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Ophthalmic surgery is one of the most frequent surgical procedures requiring anesthesia in developed countries.1 Perioperative morbidity and mortality rates associated with eye (eg, cataract) surgery are low.2,3 Nevertheless, because patients with cataracts tend to be older and to have serious comorbidities,4–9 systematic preoperative evaluation should be performed to consider a patient eligible for surgery.9 Anesthetic management may contribute to the success or failure of ophthalmic surgery. A closed-claims analysis by Gild and coworkers10 found that 30% of eye injury claims associated with anesthesia were characterized by the patient moving during ophthalmic surgery. Clinical strategies to ensure patient immobility are essential, as blindness is the outcome in many cases of eye injury. Most problems occurred during general anesthesia. Quicker patient rehabilitation and fewer complications are the main reasons why many ophthalmic surgeons are choosing local (LA) over general anesthesia.11–13

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In the past, regional anesthesia on the eye typically consisted of retrobulbar anesthesia (RBA), with the surgeon performing the block. Widespread use of the phacoemulsification technique, however, has changed the anesthesia requirements for this technique—total akinesia and lowered intraocular pressure are no longer necessary. Consequently, conventional RBA is used less frequently today, particularly since it carries a greater risk for complications than do the emerging techniques. The newer techniques do not provide akinesia of the globe paralleling that of the retrobulbar block; however, they are useful for anterior segment surgery, especially cataract surgery. Accurate knowledge of anatomy and of various anesthetic techniques are necessary to determine the appropriate block for specific clinical situations. This chapter will review the relevant anatomy of the eye, classic (retro and peribulbar) needle block techniques, emerging anesthesia techniques, and choice of LAs and adjuvant agents.

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The cavity of the orbit has a truncated pyramid shape, with a posterior apex, and a base corresponding to the anterior aperture. The orbit contains mainly adipose tissue, and the globe is suspended in the anterior part. The four rectus muscles of the eye insert anteriorly near the equator of the globe (Figure 21–1). Posteriorly, they insert together at the apex on the tendineus anulus communis of Zinn, through which the optic nerve enters the orbit. The four rectus muscles delineate the retrobulbar cone, which is not sealed by any intermuscular membrane.14–17 Sensory innervation is supplied by the ophthalmic nerve (first branch of the trigeminal nerve [V]), which passes through the muscular cone (Figure 21–2). The trochlear nerve (IV) provides motor control to the superior oblique muscles, the abducens nerve (VI) to the lateral rectus muscle, and the oculomotor nerve (III) to all other extraocular muscles. All but the trochlear nerve pass through the muscular conus. Injection of LA solution inside the cone will provide anesthesia and akinesia of the globe and the extraocular muscles. Only the motor nerve to the orbicularis muscle of the eyelids has an extraorbital course, coming from the superior branch of the facial nerve ...

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