Local anaesthetic techniques and pulsatile ocular blood flow

Area of Science:

• Ophthalmology
• Anesthesia
• Ocular Circulation

Background:

• Local anesthesia techniques are crucial for ophthalmic surgery.
• Understanding the impact of different local anesthesia methods on ocular hemodynamics is essential for patient safety.
• Pulsatile ocular blood flow (POBF) and intraocular pressure (IOP) are key indicators of ocular health.

Purpose of the Study:

• To compare the effects of peribulbar local anesthesia (LA) with and without balloon compression, and subconjunctival LA on POBF and IOP.
• To evaluate the impact of Honan's balloon compression during peribulbar LA on ocular hemodynamics.

Main Methods:

• A parallel group study involving 30 patients undergoing cataract surgery.
• Three groups received different anesthesia: peribulbar LA with balloon compression (n=10), peribulbar LA alone (n=10), and subconjunctival LA (n=10).
• POBF and IOP were measured using a modified Langham pneumatonometer immediately before LA, 1 minute after, and 10 minutes after LA.

Main Results:

• Subconjunctival LA showed no significant changes in POBF or IOP.
• Peribulbar LA (with and without balloon) significantly reduced POBF 1 minute after administration (p<0.01).
• Peribulbar LA with balloon compression significantly reduced IOP (mean drop of 4.82 mm Hg) and improved POBF at 10 minutes.

Conclusions:

• Peribulbar LA significantly decreases POBF, whereas subconjunctival LA does not affect it.
• Balloon compression during peribulbar LA effectively reduces IOP and enhances POBF.
• These findings are clinically relevant for patients with compromised ocular circulation or glaucoma.