OCT Biomarkers as Functional Outcome Predictors in Diabetic Macular Edema Treated with Dexamethasone Implant

Use of a multifocal electroretinogram to evaluate the therapeutic effect of a single intravitreal dexamethasone implant, Ozurdex®, for refractory diabetic macular oedema

AIM

To evaluate the therapeutic effect of a single intravitreal dexamethasone implant (Ozurdex®) in eyes with refractory diabetic macular oedema (DME) anatomically via optical coherence tomography (OCT) and functionally via best corrected visual acuity (BCVA) and multifocal electroretinography (mfERG).

METHODS

This prospective interventional study included twenty eyes with refractory DME that were treated using six intravitreal injections of anti-vascular endothelial growth factor (VEGF). The central retinal thickness (CRT) was measured via OCT exceeding 300 μm. The eyes were treated with a single dexamethasone (DEX) implant four weeks after the last injection of anti-VEGF. The outcomes included changes in CRT, BCVA and p1 amplitude of ring 1 on mfERG and intraocular pressure (IOP) recorded before injection and two, four and six months after DEX injection.

RESULTS

The study included fifteen males (75%) and five females (25%). The mean age was 62.83 ± 6.34 years, with the mean duration of diabetes was 16.7 ± 2.21 years. During the two-month follow-up, there were statistically significant reductions in CRT and logMAR BCVA as well as an increase in p1 of ring 1 on mfERG (P = 0.046, P < 0.001 and P < 0.001, respectively). At four months, these changes were not statistically significant (P = 0.99, P < 0.56&P < 0.58), whereas at six months, all the parameters nearly reached pre-DEX injection values (p = 0.93 P = 0.99 P = 0.81). The IOP values were not significantly increased at two, four or six months (p < 0.06, P = 0.35 and P = 1.0, respectively). There were significant negative correlations between the mfERG and OCT parameters before and six months after DEX injection (p = 0.000).

CONCLUSION

A single intravitreal injection of DEX in refractory DME patients induced significant anatomical and functional improvements, but these improvements only lasted for short periods of up to four months. This treatment exhibited an excellent safety profile. However, at six months, the therapeutic effect was null. The utility of mfERG as a sensitive biomarker of treatment efficacy was highlighted herein.

Chronic intermittent hypoxia disrupts protective microgliosis in ischemic proliferative retinopathy

Sleep apnea that leads to chronic intermittent hypoxia (CIH) is an independent risk factor for advanced, debilitating ischemic proliferative retinopathies, such as diabetic retinopathy (DR) and retinopathy of prematurity (ROP). The underlying mechanisms are unknown. Here we investigated the consequences of CIH on the ischemic retina of the oxygen-induced retinopathy model. We show that experimental CIH inhibited colony stimulating factor 1 (CSF1) expression, blunting the reactive microgliosis during the ischemic phase of OIR. CIH severely delayed beneficial revascularization of the ischemic retina and increased pathological neovascularization. CIH also induced photoreceptor segment thinning and accentuated OIR-induced inner and outer retinal functional deficits. Mechanistically we demonstrated that local CSF1R inhibition during ischemic retinopathy reduced the number of microglial cells, inhibited revascularization, and exacerbated pathological neovascularization, recapitulating the effects of CIH. Our findings provide a novel mechanism by which sleep apnea and CIH aggravate ischemic retinopathies, underscoring the importance of treating apnea in DR and ROP to help prevent sight threatening severe disease.

Efficacy of Intravitreal Dexamethasone Implant (Ozurdex®) in Naïve and Refractory Patients with Different Morphological Subtypes of Diabetic Macular Edema

Background and Objectives: To investigate anatomical and functional outcomes in different morphological subtypes of diabetic macular edema (DME) treated with an intravitreal dexamethasone implant (Ozurdex) over 6 months follow-up. Materials and Methods: A retrospective, comparative study on patients with DME who received an intravitreal dexamethasone implant. Best-corrected visual acuity (BCVA), central subfoveal thickness (CST) and maximum CST on optical coherence tomography (OCT) were measured. The recruits were divided into three groups based on the morphological patterns of DME: serous retinal detachment (SRD), cystic macular edema (CME) and diffuse retinal thickening (DRT). The presence or absence of previous treatment were considered as being previously treated with anti-VEGF (PT) vs. naïve eyes (TN). All subjects received a single injection of the dexamethasone implant. The primary outcomes included changes in BCVA, CST and CSTMax at 2-, 4- and 6-months of follow-up. Results: CST was significantly reduced following one dexamethasone injection in the whole cohort from a total mean value of 513.3 μm to 368.2 μm at 2 months, 447.2 μm at 4 months and 471.5 μm at 6 months. The change in CST was significantly greater in SRD as opposed to the DRT and CME group at all time points. Overall, BCVA improved from 0.82 at baseline to 0.75 and 0.76 LogMAR at 2 and 4 months, respectively, whilst showing an overall deterioration to 0.84 at 6 months. The CME group showed the best BCVA at 6 months. Concerning treatment status (TN vs. PT), there was no significant difference in CST at 2 and 4 months, while CST was reduced at 6 months for the PT group (p = 0.023). Similarly, BCVA was significantly better in the PT group at 6 months (p = 0.017). Conclusions: The dexamethasone implant was effective in reducing DME and providing short-term BCVA improvement. The presence of SRD was associated with more favorable anatomical results, while CME was associated with better visual acuity. Dexamethasone provided superior results in previously treated patients.

Foveal hyper-reflective vertical lines detected by optical coherence tomography: Imaging features, literature review and differential diagnoses

PURPOSE

To describe foveal hyper-reflective vertical lines (FVL) as a specific morphological finding on structural spectral-domain optical coherence tomography (SD-OCT) and discuss its differential diagnosis.

METHODS

Observational case series. Ten patients (10 eyes) with FVL were meticulously examined at the Ophthalmology Department, Shaare Zedek Medical Center, Jerusalem, Israel. Detailed analysis of SD-OCT findings, clinical records, and retinal imaging was conducted to establish correlations between FVL and various underlying conditions.

RESULTS

We established the following list of settings, supported by the clinical context and ancillary investigations, in which SD-OCT displayed FVL: inflammation (1 eye), mechanical (1 eye), resorption of fluids of various origins (4 eyes), macular telangiectasia (1 eye), age-related macular degeneration (1 eye), diabetic retinopathy (1 eye) and scar (1 eye).

CONCLUSIONS

FVL can be observed in various underlying conditions. Recognition of this pattern and formulation of an appropriate differential diagnosis is of interest for correctly diagnosing and treating patients whose structural OCT harbors this yet overlooked finding.

Hispanic Ethnicity and OCT-based Biomarkers as Predictive Factors of DME Refractory to Bevacizumab

BACKGROUND AND OBJECTIVE

While anti-vascular endothelial growth factor (anti-VEGF) therapy has revolutionized treatment for diabetic macular edema, many patients still manifest refractory disease. This study evaluated rates of diabetic macular edema (DME) refractory to intravitreal bevacizumab in a diverse real-world setting, with the aim of studying demographic and optical coherence tomography (OCT)-based morphological factors associated with refractory disease.

PATIENTS AND METHODS

This was a retrospective cohort study of patients receiving treatment. Refractory DME was defined as a gain in visual acuity of < 5 letters after three consecutive injections of bevacizumab or less than 20% reduction in central retinal thickness (CRT) after three consecutive injections of bevacizumab. OCT images from preand post-injection visits were reviewed by two independent image readers. Multivariate logistic regression analysis evaluated for statistical significance between responders and those refractory to bevacizumab, and between Hispanic and non-Hispanic groups.

RESULTS

Ninety-nine patients were included. Of the participants, 42% were Hispanic, 10% were reported as white, 11% were Asian, 11% were Black, and 26% were defined as "not reported." Fifty-four (54.5%) patients were refractory to bevacizumab and 45 were responders. Between responders and refractory patients, race was statistically significant (P = 0.04) with more refractory subjects found to be Hispanic (28/54, 51.9%). OCT morphologic characteristics (CRT, number of hyperreflective foci, disorganization of inner retinal layers, ellipsoid zone discontinuity, and sub-retinal fluid) were not statistically significant between responders and refractory subjects. Multivariate logistic regression demonstrated an odds ratio of 5.7 for refractory disease for Hispanics (CI 1.687 to 19.445, P = 0.01). When comparing Hispanics to non-Hispanics, Hispanics had an average lower baseline visual acuity, lower CSTs, and higher HbA1C.

CONCLUSIONS

Our study showed that Hispanics have a nearly 6 times relatively higher likelihood of refractory disease. There is a notable under-representation of these patients in completed clinical trials for diabetic retinopathy and DME. [Ophthalmic Surg Lasers Imaging Retina 2025;56:XX-XX.].

Twelve-Month Outcomes and Optical Coherence Tomography (OCT) Biomarkers After Intravitreal Dexamethasone Implantation in Pseudophakic Eyes with Post-Vitrectomy Cystoid Macular Edema (CME)-Refractory to Medical Therapy

Background: In this study, we evaluated the incidence of cystoid macular edema (CME) after pars plana vitrectomy (PPV) for different retinal pathologies and assessed the role of optical coherence tomography (OCT) biomarkers in guiding treatment decisions in post-surgical CME patients who were refractory to medical therapy over a follow-up period of 12 months. Methods: Medical records of consecutive pseudophakic patients, who underwent PPV for different retinal pathologies, were retrospectively evaluated in this single-center, uncontrolled study. The incidence of post-PPV CME was assessed. Eyes with post-PPV CME in the first 2 months after surgery, with available clinical and OCT data for 12 months after surgery, were included in the evaluation. The mean best-corrected visual acuity (BCVA; logMAR), mean central macular thickness (CMT; μm) change, and response to different treatments [medical therapy and intravitreal dexamethasone (DEX) implant] were evaluated 1, 3, 6, 9, and 12 months after PPV. The impact of OCT biomarkers on the exposure to DEX implants was assessed. Adverse events, potentially related to the treatment, were investigated as well. Results: Of the 346 pseudophakic patients (352 eyes) who participated in this study, 54 (54 eyes) developed CME within the first 2 months after PPV (incidence of 15.3%). Among them, 48 patients were deemed eligible for the 12-month analysis. Preoperative mean BCVA (1.44 ± 0.99 logMAR) significantly improved to 0.32 ± 0.37 logMAR after 12 months (p < 0.001). The mean baseline CMT of 347 (±123.5) μm significantly decreased to 290 μm (±80.4; p = 0.003) by the end of the follow-up. Twenty-five eyes (52%) required one or more DEX implants for CME, due to being refractory to topical therapy. Significant correlations were found between the mean CMT values at various time points. Additionally, patients who required DEX implants at months 3 and 9 were more likely to present intraretinal fluid (IRF), disorganization of inner retinal layers (DRIL), disorganization of outer retinal layers (DROL), and hyper-reflective foci (HRF) at 1-month OCT. Five patients experienced a slight increase in intraocular pressure (IOP), which was successfully managed with topical medication. Conclusions: Topical therapy alone can be a valuable option for post-PPV CME in approximately 50% of patients. Significant visual recovery and macular thickness reduction at 12 months demonstrated that DEX implants can be a safe and effective second-line treatment for pseudophakic patients with post-PPV CME and who are refractory to medical therapy. Early post-surgical OCT biomarkers may indicate a more severe CME that might benefit from the steroid implant.

Worsening of early DME after cataract surgery. The DICAT II Study report #2

PURPOSE

To analyse the long anatomical and functional outcome of a subgroup of the DICAT II study cohort, consisting of 26 patients undergoing cataract surgery and withdrawn from the study for a clinically significant worsening of early diabetic macular edema (DME).

MATERIALS

Patients who underwent cataract surgery and withdrawn from the DICAT II study for a clinically significant worsening of early DME with at least 12 months follow-up after the dropout. The study population was divided into two groups according to the clinical evaluation at one-year follow-up: ongoing treatment patients for DME (Treatment group, TG) and patients no longer treated (Non Treatment group, NTG).

RESULTS

Central foveal thickness (CFT) at baseline and dropout time were higher in TG than in the NTG, with a statistically significant difference (p < 0.05). In addition, TG patients reported a higher levels of glycated hemoglobin at time baseline compared to NTG patients (7.81 ± 1.15 vs 7.02 ± 0.56; p = 0.048). The linear regression analysis demonstrated a statistically significant relationship between the visual acuity and the ongoing treatment group at one-year follow-up (p = 0.042).

CONCLUSION

The study provides parameters to be considered when assessing the risk of developing persistent DME after cataract surgery in diabetic patients. In particular, CFT at baseline and dropout time have been reported to be an effective and predictable OCT biomarkers when evaluating DME progression. During the evaluation of the systemic disease, similar results were found for the glycated hemoglobin at baseline.

Retinal OCT biomarkers associated with reading performance in patients with persistent vs. resolved diabetic macular edema

BACKGROUND

Recent advancements in imaging technologies, particularly structural optical coherence tomography (OCT), have improved the understanding of diabetic macular edema (DME) pathophysiology and provided valuable biomarkers for disease progression and visual outcomes. This prospective study aimed to investigate the association between specific retinal biomarkers identified through OCT imaging and reading performance metrics in patients with previously treated persistent versus resolved DME and good visual acuity.

METHODS

Forty-nine eyes from 35 patients with a history of DME were enrolled. Reading performance was assessed using the Radner reading charts, which include standardized sentences with geometrically progressing print sizes. Structural alterations in the inner and outer retina, as well as the retinal pigment epithelium (RPE), were graded based on OCT images.

RESULTS

Reading performance, measured as maximum reading speed, was associated with specific retinal biomarkers. The disruption of the ellipsoid zone (EZ) in the parafoveal region and the presence of disorganization of the inner retinal layers (DRIL) in the parafovea were correlated with reduced reading speed. These associations were independent of the presence of intraretinal or subretinal fluid.

CONCLUSIONS

Understanding the relationship between retinal biomarkers and reading performance could contribute to a comprehensive evaluation of visual function and quality of life in patients with DME, leading to better management strategies and treatment outcomes.

Ultrastructural imaging biomarkers in diabetic macular edema: A major review

Diabetic macular edema (DME) is a vision-threatening complication of diabetic retinopathy and causes significant morbidity in patients. Anti-vascular endothelial growth factor (VEGF) agents are the mainstay of treatment for DME, with steroid implants being used for the treatment of anti-VEGF resistant eyes. Over the years, several classification systems have been devised to describe the patterns of DME using optical coherence tomography (OCT). With the advent of effective treatments, it has become imperative that imaging cues are not merely used for classifying the disease but also as biomarkers for prognostication of disease activity and treatment response. In this aspect, newer imaging findings such as hyperreflective dots, photoreceptor integrity, and disorganization of retinal inner layers have been characterized in detail by several authors. Macular perfusion analysis using OCT angiography is the latest in the armamentarium for imaging DME. In this narrative review, we have summarized all relevant literature related to the ultrastructural imaging-based biomarkers of DME and their correlation to treatment.

[MiHUBx: a digital progress hub for the use of intersectoral clinical data sets using the example of diabetic macular edema]

BACKGROUND

Evidence-based treatment recommendations are helpful in the corresponding discipline-specific treatment but can hardly take data from real-world care into account. In order to make better use of this in everyday clinical practice, including with respect to predictive statements about disease development or treatment success, models with data from treatment must be developed in order to use them for the development of assistive artificial intelligence.

GOAL

The aim of the Use Case 1 of the medical informatics hub in Saxony (MiHUBx) is the development of a model based on treatment and research data for a treatment algorithm supported by biomarkers and also the development of the necessary digital infrastructure.

MATERIAL AND METHODS

Step by step, the necessary partners in hospitals and practices will be brought together technically or through research questions within Use Case 1 "Ophthalmology meets Diabetology", a regional digital progress hub in health, the medical informatics hub in Saxony (MiHUBx ) of the nationwide medical informatics initiative (MII).

RESULTS

Based on joint studies with diabetologists, robust serological and imaging biomarkers were selected that provide evidence of the development of diabetic macular edema (DME). In the future, these and other scientifically proven prognostic markers will be incorporated into a treatment algorithm that is supported by artificial intelligence (AI). For this purpose, model procedures are being developed together with medical informatics specialists. At the same time, a data integration center (DIZ) was established.

CONCLUSION

In addition to the structured and technical combination of the previously disseminated and partially heterogeneous treatment data, the Use Case 1 defines the chances and hurdles for using such real-world data to develop artificial intelligence.

The effect of diabetes on short-term outcomes following epiretinal membrane surgery

PURPOSE

This study aimed to examine the association of diabetes with anatomical and functional outcomes of epiretinal membrane surgery.

METHODS

Consecutive patients who underwent epiretinal membrane surgery between 2017-2021 at Helsinki University Hospital, Finland. Here we examined the association of diabetes, glycemic control, and requirement for insulin medication with surgical outcomes at 1-month.

RESULTS

Included were 214 eyes of 214 patients, with a mean age of 71.2 ± 8.2 years. Among patients with diabetes (n = 45), neither significant differences were observed in anatomical outcomes (- 47.8 ± 72.7 μm vs. - 38.3 ± 103 μm for foveal thickness, p = 0.566 and - 41.6 ± 61.8 μm vs. - 41.7 ± 85.7 μm for central subfield macular thickness, p = 0.996) nor in best-corrected visual acuity (BCVA) gain (0.06 ± 0.22 vs 0.12 ± 0.30 LogMAR units, p = 0.214) compared to those without diabetes. In a multivariate analysis adjusted for age, gender, the existence of preoperative macular cysts, and topical nonsteroidal anti-inflammatory drugs (NSAIDs) use, the results remained consistent. The last preoperative HbA1c levels did not correlate with changes in foveal (Pearson's r = 0.218, p = 0.264) or central subfield macular thickness (r = 0.365, p = 0.056), or with BCVA gain (r = -0.177, p = 0.386). Insulin therapy for diabetes did not associate with the outcomes (p > 0.05 for anatomical and functional comparisons).

CONCLUSIONS

In a cohort of patients who underwent epiretinal membrane surgery, neither the presence of diabetes, nor glycemic control and the use of insulin medication associated with the outcomes.

The Effects of Anti-Vascular Endothelial Growth Factor Loading Injections on Retinal Microvasculature in Diabetic Macular Edema

Purpose

To evaluate changes in the retinal microvasculature using widefield swept-source optical coherence tomography angiography (SS-OCTA) following three anti-vascular endothelial growth factor (anti-VEGF) loading injections for diabetic macular edema (DME).

Methods

Thirty-four treatment-naïve patients with DME received an initial three loading injections, followed by injections on an as-needed basis. Macular ischemia was evaluated based on the foveal avascular zone (FAZ) area, perfusion density, and vessel density on a 3 × 3-mm SS-OCTA image. Midperipheral ischemia was analyzed by dividing a 12 × 12-mm image into 16 boxes to compare changes in the nonperfusion area (NPA). Participants were categorized as aggravated, stable, or improved based on changes in the NPA after three injections.

Results

Of the 34 included patients, eight (23.5%) demonstrated aggravation of the NPA, 23 (67.6%) remained stable, and three (8.8%) exhibited improvement. Although FAZ area, perfusion, and vessel density increased, the differences were not significant compared to baseline. The number of injections and glycated hemoglobin (HbA1c) levels in the NPA aggravation group were significantly higher than in the stable and improvement groups. Logistic regression analysis revealed that NPA aggravation was independently associated with the number of anti-VEGF injections.

Conclusions

Changes in NPA following anti-VEGF loading injections varied among patients with DME and were significantly associated with HbA1c levels and injection frequency. Worsening mid-peripheral NPA after the anti-VEGF injections independently risked DME recurrence.

Translational Relevance

We revealed that worsening mid-peripheral retinal ischemia after anti-VEGF loading injections contributes to the recurrence of DME.

Multi-Omics Integration With Machine Learning Identified Early Diabetic Retinopathy, Diabetic Macula Edema and Anti-VEGF Treatment Response

Purpose

Identify optimal metabolic features and pathways across diabetic retinopathy (DR) stages, develop risk models to differentiate diabetic macular edema (DME), and predict anti-vascular endothelial growth factor (anti-VEGF) therapy response.

Methods

We analyzed 108 aqueous humor samples from 78 type 2 diabetes mellitus patients and 30 healthy controls. Ultra-high-performance liquid chromatography-high-resolution-mass-spectrometry detected lipidomics and metabolomics profiles. DME patients received ≥3 anti-VEGF treatments, categorized into strong and weak response groups. Machine learning (ML) screened prospective metabolic features, developing prediction models.

Results

Key metabolic features identified in the metabolomics and lipidomics datasets included n-acetyl isoleucine (odds ratio [OR] = 1.635), cis-aconitic acid (OR = 3.296), and ophthalmic acid (OR = 0.836) for DR. For early-DR, n-acetyl isoleucine (OR = 1.791) and decaethylene glycol (PEG-10) (OR = 0.170) were identified as key markers. L-kynurenine (OR = 0.875), niacinamide (OR = 0.843), and linoleoyl ethanolamine (OR = 0.941) were identified as significant indicators for DME. Trigonelline (OR = 1.441) and 4-methylcatechol-2-sulfate (OR = 1.121) emerged as predictors for strong response to anti-VEGF. Predictive models achieved R² values of 99.9%, 97.7%, 93.9%, and 98.4% for DR, early-DR, DME, and strong response groups in the calibration set, respectively, and validated well with R² values of 96.3%, 96.8%, 79.9%, and 96.3%.

Conclusions

This research used ML to identify differential metabolic features from metabolomics and lipidomics datasets in DR patients. It implies that metabolic indicators can effectively predict early disease progression and potential weak responders to anti-VEGF therapy in DME eyes.

Translational Relevance

The identified metabolic indicators may aid in predicting the early progression of DR and optimizing therapeutic strategies for DME.

Study of Imaging Biomarkers as a Prognostic Factor and Guide in the Management of Diabetic Macular Oedema

Background: Diabetic macular oedema (DME) is a major cause of vision impairment in individuals with diabetes mellitus, characterised by fluid accumulation in the macula due to increased vascular permeability. The growing prevalence of diabetes worldwide has led to an increasing burden of DME on healthcare systems. While current treatment options such as anti-vascular endothelial growth factor (anti-VEGF) injections, corticosteroids, and laser therapy exist, the variability in patient responses highlights the need for reliable prognostic tools. Imaging biomarkers, particularly those identified using optical coherence tomography (OCT) and fluorescein angiography (FA), play a critical role in diagnosing and managing DME. This study evaluates the prognostic significance of these biomarkers in predicting disease progression and treatment outcomes. Materials and methods: This prospective observational study was conducted at Gandhi Medical College and Hamidia Hospital, Bhopal, Madhya Pradesh, from August 2022 to June 2024. A total of 123 patients with Type II diabetes mellitus diagnosed with DME were included through consecutive sampling. Comprehensive assessments, including visual acuity, slit-lamp examination, fundus evaluation, FA, and OCT, were performed. Key imaging biomarkers, such as central subfield thickness (CST), disorganisation of retinal inner layers (DRIL), intraretinal cysts, hyperreflective foci, and vitreomacular interface (VMI) abnormalities, were evaluated. Correlations between biomarkers, best-corrected visual acuity (BCVA), metabolic markers (HbA1c, serum cholesterol), and disease severity were analysed using statistical tools, including the chi-square test and Pearson's correlation. Results: The most common biomarkers observed were DRIL with external limiting membrane (ELM) disruption (38, 31%), intraretinal cysts with ELM disruption (36, 29.3%), and hyperreflective foci (28, 22.8%). VMI abnormalities were noted in 14 (11.4%) cases, while subretinal fluid with serous retinal detachment was present in seven patients (5.7%). Significant negative correlations were found between BCVA (LogMAR) and biomarkers, with intraretinal cysts (-0.526, p=0.003) and VMI abnormalities (-0.492, P=0.002) having the strongest associations. Higher glycosylated haemoglobin (HbA1c) levels were significantly associated with intraretinal cysts (P=0.014) and VMI abnormalities (P=0.042), while higher cholesterol levels correlated with hyperreflective foci (P=0.011) and subretinal fluid (P=0.014). Patients with proliferative diabetic retinopathy (PDR) exhibited worse visual outcomes and greater CST compared to those with non-proliferative diabetic retinopathy (NPDR). Conclusion: Imaging biomarkers, particularly DRIL, intraretinal cysts, and VMI abnormalities, significantly correlate with visual acuity and metabolic control in DME patients. These findings underscore the importance of OCT in the prognostic assessment of DME and highlight the need for personalised treatment approaches based on biomarker profiles. Future studies should focus on long-term follow-up and explore the potential for integrating these biomarkers into clinical decision-making to improve patient outcomes.

MACULAR THICKNESS FLUCTUATIONS AND VISUAL ACUITY OUTCOMES AFTER INTRAVITREAL DEXAMETHASONE IMPLANT FOR DIABETIC MACULAR EDEMA

PURPOSE

To assess macular thickness fluctuations and their association with visual acuity outcomes in eyes with diabetic macular edema treated with an intravitreal dexamethasone (DEX) implant.

METHODS

The SD of all postbaseline central subfield thicknesses (CST) recorded over a 12-month period after the first injection of the DEX implant was used to quantify CST fluctuations. Linear regression models were used to identify factors associated with the visual acuity at 12 months (measured with the Early Treatment of Diabetic Retinopathy Study score) and predictors of CST SD.

RESULTS

A retrospective review of 80 eyes of 80 patients treated with the DEX implant for diabetic macular edema revealed a CST SD of 75.3 ± 50.3 µ m. The CST SD was negatively associated with the visual acuity at 12 months (-7.7 Early Treatment of Diabetic Retinopathy Study letters for each 100- µ m increase in CST SD, P = 0.01), while changes in CST from baseline did not show any significant association. Eyes were stratified into quartiles based on the CST SD, and a difference by -14.2 letters in visual acuity at 12 months was observed between the first and fourth quartiles ( P <0.001). Significant predictors of CST SD included the baseline visual acuity (-12.0 µ m for each 10-letter increase, P = 0.02) and the number of DEX injections received (n = 17.1, P = 0.03).

CONCLUSION

Greater fluctuations in retinal thickness were found to be associated with poorer visual outcomes in eyes with diabetic macular edema treated with the DEX implant. Analyzing the CST SD could be a more predictive indicator of visual prognosis than individual measurements of the CST.

Clinical and optical coherence tomography biomarkers as prognostic factors in dexamethasone intravitreal implant for diabetic macular edema

PURPOSE

Aim of the study was to evaluate the efficacy of dexamethasone (DEX) 0.7 mg intravitreal implant in patients with diabetic macular edema (DME) and serous retinal detachment (SRD), and to study the prognostic factors on a follow up of 12 months.

METHODS

Forty eyes of twenty- six patients with centre involving DME and SRD, who underwent DEX implant, were enrolled. Best-corrected visual acuity (BCVA), Swept source OCT imaging and intraocular pressure were evaluated. Central macular thickness (CMT), vitreomacular adhesion (VMA), disorganization of retinal inner layers (DRILs), hyperreflective dots (HRD), SRD and ellipsoid zone (EZ) disruption were included in the analysis at baseline and 12 months after implant.

RESULTS

According to our parametric analysis, at 12 months, BVCA improvement from 48.6 ± 23.4 letters to 53.3 ± 24.5 letters was statistically significant (p = 0.04), CMT decreased from 460 ± 99.52 μm to 322.9 ± 117 μm. The presence at baseline of VMA (p = 0.01), EZ disruption (p = 0.03) and DRILs (p = 0.04), were associated with poor BCVA improvement at the end of follow-up.

CONCLUSION

In conclusion, OCT biomarkers can be considered significant prognostic factors for treatment outcome in patients with DME undergoing DEX intravitreal implant.

Intravitreal Dexamethasone Implants for Macular Edema Secondary to Acute Retinal Necrosis

PURPOSE

To assess the effectiveness and risk of intravitreal injection of dexamethasone implants in treating macular edema (ME) secondary to acute retinal necrosis (ARN).

METHODS

In this retrospective, noncomparative case series study, five patients who developed secondary ME after ARN and received an intravitreal dexamethasone implant injection were enrolled. The features of secondary ME on OCT and the outcomes of dexamethasone intravitreal implanting were presented.

RESULTS

The mean age of the patients was 59 years (range, 51-61 years). All patients had unilateral involvement, and all 5 eyes showed mild to moderate anterior uveitis, retinal necrosis, and vasculitis. Herpes zoster virus was detected in all eyes using PCR, and timely antiviral and anti-inflammatory treatment was performed. Aqueous humor samples were negative for herpes zoster virus DNA, and resolution of viral retinitis was noted upon the occurrence of ME. Additionally, three eyes received pars plana vitrectomy with silicone oil prior to ME development. All eyes presented with intraretinal fluid, hyper-reflective foci, and impairments of the external limiting membrane/ellipsoid zone at varying degrees on OCT images. Epiretinal membrane was exhibited in 80% of eyes, but no vitreoretinal traction was detected. Subretinal fluid was visible in 60% of eyes. ME was relieved effectively in all eyes after intravitreal dexamethasone implanting. One of these patients experienced three episodes of ME. No recurrence of retinal necrosis or corticosteroid-associated ocular hypertension was observed during the follow-up period.

CONCLUSION

Intravitreal injection of dexamethasone implants can effectively alleviate ME secondary to ARN and improve visual acuity with no adverse reactions.

Integrated Assessment of OCT, Multimodal Imaging, and Cytokine Markers for Predicting Treatment Responses in Retinal Vein Occlusion Associated Macular Edema: A Comparative Review of Anti-VEGF and Steroid Therapies

Retinal vein occlusion (RVO) is a significant cause of vision loss, characterized by the occlusion of retinal veins, leading to conditions such as central retinal vein occlusion (CRVO) and branch retinal vein occlusion (BRVO). Macular edema (ME), a prevalent consequence of RVO, is the primary cause of vision impairment in affected patients. Anti-VEGF agents have become the standard treatment, showing efficacy in improving visual acuity (VA) and reducing ME. However, a subset of patients exhibit a suboptimal response to anti-VEGF therapy, necessitating alternative treatments. Corticosteroids, which address inflammatory pathways implicated in ME, have shown promise, particularly in cases resistant to anti-VEGF. This review aims to identify biomarkers that predict treatment response to corticosteroids in RVO-associated ME, utilizing multimodal imaging and cytokine assessments. Baseline imaging, including SD-OCT and OCT-A, is essential for evaluating biomarkers like hyperreflective foci (HRF), serous retinal detachment (SRF), and central retinal thickness (CRT). Elevated cytokine levels, such as IL-6 and MCP-1, correlate with ME severity and poor anti-VEGF response. Early identification of these biomarkers can guide timely transitions to corticosteroid therapy, potentially enhancing treatment outcomes. The practical conclusion of this review is that integrating biomarker assessment into clinical practice enables personalized treatment decisions, allowing for earlier and more effective management of RVO-associated ME by transitioning patients to corticosteroid therapy when anti-VEGF agents are insufficient. Advanced diagnostics and machine learning may further refine personalized treatment strategies, improving the management of RVO-associated ME.

ESASO classification relevance in the diagnosis and evolution in diabetic macular edema patients after dexamethasone implant treatment

PURPOSE

To assess the clinical relevance of The European School for Advanced Studies in Ophthalmology (ESASO) classification in patients with diabetic macular edema (DME) after their first dexamethasone implant (DEXI) treatment.

METHODS

Retrospective real-world study conducted on consecutive DME patients who underwent DEXI treatment and were controlled at month-2. Subjects were initially classified according to the ESASO classification stages. The outcomes were anatomical biomarkers with spectral-domain optical coherence tomography (SD-OCT) and best-corrected visual acuity (BCVA).

RESULTS

A total of 128 patients were classified according to ESASO classification stages as early (7; 5.5%), advanced (100; 78.1%), and severe (21; 16.4%). At baseline, there were significant differences between stages in BCVA, central macular thickness (CMT), and tomography anatomical biomarkers (p < 0.05). Initial BCVA (logMAR) was 0.33 ± 0.10, 0.58 ± 0.34, and 0.71 ± 0.35 in the early, advanced, and severe stages, respectively (p < 0.05). At month-2, BCVA was 0.17 ± 0.15, 0.46 ± 0.29, and 0.69 ± 0.27 in those classified as early, advanced, and severe stages, respectively. At month-2, DME was resolved or improved in 6 (85.7%), 60 (60%), and 12 (60%) patients classified as early, advanced, and severe stages, respectively.

CONCLUSIONS

There was a good correlation between BCVA and ESASO classification stages. Patients in the severe stage did not achieve visual acuity improvement over the study period.

[Anatomical and functional outcomes of the "3+PRN" therapeutic protocol in the treatment of diabetic macular edema]

PURPOSE

To evaluate the anatomical and functional results of the "3+PRN" protocol in the treatment of diabetic macular edema (DME), determine the predictive factors for good final visual acuity, and compare it to other protocols.

MATERIALS AND METHODS

We conducted a retrospective, descriptive, comparative, cross-sectional study of patients with DME, which we dubbed HTSM. All patients were treated with three monthly initial intravitreal injections (IVT) of 1.25mg bevacizumab and followed according to the pro re nata (PRN) protocol for a period of 3years. The protocol was based on a monthly monitoring schedule for the first 3months, then increasingly spaced out over time. "On-demand" treatment was indicated with resumption of bevacizumab IVT in the event of worsening of DME.

RESULTS

A total of 52 patients were included. The mean age was 65years. Type 2 was the most frequently observed type of diabetes. The mean duration of the PRN protocol was 6months, and the mean number of injections was 6. The mean visual acuity (VA), initially 1/10, improved to 3/10 by the conclusion of the 3+PRN protocol, with an improvement of more than 5 letters in 77.6% of cases. The mean initial central macular thickness (CMT) was 451.5μm. The final mean EMC decreased to 298.5μm, which corresponds to a reduction of 153μm compared to the initial value. The mean subfoveal choroidal thickness, initially 304.2μm, decreased to a mean of 284.5μm at completion. Comparative analysis of the results before and after the PRN protocol confirmed the existence of a statistically significant correlation between VA and CMT (P<0.05). No correlation was observed between age and visual acuity or between initial and final VA. The analysis of the various tomographic parameters and VA revealed a significantly better visual improvement in the group in whom the external limiting membrane (MLE) and ellipsoid zone (ZE) were intact (P=0.04), as well as in the group in whom serous retinal detachment (SRD) was absent (P<0.001). Posterior vitreous detachment (PVD) was the most frequently observed vitreomacular anomaly. The final VA was similar in the groups with and without PVD (P=0.04).

CONCLUSION

The 3+PRN protocol is effective both functionally and tomographically in the treatment of DME. Various tomographic parameters might influence therapeutic efficacy. However, further in-depth studies are needed to better investigate these parameters.

Use of a dexamethasone implant to treat macular edema following pars plana vitrectomy and removal of the primary epiretinal membrane

PURPOSE

The purpose of this study was to evaluate the effectiveness and safety of an intravitreal dexamethasone (DEX) implant for the treatment of macular edema (ME) following pars plana vitrectomy (PPV) and removal of the primary epiretinal membrane (ERM) and to assess the impact of the integrity of the ellipsoid zone (EZ) and disorganization of the retinal inner layer (DRIL) grade on visual and anatomical outcomes.

METHODS

Forty-two pseudophakic patients who developed ME following PPV and removal of the primary stage 2-3 ERM were included. Patients were divided into two groups when ME was diagnosed via spectral domain optic coherence tomography (SD-OCT). In the DEX group (n = 22), DEX was implanted for the treatment of ME. In the control group (n = 20), only observation was conducted, without any treatment. The best-corrected visual acuity (BCVA) and macular thickness (MT) of the two groups were compared at baseline and 1, 6, and 12 months after DEX implantation. The effects of OCT parameters such as EZ integrity and DRIL grade were also evaluated in terms of decreases in MT and increases in VA in the treatment of ME with DEX implantation. Intraocular pressure (IOP), number of DEX implantations and adverse effects were also recorded.

RESULTS

While a statistically significant increase in the mean BCVA was observed in the DEX group (p < 0.001 at months 1, 6, and 12, respectively), no such increase was detected in the control group (p = 0.169, p = 0.065, and p = 0.058 at months 1, 6 and 12, respectively) compared with the baseline. A statistically significant decrease in the mean MT was observed in the DEX group (p  < 0.001 at months 1, 6, and 12); however, no significant difference was observed in the control group (p  = 0.081, p  = 0.065, and p  = 0.054 at months 1, 6 and 12, respectively) compared with the baseline. Significant differences were found between the two groups in terms of the increase in BCVA (p  < 0.01) and decrease in MT (p  < 0.01) at all visits, with the outcomes being more favorable in the DEX group. A statistically significant relationship was found between the increase in VA and EZ integrity and DRIL grade in both groups. Ten patients (45.4%) received two injections of DEX during the follow-up. An increase in IOP was observed in five patients (22.7%) who were treated with topical antiglaucomatous drops. No significant side effects were observed.

CONCLUSION

DEX implantation was found to be effective and safe for the treatment of ME following PPV and primary ERM removal, although some eyes may require repeated injections to achieve visual and anatomical success. Additionally, a relationship was found between EZ integrity, DRIL grade and visual-anatomical outcomes.

Oct biomarkers for early prognosis in diabetic macular edema treatment with ranibizumab

BACKGROUND

Diabetic macular edema is the main cause of vision loss in patients with diabetic retinopathy. In this work, we aimed to assess the role of Optical Coherence Tomography (OCT) biomarkers in patients treated with ranibizumab.

METHODS

A prospective study enrolling 46 eyes with DME under ranibizumab intravitreal therapy with 12 months of follow-up. The primary endpoint was to assess the association between OCT biomarkers at baseline and the type of treatment response.

RESULTS

Good responders, compared with partial/non responders, had lower number of inner nuclear layer cysts (INLc) at baseline, (26.5% vs 73.5%, p = 0.035) and presented, at 12 months of follow-up, lower percentage of disorganization of retinal inner layers (12.0% vs 88.0%, p = 0.001), lower disruption of outer plexiform layer (8.7% vs 91.3%, p < 0.001) and lower outer nuclear layer cysts (17.4% vs 82.6%, p = 0.013). At the end of follow-up, it was observed a higher frequency of inner nuclear layer cysts in patients with higher glycated haemoglobin (p = 0.028).

CONCLUSION

This study showed the value and importance of OCT parameters, such as absence of INLc, as a prognostic therapeutic response. A normalization of the macular anatomy with ranibizumab is more likely to happen in early complete responders. The association between INLc and higher glycated haemoglobin levels showed the importance of systemic metabolic control in systemic diabetic manifestations. Clinicaltrials.gov NCT04387604.

Exploration on OCT biomarker candidate related to macular edema caused by diabetic retinopathy and retinal vein occlusion in SD-OCT images

To improve the understanding of potential pathological mechanisms of macular edema (ME), we try to discover biomarker candidates related to ME caused by diabetic retinopathy (DR) and retinal vein occlusion (RVO) in spectral-domain optical coherence tomography images by means of deep learning (DL). 32 eyes of 26 subjects with non-proliferative DR (NPDR), 77 eyes of 61 subjects with proliferative DR (PDR), 120 eyes of 116 subjects with branch RVO (BRVO), and 17 eyes of 15 subjects with central RVO (CRVO) were collected. A DL model was implemented to guide biomarker candidate discovery. The disorganization of the retinal outer layers (DROL), i.e., the gray value of the retinal tissues between the external limiting membrane (ELM) and retinal pigment epithelium (RPE), the disrupted and obscured rate of the ELM, ellipsoid zone (EZ), and RPE, was measured. In addition, the occurrence, number, volume, and projected area of hyperreflective foci (HRF) were recorded. ELM, EZ, and RPE are more likely to be obscured in RVO group and HRFs are observed more frequently in DR group (all P ≤ 0.001). In conclusion, the features of DROL and HRF can be possible biomarkers related to ME caused by DR and RVO in OCT modality.

Comparative efficacy of anti-vascular endothelial growth factor on diabetic macular edema diagnosed with different patterns of optical coherence tomography: A network meta-analysis

Intravitreal anti-vascular endothelial growth factor (anti-VEGF) injections have emerged as the most common therapeutic approach for the management of diabetic macular edema (DME). Despite their proven superiority over other interventions, there is a paucity of data regarding the relative effectiveness of anti-VEGF agents in treating DME diagnosed with different patterns of optical coherence tomography (OCT). In this regard, we conducted a systematic review and comparative analysis of the therapeutic efficacy of intravitreal bevacizumab, ranibizumab, aflibercept, and conbercept in the management of DME with diffuse retinal thickening (DRT), cystoid macular edema (CME), and serous retinal detachment (SRD) patterns identified using OCT. Our study encompassed a comprehensive search of PubMed, Embase, Web of Science, China National Knowledge Infrastructure (CNKI), and Wan Fang Data from their inception until January 25, 2023. The network meta-analysis involved the inclusion of 1606 patients from 20 retrospective studies with a moderate risk of bias but no evidence of publication bias. The DRT group had the highest increase in best-corrected visual acuity (BCVA) with anti-VEGF, while the SRD group had the greatest reduction in Central Macular Thickness (CMT). Furthermore, conbercept, ranibizumab, and bevacizumab, respectively, showed the best treatment outcomes for patients with DRT, CME, and SRD in terms of improvement in BCVA. And, conbercept exhibited the highest reduction in CMT in the DRT, CME, and SRD groups. In conclusion, our study highlights the efficacy of anti-VEGF agents in the management of DME and provides valuable insights into the selection of anti-VEGF agents tailored to the individual needs of patients.

Selective ILM Staining and Safety of Two Vital Dyes During a Human-Like Pars Plana Vitrectomy Ex Vivo in Porcine Eyes

PURPOSE

An ideal dye for intraocular use should effectively stain the target tissue while being easy to apply and remove. Additionally, it should not have any adverse effects resulting from prolonged contact with the retinal tissue. Recently, concerns have been raised about the safety of some vital dyes during surgical procedures as they may cross the internal limiting membrane and deposit on the retina. In this study, we aimed to investigate whether commercially available vital dyes, VIEW-ILM® and TWIN® (AL.CHI.MI.A. S.r.l., Ponte San Nicolò, Padova, Italy), have the potential to cross the internal limiting membrane during vitreoretinal surgery and deposit on the retina. Furthermore, we evaluated their safety in vitro and in vivo.

METHODS

A human-like pars plana vitrectomy was performed on porcine eyes ex vivo, with VIEW-ILM® or TWIN® used to stain the internal limiting membrane either with or without subsequent internal limiting membrane peeling. The two dyes were then extracted from retinal punches with or without internal limiting membrane, and quantified using high performance liquid chromatography. Safety was evaluated through in vitro cytotoxicity tests and in vivo skin sensitization and irritation tests according to ISO standards.

RESULTS

High performance liquid chromatography analyses demonstrated that VIEW-ILM® and TWIN® effectively stained the internal limiting membrane without crossing the membrane. No residual dyes were found in the retinal layers after internal limiting membrane removal. Furthermore, both in vitro and in vivo safety tests confirmed the absence of cytotoxicity, skin sensitization, and irritation.

CONCLUSION

The results of this study support the safety and efficacy of VIEW-ILM® and TWIN® for internal limiting membrane staining. The experimental protocol described in this study could be utilized to gain a comprehensive understanding of the characteristics of vital dyes.

Morphological Biomarkers Related to Visual Acuity in Patients With Radiation Retinopathy Treated With Intravitreal Ranibizumab

BACKGROUND AND OBJECTIVE

Our objective was to monitor variables via spectral-domain optical coherence tomography (SD-OCT) and identify the most relevant biomarkers related to best-corrected visual acuity (BCVA) in radiation retinopathy (RR).

PATIENTS AND METHODS

A post-hoc analysis of the two-year Ranibizumab for Radiation Retinopathy (RRR) trial analyzed vision and OCT parameters including intraretinal fluid, ellipsoid zone (EZ) disruption, retinal pigment epithelium atrophy, hard exudates, retinal hemorrhage, retinal neovascularization, and subfoveal fluid. BCVA and SD-OCT parameters were evaluated by univariate analysis and a mixed-effects model.

RESULTS

Forty eyes from the RRR trial were included. Intraretinal cyst vertical size (week 24: P = 0.032; week 48: P = 0.021), neovascularization (week 48: P = 0.028; week 72: P = 0.025), and EZ disruption (week 72: P = 0.029; week 104: P = 0.019) were the clinical parameters most relevant to BCVA by univariate analysis in at least two time points. The mixed-effects model confirmed the relevance of intraretinal cyst vertical size (P = 0.001) and neovascularization (P = 0.001) but not EZ disruption (P = 0.119) over the course of the study.

CONCLUSIONS

This study characterizes the course of visual loss in RR by identifying intraretinal cyst vertical size, neovascularization, and EZ disruption as biomarkers of poor BCVA over a span of two years. Larger multicenter studies are needed to confirm these findings. [Ophthalmic Surg Lasers Imaging Retina 2024;55:255-262.].

Intraretinal Hyper-Reflective Foci Are Almost Universally Present and Co-Localize With Intraretinal Fluid in Diabetic Macular Edema

Purpose

In diabetic macular edema (DME), hyper-reflective foci (HRF) has been linked to disease severity and progression. Using an automated approach, we aimed to investigate the baseline distribution of HRF in DME and their co-localization with cystoid intraretinal fluid (IRF).

Methods

Baseline spectral-domain optical coherence tomography (SD-OCT) volume scans (N = 1527) from phase III clinical trials YOSEMITE (NCT03622580) and RHINE (NCT03622593) were segmented using a deep-learning-based algorithm (developed using B-scans from BOULEVARD NCT02699450) to detect HRF. The HRF count and volume were assessed. HRF distributions were analyzed in relation to best-corrected visual acuity (BCVA), central subfield thickness (CST), and IRF volume in quartiles, and Diabetic Retinopathy Severity Scores (DRSS) in groups. Co-localization of HRF with IRF was calculated in the central 3-mm diameter using the en face projection.

Results

HRF were present in most patients (up to 99.7%). Median (interquartile range [IQR]) HRF volume within the 3-mm diameter Early Treatment Diabetic Retinopathy Study ring was 1964.3 (3325.2) pL, and median count was 64.0 (IQR = 96.0). Median HRF volumes were greater with decreasing BCVA (nominal P = 0.0109), and increasing CST (nominal P < 0.0001), IRF (nominal P < 0.0001), and DRSS up to very severe nonproliferative diabetic retinopathy (nominal P < 0.0001). HRF co-localized with IRF in the en face projection.

Conclusions

Using automated HRF segmentation of full SD-OCT volumes, we observed that HRF are a ubiquitous feature in DME and exhibit relationships with BCVA, CST, IRF, and DRSS, supporting a potential link to disease severity. The spatial distribution of HRF closely followed that of IRF.

Clinical and imaging biomarkers of response to intravitreal dexamethasone implant in eyes with non-infectious uveitic macular oedema

OBJECTIVE

To investigate clinical and spectral-domain optical coherence tomography (SD-OCT) biomarkers correlating with pre-injection visual acuity (VA), post-injection VA, and the likelihood of macular oedema (MO) regression following dexamethasone (DEX) implant injection in non-infectious uveitic (NIU) patients.

METHODS

Patient data from Uveitis Services in Milan, Paris, and Berlin were analysed. Eligible participants were NIU patients aged >18 years with MO as the primary indication for DEX treatment. SD-OCT scans and clinical data were collected at the time of DEX injection (pre-injection visit) and after 3 months (post-injection visit). Multivariable regression models, adjusted for pre-injection VA and lens status, were employed to explore associations. MO regression was defined as the absence of intraretinal/subretinal fluid at the post-injection visit.

RESULTS

Our analysis comprised data from 173 DEX treatments, encompassing 103 eyes from 80 patients, with 38 eyes (37%) receiving repeated DEX injections. The absence of the ellipsoid zone (EZ) layer and disorganisation of the inner retinal layers (DRIL) were associated with worse pre- (+0.19 LogMAR, 95% CI 0.01-0.38, p = 0.06, and +0.10 LogMAR, 95% CI 0.02-0.21, p = 0.01) and post-injection VA (+0.33 LogMAR, 95% CI 0.08-0.57, p = 0.01, and +0.17 LogMAR, 95% CI 0.01-0.32, p = 0.04). EZ disruption and DRIL increased significantly (p = 0.01 and p = 0.04), and the chance of gaining ≥5 letters declined in eyes undergoing repeated DEX (p = 0.002). The rate of MO regression after each DEX was 67%. Prolonged MO duration (OR = 0.75/each year, p = 0.02) was associated with reduced likelihood of MO regression. Subretinal fluid was associated with higher rate of MO regression (OR = 6.09, p = 0.01).

CONCLUSION

Integrity of the inner and outer retina is associated with better visual response to DEX. Long-standing or recurrent MO is associated with less chance of both visual and anatomic response. Timely treatment is necessary to maximise the outcomes of MO in NIU patients.

Influence of prior treatment protocol on intravitreal dexamethasone implant behavior in patients with diabetic macular edema in real-world practice

BACKGROUND AND OBJECTIVE

Intravitreal dexamethasone implant (DEXI) has been placed as an effective option to treat diabetic macular edema (DME). However, there is no consensus on the best time to introduce it. We conducted a study to evaluate anatomical and functional behavior after the first DEXI according to previous treatment.

RESEARCH DESIGN AND METHODS

This retrospective, real-world study between 2013 and 2020 investigated changes in best-corrected visual acuity (BCVA) and central macular thickness (CMT at months 2 and 6 after the first DEXI in DME. Patients were divided into naive, early switch (≤3 anti-VEGF injections), or late switch (>3 anti-VEGF injections) groups.

RESULTS

Among 112 consecutive eyes, mean BCVA and CMT improved significantly in all groups at month 2, with no difference between them. However, this improvement was not maintained at 6 months. The Naíve group presented better BCVA all over the study period. The previously treated groups, which started with worse initial visual acuity, showed more visual gain without reaching the BCVA of the naive group. CMT performance was similar between groups.

CONCLUSIONS

There was similar anatomical and functional behavior in all groups. Poorer visual acuity at baseline was associated with worse functional outcome despite good anatomic response.

Difference of central foveal thickness measurement in patients with macular edema using optical coherence tomography in different display modes

Purpose

To assess the differences in the measurement of central foveal thickness (CFT) in patients with macular edema (ME) between two display modes (1:1 pixel and 1:1 micron) on optical coherence tomography (OCT).

Design

This is a retrospective, cross-sectional study.

Methods

Group A consisted of participants with well-horizontal OCT B-scan images and group B consisted of participants with tilted OCT B-scan. We manually measured the CFT under the two display modes, and the values were compared statistically using the paired t-test. Spearman's test was used to assess the correlations between the OCT image tilting angle (OCT ITA) and the differences in CFT measurement. The area under the curve (AUC) was calculated to define the OCT ITA cutoff for a defined CFT difference.

Results

In group A, the mean CFT in the 1:1 pixel display mode was 420.21 ± 130.61 µm, similar to the mean CFT of 415.27 ± 129.85 µm in the 1:1 micron display mode. In group B, the median CFT in the 1:1 pixel display mode is 409.00 μm (IQR: 171.75 μm) and 368.00 μm (IQR: 149.00 μm) in the 1:1 micron display mode. There were significant differences between the two display modes with the median (IQR) absolute difference and median (IQR) relative difference of 38.00 μm (75.00 μm) and 10.19% (21.91%) (all p = 0.01). The differences in CFT measurement between the two display modes were correlated with the OCT ITA (absolute differences, r = 0.88, p < 0.01; relative differences, r = 0.87, p < 0.01). The AUC for a predefined CFT difference was 0.878 (10 μm), 0.933 (20 μm), 0.938 (30 μm), 0.961 (40 μm), 0.962 (50 μm), and 0.970 (60 μm).

Conclusion

In patients with DM, when the OCT B-scan images were well-horizontal, manual CFT measurements under the two display modes were similar, but when the B-scan images were tilted, the CFT measurements were different under the two display modes, and the differences were correlated to the OCT ITA.

Correlation between multifocal electroretinogram and optical coherence tomography findings with visual acuity after vitrectomy surgery for retinal detachment: an observational study

BACKGROUND

Despite the marked increase in the anatomical success rates of macula-off rhegmatogenous retinal detachment (RRD) surgery, patients may still complain about unsatisfactory visual outcome. This study aims to correlate the postoperative corrected distance visual acuity (CDVA) with the mf-ERG (multifocal electroretinogram) and OCT (optical coherence tomography) findings following vitrectomy surgery for RRD.

PATIENTS AND METHODS

This retrospective observational study included 40 eyes of 40 patients who underwent successful vitrectomy surgery for macula-off RRD. CDVA, mf-ERG amplitudes, mf-ERG latencies, the central macular thickness (CMT) and the integrity of the inner segment/outer segment (IS/OS) junction assessed by OCT, were evaluated 6 months postoperatively. The correlations between CDVA with mf-ERG amplitudes, mf-ERG latencies, central macular thickness, and IS/OS junction integrity were analyzed.

RESULTS

There was a statistically significant moderate positive correlation between CDVA of the studied eyes with mf-ERG amplitudes of N1, P1 and N2 in ring 1 (P = 0.008; P < 0.001 and P = 0.004, respectively), CMT (P < 0.001), and the integrity of IS/OS junction (P < 0.001). There was no significant correlation between CDVA and mf-ERG latencies in ring 1 (P > 0.05). Linear regression analysis revealed that CDVA was significantly associated with mf-ERG amplitudes and the IS/OS junction integrity. In addition, there was a strong positive correlation between mf-ERG amplitudes in ring 1 and the IS/OS junction integrity.

CONCLUSIONS

The integrated interpretation of postoperative CDVA, multifocal ERG parameters, and OCT findings provides useful information about functional visual recovery and retinal microstructural changes following vitrectomy for macula-off RRD surgery. The positive correlation between the IS/OS junction integrity and the mf-ERG amplitudes was stronger than the correlation between the IS/OS junction integrity and CDVA suggesting that mf-ERG may be superior to CDVA in reflecting the extent of microstructural damage in the photoreceptor layer.

TRIAL REGISTRATION

Clinicaltrials.gov, NCT05993208. Registered 15 August 2023 - Retrospectively registered, https://classic.

CLINICALTRIALS

gov/ct2/show/NCT05993208 .

Optical coherence tomography in the management of diabetic macular oedema

Diabetic macular oedema (DMO) is the major cause of visual impairment in people with diabetes. Optical coherence tomography (OCT) is now the most widely used modality to assess presence and severity of DMO. DMO is currently broadly classified based on the involvement to the central 1 mm of the macula into non-centre or centre involved DMO (CI-DMO) and DMO can occur with or without visual acuity (VA) loss. This classification forms the basis of management strategies of DMO. Despite years of research on quantitative and qualitative DMO related features assessed by OCT, these do not fully inform physicians of the prognosis and severity of DMO relative to visual function. Having said that, recent research on novel OCT biomarkers development and re-defined classification of DMO show better correlation with visual function and treatment response. This review summarises the current evidence of the association of OCT biomarkers in DMO management and its potential clinical importance in predicting VA and anatomical treatment response. The review also discusses some future directions in this field, such as the use of artificial intelligence to quantify and monitor OCT biomarkers and retinal fluid and identify phenotypes of DMO, and the need for standardisation and classification of OCT biomarkers to use in future clinical trials and clinical practice settings as prognostic markers and secondary treatment outcome measures in the management of DMO.

Bibliometric and visualized analysis of diabetic macular edema

PURPOSE

Our aim was to identify recent research trends on diabetic macular edema (DME) and focus on publications from different countries, institutions, and authors.

METHODS

We retrieved and analyzed data from January 1, 2003 to December 31, 2022 on the DME research field from the Web of Science Core Collection (WoSCC) database. Microsoft Excel and VOSviewer were applied to perform visualization analysis and evaluate the trends.

RESULTS

A total of 4482 publications were identified, and the annual global publications increased steadily, from 36 to 390, during this period. The United States (1339 publications, 71,754 citations), Johns Hopkins University (176 publications, 17,015 citations), and Bressler NM (76 publications, 9621 citations) were the most influential and productive countries, institutions, and authors, respectively. The top 100 keywords were classified into five clusters: (1) therapy and adverse effects of DME; (2) clinical biomarkers of DME; (3) mechanistic research on DME; (4) improving bioavailability and efficacy; and (5) early diagnosis of diabetic complications. "Diabetic macular edema," "retinopathy," "ranibizumab," and "optical coherence tomography angiography" were the most frequent keywords. Regarding the average appearing years (AAYs) of the keywords, "deep learning" (AAY:2020.83), "optical coherence tomography angiography" (AAY:2019.59), "intravitreal Aflibercept" (AAY:2019.29), and "dexamethasone implant" (AAY:2019.20) were recognized as the hotspots of the DME research area in the short run.

CONCLUSION

In the past two decades, the United States was in master status in DME research. Although intravitreal drug injection has been the mainstream therapy for a long time, the effectiveness of different drugs, such as dexamethasone, new solutions for drug delivery, such as intravitreal implantation, and more accurate tools for the classification and follow-up of DME patients, such as deep learning systems, are still research hotspots.

Exploring the role of retinal fluid as a biomarker for the management of diabetic macular oedema

Anti-VEGF therapies are associated with significant gains in visual acuity and fluid resolution in the treatment of diabetic macular oedema (DMO) and have become the standard of care. However, despite their efficacy, outcomes can be unpredictable, vary widely between individual eyes, and a large proportion of patients have persistent fluid following initial treatment, with a negative impact on visual outcomes. Anatomical parameters measured by optical coherence tomography (OCT), in addition to visual acuity, are key to monitoring treatment effectiveness and guiding retreatment decisions; however, existing guidelines on the management of DMO lack clear recommendations for interpretation of OCT parameters, or proposed thresholds of various markers to guide retreatment decisions. Although central subfield thickness (CSFT) has been widely used as a marker for retreatment decisions in clinical trials in DMO, and a reduction in CSFT has generally been shown to accompany improvements in best-corrected visual acuity with treatment, analyses of the relationship between these parameters show that the correlation is small to moderate. A more direct relationship can be seen between an increased magnitude of CSFT fluctuations over time and poorer visual acuity, suggesting that control of CSFT could be important in maximising visual outcomes. The relationship between visual outcomes and qualitatively assessed intraretinal fluid and subretinal fluid is also unclear, although quantitative assessments of fluid parameters suggest that untreated intraretinal fluid and subretinal fluid negatively impact visual outcomes. These findings highlight a need for clearer guidelines on the management of retinal fluid to improve visual outcomes for patients with DMO.

Safety and Efficacy of Dexamethasone Intravitreal Implant Given Either First-Line or Second-Line in Diabetic Macular Edema

Diabetic macular edema (DME) is a common sight-threatening complication of diabetic retinopathy (DR) and the leading cause of severe visual impairment among the working-age population. Several therapeutic options are available for the management of DME, including intravitreal corticosteroids. They have been traditionally used as second-line treatment, due to the risk of intraocular pressure increase and cataract-related adverse events. However, attention has recently been focused on the primary or early use of intravitreal corticosteroids, due to growing evidence of the crucial role of inflammation in the pathogenesis of DME. Furthermore, intravitreal steroid implants offer the additional advantage of a longer duration of action compared to anti-vascular endothelial growth factor agents (anti-VEGF). This review aims to summarize the available evidence on the efficacy and safety profile of dexamethasone (DEX) intravitreal implant, with a specific focus on clinical scenarios in which it might be considered or even preferred as first-line treatment option by adequate selection of patients, considering both advantages and possible adverse events. Patients with contraindications to anti-VEGF, DME with high inflammatory OCT biomarkers, pseudophakic patients and phakic patients' candidates to cataract surgery as well as vitrectomized eyes may all benefit from first-line DEX implant. Additionally, DME not responders to anti-VEGF should be considered for a switch to DEX implant and a combination therapy of DEX implant and anti-VEGF could be a valid option in severe and persistent DME.

Optical Coherence Tomography (OCT): A Brief Look at the Uses and Technological Evolution of Ophthalmology

Medical imaging is the mainstay of clinical diagnosis and management. Optical coherence tomography (OCT) is a non-invasive imaging technology that has revolutionized the field of ophthalmology. Since its introduction, OCT has undergone significant improvements in image quality, speed, and resolution, making it an essential diagnostic tool for various ocular pathologies. OCT has not only improved the diagnosis and management of ocular diseases but has also found applications in other fields of medicine. In this manuscript, we provide a brief overview of the history of OCT, its current uses and diagnostic capabilities to assess the posterior segment of the eye, and the evolution of this technology from time-domain (TD) to spectral-domain (SD) and swept-source (SS). This brief review will also discuss the limitations, advantages, disadvantages, and future perspectives of this technology in the field of ophthalmology.

Accuracy of biomicroscopy, ultrasonography and spectral-domain OCT in detection of complete posterior vitreous detachment

BACKGROUND

To evaluate the accuracy of preoperative biomicroscopy (BM), ultrasonography (US), and spectral domain optical coherence tomography (SD-OCT) to determine complete posterior vitreous detachment (PVD) confirmed by intraoperative findings of triamcinolone acetonide-assisted pars plana vitrectomy (PPV).

METHODS

This prospective study included all consecutive patients admitted for surgical treatment of the epiretinal membrane (ERM) and macular hole (MH). The presence of complete PVD was determined one day before PPV using BM, US, SD-OCT. The preoperative findings were compared to the PVD status determined during PPV.

RESULTS

A total of 123 eyes from 123 patients were included in the study. Indications for PPV included ERM in 57 (46.3%), full thickness macular hole in 57 (46.3%) and lamellar macular hole in 9 (7.3%) patients. Complete PVD during PPV was observed in 18 (31.6%; 95%CI:18.7-49.9) patients with ERM and 13 (19.7%; 95%CI:10.4-33.7) patients with MH. The sensitivity of preoperative BM, US, SD-OCT was 48.4% (95%CI:30.2-66.9), 61.3% (95%CI:42.2-78.2) and 54.8% (95%CI:36.0-72.7) respectively. The specificity of preoperative BM, US, SD-OCT was 81.5% (95%CI:72.1-88.9), 90.2% (95%CI:82.2-95.4) and 85.9% (95%CI:77.0-92.3) respectively. With a prevalence of 25.2% of PVD in our sample the positive predictive value of preoperative BM, US, SD-OCT was 46.9% (95%CI:29.1-65.3), 67.9% (95%CI:47.6-84.1) and 56.7% (95%CI:37.4-74.5) respectively.

CONCLUSION

Preoperative BM, US, and SD-OCT showed relatively low sensitivity but also good specificity in assessing complete PVD. A combination of all three diagnostic methods can provide a good assessment of the vitreoretinal interface state.

Predicting OCT biological marker localization from weak annotations

Recent developments in deep learning have shown success in accurately predicting the location of biological markers in Optical Coherence Tomography (OCT) volumes of patients with Age-Related Macular Degeneration (AMD) and Diabetic Retinopathy (DR). We propose a method that automatically locates biological markers to the Early Treatment Diabetic Retinopathy Study (ETDRS) rings, only requiring B-scan-level presence annotations. We trained a neural network using 22,723 OCT B-Scans of 460 eyes (433 patients) with AMD and DR, annotated with slice-level labels for Intraretinal Fluid (IRF) and Subretinal Fluid (SRF). The neural network outputs were mapped into the corresponding ETDRS rings. We incorporated the class annotations and domain knowledge into a loss function to constrain the output with biologically plausible solutions. The method was tested on a set of OCT volumes with 322 eyes (189 patients) with Diabetic Macular Edema, with slice-level SRF and IRF presence annotations for the ETDRS rings. Our method accurately predicted the presence of IRF and SRF in each ETDRS ring, outperforming previous baselines even in the most challenging scenarios. Our model was also successfully applied to en-face marker segmentation and showed consistency within C-scans, despite not incorporating volume information in the training process. We achieved a correlation coefficient of 0.946 for the prediction of the IRF area.

The additive effect of intravitreal dexamethasone combined with bevacizumab in refractory diabetic macular edema

PURPOSE

To evaluate the short-term structural and visual outcomes and side effects associated with intravitreal dexamethasone (IVD) combined with bevacizumab (IVB) in treating patients with diabetic macular edema (DME) and an inadequate response to anti-vascular endothelial growth factor (anti-VEGF) agents.

METHODS

In this prospective interventional case series, a total of 81 eyes of 81 patients with type 2 diabetes mellitus (T2DM) and refractory DME were included and assigned to one of two groups: I) those receiving three monthly intravitreal injections of combined bevacizumab and dexamethasone (IVB+IVD) and II) those receiving three monthly intravitreal injections of bevacizumab alone (IVB). The primary outcome was the inter-group difference in central macular thickness (CMT); secondary outcomes included best-corrected visual acuity (BCVA), baseline optical coherence tomography (OCT) biomarkers, and intraocular pressure (IOP) one month after the last injection.

RESULTS

Reduction in CMT and improvement in BCVA were significantly greater in the IVB+IVD group than the IVB group (109.88±156.25 vs. 43±113.67, respectively, P=0.03; and -0.13±0.23 vs. -0.01±0.17, respectively, P=0.008). Presence of neurosensory retinal detachment (NSD) (P<0.001) and complete inner segment/outer segment junction (IS-OS) disruption (P=0.049) on baseline OCT scans were associated with further CMT reductions in response to IVD. Conversely, identifiable epiretinal membrane (ERM) (P=0.002) and multiple hyperreflective foci (>20) (P=0.049) were associated with smaller reductions in CMT. Vitreomacular traction correlated with worse visual outcomes in the IVB+IVD group (P=0.003). The intergroup IOP difference was not clinically significant.

CONCLUSION

In patients with refractory DME, addition of IVD to the standard IVB regimen can improve visual and structural outcomes without increasing the risk of endophthalmitis, IOP rise, or intraocular inflammation. Patients with NSD are more likely to respond well to IVD. The presence of ERM may predict poor treatment response.

Microinvasive pars plana vitrectomy combined with internal limiting membrane peeling versus anti-VEGF intravitreal injection for treatment-naïve diabetic macular edema (VVV-DME study): study protocol for a randomized controlled trial

BACKGROUND

Diabetic macular edema (DME) is the main cause of vision loss in diabetic patients. Currently, anti-vascular endothelial growth factor (VEGF) intravitreal injection stands as the first-line therapy for DME. However, some patients exhibit insufficient response to anti-VEGF agents and often require multiple injections, imposing psychological and economic burdens. While microinvasive pars plana vitrectomy (PPV) has been shown to be safe and effective in treating refractory DME, scant research has explored its application to treatment-naïve DME. The purpose of this study is to determine whether early PPV combined with internal limiting membrane (ILM) peeling can lessen the therapeutic burden of DME patients, prevent vision loss, and maintain long-term stabilization of diabetic retinopathy.

METHODS

This is a single-center, prospective, parallel-group, non-inferiority randomized controlled trial involving 102 DME participants. Participants will be randomly assigned to either the study group (PPV combined with ILM peeling) or the control group (conbercept intravitreal injection (IVC)) at a 1:1 ratio, with a scheduled follow-up at 12 months post-operation. Comparative analysis of results between the two groups will be conducted at months 1, 3, 6, and 12 after the intervention. The primary outcomes involve evaluating the changes in central subfield thickness (CST) and best corrected visual acuity (BCVA). The secondary outcomes include assessment of optical coherence tomography (OCT) and OCT angiography (OCTA) biomarkers, re-treatment and adverse events rates, diabetic retinopathy (DR) development, cost-effectiveness analysis, and vision-related quality of life (VRQL).

DISCUSSION

Some patients do not respond well to anti-VEGF drugs and repeated intravitreal injections increase the treatment burden for patients. The VVV study aims to explore whether PPV combined with ILM peeling could become an initial treatment option for treatment-naïve DME patients.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05728476. Registered on 15 February 2023.

Association of a Bioimpedance Profile with Optical Coherence Tomography Features in Diabetic Macular Edema

We examined the association between bioimpedance profiles and optical coherence tomography (OCT) features in patients with diabetic macular edema (DME). This cross-sectional study included 100 eyes of 100 patients with type 2 diabetes mellitus. The systemic fluid status was assessed using extracellular water-to-total body water ratio (ECW/TBW) and phase angle (PhA), which was measured using bioimpedance equipment. ECW/TBW was higher in the DR (diabetic retinopathy) with DME group than in the no DR and DR without DME groups (p = 0.007 and p = 0.047, respectively); however, no significant difference was observed between the no DR and DR without DME groups. The PhA values were significantly lower in the DR with DME group (5.45 ± 0.84) than in the no DR (6.69 ± 0.69) and DR without DME groups (6.05 ± 1.15) (p < 0.001, p = 0.032, respectively). The presence of multiple HRF (hyper-reflective foci) was associated with a significantly higher ECW/TBW (p = 0.001). In the group with the most significant HRF, PhA was lower than in those with none or moderate amounts of HRF (p < 0.05). Bioimpedance fluid profiles of patients with OCT features of DME suggest a connection between the overall systemic state, including fluid status and DME development. Further research is required to fully understand and utilize this information for effective clinical assessment and treatment planning.

Prevalence of bacillary layer detachment in diabetic macular edema and response to 3 anti-vascular endothelial growth factor treatment

Spectral-domain optical coherence tomography is widely used in maculopathy, including diabetic macular edema (DME). Bacillary layer detachment (BALAD) is a novel optical coherence tomography finding, defined as the separation of the intraretinal layer between the inner segment myoids and ellipsoids. A total of 161 treatment-naïve eyes with centrally involved DME that underwent 3 monthly loading doses of anti-vascular endothelial growth factor (anti-VEGF) intravitreal injections were enrolled and analyzed retrospectively. BALAD was found in 6.2% of eyes with concurrent subretinal fluid (SRF). All eyes were divided into 3 groups: no either group had neither SRF or BALAD; the SRF only group had SRF but no BALAD; and the BALAD group had both SRF and BALAD. A significant increase in baseline central foveal thickness (CFT) in the BALAD group was observed (no either vs SRF only vs BALAD, baseline CFT: 387.6 ± 74.29 vs 440.6 ± 106.79 vs 642.0 ± 188.86; P < .01). Total resolution of BALAD was noted after anti-VEGF therapy, along with a significant decrease in CFT in all groups (CFT decrease: 82.4 ± 87.07 vs 187.6 ± 138.88 vs 252.1 ± 127.63; P < .01). Eyes with BALAD tended to have the worst baseline visual acuity (baseline logarithm of the minimum angle of resolution VA: 0.76 ± 0.353 vs 0.63 ± 0.303 vs 1.15 ± 0.300; P = .046) but showed the most improvement after treatment (logarithm of the minimum angle of resolution VA change: -0.14 ± 0.235 vs -0.22 ± 0.275 vs -0.27 ± 0.250; P = .079). After resolution of BALAD, all eyes in the BALAD group exhibited ellipsoid zone and/or interdigitation zone disruption corresponding to the BALAD area. BALAD is a novel optical coherence tomography finding associated with a spectrum of diseases including DME. With anti-VEGF therapy, total resolution of BALAD and a significant decrease in CFT can be obtained. However, ellipsoid zone/interdigitation zone disruption tended to develop.

Automated evaluation of retinal hyperreflective foci changes in diabetic macular edema patients before and after intravitreal injection

Purpose

Fast and automated reconstruction of retinal hyperreflective foci (HRF) is of great importance for many eye-related disease understanding. In this paper, we introduced a new automated framework, driven by recent advances in deep learning to automatically extract 12 three-dimensional parameters from the segmented hyperreflective foci in optical coherence tomography (OCT).

Methods

Unlike traditional convolutional neural networks, which struggle with long-range feature correlations, we introduce a spatial and channel attention module within the bottleneck layer, integrated into the nnU-Net architecture. Spatial Attention Block aggregates features across spatial locations to capture related features, while Channel Attention Block heightens channel feature contrasts. The proposed model was trained and tested on 162 retinal OCT volumes of patients with diabetic macular edema (DME), yielding robust segmentation outcomes. We further investigate HRF's potential as a biomarker of DME.

Results

Results unveil notable discrepancies in the amount and volume of HRF subtypes. In the whole retinal layer (WR), the mean distance from HRF to the retinal pigmented epithelium was significantly reduced after treatment. In WR, the improvement in central macular thickness resulting from intravitreal injection treatment was positively correlated with the mean distance from HRF subtypes to the fovea.

Conclusion

Our study demonstrates the applicability of OCT for automated quantification of retinal HRF in DME patients, offering an objective, quantitative approach for clinical and research applications.

Evaluation of the efficacy of anti-vascular endothelial growth factors in diabetic macular edema with retinal inner and outer layers disorganization

AIMS

This study aims to compare the effectiveness of treatment between anti-vascular endothelial growth factor (anti-VEGF) agents in diabetic macular edema (DME) patients with disorganization of retinal inner layers (DRIL). Epiretinal membrane, serous macular detachment, ellipsoid zone (EZ) disorder, external limiting membrane (ELM) disorder, and hyperreflective foci were also examined.

METHODS

Patients treated for DME and also had DRIL were included in the study. The study design was retrospective and cross-sectional. The complete ophthalmologic records and imaging were scanned at the beginning, 3rd-month, 6th-month, and 12th-month follow-up, and the treatments administered were recorded. Anti-VEGF agents administered to the patients were examined in three groups: bevacizumab, ranibizumab, and aflibercept.

RESULT

A total of 141 eyes of 100 patients were included in our study. One hundred and fifteen eyes (81.6%) had a BCVA of 0, 5, or less at the beginning. There was no statistically significant difference between the three groups regarding initial BCVA and CMT and the change in BCVA and CMT at the beginning and the 12th month (p > 0.05). There was a negative correlation between EZ and ELM disorders in patients and the change in BCVA at 12 months (r: 0.45 p < 0.001, r: 0.32 p < 0.001, respectively). The number of injections over five was positively correlated with the change in CMT but not with BCVA (r: - 2.35 p = 0.005 and r: 0.147 p = 0.082, respectively).

CONCLUSIONS

No statistically significant difference was found between anti-VEGF agents when treating DME patients with DRIL. In addition, we have shown that anatomically better results were obtained in those who had five or more injections, although not in terms of BCVA.

In Vivo Electroporation Improves Retinal Delivery of Intravitreally Injected Exosomes

Purpose: Mesenchymal stem cell (MSC)-derived exosomes are promising therapeutic agents and natural nanoscale delivery platforms for treating degenerative retinal diseases. This study investigated the effect of electroporation on the retinal delivery of intravitreally administered MSC-derived exosomes in a murine model. Methods: Exosomes isolated from adipose tissue-derived MSCs were stained with ExoGlow exosome-specific dye and administered to the right eyes of 40 Sprague-Dawley rats. Electroporation was performed in 20 rats immediately after intravitreal injection (electroporation group); 5 square pulses of 40 V/cm for 50 ms each with 950-ms intervals were administered. The remaining 20 rats were assigned to the no-electroporation group. The eyeballs were harvested 24 h later for evaluation. The total number of fluorescent particles per hyperfield was counted from the retinal flat mounts to quantify the retinal delivery of exosomes. Tissue damage after electroporation was evaluated using retinal histological sections and a terminal deoxynucleotidyl transferase-mediated deoxyuridine nick end labeling (TUNEL) assay. Results: A significantly higher number of fluorescent particles per hyperfield were observed in the retinal flat mounts of the electroporation group compared with that in the no-electroporation group (599.0 ± 307.5 vs. 376.9 ± 175.4; P = 0.013). Retinal histological sections and TUNEL assays showed no signs of tissue damage after electroporation. Conclusions: In vivo electroporation can improve the retinal delivery of intravitreally injected exosomes.

Macular Thickness Fluctuations in Eyes With Diabetic Macular Edema Treated With Intravitreal Steroid

BACKGROUND AND OBJECTIVE

Macular thickness fluctuations (MTF) over time may be more predictive of visual outcomes than absolute macular thickness in patients with diabetic macular edema (DME) treated with anti-vascular endothelial growth factor (anti-VEGF). It is unclear whether this association exists in DME patients treated with intravitreal steroids or whether steroids confer reduced MTF versus anti-VEGF treatments.

PATIENTS AND METHODS

MTF was compared before and after initiation of steroids in DME patients treated with intravitreal steroids. A mixed-effects linear regression model was used to determine the association between MTF and best-corrected visual acuity (BCVA).

RESULTS

Mean 12-month MTF significantly decreased after steroid initiation (61.1 μm versus 53.5 μm, P = 0.04, n = 105 eyes). Mean BCVA after 12 months was not significantly different from baseline. No significant association between post-steroid MTF and 12-month BCVA was found.

CONCLUSION

Steroid treatment decreases MTF while BCVA remains stable in DME patients previously treated with anti-VEGF. [Ophthalmic Surg Lasers Imaging Retina 2023;54:454-460.].

Widefield choroidal vasculature associated with future condition of subretinal fluid in central serous chorioretinopathy

Purpose

To examine choroidal angiographic features in the posterior pole associated with resolution or persistency of subretinal fluid (SRF) in eyes with central serous chorioretinopathy (CSC).

Design

Observational case series.

Methods

Twenty-nine patients with treatment-naïve CSC were divided into two groups based on the presence or absence of SRF 3 months after the initial visit (month 3) without any treatment. Using enhanced depth imaging of widefield swept-source optical coherence tomography, the choroidal thickness (CT), vessel density (VD), and vessel diameter index (VDI) in the superotemporal and inferotemporal subfields on the temporal side of the 18-mm circle from the disc were measured at the initial visit. We calculated the vertical difference in CT and other choroidal angiographic parameters and evaluated their association with the SRF condition at 3 months.

Results

The SRF-resolved and SRF-persistent groups included 10 and 19 patients, respectively. At the initial visit, sex, age, axial length, symptom duration, the logarithm of the minimum angle of resolution visual acuity, and foveal thickness were not significantly different between the two groups. The SRF status at month 3 was not associated with the vertical difference in CT and choroidal VD (P = .614, .065, respectively). However, the vertical difference in choroidal VDI was positively associated with the future presence of SRF (P = .017).

Conclusions

Vertically asymmetric dilation of choroidal vessels in the posterior pole may be a vasculature feature associated with SRF from CSC and may be a good predictor of future SRF status.

Fuzzy Logic-Based System for Identifying the Severity of Diabetic Macular Edema from OCT B-Scan Images Using DRIL, HRF, and Cystoids

Diabetic Macular Edema (DME) is a severe ocular complication commonly found in patients with diabetes. The condition can precipitate a significant drop in VA and, in extreme cases, may result in irreversible vision loss. Optical Coherence Tomography (OCT), a technique that yields high-resolution retinal images, is often employed by clinicians to assess the extent of DME in patients. However, the manual interpretation of OCT B-scan images for DME identification and severity grading can be error-prone, with false negatives potentially resulting in serious repercussions. In this paper, we investigate an Artificial Intelligence (AI) driven system that offers an end-to-end automated model, designed to accurately determine DME severity using OCT B-Scan images. This model operates by extracting specific biomarkers such as Disorganization of Retinal Inner Layers (DRIL), Hyper Reflective Foci (HRF), and cystoids from the OCT image, which are then utilized to ascertain DME severity. The rules guiding the fuzzy logic engine are derived from contemporary research in the field of DME and its association with various biomarkers evident in the OCT image. The proposed model demonstrates high efficacy, identifying images with DRIL with 93.3% accuracy and successfully segmenting HRF and cystoids from OCT images with dice similarity coefficients of 91.30% and 95.07% respectively. This study presents a comprehensive system capable of accurately grading DME severity using OCT B-scan images, serving as a potentially invaluable tool in the clinical assessment and treatment of DME.

Visual and Anatomical Outcomes of a Single Intravitreal Dexamethasone in Diabetic Macular Edema: An 8 Year Real-World Study

IMPORTANCE

Diabetic macular edema (DME) is a major cause of vision loss in patients with diabetes mellitus. Intravitreal dexamethasone is a treatment option for patients unsuitable for or non-responsive to anti-angiogenic agents.

OBJECTIVE

To quantify visual and anatomical outcomes from an initial intravitreal dexamethasone injection over the expected 6-month period of dexamethasone release by the implant. Design and enrolment: This is a retrospective cohort study using electronic medical records of patients reviewed between 1 January 2012 and 1 April 2022.

SETTING

A tertiary eye-care center in London, United Kingdom; Moorfields Eye Hospital National Healthcare System Foundation Trust.

PARTICIPANTS

The cohort comprised 418 adult patients with DME who received an initial treatment of 700 µg intravitreal dexamethasone in the study period. Of these, 240 patients met the inclusion criteria of ≥2 hospital visits following initial injection (≥1 beyond 6 months) and no previous ocular corticosteroid treatment or missing assessment at baseline.

EXPOSURE(S)

Intravitreal dexamethasone implant (700 µg).

MAIN OUTCOME(S) AND MEASURE(S)

Probability of a positive visual outcome, defined as ≥5 or ≥10 Early Treatment Diabetic Retinopathy Study (ETDRS)-letter gain after treatment when compared to baseline (Kaplan-Meier models).

RESULTS

From the initial intravitreal dexamethasone injection alone, we observed a >75% chance of gaining ≥5 ETDRS letters and >50% chance of gaining ≥10 ETDRS letters within 6 months. There was less than a 50% chance of sustaining either positive visual outcome beyond 4 months.

CONCLUSIONS AND RELEVANCE

Most patients can be expected to have a positive visual outcome following an initial injection of dexamethasone implants that subsides within 4 months. Real-world re-treatment was observed to be delayed until after visual benefits were lost in half of the cohort. Further research will be needed to study the effects of delays in re-treatment.

Current Treatments for Diabetic Macular Edema

Diabetic retinopathy is a major retinal disorder and a leading cause of blindness. Diabetic macular edema (DME) is an ocular complication in patients with diabetes, and it can impair vision significantly. DME is a disorder of the neurovascular system, and it causes obstructions of the retinal capillaries, damage of the blood vessels, and hyperpermeability due to the expression and action of vascular endothelial growth factor (VEGF). These changes result in hemorrhages and leakages of the serous components of blood that result in failures of the neurovascular units (NVUs). Persistent edema of the retina around the macula causes damage to the neural cells that constitute the NVUs resulting in diabetic neuropathy of the retina and a reduction in vision quality. The macular edema and NVU disorders can be monitored by optical coherence tomography (OCT). Neuronal cell death and axonal degeneration are irreversible, and their development can result in permanent visual loss. Treating the edema before these changes are detected in the OCT images is necessary for neuroprotection and maintenance of good vision. This review describes the effective treatments for the macular edema that are therefore neuroprotective.