Abstract
Purpose :
Ophthalmodynamometry (ODM) is a non-invasive technique used to estimate central retinal artery (CRA) pressure, while transcranial doppler (TCD) provides direct imaging of hemodynamics in cerebral and cervical arteries via ultrasound imaging. This study aims to investigate the utility of ODM as an insight into compromised vascular hemodynamics by comparing patients exhibiting decreased perfusion pressure on ODM with the frequency of abnormal findings observed on direct ultrasound imaging of relevant vessels.
Methods :
A total of 36 patients with diminished mean ocular perfusion pressure (OPP) of 45 mmHg on ODM were further evaluated with TCD. Patients with ODM readings of OPP greater than 45 mmHg and percent error on ODM greater than 10% were excluded. The study cohort comprised of patients with hypertension (n = 30, 83%), hyperlipidemia (n = 22, 61%), type-2 diabetes mellitus (n = 17, 47%), and ocular ischemia (n = 3, 8%). The mean age was 79.2 ± 11.43 years old, with a female majority (n= 24, 66.6%). ODM measured the OPP, defined as the mean central retinal artery pressure (MCRAP) minus the mean intraocular pressure (mIOP). TCD evaluation parameters included resistance to blood flow (Pulsalitility Index, PI), vasomotor reactivity (VMR), and mean flow velocity (MFV) measurements. Major vessels captured on TCD included ophthalmic, carotid, vertebral, basilar, and cerebral arteries.
Results :
ODM measured a mean OPP of 32.14 ± 6.30 mmHg (range: 15.9–43.7 mmHg), MCRAP 48.96 ± 3.87, and mIOP 16.45 ± 5.49 mmHg. TCD revealed elevated PI in 15 (42%) patients, diminished VMR in 8 (22%) patients, and low MFV in 2 (5.5%) patients indicating abnormal systemic vascular findings. Further, 4 patients had both elevated PI and diminished VMR. A 50% left carotid siphon stenosis was observed in one patient. A left carotid siphon and middle cerebral artery stenosis of 50% were observed in another patient.
Conclusions :
Doppler ultrasonography and ODM in the ophthalmology clinic can serve as a useful routine examination in high-risk vascular disease patients. Uncovering microvascular disease or significant carotid stenosis can prompt ophthalmologists to immediately manage vascular disease and prevent the risk of potential stroke or blindness.
This abstract was presented at the 2024 ARVO Imaging in the Eye Conference, held in Seattle, WA, May 4, 2024.