Effects of sub-Tenon's anaesthesia on ocular hemodynamics.

OBJECTIVE

To research the effects of sub-Tenon's anaesthesia (STA) on ocular hemodynamics in patients with cataract using colour Doppler imaging (CDI).

DESIGN

Prospective clinical study.

PARTICIPANTS

Thirty-four eyes of 34 patients with age-related cataract.

METHODS

Peak systolic velocity (PSV), end-diastolic velocity (EDV), and resistive index (RI) values of the ophthalmic artery (OA), central retinal artery, and central retinal vein were measured by CDI before and immediately after performing sub-Tenon block using 2 mL of 2% lidocaine with adrenaline (1:200 000).

RESULTS

Both PSV and EDV values were significantly decreased after sub-Tenon injection in all the studied vessels of the patients. However, no important changes were observed in the RI values of the vessels.

CONCLUSIONS

STA markedly reduced ocular blood flow. The reduction may be more acceptable compared with other retrobulbar block methods. Sub-Tenon block should be performed carefully to senile patients with cataract with vascular occlusive disorder.