Microaneurysms shed light on diabetic retinopathy

June 24, 2014 

SAN FRANCISCO — The identification of microaneurysm wall features have been correlated with anatomic and functional outcomes in the eyes of diabetes patients, according to data presented at the American Diabetes Association’s 74th Scientific Sessions.

“We have classically graded hallmark vascular lesions, allowing staging of diabetic retinopathy severity and risk for diabetic retinopathy progression, but we are generally unable to assess new microaneurysm vessels and other pathology at the cellular level in vivo in human eyes,” Jennifer K. Sun, MD, said during a presentation here.

Sun and colleagues sought to understand why leakage only sometimes results in neural damage. They obtained confocal and pinhole aperture offset ophthalmoscope images and measurements of wallhyperreflectivity, wall deformability and perfusion patterns for 109 microaneurysms of 30 eyes. Patients’ mean age was 46 years, with mean diabetes duration of 26 years.

Unadjusted analyses indicated that microaneurysms with wall hyperreflectivity were larger, more visible on 30° photos and more likely to have lumen clots. Additionally, they were more likely to be partially rather than completely perfused, and to be associated with retinal inner layer disorganization, according to Sun.

Wall hyperreflectivity was not significantly associated with wall deformability or spectral-domain optical coherence tomography hyper/hyporeflectivity. Fluorescein angiography leakage was observed among 17 of 38 microaneurysms, but more likely among microaneurysms with wall deformability compared with those without (41% vs. 0%, P = .001). However, fluorescein angiography leakage was not associated with microaneurysm wall hyperreflectivity, size or perfusion pattern, according to Sun.

Of 41 microaneurysms located within 500 µm of the foveal center, those with wall hyperreflectivity were more likely to be found in eyes with worse logMAR visual acuity.

“The ability to identify microaneurysms might give insight into mechanisms for diabetic retinopathy onset and early stage worsening, interactions with neural retina and mechanisms for neural damage leading to vision loss, new vessel regression, persistence or worsening,” Sun said. – by Samantha Costa

Disclosure: Sun has no relevant financial disclosures.

For more information:

Sun JK. Abstract #353-OR. Presented at: American Diabetes Association’s 74th Scientific Sessions; June 13-17, 2014; San Francisco.

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