Abstract
Abstract: :
Purpose: In this study Color Doppler imaging was performed to investigate the effect of retrobulbar anesthesia on retrobulbar hemodynamics. Furthermore the additive effect epinephrine was examined. Methods: 36 patients (age 74.2 ±; 21 f, 15 m) with cataract were included in a prospective study. Color Doppler imaging (Siemens Sonoline Sienna) was performed before and directly after retrobulbar anesthesia and after cataract surgery to measure the peak systolic (PSV) and end-diastolic velocities (EDV) in the ophthalmic artery (OA), central retinal artery (CRA), and central retinal vein (CRV). In 18 patients Xylocain 2% without additives (2ml, retrobulbar transconjunctival) and in 18 patients Xylocain 2% with epinephrine 1:200 000 was used. Results: After retrobulbar anesthesia both groups had a significant reduction of the PSV (OA by 29%, p <0.0001; CRA by 22%, p<0.0001; CRV by 27% p<0.0001) and of the EDV (OA by 20%, p<0.0025; CRA by 20%, p<0.0001; CRV by 20%, p<0.0001). After surgery flow velocities raised again (PSV: OA by 23%, p<0.0001; CRA by 16%, p<0.0001; CRV by 14% p<0,0058 and EDV: OA by 37%, p<0.0001; CRA by 15%, p<0.0046; CRV by 18%, p<0.0027). The addition of epinephrine resulted in higher reductions and slower recovery of flow velocities (PSV: OA p<0.0013, CRA p<0.0001; EDV: CRV p<0.0076). Conclusions: Retrobulbar anesthesia induces a marked reduction of velocity in the retrobulbar vessels. The supplement epinephrine increases this effect and recovery is much slower. Particularly in patients with disturbed ocular hemodynamics (e.g. glaucoma) epinephrine should not be used to avoid irreversible functional damage.
Keywords: blood supply • cataract • drug toxicity/drug effects