Retinal Microvasculature Reduced in Patients With Prediabetes

View of retina showing severity 1-A of diabetic retinopathy, associated with diabetes mellitus. At bottom center is a microvascular obstruction, which can lead to ischemia. A small patch of yellow exudate is also visible.
Superficial vessel density may show early risk for diabetic retinopathy, according to the study.

Superficial retinal vessel densities are significantly lower in patients who are 65 years of age or older who have prediabetes compared with patients in the same age group who do not have prediabetes, according to a study published in Retina. The findings imply that even patients in early stages of systemic disease experience retinal microvascular changes. 

The investigators relied on optical coherence tomography angiography (OCT-A) technology to image 452 eyes of 301 participants older than 65 years. The researchers divided the participants into 3 groups, patients without diabetes mellitus (DM), patients with prediabetes, and patients with type 2 DM. Each patient was examined to establish retinal microvascular parameters of the superficial vessel density, deep vessel density, superficial foveal avascular zone area, and deep foveal avascular zone area. The patients without DM (225, 70.1±5.5, 97 men, 128 women) had a mean superficial vessel density value of 35.17±0.76%. Patients with prediabetes (177, 70.3±5.7, 59 men, 118 women) had a mean superficial vessel density of 34.93±0.80%, and patients with DM (50, 71.6±5.7, 29 men, 21 women) had values of 34.82±0.66%. Researchers explain these findings show significantly lower values in the prediabetes and DM groups vs the nonDM group, “whereas there was no apparent difference in the [superficial vessel density] between the [prediabetes] and DM groups.”

“In contrast, the deep vessel density of the DM group was significantly lower than that of the nonDM and prediabetes groups,” the researchers explain. However, they report no apparent difference between the nonDM and prediabetes groups (34.99±1.20% vs 34.96±1.16%, P =.97). There was also no significant association between FAZ area and DM stages, researchers report.

Prior research has suggested that loss of these microvascular structures may precede the clinically evident development of diabetic retinopathy. This research demonstrates that changes to these microvascular structures can begin in the prediabetic stage.

Limitations of the study include its single age-group and ethnic (Japanese) participant base, it’s lack of comprehensive ophthalmic testing, and variations in testing technologies.


Wang Y, Toyama T, Hashimoto Y, et al. Association of prediabetes with retinal microvasculature on swept-source optical coherence tomography angiography in the elderly: OTASSHA study. Retina. Published online January 20, 2022. doi:10.1097/IAE.0000000000003416