Non-invasive Assessment of Central Retinal Artery Pressure: Age and Posture-dependent Changes

Maja Kostic, Phillip Gordon, Pedro Monsalve, Hong Jang, Byron L. Lam, John Guy, John McSoley, Luis Vazquez, Elizabeth Hodapp, Vittorio Porciatti

Research output: Contribution to journalArticlepeer-review

Abstract

Purpose: Assessment of Ocular Perfusion Pressure (OPP) requires estimation of the Mean Central Retinal Artery Pressure (MCRAP) [OPP = MCRAP-IOP]. In a seated position, MCRAP is currently estimated as 2/3 of the Mean Arterial Pressure (MAP) to account for the hydrostatic reduction of MAP at eye level. We tested a surrogate method for direct MCRAP assessment by measuring MAP with Arm-Up and cuff at eye level (AUMAP) at different postures and ages. Methods: MAP and AUMAP were assessed in a mixed population of 136 subjects (mean age 44 ± 17.39 years) including healthy participants (N = 30) and patients with optic neuropathies (Glaucoma suspects, N = 14; Open-Angle Glaucoma, N = 26, LHON, N = 19; MS, N = 47) not expected to alter systemic blood pressure. None of the subjects had history of carotid stenosis or pharmacological treatment to regulate blood pressure. AUMAP was also tested in two subgroups in supine (N = 42) and −10° Head Down body Tilt position (HDT, N = 46). Results: In the seated position, both 2/3MAP and AUMAP increased with increasing age, however with steeper (2x) slope for AUMAP (P < .0001). With decreasing angle of body tilt, AUMAP increased while MAP decreased. The mean AUMAP/MAP ratio (posture coefficient) was, seated, 0.73 (SE 0.003); supine, 0.90 (SE 0.005); HDT, 0.97 (SE 0.005). In the seated position only, the AUMAP/MAP ratio significantly increased with age (P < .0001). Mean posture coefficients obtained with AUMAP were in the range of those based on either direct ophthalmodynamometric measurements or hydrostatic estimations. Conclusions: Surrogate measurement of MCRAP in individual subjects is feasible using the simple AUMAP approach that provides a straightforward estimation of OPP (OPP = AUMAP–IOP) at different body postures. The standard method OPP = 2/3*MAP-IOP in the seated posture underestimates OPP at older ages. Clinical estimation of OPP would benefit from the use of AUMAP, in particular for head-down postures.

Original languageEnglish (US)
Pages (from-to)135-139
Number of pages5
JournalCurrent Eye Research
Volume46
Issue number1
DOIs
StatePublished - 2021

Keywords

  • Ocular perfusion pressure
  • age
  • central artery pressure
  • mean arterial pressure
  • posture

ASJC Scopus subject areas

  • Ophthalmology
  • Sensory Systems
  • Cellular and Molecular Neuroscience

Fingerprint Dive into the research topics of 'Non-invasive Assessment of Central Retinal Artery Pressure: Age and Posture-dependent Changes'. Together they form a unique fingerprint.

Cite this