Quantitative Parameters Relevant for Diabetic Macular Edema Evaluation by Optical Coherence Tomography Angiography

Abstract

Diabetic macular edema (DME) is one of the main ocular complications of diabetes mellitus (DM) that can lead to important vision loss in diabetic patients. In clinical practice, there are cases of DME with unsatisfying treatment responses, despite adequate therapeutic management. Diabetic macular ischemia (DMI) is one of the causes suggested to be associated with the persistence of fluid accumulation. Optical coherence tomography angiography (OCTA) is a non-invasive imaging modality, able to give in-depth information about retinal vascularization in a 3-dimensional manner. The OCTA devices currently available can provide various OCTA metrics that quantitatively assess the retinal microvasculature. In this paper, we reviewed the results of multiple studies that investigated the changes in OCTA metrics in the setting of DME and their possible contribution to the diagnosis, therapeutic management, follow-up and prognosis of patients with DME. We analyzed and compared relevant studies that investigated OCTA parameters related to changes in macular perfusion in the setting of DME and we evaluated the correlations between DME and several quantitative parameters, such as vessel density (VD), perfusion density (PD), foveal avascular zone (FAZ)-related parameters, as well as complexity indices of retinal vasculature. The results of our research showed that OCTA metrics, evaluated especially at the level of the deep vascular plexus (DVP), are useful instruments that can contribute to the assessment of patients with DME.

Optical Coherence Tomography Angiography as a Diagnostic Tool for Diabetic Retinopathy

“…DMO is a leading cause of vision loss in patients with DM, affecting approximately 18.8 million DM patients globally in 2020 [4]. On OCTA, DMO is characterised by abnormal fluid accumulation within the inner retinal layers at the macula, driven by angiogenesis and inflammation [98]. Importantly, DMO can occur at any stage of DR and progress independently of DR severity [99].…”

Innovations in Diabetic Macular Edema Management: A Comprehensive Review of Automated Quantification and Anti-vascular Endothelial Growth Factor Intervention

“…A study published in Investigative Ophthalmology & Visual Science scrutinized the value of reading center error correction in automated OCT retinal thickness measurements for DME, concluding that correcting automated errors had negligible effects on interpreting results from DME clinical trials, provided adequate quality control measures were in place [20]. Moreover, the precision of manual correction is contingent on the operator, and images with segmentation errors may necessitate manual correction, introducing potential variability in the results [21]. In contrast, the application of artificial intelligence (AI) in precision medicine for DME demonstrates promise in automating the quantification of macular fluid in retinal diseases and assessing their response to anti-VEGF therapy.…”