Combined central and peripheral retinal lesions are associated with greater microvascular impairment, and age and glycemic control are key determinants of early retinal microvascular changes in T2DM, while age and body mass index relate to GCL-IPL thickness.
Key Findings
Results
About one quarter of eyes in the T2DM screening cohort showed visible retinal lesions, most often peripheral only.
Retrospective cross-sectional study of 1978 eyes from 998 participants in a diabetic retinopathy screening program.
1468 eyes (74%) had no visible lesions and 510 (26%) showed lesions.
Among eyes with lesions: 229 peripheral only, 132 central only, and 149 both central and peripheral.
Imaging used ultra-widefield fundus photography, OCT, and OCTA (CIRRUS 5000 HD-OCT with AngioPlex).
Results
Eyes with both central and peripheral lesions had significantly reduced skeletonized vessel density compared with eyes without lesions.
Superficial capillary plexus (SCP): P = 0.019 versus no lesions.
Deep capillary plexus (DCP): P = 0.035 versus no lesions.
SVD was assessed by OCTA; mixed-effects models were used to compare lesion groups.
Results
Eyes with both central and peripheral lesions also had significantly reduced vessel density compared with eyes with peripheral-only lesions.
SCP: P = 0.005 versus peripheral-only lesions.
DCP: P = 0.019 versus peripheral-only lesions.
This suggests greater microvascular impairment when lesions involve both retinal regions.
Results
GCL-IPL thickness did not differ significantly among lesion groups.
GCL-IPL thickness was measured by OCT.
No significant differences were found between eyes with no lesions, peripheral-only, central-only, or both lesion types.
Results
GCL-IPL thickness was associated with older age and higher body mass index.
Older age: P < 0.001.
Higher body mass index: P = 0.020.
Associations were assessed using mixed-effects models including systemic and lifestyle factors.
Results
Reduced SVD in the superficial capillary plexus was associated with older age and higher glycated hemoglobin.
Older age: P < 0.001.
Higher HbA1c: P = 0.004.
Authors conclude age and glycemic control are key determinants of early retinal microvascular changes in T2DM.
What This Means
This study looked at retinal images from nearly 1,000 people with type 2 diabetes who took part in an eye screening program. Using wide-field photos and scans that measure retinal thickness and small blood vessel density, the researchers compared eyes with no visible diabetic lesions to eyes with lesions in the center of the retina, the periphery, or both. About three quarters of eyes showed no visible lesions.
Eyes with lesions in both the central and peripheral retina had lower density of small blood vessels than eyes with no lesions or with peripheral-only lesions. The thickness of the nerve-related retinal layers (GCL-IPL) did not differ among these groups. Older age and higher blood sugar control markers (HbA1c) were linked to reduced vessel density, while older age and higher body mass index were linked to GCL-IPL thickness.
This research suggests that early changes in retinal blood vessels in type 2 diabetes relate to age and blood sugar control, and that body weight may relate to nerve-layer thickness. Because the study is cross-sectional, it shows associations rather than cause and effect, but it supports a combined eye and whole-body approach to detecting and managing early diabetic eye changes.
Almeida A, Pais M, Pinto I, Reste-Ferreira D, Marques I, Santos T, et al.. (2026). Retinal Microvascular and Neuronal Alterations in Type 2 Diabetes: Insights From a Population-Based Screening Program (START2).. Investigative ophthalmology & visual science. https://doi.org/10.1167/iovs.67.12.61