Diabetic retinopathy develops through complex microvascular damage driven by chronic hyperglycemia, yet traditional risk factors such as disease duration or glycemic control explain only part of individual risk. The retina offers a unique, non-invasive view of microvascular health, where early functional abnormalities may appear before visible retinal lesions. Under normal conditions, retinal vessels automatically constrict or dilate to maintain stable blood flow when body position changes. In diabetes, this autoregulatory capacity is often impaired, reflecting endothelial and neurovascular dysfunction. However, evaluating these dynamic vascular responses has been limited by bulky imaging systems. Based on these challenges, there is a need to explore whether posture-induced retinal vascular changes can serve as early predictors of disease progression.
Researchers from The Chinese University of Hong Kong, reporting (DOI: 10.1186/s40662-025-00471-z) in January 2026 in the journal Eye and Vision, investigated whether retinal vascular responses to postural changes could predict the progression of diabetic retinopathy in people with type 2 diabetes. Using smartphone-based fundus imaging, the team captured retinal images in both sitting and supine positions and followed participants for five years. They found that abnormal posture-related changes in specific retinal vascular parameters were strongly associated with future worsening of diabetic retinopathy, independent of established clinical risk factors.
The study compared retinal vascular responses among healthy individuals, patients with diabetes without retinopathy, and patients with existing diabetic retinopathy. In healthy eyes, moving from a sitting to a supine position triggered a normal constriction of both arterioles and venules, reflecting intact autoregulatory control. In contrast, participants with diabetes showed blunted or even paradoxical vascular responses, indicating impaired microvascular regulation.
Long-term follow-up revealed that two posture-dependent vascular features were particularly informative. Greater increases in retinal arteriolar tortuosity during postural change were associated with more than a two-fold higher risk of retinopathy progression. This exaggerated vascular bending likely reflects structural fragility and endothelial dysfunction caused by chronic hyperglycemia. Conversely, wider venular branching angles during posture change were linked to a significantly lower risk of disease progression, suggesting preserved vascular adaptability.
Importantly, incorporating these dynamic vascular measures improved predictive accuracy beyond conventional factors such as HbA1c levels, diabetes duration, and baseline retinopathy severity. The findings indicate that how retinal vessels respond to everyday physiological stressors may reveal subclinical disease activity that static imaging cannot capture.
“Our findings suggest that the retina’s ability to adapt to routine physiological changes carries meaningful information about future disease risk,” said the study’s senior investigator. “By observing how retinal vessels respond to a simple change in body position, we can detect early microvascular dysfunction that may otherwise go unnoticed. This dynamic approach moves beyond traditional snapshot imaging and highlights the potential of functional vascular biomarkers to support more personalized monitoring strategies for people with diabetes.”
This research highlights a practical pathway toward more accessible and individualized diabetic retinopathy risk assessment. Smartphone-based retinal imaging is portable, cost-effective, and well suited for primary care or resource-limited settings, where conventional ophthalmic equipment may be unavailable. Integrating posture-responsive vascular metrics into screening programs could help identify high-risk patients earlier and tailor follow-up intervals more precisely. Combined with telemedicine platforms and automated image analysis, this approach could shift diabetic eye care from reactive treatment to proactive prevention—reducing unnecessary screenings while ensuring timely intervention for those most at risk.
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References
DOI
10.1186/s40662-025-00471-z
Original Source URL
https://doi.org/10.1186/s40662-025-00471-z
About Eye and Vision
Eye and Vision is an open access, peer-reviewed journal for ophthalmologists and visual science specialists. It welcomes research articles, reviews, commentaries, case reports, perspectives and short reports encompassing all aspects of eye and vision. Topics of interest include but are not limited to: current developments of theoretical, experimental and clinical investigations in ophthalmology, optometry and vision science which focus on novel and high-impact findings on central issues pertaining to biology, pathophysiology and etiology of eye diseases as well as advances in diagnostic techniques, surgical treatment, instrument updates, the latest drug findings, results of clinical trials and research findings. It aims to provide ophthalmologists and visual science specialists with the latest developments in theoretical, experimental and clinical investigations in eye and vision.