A Pilot Study of Subclinical Non-Capillary Peripapillary Perfusion Changes in Thyroid-Related Orbitopathy Detected Using Optical Coherence Tomography Angiography

Abstract

Purpose Hemodynamic changes surrounding the optic nerve head are known to occur in thyroid-related orbitopathy (TRO). This pilot study explores the capillary and non-capillary peripapillary perfusion changes of the retina in TRO eyes without dysthyroid optic neuropathy (DON) using optical coherence tomography angiography (OCT-A). Methods Non-capillary and capillary peripapillary perfusion densities were calculated using single 4.5 × 4.5mm en face “RPC layer” OCT-A scans of 8 TRO patients without DON (8 eyes, mean age 40.6 years, range 23–69 years). Results were compared to a previously published dataset of 133 healthy controls (133 eyes, mean 41.5 years, range 11–83 years). The strength of association was measured between OCT-A perfusion densities and clinical measures of TRO. Results Non-capillary peripapillary perfusion density in TRO eyes was found to be significantly decreased compared to healthy controls (TRO group 15.4 ± 2.9% vs controls 21.5 ± 3.1%; p < 0.0001). Capillary peripapillary perfusion densities showed no significant difference (TRO group 42.5 ± 1.8% vs controls 42.5 ± 1.5%; p = 1.0). Clinical measures of disease did not correlate well with OCT-A perfusion densities (p>0.05). Conclusion These findings may represent decreased blood flow and subclinical ischemia to the optic nerve. We discuss possible pathogenic mechanisms of thyroid-related vasculopathy, including vessel wall thickening due to immunologically-induced media enlargement.

Optic nerve head optical coherence tomography angiography findings in patients with thyroid eye disease: a case–control study

“…They found that the non-capillary VD decreased significantly in the TED group, but the capillary VD did not show a significant difference. However, their study population was tiny [ 20 ].…”

Optical coherence tomography angiography in neuro-ophthalmology

“…Furthermore, decrease in peripapillary and macular vascular density as well as increase in RNFL thickness are noted in active TED compared with inactive TED and healthy eyes [53 ▪ ]. In the pilot study of Pinhas et al [54 ▪▪ ], where the capillary and noncapillary peripapillary perfusion changes of the retina were evaluated in TED eyes without dysthyroid optic neuropathy, it was demonstrated that noncapillary peripapillary perfusion density is significantly lower compared with healthy eyes in contrast to the capillary perfusion density where there were no significant differences.…”

Thyroid-Associated Peripapillary Vascular Remodelling – A Novel Area for Research? [Letter]

“…We read the study on changes in the capillary and non-capillary peripapillary perfusion (NCPP) in inactive thyroid eye disease (TED) without dysthyroid optic neuropathy (DON) using ocular coherence angiography (OCTA) for the radial peripapillary capillary (RPC) layer scans with great interest. 1 …”