Retinal hemodynamic effects of sub-Tenon anesthesia

Area of Science:

• Ophthalmology
• Anesthesiology
• Medical Imaging

Background:

• Sub-Tenon anesthesia is common in ophthalmology but may affect ocular hemodynamics.
• Patients with diabetic maculopathy (DM) or retinal vein occlusion (RVO) have compromised ocular perfusion.
• The potential impact of sub-Tenon anesthesia on these vulnerable eyes requires investigation.

Purpose of the Study:

• To evaluate the effect of sub-Tenon anesthesia on retinal vessel density (VD) and perfusion density (PD).
• To assess these changes in patients with DM or RVO undergoing cataract surgery.
• To determine if sub-Tenon anesthesia induces hemodynamic alterations in the retina.

Main Methods:

• Prospective study of 20 patients (10 DM, 10 RVO) undergoing unilateral cataract surgery with sub-Tenon anesthesia.
• Optical coherence tomography angiography (OCTA) used to measure VD and PD before and after anesthesia.
• Contralateral untreated eye served as a control; blood pressure and intraocular pressure monitored.

Main Results:

• Initial analysis suggested a negative association between sub-Tenon anesthesia and VD/PD.
• Further analysis excluding low-quality OCTA images revealed no statistically significant differences between treated and control eyes.
• No significant changes in blood pressure or intraocular pressure were observed post-anesthesia.

Conclusions:

• Sub-Tenon anesthesia did not induce significant retinal microvascular changes in the studied population.
• Observed VD and PD reductions were likely due to OCTA image artifacts, not true hemodynamic effects.
• The safety of sub-Tenon anesthesia regarding retinal hemodynamics in DM/RVO patients is supported by these findings.