OCT-A May Detect Diabetic Retinopathy in Eyes Without Clinical Signs

Ultra-wide field swept-source optical coherence tomography angiography (UWF SS OCT-A) may detect vascular alterations in diabetic eyes without clinical signs, according to findings published in BMC Ophthalmology.

Previous studies have found that SS OCT-A systems can visualize alterations on UWF montage images of diabetic retinopathy (DR), according to the investigators. This led them to question if UWF OCT-A images could be used to detect microvascular changes in eyes with preclinical DR.

To test this hypothesis, the team recruited 30 patients with diabetes (55 eyes) who did not have clinical retinal signs. All patients underwent OCT-A examination with a 12×12 mm² field of view of 5 visual fixations (1 central fixation and 4 peripheral fixations) to compose a UWF OCT-A image. In the UWF images, the central area corresponded to the original central image obtained using central fixation, and the peripheral area was the remaining area. Lesions, including nonperfusion areas, microvascular dilation and tortuosity, and neovascularization, were recorded in different areas. Patients’ history of diabetes also was noted.

Investigators found that peripheral areas of the eye presented significantly more microvascular dilation and tortuosity than central areas (P = 0.024) and more nonperfusion areas than central areas, with borderline significance (P = 0.085). In addition, the number of lesion types was associated with HbA1c levels in the peripheral and overall areas (all P <.001).

The limitations of this study include its sample size and the lack of universal consensus or guidelines for UWF OCT-A. The study also didn’t include a control group without diabetes. Because the included patients had relatively normal fundi, fluorescein angiography wasn’t performed. Additionally, more information about the demographics of the study population, including blood pressure, cardiovascular health, and more laboratory data, might help evaluate these elements more comprehensively in future studies. Lastly, the investigators concede that the quality of the figures in their study could be better. 

Disclosure: One of the study’s authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.  

Reference

Yang, J., Zhang, B., Wang, E. et al. Ultra-wide field swept-source optical coherence tomography angiography in patients with diabetes without clinically detectable retinopathy. BMC Ophthalmol. Published online May 1, 2021. doi:10.1186/s12886-021-01933-3