Abstract
Purpose :
To describe the use of OCTA in imaging scleral vasculature of TED patients with varying severity and response to treatment
Methods :
OCTA scans (Optovue, Inc) were taken of 8 patients with mild inactive TED (n=5) and active severe TED (n=3) (before and after treatment). The Optovue has an anterior segment lens adapter verified to image vasculature.
Superior,inferior, nasal and temporal quadrants scans in each eye were obtained by a trained, independent operator.
Mild TED patients had baseline scans. Severe patients had scans pre and post intravenous pulsed steroid therapy and /or orbital decompression.
Manual segmentation of the scleral vasculature was used to determine extent of venous congestion. Segmentation lines were assigned to the anterior and posterior sclera that was in line with the posterior cornea surface. Flow speeds in selected cross sectional scan areas (temporal and nasal) were matched by spatial location before and after therapy and expressed as % area. Vessel density in all gaze directions was also measured.
Results :
Deep epicleral venous flow speeds and vessel density had an increased trend post orbital decompression in severe TED patients. There was minimal change post steroid therapy.
Mild TED patients showed higher better vessel density and flow compared to congested severe TED patientsat baseline.
Conclusions :
Recent adaptations of OCTA (normally optimized for posterior segment imaging) in visualising anterior segment vasculature has allowed better understanding vascular blood flow in orbital inflammatory disease. This is the first report to describe OCTA imaging of TED scleral vasculature
Orbital congestion in TED is attributed to increased episcleral venous pressure with resultant venous outflow disturbances. Severe patients who do not respond to medical therapy require decompression to relieve orbital congestion and optic neuropathy. Despite limitations by motion artefacts caused in part by restrictive myopathy, our study data confirms this venous stasis reduction with increased density and flow post surgery.
OCTA’s rapid non-invasive acquisition of images allows for further studies in correlating inflammatory scores with venous congestion and in doing so deciphering differences in disease activity for thyroid patients, determine adequacy of treatment and aid subsequent management.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.