Glycemic Control and Retinal Microvascular Changes

Glycemic Control and Retinal Microvascular Changes in Type 2 Diabetes Mellitus Patients Without Clinical Retinopathy

The goal of this prospective, observational study is to compare in the association of glycemic control and retinal microvascular changes in patients with type 2 diabetes mellitus (T2DM) without diabetic retinopathy (DR).

The main question it aims to answer are:

• Do degenerative changes in retinal microvasculature or nerves depend on glycemic control even before diabetic retinopathy is detected?

Participants will receive an annual routine comprehensive examination including ultra-widefield fundus photography, spectral domain optical coherence tomography (OCT), and swept-source optical coherence tomography angiography (OCTA).

Study Overview

• Status: Active, not recruiting
• Conditions: Diabetic Retinopathy; Neurodegeneration; Blood Sugar; High

• Study Type: Observational
• Enrollment (Actual): 259

Contacts and Locations

Study Locations

• Korea, Republic of
  • Republic Of Korea
    • Goyang-si, Republic Of Korea, Korea, Republic of, 10324
      • Dongguk University Ilsan Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

• Sampling Method: Non-Probability Sample

Study Population

The study included 30-70-year-old patients with T2DM without known DR at baseline who underwent regular screening for DR at the department of ophthalmology. The controls included patients without DM who presented for regular ophthalmic examination. One eye each of DM patients and controls was included in the study. The eye without significant ocular disease was selected from both eyes; if both eyes were eligible, the right eye was selected. The participants underwent comprehensive ophthalmic examination, including best-corrected visual acuity assessment using the Snellen chart, slit-lamp biomicroscopy, dilated fundus examination, ultra-widefield fundus photography, spectrum-domain OCT, and SS-OCTA. Patients with T2DM were included in the study after a retinal specialist confirmed absence of signs of DR on clinical examination and ultra-wide fundus photography.

Description

Inclusion Criteria:

• The study included 30-70-year-old patients with T2DM without known DR at baseline who underwent regular screening for DR at the department of ophthalmology.
• Who underwent regular checkups for DR between January 2019 and August 2022 at Dongguk University Ilsan Hospital.
• The controls included patients without DM who presented for regular ophthalmic examination.

Exclusion Criteria:

• patients with a history of retinal or choroidal diseases (i.e., age-related macular degeneration, retinal vein occlusion, uveitis, retinal detachment, and central serous chorioretinopathy), glaucoma, or optic neuropathy
• patients with neurodegenerative diseases, such as Parkinson's disease and dementia.

Study Plan

How is the study designed?

Number of groups / cohorts

3

Cohorts and Interventions

Group / Cohort
Healthy control; The controls included patients without DM who presented for regular ophthalmic examination.
intensive control (IC) group; The mean HbA1c level was calculated during the 12 months prior to the OCT and OCTA. Based on the mean HbA1c level, T2DM patients were divided into intensive control (IC; mean HbA1c ≤ 7.0%) and moderate control (MC; mean HbA1c > 7.0%) groups
moderate control (MC) group; The mean HbA1c level was calculated during the 12 months prior to the OCT and OCTA. Based on the mean HbA1c level, T2DM patients were divided into intensive control (IC; mean HbA1c ≤ 7.0%) and moderate control (MC; mean HbA1c > 7.0%) groups

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The foveal avascular zone (FAZ) area (mm^2)	FAZ was defined as the avascular area in the foveal center.	Upon initial registration and through study completion, an average of 1 year
central foveal retinal thickness (um) and macular ganglion cell-inner plexiform layer (GC-IPL) thickness (um)	Retinal layer thickness were calculated automatically using the bundled software	Upon initial registration and through study completion, an average of 1 year
Retinal vessel density (VD, %)	The VD (%) was calculated using the following formula: VD (%) = vascular area (pixel) / (total area - FAZ area) (pixel) × 100.	Upon initial registration and through study completion, an average of 1 year

Collaborators and Investigators

• Sponsor: Seoul National University Hospital

Study record dates

Study Major Dates

• Study Start (Actual): January 1, 2019
• Primary Completion (Actual): August 31, 2022
• Study Completion (Estimated): December 31, 2025

Study Registration Dates

• First Submitted: November 12, 2023
• First Submitted That Met QC Criteria: November 20, 2023
• First Posted (Actual): November 29, 2023

Study Record Updates

• Last Update Posted (Actual): November 29, 2023
• Last Update Submitted That Met QC Criteria: November 20, 2023
• Last Verified: November 1, 2023

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Pathologic Processes; Cardiovascular Diseases; Vascular Diseases; Glucose Metabolism Disorders; Metabolic Diseases; Eye Diseases; Endocrine System Diseases; Diabetic Angiopathies; Diabetes Complications; Diabetes Mellitus; Hyperglycemia; Retinal Diseases; Diabetic Retinopathy; Nerve Degeneration
• Other Study ID Numbers: IRB no. 2021-06-029

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No