Effect of acute intraocular pressure changes on short posterior ciliary artery haemodynamics

Karen M. Joos, Matthew D. Kay, L. E. Pillunat, Alon Harris, E. Kym Gendron, W. J. Feuer, Brett E. Steinwand

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Abstract

Background/aims - Vascular insufficiency due to abnormal autoregulation has been proposed as a major factor in the development of glaucoma. The anterior optic nerve is primarily perfused by the short posterior ciliary arteries. The autoregulatory capacity of these vessels in response to acutely elevated intraocular pressure (IOP) was examined in normal human subjects. Methods - Colour Doppler imaging was performed on the short posterior ciliary arteries of 10 normal subjects at baseline and during four incremental IOP elevations. Using a scleral suction cup placed temporally, IOP was elevated to approximately 25, 30, 40, and 50 mm Hg. Additional measurements were performed immediately after pressure release. Systolic and diastolic flow velocities were measured and Pourcelot's resistivity index was calculated. Results - Systolic and diastolic flow velocities decreased linearly with each incremental increase in IOP (p < 0.001). Pourcelot's resistivity index increased linearly with each incremental increase in IOP (p < 0.001). Changes in end diastolic velocity, peak systolic velocity, and Pourcelot's resistivity index were linearly related to changes in IOP. Conclusion - The normal healthy eye is not able to autoregulate to maintain PCA blood flow velocities in response to acute large elevations in IOP.

Original languageEnglish (US)
Pages (from-to)33-38
Number of pages6
JournalBritish Journal of Ophthalmology
Volume83
Issue number1
DOIs
StatePublished - Jan 1 1999

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ASJC Scopus subject areas

  • Ophthalmology
  • Sensory Systems
  • Cellular and Molecular Neuroscience

Cite this

Joos, K. M., Kay, M. D., Pillunat, L. E., Harris, A., Gendron, E. K., Feuer, W. J., & Steinwand, B. E. (1999). Effect of acute intraocular pressure changes on short posterior ciliary artery haemodynamics. British Journal of Ophthalmology, 83(1), 33-38. https://doi.org/10.1136/bjo.83.1.33