPERO, CRD42020219870.

Diabetic macular edema: Safe and effective treatment with intravitreal triamcinolone acetonide (Taioftal)

Purpose

To suggest the safety and efficacy of preservative-free triamcinolone acetonide intravitreal injectable suspension (Taioftal) for the treatment of diabetic macular edema.

Methods

A prospective clinical study involved 49 patients (49 eyes), that were treated with Taioftal and followed-up for six months. Complete ophthalmic examination, including spectral domain optical coherence tomography, was performed at baseline, and at month 1, 3, 6 after the intravitreal injection. Accurate collection and analysis of best-corrected visual acuity (BCVA), central foveal thickness (CFT), intraocular pressure (IOP), and adverse events (AEs) were carried out in order to evaluate visual function and macular morphology before and after treatment

Results

Median BCVA value chosen as comparing statistics was significantly improved at every follow-up time points (gain of 6 letters at month 1, 12 at month 3 –improvement up to 24% at month 3 with stabilization until month 6) compared to baseline, as certified by Kruskal-Wallis rank sum test (P<0.05). Median CFT significantly waned at each follow-up times (decrease of about 65 μm at month 1, 155 at month 3 –reduction up to 28% at month 3 keeping good outcome until month 6) compared to baseline (P<0.05). IOP elevation, with no severe increases, was the most common among spotted AEs (median of 23 mmHg at month 1, 20 at month 3).

Conclusion

Intravitreal injection of preservative-free triamcinolone (Taioftal) is an effective, safe and inexpensive drug used to improve visual acuity and reduce central foveal thickness in eyes affected by diabetic macular edema during an average time of 6 months. Temporary, never severe, elevation of IOP is totally manageable with topical medications. No serious vision-threatening complications are related to the use of intravitreal triamcinolone injections.

Assessment of Reinjection Numbers and Intervals for Diabetic Macular Edema Patients Who Received Dexamethasone Intravitreal Implants in Germany and Switzerland

PURPOSE

The purpose was to assess the number and intervals of dexamethasone intravitreal implant (DEX) reinjections in a real-world setting for the treatment of diabetic macular edema (DME) and to determine the relationship with effectiveness and safety.

PATIENTS AND METHODS

Data were abstracted from medical records of DME patients in Germany and Switzerland for this retrospective, multicenter, drug utilization study. Best-corrected visual acuity (BCVA) and central retinal thickness (CRT) changes 7-12 weeks post-injection(s) measured effectiveness. Adverse events (AEs) of special interest were reported.

RESULTS

A total of 141 patients, 108 from Germany and 33 from Switzerland, were assessed. Mean (SD) reinjection interval was 5.7 (4.2) months. Mean baseline BCVA was 61.6 letters, and mean baseline CRT was 413.3 µm. The mean BCVA and CRT changes at 7-12 weeks after baseline, reinjection 1, 2, and 3 were +3.4, +3.7, +3.2, and -1.4 letters and -88.3, -81.6, -102.4, and -124.1 μm, respectively. The Spearman correlation between change in BCVA and CRT and DEX reinjection interval was r=0.03 (P=0.66) and r=0.07 (P=0.38), respectively. Only 18% of patients experienced at least 1 AE.

CONCLUSION

There was no statistically significant correlation between drug effectiveness and reinjection intervals in either country. Although these results are preliminary, they indicate that DEX improves BCVA and CRT in real-world clinical practice.

IL-17A Damages the Blood-Retinal Barrier through Activating the Janus Kinase 1 Pathway

Blood-retinal barrier (BRB) dysfunction underlies macular oedema in many sight-threatening conditions, including diabetic macular oedema, neovascular age-related macular degeneration and uveoretinitis. Inflammation plays an important role in BRB dysfunction. This study aimed to understand the role of the inflammatory cytokine IL-17A in BRB dysfunction and the mechanism involved. Human retinal pigment epithelial (RPE) cell line ARPE19 and murine brain endothelial line bEnd.3 were cultured on transwell membranes to model the outer BRB and inner BRB, respectively. IL-17A treatment (3 days in bEnd.3 cells and 6 days in ARPE19 cells) disrupted the distribution of claudin-5 in bEnd.3 cells and ZO-1 in ARPE19 cells, reduced the transepithelial/transendothelial electrical resistance (TEER) and increased permeability to FITC-tracers in vitro. Intravitreal (20 ng/1 μL/eye) or intravenous (20 ng/g) injection of recombinant IL-17A induced retinal albumin leakage within 48 h in C57BL/6J mice. Mechanistically, IL-17A induced Janus kinase 1 (JAK1) phosphorylation in bEnd.3 but not ARPE19 cells. Blocking JAK1 with Tofacitinib prevented IL-17A-mediated claudin-5 dysmorphia in bEnd.3 cells and reduced albumin leakage in IL-17A-treated mice. Our results suggest that IL-17A can damage the BRB through the activating the JAK1 signaling pathway, and targeting this pathway may be a novel approach to treat inflammation-induced macular oedema.

Assessing the Clinical Utility of Expanded Macular OCTs Using Machine Learning

Purpose

Optical coherence tomography (OCT) is widely used in the management of retinal pathologies, including age-related macular degeneration (AMD), diabetic macular edema (DME), and primary open-angle glaucoma (POAG). We used machine learning techniques to understand diagnostic performance gains from expanding macular OCT B-scans compared with foveal-only OCT B-scans for these conditions.

Methods

Electronic medical records were extracted to obtain 61 B-scans per eye from patients with AMD, diabetic retinopathy, or POAG. We constructed deep neural networks and random forest ensembles and generated area under the receiver operating characteristic (AUROC) and area under the precision recall (AUPR) curves.

Results

After extracting 630,000 OCT images, we achieved improved AUROC and AUPR curves when comparing the central image (one B-scan) to all images (61 B-scans). The AUROC and AUPR points of diminishing return for diagnostic accuracy for macular OCT coverage were found to be within 2.75 to 4.00 mm (14–19 B-scans), 4.25 to 4.50 mm (20–21 B-scans), and 4.50 to 6.25 mm (21–28 B-scans) for AMD, DME, and POAG, respectively. All models with >0.25 mm of coverage had statistically significantly improved AUROC/AUPR curves for all diseases (P < 0.05).

Conclusions

Systematically expanded macular coverage models demonstrated significant differences in total macular coverage required for improved diagnostic accuracy, with the largest macular area being relevant in POAG followed by DME and then AMD. These findings support our hypothesis that the extent of macular coverage by OCT imaging in the clinical setting, for any of the three major disorders, has a measurable impact on the functionality of artificial intelligence decision support.

Translational Relevance

We used machine learning techniques to improve OCT imaging standards for common retinal disease diagnoses.

Is immediate treatment necessary for diabetic macular edema after pars plana vitrectomy for tractional complications of proliferative diabetic retinopathy?

PURPOSE

To assess the treatment benefit of eyes with diabetic macular edema (DME) in vitrectomized eyes for tractional complications of proliferative diabetic retinopathy (PDR).

METHODS

In a retrospective multicentre observational study in India, the clinical outcomes of eyes with center-involving DME in vitrectomized eyes for tractional complications of PDR in people with type 2 diabetes with at least 12 months follow-up data were assessed. The DME status and visual acuity outcomes were compared between those who received treatment versus those observed.

RESULTS

In the 10-year study period, 45 eyes of 44 patients from 5 tertiary centers in India met the inclusion criteria. Center-involving DME was documented after a mean of 7 ± 7 months following pars plan vitrectomy (PPV) for tractional complications of PDR. More than half of the (n = 25) eyes were immediately treated for DME, and treatment was deferred for the rest. At one year, there was a statistically significant reduction in mean central subfield thickness in treated (467.9 ± 124.8 μm to 367.8 ± 143.7 μm; p < 0.001) as well as observed (405.2 ± 132.6 μm to 325.6 ± 149 μm; p < 0.001) eyes, and the change was comparable (p = 0.574). The change in vision was also comparable (0.12 ± 0.31 and 0.22 ± 0.54 Log MAR in the treated and observed group, respectively; p = 0.443).

CONCLUSION

Treatment for pre-existing or new-onset DME after PPV for tractional complications of PDR may be deferred for up to one year because the DME may resolve spontaneously with time.

Quantifying frequency content in cross-sectional retinal scans of diabetics vs. controls

Purpose

To examine subtle differences in the structure of diabetic vs. control retinas.

Methods

Spectral-domain optical coherence tomography (SD-OCT) images were compared for the retinas of 33 diabetic subjects who did not have clinical evidence of diabetic macular edema and age-matched controls, with central macular thicknesses of 275 and 276 microns, respectively. Cross-sectional retinal images through the fovea, called B-scans, were analyzed for spatial frequency content. The B-scans were processed to remove and smooth the portions of the retinal image not within regions of interest in the retina. The remaining retinal images were then quantified using a Fast Fourier Transform (FFT) approach that provided amplitude as a function of spatial frequency.

Results

The FFT analysis showed that diabetic retinas had spatial frequency content with significantly higher power compared to control retinas particularly for a deeper fundus layer at mid-range spatial frequencies, ranging from p = 0.0030 to 0.0497 at 16.8 to 18.2 microns/cycle. There was lower power at higher spatial frequencies, ranging from p = 0.0296 and 0.0482 at 27.4 and 29.0 microns/cycle. The range of mid-range frequencies corresponds to the sizes of small blood vessel abnormalities and hard exudates. Retinal thickness did not differ between the two groups.

Conclusions

Diabetic retinas, although not thicker than controls, had subtle but quantifiable pattern changes in SD-OCT images particularly in deeper fundus layers. The size range and distribution of this pattern in diabetic eyes were consistent with small blood vessel abnormalities and leakage of lipid and fluid. Feature-based biomarkers may augment retinal thickness criteria for management of diabetic eye complications, and may detect early changes.

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

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

Microvascular Changes in Macular Area After Phacoemulsification and Its Influencing Factors Assessed by Optical Coherence Tomography Angiography

OBJECTIVE

To investigate macular vascular changes and underlying influencing factors using optical coherence tomography angiography (OCTA) after phacoemulsification in patients with cataracts.

METHODS

Patients diagnosed with cataracts at the First Affiliated Hospital of Anhui Medical University from March to September 2019 were included. The macular retinal thickness, the microvascular density in the foveal, parafoveal, and perifoveal area, and the area of the foveal avascular zone (FAZ) were measured using OCTA at baseline, 1-week, 1-month, and 3-month post-operation.

RESULTS

Forty-seven cataract patients (58 eyes) were eligible for this study. Compared with baseline thickness, the foveal, parafoveal, and perifoveal thicknesses, particularly in the inner retina, significantly increased at 1- and 3-month post-operation (P<0.05). There was a nonsignificant difference in the microvascular density of the foveal and perifoveal areas at 1-week, 1-month, and 3-month post-operation (P>0.05). At 1-month post-operation, the deep vessel density at the perifovea significantly increased (P<0.05). The FAZ area significantly diminished at 1- and 3-month post-operation compared with the baseline data (P<0.05).

CONCLUSION

Phacoemulsification offers a satisfactory efficacy response, with an increased macular thickness, reduced FAZ area, and nonsignificant changes in the microvascular density at the perifovea after surgery.

Management of Patients With DME With Good Visual Acuity in Routine Clinical Practice

BACKGROUND AND OBJECTIVE

To determine outcomes of eyes with diabetic macular edema (DME) and best visual acuity (BVA) of 20/25 or better in routine clinical practice.

PATIENTS AND METHODS

Retrospective study of 72 patients with DME and BVA of 20/25 or better. Patients were divided by anti-vascular endothelial growth factor (VEGF) treatment regimen: early (Group A), delayed (Group B), and none (Group C).

RESULTS

Group A had higher baseline central subfield thickness (CST) (325 ± 62 µm) compared to Groups B (292 ± 24 µm) and C (296 ± 35 µm) (P = .033). All groups had similar 24-month CST (299 ± 62 µm, 280 ± 64 µm, 296 ± 65 µm; P = .61). There was no difference in baseline BVA among groups (81.9 ± 2.4, 83.2 ± 2.4, 82.4 ± 2.5 Early Treatment Diabetic Retinopathy Study [ETDRS] letters, respectively; P = .290), but at 6 months, Group A had lower BVA (76.6 ± 9.6 ETDRS letters) than groups B (81.9 ±3.3 ETDRS letters) and C (82.4 ± 5.0 ETDRS letters) (P = .008). There was no difference among groups in 24-month BVA (78.9 ± 6.6, 78.4 ± 12.3, and 80.6 ± 6.9 ETDRS letters, respectively; P = .448).

CONCLUSION

Although observation may be indicated in eyes with stable BVA and CST less than 300 µm, anti-VEGF stabilizes BVA in eyes with CST greater than 300 µm and eyes with declining BVA. [Ophthalmic Surg Lasers Imaging Retina. 2021;52:247-256.].

Topical ketorolac as an adjunctive treatment with intravitreal bevacizumab in the management of diabetic macular edema: A double-masked placebo-controlled randomized clinical trial

PURPOSE

To evaluate the additional effect of ketorolac eye drops on therapeutic effects of intravitreal Bevacizumab in patients with diabetic macular edema (DME) METHODS: In a randomized clinical trial, 50 patients with center involved DME (macular thickness ≥ 300 microns accompanied by decreased VA (24 < BCVA ≤ 70 ETDRS letters) were enrolled consecutively and randomized 1:1 to receive either bevacizumab plus topical ketorolac (25 patients) or bevacizumab plus artificial tears (25 patients). Patients with proliferative diabetic retinopathy, history of intraocular surgery, intravitreal injection in less than three months, macular photocoagulation less than 6 months and any other concomitant ocular pathologies were excluded from the study. All the patients received three consecutive monthly injections of intravitreal bevacizumab (IVB). After that, patients were examined every 6 weeks and reinjection was administered based on the "as needed" protocol if macular thickness was 300 microns or more and VA was 70 ETDRS letters or less.. Patients also received either topical ketorolac or artificial tears three times a day over the study period (6 months). Changes in central subfield thickness (CST), best-corrected visual acuity (BCVA, ETDRS letters), and number of IVB injections were compared between the study groups.

RESULTS

Fifty eyes of 50 patients were included (25 eyes in each group). Mean CST was significantly decreased in both study groups at 14^th week (-87 ± 98 µm, P = 0.012 and -100 ± 147 µm, P = 0.006 in bevacizumab plus ketorolac and bevacizumab plus artificial tears groups, respectively). Nevertheless, the changes of mean CST remained significant only in bevacizumab plus ketorolac group up to 26^th week (-147 ± 124 µm, P < 0.001 and -51 ± 145 µm, P = 0.245, respectively). Comparing two groups, reduction of mean CST from baseline was significantly greater in bevacizumab plus ketorolac group compared with the control group at 26^th week. (difference = -97 µm, 95%CI = -182 to -11, P = 0.017). In the study group, mean BCVA significantly increased at both 20^th week (6.2 ± 10.1, P = 0.04) and 26^th week (8.2 ± 10.9, P = 0.03). In contrast, visual acuity did not significantly improve at any time points in bevacizumab plus artificial tears group, While insignificant, the 26-week mean change of visual acuity from baseline was greater in bevacizumab plus ketorolac group (difference = 6.5 ETDRS letter; 95%CI = -14.4 to 1.4) Two groups were comparable regarding number of IVB injections (P = 0.99).

CONCLUSION

Topical ketorolac 0.5% three times a day could enhance and sustain the efficacy of intravitreal bevacizumab in the treatment of DME.

En face image-based classification of diabetic macular edema using swept source optical coherence tomography

This retrospective study was performed to classify diabetic macular edema (DME) based on the localization and area of the fluid and to investigate the relationship of the classification with visual acuity (VA). The fluid was visualized using en face optical coherence tomography (OCT) images constructed using swept-source OCT. A total of 128 eyes with DME were included. The retina was segmented into: Segment 1, mainly comprising the inner nuclear layer and outer plexiform layer, including Henle’s fiber layer; and Segment 2, mainly comprising the outer nuclear layer. DME was classified as: foveal cystoid space at Segment 1 and no fluid at Segment 2 (n = 24), parafoveal cystoid space at Segment 1 and no fluid at Segment 2 (n = 25), parafoveal cystoid space at Segment 1 and diffuse fluid at Segment 2 (n = 16), diffuse fluid at both segments (n = 37), and diffuse fluid at both segments with subretinal fluid (n = 26). Eyes with diffuse fluid at Segment 2 showed significantly poorer VA, higher ellipsoid zone disruption rates, and greater central subfield thickness than did those without fluid at Segment 2 (P < 0.001 for all). These results indicate the importance of the localization and area of the fluid for VA in DME.

Ultra-wide field retinal imaging: A wider clinical perspective

The peripheral retina is affected in a variety of retinal disorders. Traditional fundus cameras capture only a part of the fundus even when montaging techniques are used. Ultra-wide field imaging enables us to delve into the retinal periphery in greater detail. It not only facilitates assessing color images of the fundus, but also fluorescein angiography, indocyanine green angiography, fundus autofluorescence, and red and green free images. In this review, a literature search using the keywords "ultra-widefield imaging", "widefield imaging", and "peripheral retinal imaging" in English and non-English languages was done and the relevant articles were included. Ultra-wide field imaging has made new observations in the normal population as well as in eyes with retinal disorders including vascular diseases, degenerative diseases, uveitis, age-related macular degeneration, retinal and choroidal tumors and hereditary retinal dystrophies. This review aims to describe the utility of ultra-wide field imaging in various retinal disorders.

Evaluation of morphological characteristics of diabetic macular edema in patients with non-proliferative versus proliferative diabetic retinopathy: a spectral-domain optical coherence tomography study

PURPOSE

To evaluate the morphological characteristics in patients with diabetic macular edema (DME), either with co-existent non-proliferative diabetic retinopathy (NPDR) or with PDR.

METHODS

Retrospective study includes 138 treatment naïve patients with DME, either with NPDR (n = 96) or in combination with PDR (n = 42). All patients underwent best corrected visual acuity (BCVA) measurement, spectral domain-optical coherence tomography (SD-OCT) and fluorescein angiography, while demographic characteristics were also recorded. Specific clinical and morphological characteristics were analyzed and compared between the two groups.

RESULTS

Patients with DME and PDR presented higher central retinal thickness and mixed type of edema, with predominantly cystoid component and large cysts, extending in the foveal, peri- and para-foveal area, compared to patients with DME and NPDR. The presence of non-perfusion areas in patients with DME and PDR led to additional ellipsoid zone and external limiting membrane disruption in a higher percentage, accompanied with worse visual acuity compared to patients with DME and NPDR. Patients with DME and PDR had also higher vitreomacular traction percentage and higher HbA1c levels than those with DME and NPDR.

CONCLUSION

Variations in morphological characteristics of DME on SD-OCT existed between patients with NPDR and those with PDR. These differences may explain the alterations in visual acuity and prognosis.

Outcome of Single Dexamethasone Implant Injection in the Treatment of Persistent Diabetic Macular Edema After Anti-VEGF Treatment: Real-Life Data from a Tertiary Hospital in Jordan

Purpose

To analyze the real-life clinical outcome of a single dexamethasone implant (DEX) injection in the treatment of persistent diabetic macular edema (DME) after anti-vascular endothelial growth factor (anti-VEGF) agents in a sample of the Jordanian population.

Methods

An observational case study design that involved a retrospective chart review analysis in a tertiary hospital in Amman, Jordan. Patients who showed persistent DME after receiving at least six doses of anti-VEGF agents for DME treatment were included.

Results

The study population consisted of 72 participants (29 females, 43 males) having an average age of 66 years. All patients had best-corrected visual acuity (BCVA) less than 0.7 (6/9) and SD-OCT documented center-involved DME. The study results showed that the average baseline BCVA improved from 0.205±0.1 before DEX injection to 0.358±0.1 at 3 months post-injection (p<0.0001). The central mean thickness (CMT) showed significant improvement also (539.347±132.402 to 379.041±99.430, p<0.0001). There was a mean of 3 mmHg increase in intraocular pressure at 3 months post-injection (p<0.0001), however, only 4% of patients required medical treatment. Other inflammatory biomarkers in OCT, such as intraretinal hyper-reflective dots (HRD), showed significant improvement also (23.67±16 to 14.83±13, p<0.0001). No other significant safety concerns were noticed.

Conclusion

A single DEX injection showed significant clinical and anatomical improvement in DME cases that are persistent after anti-VEGF treatment in our sample, with an excellent safety profile. In case of supply shortage of intravitreal injections, which occurs frequently at our center, a single DEX injection may be utilized as an effective DME therapy. Further research is mandated to identify clinical response in a larger sample and more frequent injections.

Vitreomacular interface after anti-VEGF injections in diabetic macular edema

Background

The purpose of this study was to evaluate the incidence of vitreomacular adhesion (VMA) release after anti-VEGF therapy for the treatment of diabetic macular edema (DME) and to evaluate further changes in outcome.

Methods

This was a retrospective study that enrolled 66 eyes of 66 patients with DME who presented with VMA diagnosed by spectral-domain optical coherence tomography (OCT) at baseline. VMA was classified as focal (attachment: ≤ 1500 μm) or broad (attachment: > 1500 μm). All patients received at least three monthly intravitreal injections of an anti-VEGF agent. Follow-up visits were performed 1 month after each injection to evaluate the incidence of VMA release.

Results

The mean patient age was 61.4 years (range: 29 to 78 years), and 72.7 % were male. The mean best-corrected visual acuity was 0.62 logMAR, and the mean central retinal thickness (CRT) was 473 μm at baseline. The mean length of follow-up was 18.5 months, and the mean number of injections was 5.8. The intravitreal drugs used were aflibercept (40.9 %), ranibizumab (37.9 %) and bevacizumab (21.2 %). Forty-seven eyes had broad VMA, and 19 had focal VMA. Twenty-two eyes (33.3 %) developed VMA release following a mean of 5.7 injections (range: 3–13). Sixteen eyes (72.7 %) with focal VMA and 6 eyes (27.3 %) with broad VMA at baseline developed VMA release. Twenty-one eyes that developed VMA release showed an improvement in CRT following VMA release (mean: -106 μm; range: 22 to 289 μm).

Conclusions

VMA release occurs in approximately 1/3 of patients with DME following anti-VEGF therapy. Most of them show a short-term decrease in CRT.

Intravitreal Aflibercept versus Ranibizumab for Diabetic Macular Edema in a Taiwanese Health Service Setting

Purpose: To compare the visual and anatomical outcomes between intravitreal aflibercept and ranibizumab for diabetic macular edemaMethods: A total of 194 eyes from 194 patients (aflibercept n = 95, ranibizumab n = 99) were retrospectively enrolled in the study. All eyes fulfilled the key criteria including a baseline best-corrected visual acuity (BCVA) between 20 and 70 ETDRS letters, a central subfield thickness (CST) 300 µm or more. Primary outcomes were BCVA and CST at 1, 3, 6, and 12 months. Maintenance of vision was defined as visual loss of less than 5 letters over 6 to 12 months. Predictors for final visual acuity and visual maintenance were analyzed using multivariate regression models.Results: Both agents achieved comparable visual and anatomical outcomes at any time point over the course of follow-up (all p > .05). At 12 months, aflibercept group had higher proportions of visual gains 5, 10 and 15 letters or more (p = .014, p = .011, and p = .034, respectively). The mean number of injections was 5.0 ± 1.9 in ranibizumab group and 4.5 ± 1.9 in aflibercept group (p = .09). Ranibizumab predicted poor maintenance of vision (p = .009), but not the final visual acuity (univariate p = .1). Ranibizumab was more likely to have recurrence of subretinal fluid than aflibercept in 12 months after resolution of subretinal fluid at baseline (p = .016). Both aflibercept and ranibizumab had similar rates of loss to follow-up (p = .47) and occurrence of vitreous hemorrhage (p = .21).Conclusion: While both agents improved vision with resolution of edema, aflibercept maintained vision more effectively with less recurrence of subretinal fluid at 12 months in real-world settings.

Aflibercept for treatment-naïve diabetic macula oedema in a multi-ethnic population: Real-world outcomes from North West London

Purpose

To evaluate the clinical outcomes of patients with treatment–naïve diabetic macula oedema (DMO) treated with Aflibercept in routine clinic settings in ethnically diverse North West London (NWL) and compare to outcomes reported in the VIVID and VISTA clinical trials

Methods

This was a retrospective multicentre interventional case series. Two hundred and seventy eyes of 221 treatment-naïve patients at three NWL hospitals initiated on Aflibercept and who had at least 12 months follow-up were included in the study. Visual acuity, central subfield thickness and macula volume were recorded at baseline, month 3, 6 and 12.

Results

There were significant differences between the NWL cohort and participants in the VIVID and VISTA trials at baseline including higher HbA1c and a higher proportion of eyes with proliferative diabetic retinopathy in the NWL cohort. The mean VA, mean CSFT and mean MV at baseline was 66.4 (± 14.6) letters, 417 (± 94) μm and 10.3 (± 1.9) mm³. The mean VA gain at 12 months was 4.0 (± 11.8) letters (p < 0.001); a total of 26% of eyes gained ≥ 10 letters, 15% of eyes gained ≥ 15 letters and 6% lost ≥15 letters. At 12-months, the mean reduction in CSFT was 108 (± 96) μm (p<0.001) and the mean reduction in MV was 1.05 (± 1.21) mm³ (p<0.001). An average of 6.2 (± 2.3) injections was given over 12 months. There was a significant association between functional and anatomical response category at 3 months and response category at 12 months (p<0.001).

Conclusion

The effectiveness of treatment with Aflibercept for patients in NWL was meaningfully lower than was reported in the VIVID and VISTA clinical trials. A high proportion of patients with good visual acuity at baseline, poorer glycaemic control, worse diabetic retinopathy and under-treatment likely contributed to lower functional and anatomical outcomes.

Saudi Arabia Guidelines for diabetic macular edema: A consensus of the Saudi Retina Group

Diabetes mellitus (DM) and its complications are major public health burdens in Saudi Arabia. The prevalence of diabetic retinopathy (DR) is 19.7% and the prevalence of diabetic macular edema (DME) is 5.7% in Saudi Arabia. Diabetic macular edema is a vision-threatening complication of DR and a major cause of vision loss worldwide. Ocular treatments include retinal laser photocoagulation, anti-vascular endothelial growth factor (anti-VEGF) agents, intravitreal corticosteroids, and vitreoretinal surgery when necessary. The present consensus was developed as a part of the Saudi Retina Group's efforts to generate Saudi guidelines and consensus for the management of DME, including recommendations for its diagnosis, treatment, and best practice. The experts' panel stipulates that the treatment algorithm should be categorized according to the presence of central macula involvement. In patients with no central macular involvement, laser photocoagulation is recommended as the first-line option. Patients with central macular involvement and no recent history of cardiovascular (CVS) or cerebrovascular disorders can be offered anti-VEGF agents as the first-line option. In the case of non-responders (defined as an improvement of <20% in optical coherence tomography or a gain of fewer than 5 letters in vision), switching to another anti-VEGF agent or steroids should be considered after 3 injections. Within the class of steroids, dexamethasone implants are recommended as the first choice. In patients with a recent history of CVS events, the use of anti-VEGF agents is not recommended, regardless of their lens status. The experts' panel recommends that a future study be conducted to provide a cut-off point for early switching to steroid implants in pseudo-phakic eyes.

Endophthalmitis following Intravitreal Anti-Vascular Endothelial Growth Factor Therapy: Changes in Incidence and Outcomes over a 9-Year Period

Aims: To evaluate whether the incidence, microbial spectrum, and visual outcomes of endophthalmitis following intravitreal injections have changed over time.Methods: Retrospective cohort study of endophthalmitis in eyes receiving intravitreal injection of anti-vascular endothelial growth factor between 2009-2012 and 2016-2017 at a single, large retina practice.Results: A total of 283,315 injections resulted in 96 suspected infectious endophthalmitis cases. Comparing 2009-2012 and 2016-2017, the rate of suspected endophthalmitis changed from 1 in 2,663 injections to 1 in 3,195 injections (p = .37). Visual outcomes 6 months after endophthalmitis were significantly better during the latter period (p = .04), with an average loss of 6.3 lines of VA in 2009-2012 compared to a loss of 3.6 lines in 2016-2017. In multivariate analysis, a "no-talking" policy during injections resulted in a trend towards a decrease in endophthalmitis incidence (p = .08). Cessation of post-injection topical antibiotic use did not independently decrease endophthalmitis incidence (p = .24) when the effect of a "no-talking" policy was taken into account. A lower rate of endophthalmitis was seen after prefilled vs. conventionally prepared ranibizumab syringe use for injection (0.014% vs. 0.035%, respectively), though this difference did not meet statistical significance (p = .16).Conclusion: The incidence of endophthalmitis after intravitreal injection decreased and visual outcomes improved between the periods of 2009-2012 and 2016-2017. A "no-talking" policy during injections was associated with a trend toward a decrease in endophthalmitis rate.

Micropulse laser in patients with refractory and treatment-naïve center-involved diabetic macular edema: short terms visual and anatomic outcomes

Purpose:

The purpose of the study is to describe visual and anatomic outcomes of 5774nm micropulse laser photocoagulation in eyes with either treatment-naïve or refractory diabetic macular edema (DME) at 3 months.

Methods:

This was a prospective case series that recruited 23 consecutive patients (33 eyes) with center-involved DME that was either treatment-naïve or had not responded to prior treatment. Micropulse therapy was performed with the Easy Ret 577 (Quantel Medical, Cournon d’Auvergne, France) diode laser in a high-density manner in eyes with treatment-naïve or refractory DME. The primary outcome was the change of best-corrected visual acuity (BCVA; logMAR) at 1 and 3 months. Secondary outcomes were changes in the central macular thickness (CMT), thickness area, macular volume, and macular capillary leakage at 1 and 3 months.

Results:

There were no significant changes in BCVA at 3 months, with mean ± standard deviation (SD) of −0.08 ± 0.01 (p = 0.228) and + 0.01 ± 0.01 (p = 0.969) for treatment-naïve and refractory groups, respectively. The change in CMT at 3 months was statistically but not clinically significant in the treatment-naïve group only (mean ± SD; –30 ± 130 µm; p = 0.011). The macular volume and area thickness change were not statistically significant (p = 0.173 and p = 0.148 for macular volume and area thickness, respectively) in the treatment-naïve group. There was no difference concerning the leakage area in both groups. No adverse events were reported.

Conclusion:

We concluded that micropulse 577nm laser therapy maintained the visual acuity and macular thickness at 3 months in both treatment-naïve and refractory DME.

Quantitative Color Fundus Autofluorescence in Patients with Diabetes Mellitus

A new short wavelength confocal blue-light 450 nm-fundus autofluorescence (color-FAF) allows for visualization of minor fluorophores (e.g., advanced glycation end products, AGEs), besides lipofuscin. The aim of the present pilot study was to quantitatively evaluate color-FAF in patients with diabetes mellitus (DM) and to correlate these data with different stages of retinal disease severity. Optical coherence tomography and color-FAF images of 193 patients/eyes and 18 controls were analyzed using a custom software for quantification of the long (red) and short (green) wavelength components of the emission spectrum (REFC/GEFC). Measurements were performed in nine quadrants of the 6-mm ETDRS macular grid. Foveal GEFC and REFC intensities were higher in patients with DM compared to controls (p = 0.015 and p = 0.006 respectively) and in eyes with center involving diabetic macular edema (DME) compared to eyes without DME (p < 0.001). A positive correlation was found between GEFC and REFC intensities and central retinal thickness, r = 0.37 (p < 0.001) and r = 0.42 (p < 0.001), respectively. No differences were found in color-FAF among different DR severity groups. Quantitative color-FAF could become helpful for the metabolic evaluation of retina in patients with DM and in DME; however, further histologic and immunohistochemical studies on distribution of different retinal fluorophores in DM are needed to better understand its role.

Differential response to intravitreal dexamethasone implant in naïve and previously treated diabetic macular edema eyes

Background

To identify different response patterns to intravitreal dexamethasone implants (IDI) in naïve and previously treated (PT) diabetic macular edema (DME) eyes in a real-life setting.

Methods

342 IDI injections (203 DME eyes) were included. Number of IDI injections, percentage (%) of eyes with 1, 2, 3 and ≥ 4 injections, time to reinjections, visual acuity (VA), intraocular pressure (IOP) and central retinal thickness (CRT) were evaluated for naïve and PT DME eyes over 24 months.

Results

Mean number of injections was significantly lower in naïve vs PT DME eyes (1.40 ± 0.9 vs 1.82 ± 0.9, p < 0.001). The percentage of eyes receiving 1 injection was significantly higher in naïve vs PT DME eyes (76.1 vs 47.7), (p < 0.001). However, it was significantly lower for 2 (16.4 vs 29.4), or 3 injections (1.4 vs 17.6) (both p < 0.001), with no differences in eyes receiving ≥4 injections (5.9 vs 5.1 respectively, p = 0.80). Mean time to reinjection was not significantly different between both groups for the second, third and fourth injection (9.6 ± 4.0 vs 10.0 ± 5.5, p = 0.75, 13.2 ± 4.0 vs 16.0 ± 3.5, p = 0.21 and 21.7 ± 3.8 vs 19.7 ± 5.8, p = 0.55). VA scores were consistently better in naïve vs PT DME eyes at all studied timepoints, with no significant differences in CRT reduction or adverse effect rates.

Conclusion

Naïve DME eyes received lower number of IDI injections and showed better VA levels than PT DME eyes for 24 months in a real-world setting. This data supports the IDI use in early DME stages and provide further evidence of better IDI response when used as first-line therapy.