Work

Correlation between fundus color and retinal microcirculation in type 2 diabetes mellitus patients

Year: 2026

Type: article

Abstract: • Quantified fundus color using RGB, Lab, and HSV models for T2DM patients. • Correlated color parameters with systemic metabolic status in type 2 diabetes. • Linked color variations directly to retinal microcirculatory parameters. • Identified color features as non-invasive biomarkers for microvascular damage. This study quantified retinal color parameters from fundus photography and integrated microcirculatory metrics from retinal oximetry, optical coherence tomography angiography (OCTA), and color doppler imaging (CDI) to investigate the specific application of fundus color in assessing microcirculation in type 2 diabetic Mellitus (T2DM) patients. Participants underwent fundus photography, retinal oximetry, OCTA, and CDI. Fundus color features were extracted using Photoshop and Python based on Red-Green-Blue (RGB), Commission Internationale de l'Éclairage Color Space (Lab), and Hue-Saturation-Value (HSV) models. Microvascular parameters were assessed via oximetry, OCTA, and CDI. Data were analyzed with SPSS 24.0. Fundus color parameter RGB-B correlated positively with age ( r =0.221, P =0.033, Q =0.297), venous oxygen saturation (SvO 2 ) ( r =0.404, P =0.000, Q =0.000), diameter of vein (D-V) ( r =0.246, P =0.018, Q =0.197), and negatively with arteriovenous difference (A-V) ( r=-0.385, P=0.000, Q=0.000) . Lab-a correlated positively with age ( r =0.392, P= 0.000, Q =0.000) and disease duration ( r =0.357, P= 0.000, Q =0.000), and negatively with end diastolic velocity of the central retinal artery ( r =-0.206, P =0.047, Q =0.378). Lab-b correlated positively with foveal density-300 (FD-300) ( r =0.285, P =0.006, Q =0.092). HSV-H correlated positively with age ( r =0.513, P= 0.000, Q =0.000), A-V ( r =0.313, P =0.002, Q =0.034) and FD-300 ( r =0.237, P =0.022, Q =0.224), and negatively with disease duration ( r =-0.409, P= 0.000, Q =0.000), Glycated Hemoglobin A1c (HbA1c) ( r =-0.252, P =0.015, Q =0.177), and SvO 2 ( r =-0.297, P =0.007, Q =0.097). HSV-S correlated negatively with age ( r =-0.229, P =0.027, Q =0.258), SvO 2 ( r =-0.412, P= 0.000, Q =0.000), and D-V ( r =-0.215, P =0.038, Q =0.323), and positively with A-V ( r =0.387, P= 0.000, Q =0.000) and FD-300 ( r =0.270, P =0.009, Q =0.115). Quantitative fundus color may serve as a non-invasive potential surrogate marker for systemic state and retinal microcirculatory status of T2DM.

Source: Photodiagnosis and Photodynamic Therapy

DOI: 10.1016/j.pdpdt.2026.105493

Authors: Lu Chang, Dan Li, Keyin Zhu, Haoming Geng, Wenyuan Jian, Junguo Duan

Institutions: Chengdu University of Traditional Chinese Medicine, Wenzhou Medical University, Shandong University of Traditional Chinese Medicine

Language: English

Topic: Retinal Imaging and Analysis

Subfield: Radiology, Nuclear Medicine and Imaging

Field: Medicine

Domain: Health Sciences

SDG: Good health and well-being

Open Access status: gold

Estimated APC paid: $2,610