Principles of Opthalmic Anaesthesia

Intra-Ocular Pressure

Control of intraocular pressure of IOP is important in many complex eye operations.
* Blood volume * Avoid hypertension
Choroidal vessels cannot autoregulate and will dilate. * Vasodilation * Hypoxaemia * Hypercarbia * ↑ metabolic rate * Low venous pressure
Greatest determinant.
* Slight head up facilitates venous drainage * Minimise coughing with extubation * PONV prophylaxis * Anaesthetic blocks * Peribulbar associated with an ↑ in IOP * Sub-Tenon’s blocks associated with ↓ in IOP

Treatment of Raised IOP

Intravenous: * Acetazolamide * Mannitol

Topical: * Atropine * Timolol

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References

1. Murgatroyd H, Bembridge J. Intraocular pressure. Contin Educ Anaesth Crit Care Pain. 2008;8(3):100-103. doi:10.1093/bjaceaccp/mkn015