Prognostic Imaging Biomarkers in Diabetic Macular Edema Eyes Treated with Intravitreal Dexamethasone Implant

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.

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.

OCT angiography 2023 update: focus on diabetic retinopathy

Optical coherence tomography angiography (OCTA) has become part of the clinical practice and its growing applications are in continuous development. Coherently with the growing concern about the human and economic cost of diabetes, diabetic retinopathy (DR) was the most popular topic for OCTA studies in the past year. The analysis of the literature reveals that applications of OCTA in DR are in continuous growth. In particular, ultrawide field (UWF) OCTA and artificial intelligence (AI) based on OCTA images are affirming as the new frontiers of scientific research in the field. Diagnostic accuracy of AI methods based on OCTA is equal or superior to the one based on OCT methods and also bears potential to detect systemic associations. UWF OCTA is noninvasive method that is reaching similar accuracy of FA in detection of neovascularization and intraretinal microvascular abnormalities (IRMAs) and has allowed better characterization of microvascular peripherical changes in DR. Lastly, deep capillary plexus (DCP) characteristics seem to play a pivotal role in the development of diabetic macular edema (DME) and refinement of biomarkers for different phenotypes of DME and diabetic macular ischemia (DMI) is currently on its way.

Predictive Factors of Visual Outcome in Treatment-Naïve Diabetic Macular Edema: Preliminary Results from the Clinical Study "FOVEA"

Diabetic macular edema (DME) is a common cause of vision impairment in diabetic retinopathy. The aim of this study was to analyze the relationship between visual outcome and anatomic changes detected by traditional multimodal retinal imaging and optical coherence tomography angiography (OCTA) in DME eyes under treatment with Aflibercept.

METHODS

Sixty-six DME eyes of 62 patients under treatment with intravitreal Aflibercept and with one-year follow-up were enrolled. All participants underwent a full ophthalmic evaluation, including best correct visual acuity (BCVA) measurement, spectral-domain optical coherence tomography, fluorescein angiography and OCTA, both at baseline and final examination. Fractal OCTA analysis of the superficial and deep capillary plexus (SCP and DCP) was performed to estimate vascular perfusion density and lacunarity (LAC).

RESULTS

At the final examination, there was a significant improvement in terms of BCVA and central macular thickness (CMT). Furthermore, eyes with CMT <373 µm at baseline reached the higher BCVA at the last follow-up. Eyes with CMT ≥373 µm and DCP LAC <0.41 reached a higher final BCVA, if compared with eyes showing the same CMT but higher initial LAC.

CONCLUSION

A 12-month treatment with intravitreal Aflibercept for DME resulted in significant visual and anatomic improvement. Multimodal retinal imaging, together with fractal OCTA analysis, may provide useful biomarkers, predictive of visual outcome in DME.