March 1993
Volume 34, Issue 3
Free
Articles  |   March 1993
Stimulation of the cervical sympathetic nerves increases intraocular pressure.
Author Affiliations
  • J Gallar
    Institute of Neurosciences, University of Alicante, Spain.
  • J H Liu
    Institute of Neurosciences, University of Alicante, Spain.
Investigative Ophthalmology & Visual Science March 1993, Vol.34, 596-605. doi:
  • Views
  • PDF
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      J Gallar, J H Liu; Stimulation of the cervical sympathetic nerves increases intraocular pressure.. Invest. Ophthalmol. Vis. Sci. 1993;34(3):596-605.

      Download citation file:


      © ARVO (1962-2015); The Authors (2016-present)

      ×
  • Supplements
Abstract

PURPOSE: To test the hypothesis that a moderate electrical stimulation of the cervical sympathetic nerves in rabbits can increase intraocular pressure (IOP). METHODS: Electrical stimulations of the cervical sympathetic nerves were performed in anesthetized and conscious rabbits. Intraocular pressure, pupil size, and concentrations of aqueous humor components were monitored. RESULTS: In urethane-anesthetized rabbits, stimulations of 5 V and 1 ms at 2.5 Hz for 1 hr and then at 20 Hz for 2 hr caused a short inhibition of IOP decrease and a prolonged mydriasis. Concentrations of norepinephrine (NE), neuropeptide Y (NPY), and cyclic AMP (cAMP) in aqueous humor were elevated. Aqueous humor protein concentration was not changed. In rabbits anesthetized with ketamine, chlorpromazine, and pentobarbital, electrical stimulations with the same parameters caused prolonged increases in IOP and pupil size. Aqueous humor NE and cAMP concentrations increased, while NPY and protein concentrations did not change. When the stimulations were set at 5 Hz for 3 hr under this anesthesia, the increase of IOP and mydriasis persisted. However, only the NE concentration increased. In conscious rabbits, stimulations of 5 V and 1 ms at either 5 Hz or 20 Hz were delivered from a portable stimulator for 4 hr, starting 2 hr before the onset of the dark. Stimulations at 5 Hz caused an increase in IOP in the light phase. The circadian IOP elevation in the dark phase persisted. When 20 Hz was used, a transient fall in IOP was observed, and the circadian IOP elevation was eliminated. Aqueous humor NE concentration doubled in conscious rabbits receiving electrical stimulations at 5 Hz for 1 hr. CONCLUSIONS: A moderate electrical stimulation of the cervical sympathetic nerves can increase IOP in anesthetized rabbits and in conscious rabbits in the light phase.

×
×

This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.

×