Complications After Sub-Tenon’s Eye Block

Abstract

The use of blunt instead of sharp needles for ophthalmic local anesthesia techniques has reduced the incidence of injury to intra-orbital structures. This case review of complications from blunt needle sub-Tenon's block suggests that sight-threatening or even life-threatening complications can still occur.

Sub-Tenon's anesthesia: an update

“…Massaging of the globe in an attempt to disperse the local anesthetic solution has been shown to cause peaks in IOP of up to 400 mmHg16 and is associated with reports of bleeding in the anterior chamber 17. Gentle, steady pressure on the globe with a finger resting over the incision site will reduce local subconjunctival bleeding, but massage should not be performed.…”

“…Also, accidental perforation of the optic nerve sheath due to excessively deep dissection with the Westcott scissors is theoretically possible. There have been two cases of transient loss of consciousness17 and one death possibly caused by central spread of local anesthetic to the brain stem following STB 50. It must be borne in mind that this complication is much rarer than with a retrobulbar block.…”

Complications of Ophthalmic Regional Blocks: Their Treatment and Prevention

“…Major complications such as rectus muscle paresis [51], orbital and retrobulbar haemorrhage [52, 53], globe perforation [54], orbital cellulitis [55,56,57], muscle trauma [58], central spread of local anaesthetic agent [59], optic neuritis [60], choroidal and vascular damage [61] have been described in case reports following the use of posterior metal sub-Tenon’s cannula. The exact mechanism of these complications is not clear but they may be due to forceful or inappropriate placement of the metal posterior sub-Tenon’s cannula.…”

Comparison of olive tipped and conventional steven′s cannula for sub-tenon ophthalmic anesthesia

“…[2] However, some complications of STB have also been reported including, rectus muscle paresis, diplopia, central spread, orbital cellulitis, and/or other vascular damage. [3] Globe perforation after STB is a rare but catastrophic complication. [45] The risk factor is higher with an inexperienced user, poor technique and in a previously operated eye due to adhesions.…”