Optical Coherence Tomography Angiography in Type 1 Diabetes Mellitus. Report 4: Glycated Haemoglobin

Abstract

The purpose of this study was to evaluate specifically the relationship between glycated haemoglobin (HbA1c) levels and retinal optical coherence tomography (OCT) and OCT angiography (OCTA) parameters in type 1 Diabetes Mellitus (DM). A total of 478 type 1 DM patients and 115 controls were included in a prospective OCTA trial (ClinicalTrials.gov NCT03422965). Subgroup analysis was performed for controls, no diabetic retinopathy (DM-no DR) and DR patients (DM-DR), and HbA1c levels. OCT and OCTA measurements were compared with HbA1c levels (current and previous 5 years). DM-no DR patients with HbA1c levels >7.5% showed lower VD than DM-DR and controls (20.16 vs. 20.22 vs. 20.71, p < 0.05), and showed a significant correlation between HbA1c levels and FAZc (p = 0.04), after adjusting for age, gender, signal strength index, axial length, and DM disease duration. DM-DR patients with HbA1c > 7.5% presented greater CRT than DM-no DR and controls (270.8 vs. 260 vs. 251.1, p < 0.05) and showed a significant correlation between HbA1c and CRT (p = 0.03). In conclusion, greater levels of HbA1c are associated with OCTA changes in DM-no DR patients, and with structural OCT changes in DM-DR patients. The combination of OCTA and OCT measurements and HbA1c levels may be helpful to identify patients at risk of progression to greater stages of the diabetic microvascular disease.

Radiomics-Based Assessment of OCT Angiography Images for Diabetic Retinopathy Diagnosis

“…However, this also confers high internal validity because it is allegedly the largest type 1 DM retinal imaging dataset of the literature. 38 , 39 , 40 Second, control and DM groups differed in some baseline characteristics, such as age, smoking status, and body mass index, which may have influenced the results. Third, for OCT images, only a single B scan centered in the fovea has been used to extract the radiomics features, when each macular cube scan consists of 128 consecutive B scans, which could potentially under or overestimate the results reported either way.…”

“…A total of 593 individuals with retinal images corresponding to 1186 eyes and ocular and systemic data were recruited, 478 patients with type 1 DM (n = 956 eyes) and 115 healthy controls (n = 230 eyes). Systemic, ocular, and retinal images quality exclusion criteria were applied as described elsewhere 39 , 40 41 and 439 individuals (n = 726 eyes) with a complete battery of all retinal images constituted the primary dataset for analysis. To evaluate the influence of a potential bilaterality bias, a secondary analysis was conducted by randomly selecting only 1 eye per patient (1 eye/1 patient) that included 439 patients (n = 439 eyes).…”

Optical Coherence Tomography Angiography in Type 1 Diabetes Mellitus—Report 2: Diabetic Kidney Disease

“…One of the most clinically relevant findings of this study is the identification of FAZc as a potential indirect biomarker of DKD progression. The status of the FAZ and its different parameters, such as area, perimeter or circularity, has been previously described as a marker associated with DR stage [ 9 , 15 , 18 ], a surrogate marker of VA [ 40 ] or associated to HbA1c levels [ 24 ]. With regard to kidney function, some previous reports have described an association between FAZa and GFR [ 13 ] or ACR [ 27 ], although other authors have not found any association between these parameters [ 29 ].…”

“…Optical coherence tomography angiography (OCTA) [ 6 ] is a newly developed, non-invasive, retinal imaging technique that allows objective quantification of microvascular parameters in the perifoveal vascular network, such as vessel density or flow impairment areas [ 7 , 8 ]. Recent studies have analyzed the relationship between OCTA and DR stage [ 7 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 ] and systemic markers of disease, such as glycated hemoglobin levels [ 24 ]. Since this technique allows direct noninvasive in vivo visualization of the microvascular circulation, it is sensible to think that the detection of microvascular changes may be associated to other clinical manifestations elsewhere in the body.…”

Review of OCT Angiography Findings in Diabetic Retinopathy: Insights and Perspectives

“…Numerous studies have made evident that OCTA measurements of the microvasculature may differ based on age [153][154][155], sex [156,157], HbA1c levels [102,158,159], and a variety of other systemic or metabolic vascular risk factors [160][161][162][163]. Additionally, previous work by Chun et al illuminated differences in OCTA quantitative parameters between healthy, young Black and White patients [164].…”