Characterization of Disease Progression in the Initial Stages of Retinopathy in Type 2 Diabetes: A 2-Year Longitudinal Study

Abstract

PURPOSE. To characterize 2-year changes occurring in neurodegeneration, edema, and capillary dropout in nonproliferative diabetic retinopathy. METHODS. Two-year prospective longitudinal observational cohort of eyes/patients with type 2 diabetes using spectral domain optical coherence tomography (SD-OCT) and optical coherence tomography angiography (OCTA). Eyes were examined three times with intervals of 1 year. Thickness of the full retina and layer-by-layer measurements were used to identify edema or neurodegeneration. OCTA vessel density maps of the retina were used to identify capillary dropout. Early Treatment Diabetic Retinopathy Study (ETDRS) classification was performed using the seven-field ETDRS protocol. RESULTS. A total of 62 eyes from 62 patients with diabetes were followed for 2 years. After verification for image quality, a total of 44 eyes from 44 patients (30% women) aged 52 to 80 years were retained for data analysis. There were 18 eyes with ETDRS grades 10 to 20, 17 eyes with ETDRS grade 35, and 9 eyes with ETDRS grades 43 to 47. During the 2-year follow-up period, there was a progressive increase in capillary dropout, whereas edema and neurodegeneration remained stable. In multivariate analysis, considering a model adjusted for age, sex, hemoglobin A 1C , visual acuity, and diabetes duration, vessel density remained significantly different between Diabetic Retinopathy Severity Scale groups (Wilks' λ = 0.707; P = 0.015) showing association with disease progression. CONCLUSIONS. Capillary dropout increased in a period of 2 years in eyes with minimal, mild, and moderate diabetic retinopathy, whereas the presence of edema and neurodegeneration remained stable.

Retinopathy Phenotypes in Type 2 Diabetes with Different Risks for Macular Edema and Proliferative Retinopathy

“…The Macular Cube 512 × 128 acquisition protocol, consisting of 128 B-scans with 512 A-scans each, was used to assess the subjects' average central retinal thickness (CRT). Retinal layers segmentation for layer thickness calculation was performed on the structural OCT or OCTA (in the last visit) using the segmentation software implemented by AIBILI [17]. In the first step of our implementation, the algorithm segments large voxel intensity variations, i.e., vitreous to Retinal Nerve Fiber Layer (RNFL), Inner Segment (IS) to Outer Segment (OS), and Retinal Pigment Epithelium (RPE) to choroid interfaces.…”

“…Eyes with CIME were identified in agreement with the reference values established by the DRCR.net for Cirrus SD-OCT (retinal thickness greater than or equal to 290 µm in women and 305 µm in men [12]). Retinal Nerve Fiber Layer (RNFL) and/or GCL + IPL thickness decreases were considered to identify neurodegeneration [18], whereas full retina thickness increases were considered to identify edema [9], comparing to a healthy control population [17].…”

Different retinopathy phenotypes in type 2 diabetes predict retinopathy progression

“…The Macular Cube 512 × 128 acquisition protocol, consisting of 128 B-scans with 512 A-scans each, was used to assess the subjects’ CRT, collected from the standard Cirrus examination reports. Segmentation of retinal layers to assess the average thickness value of the ganglion cell layer plus inner plexiform layer (GCL + IPL) in both central subfield (CSF) and Inner Ring (InRing) were performed using the segmentation software implemented by AIBILI [ 6 , 13 ]. Automated analysis results were reviewed by a masked grader.…”

“…Eyes with CIME were identified following the reference values established by the DRCR.net for Cirrus SD-OCT [ 7 ]. GCL + IPL thickness decreases were considered as a surrogate marker of neurodegeneration [ 14 ] whereas full CRT increases were considered to identify edema [ 15 ], comparing to a healthy control population [ 13 , 16 ].…”

Microaneurysm Turnover in Mild Non-Proliferative Diabetic Retinopathy is Associated with Progression and Development of Vision-Threatening Complications: A 5-Year Longitudinal Study

“…Exclusion criteria were: (1) glycated hemoglobin A1c (HbA1c) level > 10% (85.8 mmol/mol); (2) any intravitreal injections or previous laser treatment; (3) presence of age-related macular degeneration, glaucoma, or vitreomacular disease; (4) high ametropia (spherical equivalent greater than − 6 and +2 DPT); (5) any other systemic disease that could affect the eye, with special attention for uncontrolled systemic hypertension and history of ischemic heart disease. Eyes with a baseline central retinal thickening identifying center-involving macular edema (CIME) [ 6 , 7 ] were also excluded.…”