Identifying Parkinson Disease With OCT-A May Be Superior to OCT 

Identifying Parkinson disease (PD) via the retinal microvasculature is best performed with optical coherence tomography angiography (OCT-A) when compared with high-resolution OCT alone, according to research presented at the North American Neuro-Ophthalmology Society’s 2023 Annual Meeting held in Orlando, Florida from March 11 to March 16, 2023. The research shows that OCT-A evaluation can reveal macular microvascular abnormalities associated with Parkinson disease even when structural damages are not observable with OCT. 

“Parkinson’s disease (PD)-associated non-motor symptoms have gained importance in the last years, especially the retina given its easy structure and function in vivo evaluation,” according to the presentation.

In this cross-section study, researcher Mário L. Monteiro, MD, PhD, and colleagues evaluated 41 eyes from 21 patients (mean age, 58.5 years; 14 men, 7 women) with Parkinson disease, and 38 eyes from 19 patients placed into a healthy control group (mean age, 52.5 years; 11 women, 8 men). All participants underwent neurologic and ophthalmic examinations with high-resolution OCT and OCT-A. To identify Parkinson disease, the research team assessed disease duration, severity, motor symptoms, and the use of antiparkinsonian drugs. 

They used OCT to obtain the peripapillary retinal nerve fiber layer, Bruch’s membrane opening-minimum rim width, peripapillary choroid, segmented macular layers, and choroidal thickness. They exported and analyzed macular and peripapillary en-face OCT-A images using an automated method and obtained vessel density of segmented vascular complexes, plexus, foveal avascular zone area, perimeter, and circularity. 

Compared with those in the healthy control group, Parkinson disease patients exhibited a significantly lower vascular density in the deep vascular complex (18.1±4.6 vs 22.7±6.2; P =.005) and deep capillary plexus (18.3±4.3 vs 20.9±4.2; P =.027) of the macular area. The researchers report no statistically significant difference in OCT data between groups. They found no association between statistically significant measurements and clinical data.

The researchers explain that the macular microvascular abnormalities found using OCT-A can assist in identifying Parkinson disease even when structural damages, even before changes are visible on OCT.