Updates in the management of diabetic macular edema

Recommendations for diabetic macular edema management by retina specialists and large language model-based artificial intelligence platforms

PURPOSE

To study the role of artificial intelligence (AI) in developing diabetic macular edema (DME) management recommendations by creating and comparing responses to clinicians in hypothetical AI-generated case scenarios. The study also examined whether its joint recommendations followed national DME management guidelines.

METHODS

The AI hypothetically generated 50 ocular case scenarios from 25 patients using keywords like age, gender, type, duration and control of diabetes, visual acuity, lens status, retinopathy stage, coexisting ocular and systemic co-morbidities, and DME-related retinal imaging findings. For DME and ocular co-morbidity management, we calculated inter-rater agreements (kappa analysis) separately for clinician responses, AI-platforms, and the "majority clinician response" (the maximum number of identical clinician responses) and "majority AI-platform" (the maximum number of identical AI responses). Treatment recommendations for various situations were compared to the Indian national guidelines.

RESULTS

For DME management, clinicians (ĸ=0.6), AI platforms (ĸ=0.58), and the 'majority clinician response' and 'majority AI response' (ĸ=0.69) had moderate to substantial inter-rate agreement. The study showed fair to substantial agreement for ocular co-morbidity management between clinicians (ĸ=0.8), AI platforms (ĸ=0.36), and the 'majority clinician response' and 'majority AI response' (ĸ=0.49). Many of the current study's recommendations and national clinical guidelines agreed and disagreed. When treating center-involving DME with very good visual acuity, lattice degeneration, renal disease, anaemia, and a recent history of cardiovascular disease, there were clear disagreements.

CONCLUSION

For the first time, this study recommends DME management using large language model-based generative AI. The study's findings could guide in revising the global DME management guidelines.

Liposome-polyethylenimine complexes for the effective delivery of HuR siRNA in the treatment of diabetic retinopathy

Diabetic retinopathy (DR) is a vision-impairing complication of diabetes, damaging the retinal microcirculatory system. Overexpression of VEGF (vascular endothelial growth factor) is implicated in the pathogenesis of DR. Human antigen R (HuR) is an RNA-binding protein that favorably regulates VEGF protein expression by binding to VEGF-encoding mRNA. Downregulating HuR via RNA interference strategies using small interfering RNAs (siRNAs) may constitute a novel therapeutic method for preventing VEGF protein overexpression in DR. Delivery of siRNAs to the cellular cytoplasm can be facilitated by cationic peptides or polymers and lipids. In this study, a cationic polymer (polyethylenimine (PEI)) and lipid nanoparticles (liposomes) were co-formulated with siRNA to form lipopolyplexes (LPPs) for the delivery of HuR siRNA. LPPs-siRNA were analyzed for size, zeta potential, serum stability, RNase stability, heparin stability, toxicity, and siRNA encapsulation efficiency. Cellular uptake, downregulation of the target HuR (mRNA and protein), and associated VEGF protein were used to demonstrate the biological efficacy of the LPPs-HuR siRNA, in vitro (human ARPE-19 cells), and in vivo (Wistar rats). In vivo efficacy study was performed by injecting LPPs-HuR siRNA formulations into the eye of streptozotocin (STZ)-induced diabetic rats after the development of retinopathy. Our findings demonstrated that high retinal HuR and VEGF levels observed in the eyes of untreated STZ rats were lowered after LPPs-HuR siRNA administration. Our observations indicate that intravitreal treatment with HuR siRNA is a promising option for DR using LPPs as delivery agents.

Prevalence and severity of diabetic retinopathy at first presentation to vitreoretinal services in Bhutan: a 3-year national study

PURPOSE

To determine the prevalence and severity of diabetic retinopathy (DR) at first presentation among diabetic patients attending national vitreoretinal (VR) services in Bhutan STUDY DESIGN: Retrospective cross-sectional study METHODS: We included all diabetic patients in Bhutan who presented for retinal evaluation for the first time over a 3-year period (2013-2016). Data including demography, clinical details, diagnostic tests, and clinical staging of DR were analyzed.

RESULTS

A total of 843 diabetic patients, aged 57.2 ± 12.0 (range 18-86) years, were enrolled. The majority were male (452, 53.6%; cumulative frequency [cf] 391, 46.4%; P = .14) and from urban settings (570, 67.6%; cf 273; 32.4%) and did not have modern schooling (555, 65.8%). Hypertension was the most common systemic comorbidity (501, 59.4%). The prevalence of DR was 42.7%, with mild nonproliferative DR (NPDR) being the most common type (187, 51.9%), followed by moderate NPDR (88, 24.4%) and proliferative DR (45, 12.5%). In addition, 120 patients had clinically significant macular edema (CSME), with a prevalence of 14.2%. Best-corrected visual acuity (BCVA) of 6/60 or worse occurred in 231 eyes (13.7%), and 41 patients (4.86%) had BCVA of 6/60 or worse bilaterally due to DR/CSME. A logistic regression model indicated that the major determinant of DR was the duration of diabetes, the odds rising by 1.27× with each year of disease (P < .0001).

CONCLUSION

The prevalence of DR, including CSME, was high. Although a national DR screening program is established in Bhutan, there is a need to accelerate health education, community screening, and referral systems to reduce the prevalence of DR and CSME.

Prediction of OCT images of short-term response to anti-VEGF treatment for diabetic macular edema using different generative adversarial networks

PURPOSE

This study sought to assess the predictive performance of optical coherence tomography (OCT) images for the response of diabetic macular edema (DME) patients to anti-vascular endothelial growth factor (VEGF) therapy generated from baseline images using generative adversarial networks (GANs).

METHODS

Patient information, including clinical and imaging data, was obtained from inpatients at the Ophthalmology Department of Qilu Hospital. 715 and 103 pairs of pre-and post-treatment OCT images of DME patients were included in the training and validation sets, respectively. The post-treatment OCT images were used to assess the validity of the generated images. Six different GAN models (CycleGAN, PairGAN, Pix2pixHD, RegGAN, SPADE, UNIT) were applied to predict the efficacy of anti-VEGF treatment by generating OCT images. Independent screening and evaluation experiments were conducted to validate the quality and comparability of images generated by different GAN models.

RESULTS

OCT images generated f GAN models exhibited high comparability to the real images, especially for edema absorption. RegGAN exhibited the highest prediction accuracy over the CycleGAN, PairGAN, Pix2pixHD, SPADE, and UNIT models. Further analyses were conducted based on the RegGAN. Most post-therapeutic OCT images (95/103) were difficult to differentiate from the real OCT images by retinal specialists. A mean absolute error of 26.74 ± 21.28 μm was observed for central macular thickness (CMT) between the synthetic and real OCT images.

CONCLUSION

Different generative adversarial networks have different prognostic efficacy for DME, and RegGAN yielded the best performance in our study. Different GAN models yielded good accuracy in predicting the OCT-based response to anti-VEGF treatment at one month. Overall, the application of GAN models can assist clinicians in prognosis prediction of patients with DME to design better treatment strategies and follow-up schedules.

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

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

Dosing Regimens of Intravitreal Aflibercept for Diabetic Macular Edema Beyond the First Year: VIOLET, a Prospective Randomized Trial

INTRODUCTION

The purpose was to compare two flexible regimens of intravitreal aflibercept (IVT-AFL) with fixed dosing every 8 weeks, beyond the first year of treatment, in patients with diabetic macular edema (DME). VIOLET was a 100-week, randomized, Phase IIIb, non-inferiority study in patients with center-involving DME previously treated with IVT-AFL for ≥ 1 year according to the European label.

METHODS

Patients received an initial dose of IVT-AFL at study baseline and were randomly assigned (1:1:1) to treat-and-extend (T&E), pro re nata (PRN), or fixed regimens. The primary endpoint was mean change in best-corrected visual acuity (BCVA) from baseline (randomization) to Week 52.

RESULTS

Full analysis set comprised 458 patients (baseline mean BCVA: 72.5, 71.0, and 72.7 letters in the T&E, PRN, and fixed-dose groups, respectively). Patients received a mean (min-max) of 10.0 (2-14; T&E), 11.5 (1-25; PRN), and 12.3 (3-13; fixed) injections over 100 weeks, with 13.3 (4-23), 25.0 (3-29), and 16.1 (5-25) clinic visits, respectively. At Week 52, mean (± standard deviation) BCVA changes from baseline were + 0.5 ± 6.7 (T&E), + 1.7 ± 6.8 (PRN), and + 0.4 ± 6.7 (fixed-dosing) letters (least squares mean difference [95% confidence interval]: T&E 0.01 [- 1.46, 1.47] and PRN 0.95 (- 0.52, 2.42) letters versus fixed dosing; p < 0.0001 for both non-inferiority tests [4-letter margin]). The IVT-AFL safety profile was consistent with previous studies.

CONCLUSION

The treatment burden associated with intravitreal injections for DME is lowest with T&E regimens, but there are a range of flexible IVT-AFL dosing regimens, allowing physicians to adopt an individualized treatment plan.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT02818998.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS AND RELEVANCE

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

Diabetic Macular Edema Management in Asian Population: Expert Panel Consensus Guidelines

PURPOSE

The aim of this consensus article was to provide comprehensive recommendations in the management of diabetic macular edema (DME) by reviewing recent clinical evidence.

DESIGN

A questionnaire containing 47 questions was developed which encompassed clinical scenarios such as treatment response to anti-vascular endothelial growth factor and steroid, treatment side effects, as well as cost and compliance/reimbursement in the management of DME using a Dephi questionnaire as guide.

METHODS

An expert panel of 12 retinal specialists from Singapore, Malaysia, Philippines, India and Vietnam responded to this questionnaire on two separate occasions. The first round responses were compiled, analyzed and discussed in a round table discussion where a consensus was sought through voting. Consensus was considered achieved, when 9 of the 12 panellists (75%) agreed on a recommendation.

RESULTS

The DME patients were initially profiled based on their response to treatment, and the terms target response, adequate response, nonresponse, and inadequate response were defined. The panellists arrived at a consensus on various aspects of DME treatment such as need for classification of patients before treatment, first-line treatment options, appropriate time to switch between treatment modalities, and steroid-related side effects based on which recommendations were derived, and a treatment algorithm was developed.

CONCLUSIONS

This consensus article provides comprehensive, evidence-based treatment guidelines in the management of DME in Asian population. In addition, it also provides recommendations on other aspects of DME management such as steroid treatment for stable glaucoma patients, management of intraocular pressure rise, and recommendations for cataract development.

Pattern of vitreo-retinal diseases at the national referral hospital in Bhutan: a retrospective, hospital-based study

BACKGROUND

Knowing the pattern and presentation of the diseases is critical for management strategies. To inform eye-care policy we quantified the pattern of vitreo-retinal (VR) diseases presenting at the national referral hospital in Bhutan.

METHODS

We reviewed all new patients over three years from the retinal clinic of the Jigme Dorji Wangchuck National Referral Hospital. Demographic data, presenting complaints and duration, treatment history, associated systemic diseases, diagnostic procedures performed, and final diagnoses were quantified. Comparisons of the expected and observed frequency of gender used Chi-squared tests. We applied a sampling with replacement based bootstrap analysis (10,000 cycles) to estimate the population means and the standard errors of the means and standard error of the 10th, 25th, 50th, 75th and 90th percentiles of the ages of the males and females within 20-year cohorts. We then applied t-tests employing the estimated means and standard errors. The 2913 subjects insured that the bootstrap estimates were statistically conservative.

RESULTS

The 2913 new cases were aged 47.2 ± 21.8 years. 1544 (53.0%) were males. Housewives (953, 32.7%) and farmers (648, 22.2%) were the commonest occupations. Poor vision (41.9%), screening for diabetic and hypertensive retinopathy (13.1%), referral (9.7%), sudden vision loss (9.3%), and trauma (8.0%) were the commonest presenting symptoms. Coexistent diabetes and hypertension were the most common associated systemic diseases. Haematological tests (blood sugar, HbA1c and lipid profile, 31.8%), OCT (27.4%), refraction (9.9%), B-scan (8.7%), fundus photography (8.0%) were the most commonly performed diagnostic tests. Hypertensive retinopathy (18.9%) was the commonest VR disease, followed by refractive errors referred for retinal evaluation (16.7%), diabetic retinopathy with macular oedema (15.8%), and AMD (11.0%). Retinal detachment was more prevalent in females (83 vs. 41, p = 0.007). Rare vision-threatening diseases like seasonal hyper-acute pan-uveitis also presented.

CONCLUSIONS

The developing VR service in Bhutan is challenged by the spectrum of diseases, limited human resources (e.g. one retinal surgeon during the study), and accessibility to tertiary eye-care services, all amidst difficult terrain. Sustained effort and robust coordination among the eye-care professionals, government and non-governmental organisations are critical for optimising VR services, especially as rates of diseases such as diabetes and hypertension grow.

Diabetic Macular Edema: State of Art and Intraocular Pharmacological Approaches

Diabetic macular edema (DME) is the main cause of vision loss in diabetic retinopathy (DR). Although it is one of the main complications of diabetes, the pathogenesis of DME is not completely understood. The hyperglycemic state promotes the activation of multiple interlinked pathways leading to DME. Different classifications have been proposed: based on clinical features, on pathogenesis or on diagnostic tests (optical coherence tomography - OCT and fluorescin angiography - FA). The multimodal imaging allows a better analysis of the morphological features of the DME. Indeed, new inflammatory biomarkers have been identified on OCT. Also, several studies are evaluating the role of the morphological features, identified on multimodal imaging, to find new prognostic factors. Over the past decade, great progresses have been made in the management of DME. Therapeutic alternatives include intraocular injection of anti-vascular endothelial grow factor agents (anti-VEGF) and steroid molecules, focal/grid laser photocoagulation and vitreo-retinal surgery. This review is focused on the description and analysis of the current intravitreal therapeutic pharmacological strategies. Current guidelines recommend anti-VEGF as first line therapy in DME. Corticosteroids are becoming increasingly relevant blocking the inflammatory cascade and indirectly reducing VEGF synthesis.

Association of Body Fluid Expansion With Optical Coherence Tomography Measurements in Diabetic Retinopathy and Diabetic Macular Edema

Purpose

To evaluate associations of body fluid status with optical coherence tomography measurements in patients with diabetic retinopathy (DR).

Methods

This prospective, cross-sectional study enrolled a total of 104 eyes from 104 patients with diabetes mellitus for fundus evaluations of DR and optical coherence tomography examinations. DR severity was graded via fundus photography. Systemic body fluid status was recorded via a body composition monitor with output values of total body water, extracellular water (ECW), intracellular water, and overhydration (OH). Relative overhydration (ROH) was defined as OH/ECW. Volume overload was defined as ROH ≥7%. Correlations of central subfield thickness (CST) with body fluid status were analyzed by partial correlation with adjustment for age, sex, and body mass index (BMI). Logistic regression analysis was used to evaluate factors associated with diabetic macular edema (DME).

Results

Higher levels of ECW, OH, and ROH were correlated with thick CST in patients with DR (P = 0.006, 0.021, and 0.008, respectively), but not in those without any DR (all P > 0.05), after adjusting for age, sex, and BMI. Patients with DME (n = 31) had higher OH than DR patients without DME (n = 28) or those without any DR (n = 45) (P = 0.002 and P < 0.001, respectively). Multiple regression model showed that volume overload was the independent factor for the presence of DME (odds ratio, 9.532; 95% confidence interval, 2.898-31.348; P < 0.001).

Conclusions

While both ECW and OH reflect CST in patients with DR, overhydration had particularly strong associations with DME. This study provides a novel insight into our current understanding regarding the pathogenesis for DME.

BMP9 (Bone Morphogenetic Protein-9)/Alk1 (Activin-Like Kinase Receptor Type I) Signaling Prevents Hyperglycemia-Induced Vascular Permeability

Objective- Diabetic macular edema is a major cause of visual impairment. It is caused by blood-retinal barrier breakdown that leads to vascular hyperpermeability. Current therapeutic approaches consist of retinal photocoagulation or targeting VEGF (vascular endothelial growth factor) to limit vascular leakage. However, long-term intravitreal use of anti-VEGFs is associated with potential safety issues, and the identification of alternative regulators of vascular permeability may provide safer therapeutic options. The vascular specific BMP (bone morphogenetic protein) receptor ALK1 (activin-like kinase receptor type I) and its circulating ligand BMP9 have been shown to be potent vascular quiescence factors, but their role in the context of microvascular permeability associated with hyperglycemia has not been evaluated. Approach and Results- We investigated Alk1 signaling in hyperglycemic endothelial cells and assessed whether BMP9/Alk1 signaling could modulate vascular permeability. We show that high glucose concentrations impair Alk1 signaling, both in cultured endothelial cells and in a streptozotocin model of mouse diabetes mellitus. We observed that Alk1 signaling participates in the maintenance of vascular barrier function, as Alk1 haploinsufficiency worsens the vascular leakage observed in diabetic mice. Conversely, sustained delivery of BMP9 by adenoviral vectors significantly decreased the loss of retinal barrier function in diabetic mice. Mechanistically, we demonstrate that Alk1 signaling prevents VEGF-induced phosphorylation of VE-cadherin and induces the expression of occludin, thus strengthening vascular barrier functions. Conclusions- From these data, we suggest that by preventing retinal vascular permeability, BMP9 could serve as a novel therapeutic agent for diabetic macular edema.

Fluocinolone acetonide 0.19 mg intravitreal implant improves foveal thickness and reduces treatment burden for up to 1 year in eyes with persistent diabetic macular edema

Objective: To assess the effectiveness, safety, and treatment burden in eyes with persistent diabetic macular edema (DME) for up to 1 year after administration of 0.19 mg fluocinolone acetonide (FAc) implant (Iluvien^®).

Methods: This retrospective study at one private practice in the US included 40 eyes from 33 patients treated with an FAc implant. Eyes had previously been treated with VEGF antagonists, dexamethasone, or focal laser. The primary outcome was change in central foveal thickness from baseline. Data were also collected on demographics, visual acuity, intraocular pressure (IOP), use of IOP-lowering drugs for elevated IOP, lens clarity, and treatment burden before and after the implant.

Results: Average duration of diabetes and DME at baseline was 19 and 5 years, respectively, and average glycated hemoglobin was 7.21%. Severity of diabetic retinopathy before the implant had a slight bimodal distribution: moderate nonproliferative diabetic retinopathy (35%) and proliferative diabetic retinopathy (40%). Improvements in central foveal thickness from baseline were evident at 3 months (mean change –74.2 µm, P<0.001) and sustained through 12 months (–55.3 µm; P=0.005) for most eyes. Mean visual acuity remained stable (66.2 letters at baseline versus 67.2 letters at 12 months, roughly equivalent to 20/50 vision; P=0.855). On average, eyes required one anti-VEGF injection every 1.9 months before and one every 6.6 months after the implant, while 60% of eyes did not require additional anti-VEGF injections. Small but significant increases in IOP at months 3, 6, and 9 were not sustained to month 12, and mean IOP was normal throughout follow-up.

Conclusion: In patients with DME previously treated with a steroid, and treated according to licensed indications in the US, an FAc implant not only reduces the burden of disease in the real-world setting, but also the burden of injections and office visits for patients.

Early adoption of the fluocinolone acetonide (FAc) intravitreal implant in patients with persistent or recurrent diabetic macular edema (DME)

Objective: To assess long-term outcomes for effectiveness, safety, and treatment burden after injection of 0.2 µg/day fluocinolone acetonide [FAc] intravitreal implant (ILUVIEN^®) in patients with persistent or recurrent diabetic macular edema (DME) and 6–18 months of follow-up.

Methods: Retrospective case series in 18 eyes (13 patients) treated with the FAc implant. Prior to the implant, eyes were treated with an anti-VEGF therapy, dexamethasone implant, or focal or panretinal photocoagulation. Effectiveness outcomes included changes in visual acuity and macular edema. Safety outcomes included intraocular pressure (IOP) changes, IOP drugs, and IOP-related surgeries/interventions. Treatment burden was assessed by comparing the number of DME treatments before and after FAc implantation.

Results: The FAc implant reduced macular volume in 16/18 (89%) eyes, with a statistically significant mean change of –1.33 mm³ (p=0.001). The average central retinal thickness reduction for all 18 eyes was statistically significant, decreasing from 444 µm at baseline to 359 µm after the FAc implant (p<0.001). In 90% of eyes, visual acuity was stable throughout the follow-up period, with increases or no worsening in Early Treatment Diabetic Retinopathy Study letter score. Although mean IOP was statistically higher after treatment, it was within the normal range at all timepoints, and most (83.3%) eyes remained in the IOP category 0–22 mmHg, and the number of IOP treatments required did not increase and no patients required IOP-lowering surgery. Treatment burden for DME was reduced after the implant was administered, with 56% of eyes not requiring any additional treatment. The average number of treatments was 1.3 in the 6 months after the FAc implant versus 4.6 in the 12 months preceding the implant.

Conclusion: The FAc implant is an appropriate option to incorporate earlier in the DME treatment process, leading to positive long-term outcomes with an acceptable safety profile, and a reduced treatment burden for patients, and reduced clinical staff time.

The efficacy and safety outcomes of the 0.19 mg fluocinolone acetonide implant after prior treatment with the 0.7 mg dexamethasone implant in patients with diabetic macular edema

Purpose

There are little or no published data comparing the outcomes of ILUVIEN^® (0.19 mg fluocinolone acetonide [FAc]) and OZURDEX^® (0.7 mg dexamethasone [DEX]) implants in patients with diabetic macular edema (DME), and this case sought to compare their outcomes.

Methods

This case was extracted from a monocentric audit involving a pool of 25 patients (33 eyes) with DME and treated with a single FAc implant between October 2013 and December 2016. This case, a 61-year-old male with a pseudophakic lens, is from a patient that had received 4 intravitreal injections of a DEX implant prior to FAc implant and then was monitored for 3 years until re-treatment with a second FAc implant. Parameters measured included visual acuity (VA), central retinal thickness (CRT), and intraocular pressure (IOP).

Results

After the DEX implants, CRT transiently improved. In March 2014, the decision was taken to administer an FAc implant, and this led to a reduction in CRT below 300 µm (from a baseline of 748 µm), and this was sustained for 30 months. VA remained above 65 Early Treatment Diabetic Retinopathy Study letters to month 36, after which time a second FAc implant (in April 2017) was administered due to recurrence of edema and CRT decreased to below 300 µm and VA improved to 70 letters. Side effects included elevated IOP, which was effectively managed with IOP-lowering drops.

Conclusion

A single injection of FAc implant led to sustained improvements in CRT and VA that lasted for between 30 and 36 months, which is in contrast to the DEX implant where re-treatment was generally required within 6–7 months. After 36 months, re-treatment with the FAc implant again led to improved VA and CRT, and responses that were similar to those achieved with the first FAc implant.

EFFECTS OF INTRAVITREAL RANIBIZUMAB AND BEVACIZUMAB ON THE RETINAL VESSEL SIZE IN DIABETIC MACULAR EDEMA

PURPOSE

The goal of this study was to assess the effects of a single injection of intravitreal ranibizumab (RAN) or bevacizumab (BEV) on the retinal vessel size in eyes with diabetic macular edema.

MATERIALS AND METHODS

In total, 32 patients were enrolled in the RAN group, and 30 patients were included in BEV group. Each of these groups was also subdivided into two others groups: a study group and a control group. The study groups were composed of the injected eyes, whereas the noninjected fellow eyes served as the control groups. The patients underwent complete ophthalmic examinations, including optical coherence tomography and fundus fluorescein angiography, and the primary outcome measures included the central retinal artery equivalent, central retinal vein equivalent, and artery-to-vein ratio.

RESULTS

In the RAN study group (n = 32), the preinjection mean central retinal artery equivalent (175.42 μm) decreased to 169.01 μm after 1 week, and to 167.47 μm after 1 month (P < 0.001), whereas the baseline central retinal vein equivalent (235.29 μm) decreased initially to 219.90 μm after 1 week, and to 218.36 μm after 1 month (P < 0.001). In the BEV study group (n = 30), the preinjection central retinal artery equivalent (150.21 μm) decreased to 146.25 μm after 1 week, and to 145.89 μm after 1 month (P < 0.001); whereas the baseline central retinal vein equivalent (211.87 μm) decreased initially to 204.59 μm after 1 week and was 205.24 μm after 1 month (P < 0.001). The preinjection artery-to-vein ratio values changed significantly (P = 0.001) after 1 week and after 1 month in the RAN group, but no significant alteration in the artery-to-vein ratio was observed in the BEV group (P = 0.433). In both the RAN (n = 32) and BEV (n = 30) control groups, none of the 3 parameters changed throughout the study period, when compared with the baseline.

CONCLUSION

The results of this study showed that both RAN and BEV injections significantly constricted the retinal blood vessel diameters.

Diabetic Macular Edema: Current Understanding, Pharmacologic Treatment Options, and Developing Therapies

Diabetic retinopathy and diabetic macular edema comprise a major source of visual disability throughout the developed world. The etiology and pathogenesis of macular edema is intricate and multifactorial, in which the hyperglycemic state in diabetes induces a microangiopathy. Through several inflammatory and vasogenic mediators, including vascular endothelial growth factor (VEGF) upregulation and inflammatory cytokines and chemokines, pathologic changes are induced in the vascular endothelium triggering breakdown of the blood retinal barrier, causing extravasation of fluid into the extracellular space and manifesting clinically as macular edema, resulting in visual loss. The advent of medications targeting the VEGF pathway has led to great clinical improvements compared with the previous standard of care of laser therapy alone, as shown in studies such as RISE, RIDE, VIVID, VISTA, and DRCR. However, analyses have shown that many patients have inadequate response or are nonresponders to anti-VEGF therapy, demonstrating the need for additional therapies to more comprehensively treat this disease. Although corticosteroid treatments and implants have demonstrated some efficacy in adjunctive and supplemental treatment, the need to more adequately treat macular edema remains. Our knowledge of diabetic macular edema continues to grow, leading to new currently available and emerging pharmacotherapies to further enhance our treatment and restore vision in those affected by diabetic macular edema. This review will discuss the pathogenesis of diabetic macular edema and the pharmacologic therapies available for its treatment, including anti-VEGF, steroids, and newer therapies still in development, such as angiopoietin antagonists, Tie2 agonists, kallikrein inhibitors, interleukin inhibitors, and others.

Dexamethasone implant with fixed or individualized regimen in the treatment of diabetic macular oedema: six-month outcomes of the UDBASA study

PURPOSE

To evaluate a pro re nata administration of Ozurdex^® implant versus a single administration for treating diabetic macular oedema (DME).

METHODS

This exploratory study is designed as a comparative, multicentre, randomized study with a follow-up of 6 months. Patients with DME were assigned to treatment at baseline either with a single Ozurdex^® implant during the entire six-month follow-up (fixed group) or Ozurdex^® implant followed by retreatment on an individualized basis (PRN group). Patients were scheduled for monthly evaluation based on assessment of best-corrected visual acuity (BCVA) and optical coherence tomography.

RESULTS

Twenty eyes were enrolled to the PRN group, and 22 were included in the fixed group. Following an equally steady, initial gain up to month 1, and maintenance up to month 3, vision started to decline in the fixed regimen group. At 6 months, a difference of 0.11 logMAR in BCVA was observed in favour of the PRN group. Compared to baseline, a significant reduction in retinal thickness was achieved up to month 2, when the fixed regimen group had begun to revert to pretreatment level. At 4 and 5 months, the difference in thickness between the two groups was statistically significant (p < 0.05). Mean number of treatments was 1.6 in the PRN group. Both fixed and PRN administration of Ozurdex showed a good safety profile.

CONCLUSION

A personalized treatment with monthly monitoring and retreatment as needed is effective in maintaining functional and anatomical benefits of Ozurdex^® .

Clinical Characteristics of Patients with Newly Diagnosed Diabetic Macular Edema in Turkey: A Real-Life Registry Study-TURK-DEM

Purpose. To evaluate the clinical and diagnostic characteristics of patients with newly diagnosed diabetic macular edema (DME) in Turkey in a real-life setting. Methods. A total of 945 consecutive patients (mean (SD) age: 61.3 (9.9) years, 55.2% male) with newly diagnosed DME were included. Data on patient demographics, comorbidities, ocular history, ophthalmic examination findings including type of DME, central macular thickness (CMT) via time domain (TD) and spectral domain (SD) optical coherence tomography (OCT), and planned treatments were recorded. Results. OCT (98.8%) and fundoscopy (92.9%) were the two most common diagnostic methods. Diffuse and focal DMEs were detected in 39.2% and 36.9% of cases, respectively. Laser photocoagulation (32.1%) and antivascular endothelial growth factors (anti-VEGF; 31.8%) were the most commonly planned treatments. The median CMT in the right eye was significantly greater in untreated than in treated patients [376.5 μm (range: 160–840) versus 342 μm (range: 146–999) (p = 0.002)] and in the left eye [370 μm (range: 201–780) versus 329 μm (range: 148–999) (p < 0.001)]. Conclusions. This study is the first large-scale real-life registry of DME patients in Turkey. SD-OCT and fundoscopy were the most common diagnostic methods. Laser photocoagulation and anti-VEGF therapy were the most common treatments.

Neurovascular cross talk in diabetic retinopathy: Pathophysiological roles and therapeutic implications

Diabetic retinopathy (DR) is the leading cause of blindness in the working-age population in developed countries, and its prevalence will increase as the global incidence of diabetes grows exponentially. DR begins with an early nonproliferative stage in which retinal blood vessels and neurons degenerate as a consequence of chronic hyperglycemia, resulting in vasoregression and persistent retinal ischemia, metabolic disequilibrium, and inflammation. This is conducive to overcompensatory pathological neovascularization associated with advanced proliferative DR. Although DR is considered a microvascular complication, the retinal microvasculature is intimately associated with and governed by neurons and glia; neurodegeneration, neuroinflammation, and dysregulation of neurovascular cross talk are responsible in part for vascular abnormalities in both early nonproliferative DR and advanced proliferative DR. Neuronal activity directly regulates microvascular dilation and blood flow in the process of neurovascular coupling. Retinal neurons also secrete guidance cues in response to injury, ischemia, or metabolic stress that may either promote or suppress vascular outgrowth, either alleviating or exacerbating DR, contingent on the stage of disease and retinal microenvironment. Neurodegeneration, impaired neurovascular coupling, and dysregulation of neuronal guidance cues are key events in the pathogenesis of DR, and correcting these events may prevent or delay development of advanced DR. The review discusses the mechanisms of neurovascular cross talk and its dysregulation in DR, and their potential therapeutic implications.

Contemporary retinal imaging techniques in diabetic retinopathy: a review

Over the last decade, there has been an expansion of imaging modalities available to clinicians to diagnose and monitor the treatment and progression of diabetic retinopathy. Recently, advances in image technologies related to OCT and OCT angiography have enabled improved visualization and understanding of this disease. In this review, we will describe the use of imaging techniques such as colour fundus photography, fundus autofluorescence, fluorescein angiography, infrared reflectance imaging, OCT, OCT-Angiography and techniques in adaptive optics and hyperspectral imaging in the diagnosis and management of diabetic retinopathy.

Aflibercept for the treatment of diabetic macular edema

Diabetic macular edema (DME) is an accumulation of fluid in the central retina, secondary to vascular-leakage from diabetic vascular damage. DME and other ophthalmic sequela of diabetes are the leading cause of blindness in 20 to 74-year-olds. The development of VEGF-inhibitors (anti-VEGF) has revolutionized DME treatment improving the clinician's ability to remove excess fluid from the macula, improving visual-acuity. Aflibercept is an anti-VEGF agent made of a recombinant fusion protein (consisting of VEGF receptors 1 and 2 extracellular domains) fused with the Fc-portion of human-IgG1, which binds both VEGF isoforms A and B, and placental growth factor. Phase III clinical trials and published scientific studies have demonstrated the efficacy of intravitreal aflibercept injection in the treatment of DME.