Canadian Anaesthetists’ Society Journal

, Volume 33, Issue 2, pp 195–208

Intraocular pressure -physiology and implications for anaesthetic management

  • Anthony J. Cunningham
  • Peter Barry
Review Article

DOI: 10.1007/BF03010831

Cite this article as:
Cunningham, A.J. & Barry, P. Can Anaesth Soc J (1986) 33: 195. doi:10.1007/BF03010831


The major factors controlling intraocular pressure during surgery are the dynamic balance between aqueous humour production in the ciliary body and its elimination via the canal of Schlemm; the autoregulation and chemical control of choridal blood volume; the extraocular muscle tone and vitreous humour volume. Prior to surgical incision of the anterior chamber in open intraocular procedures, a low-normal intraocular pressure is mandatory to avoid the hazards of iris or lens prolapse and vitreous loss associated with sudden decompression. In general, the central nervous system depressant drugs, hypnotics, narcotics, major tranquillizers, volatile anaesthetic agents are associated with a reduction in intraocular pressure, with the exception of ketamine and possibly trichloroethylene.

The mechanism of action of anaesthetic agents in reducing intraocular pressure may involve a direct effect on central diencephalic control centres, reduction of aqueous production, facilitation of aqueous drainage or relaxation of extraocular muscle tone. Succinylcholine administration is associated with a significant rise in intraocular pressure, with a peak increase between two to four minutes following administration and a return to base line values after six minutes. The intraocular hypertensive effect may be due to a tonic contraction of the extraocular muscles, choroidal vascular dilatation or relaxation of orbital smooth muscle. Despite many claims to the contrary, no reported method to date has been shown to consistently prevent the intraocular hypertensive response to intravenous succinylcholine administration.

Because the non-depolarizing relaxants are associated with a reduced intraocular pressure, a barbiturate-non-depolarizing relaxant technique utilizing preoxygenation and cricoid pressure has evolved as the most commonly employed induction technique for the emergency repair of a penetrating eye injury. The alternative non-depolarizing relaxant pretreat-ment-barbiturate-succinylcholine technique may offer the advantages of more rapid onset of relaxation with only minor increases in intraocular pressure and in a carefully controlled rapid sequence induction technique may be the most acceptable method of handling emergency penetrating eye injuries.

Key words

eye: intraocular pressure anaesthesia: ophthalmic 
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Copyright information

© Canadian Anesthesiologists 1986

Authors and Affiliations

  • Anthony J. Cunningham
    • 1
  • Peter Barry
    • 1
  1. 1.Departments of Anaesthesia (Dr. Cunningham) and Ophthalmology (Dr. Barry)St. Vincent’s HospitalDublin 4Ireland

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