Original Articles
Effects of peribulbar anesthesia on ocular blood flow in patients undergoing cataract surgery

https://doi.org/10.1016/S0002-9394(99)00066-5Get rights and content

Abstract

PURPOSE:

The effects of extraconal, peribulbar anesthesia on ocular blood flow may be caused by concomitant elevations in intraocular pressure or direct pharmacologic alteration of vascular tone. We quantified the effect on ocular circulation with a new technique for assessment of ocular hemodynamics.

METHODS:

In a prospective study, ocular hemodynamics were measured before and 1 and 5 minutes after peribulbar anesthesia in 22 eyes with age-related cataract. Measurements included fundus pulsation amplitude with a laser interferometric method assessing the pulsatile choroidal blood flow and mean blood flow velocity as well as resistive index in the ophthalmic and central retinal artery with Doppler sonography. Systemic blood pressure and pulse were monitored throughout the period of ocular hemodynamic measurements.

RESULTS:

Fundus pulsation amplitude decreased significantly after peribulbar anesthesia (after 1 minute and 5 minutes: −13% and −8%; P< .001). In the central retinal artery, mean blood flow velocity dropped (−15%; P < .001) and resistive index increased (+3%; P = .02) 1 minute after peribulbar anesthesia compared with baseline. There were no changes in ophthalmic artery hemodynamics. Intraocular pressure was elevated 1 minute after peribulbar anesthesia (+29%; P = .003) but reached baseline values after 5 minutes.

CONCLUSION:

Pulsatile choroidal blood flow and retinal blood flow velocities were reduced after peribulbar anesthesia. These reductions were still present 5 minutes after peribulbar anesthesia, when intraocular pressure had returned to baseline values. This supports the theory of drug-induced vasoconstriction after peribulbar anesthesia. A loss of vision may be a risk of peribulbar anesthesia in patients who have compromised ocular blood flow before surgery.

Section snippets

Patients and methods

The study protocol was approved by the ethics committee of the University of Vienna, School of Medicine, Vienna, Austria and all patients signed an informed consent. In this prospective study, 22 eyes of 22 patients with age-related cataract (age range, 37 to 91 years; mean ± SD, 74.9 ± 15.3 years; 14 women and eight men) were studied. This number of patients was chosen according to the short-term variability of the methods of measurement applied.11 For color Doppler imaging, which has a lower

Results

Baseline mean arterial pressure and pulse rate were 101 ± 13 mm Hg (mean ± SD; confidence interval, 95 to 106 mm Hg) and 71 ± 12 per minute (confidence interval, 66 to 76/min), respectively. Baseline values of ocular hemodynamic measures were as follows: fundus pulsation amplitude, 3.6 ± 1.0 μm (confidence interval, 3.1 to 4.0 μm); mean blood flow velocity and resistive index in the ophthalmic artery, 22.5 ± 6.1 cm per second (confidence interval, 19.6 to 25.4 cm/s) and 0.85 ± 0.05 (confidence

Discussion

The decrease in fundus pulsation amplitude after peribulbar anesthesia reflects a decrease in pulsatile choroidal blood flow. In addition, the decrease in mean blood flow velocity and the increase in resistive index in the central retinal artery indicate a fall in retinal blood flow. This result is in accordance with earlier studies of peribulbar anesthesia–induced effects in ocular hemodynamics.7, 8 By contrast, the lack of effect on mean blood flow velocity and resistive index in the

References (22)

  • D.B. Davis et al.

    Posterior peribulbar anesthesiaan alternative to retrobulbar anesthesia

    J Cataract Refract Surg

    (1986)
  • R.C. Hamilton

    Retrobulbar block revisited and revised

    J Cataract Refract Surg

    (1996)
  • D.B. Davis et al.

    Peribulbar anesthesiaa review of technique and complications

    Ophthalmol Clin North Am

    (1990)
  • R. Bowman et al.

    Intraocular pressure changes after peribulbar injections with and without ocular compression

    Br J Ophthalmol

    (1996)
  • N. Joshi et al.

    An assessment of intraocular pressure during fractionated peribulbar anaesthesia

    Eye

    (1996)
  • T. Gillart et al.

    The effects of volume and speed of injection in peribulbar anaesthesia

    Anaesthesia

    (1998)
  • V. Hessemer et al.

    Veranderungen der uvealen und retinalen Hamodynamik durch Retrobulbaranasthesie mit unterschiedlichen Injektionsvolumen. Fortschr Ophthalmol

    (1989)
  • V. Hessemer

    Anasthesie-Effekte auf den okularen Kreislauf

    Fortschr Ophthalmol

    (1991)
  • L. Schmetterer et al.

    Topical measurement of fundus pulsations

    Opt Eng

    (1995)
  • L. Schmetterer et al.

    The effect of isoproterenol, phenylephrine and sodium nitropusside on fundus pulsations in healthy volunteers

    Br J Ophthalmol

    (1996)
  • L. Schmetterer et al.

    Noninvasive investigations of the normal ocular circulation in humans

    Invest Ophthalmol Vis Sci

    (1998)
  • Cited by (0)

    View full text