Ocular perforation following retrobulbar anesthesia for retinal detachment surgery

Inadvertent globe perforation during retrobulbar and peribulbar anesthesia. Patient characteristics, surgical management, and visual outcome

The authors report a series of 20 eyes from 20 patients in whom inadvertent perforation of the globe occurred during local anesthesia for ocular surgery. Perforation resulted from retrobulbar anesthesia in 18 eyes and from peribulbar anesthesia in 2 eyes. Nine (45%) of 20 eyes had an axial length greater than or equal to 26.00 mm. Combining this figure with axial length data for the general population and estimates for the risk of globe perforation during local anesthesia yields an approximate incidence of perforation in eyes with axial length greater than or equal to 26.00 mm of 1 in 140 injections. Proliferative vitreoretinopathy (PVR) developed in 8 of the 20 eyes (40%) in this series. Overall, 15 (75%) of the 20 eyes were successfully repaired, and, in five eyes (25%), the final visual acuity was 20/70 or better.

Peribulbar anesthesia for strabismus surgery

We prospectively studied 76 patients to analyze the effectiveness of peribulbar anesthesia during strabismus surgery. The patients, ranging in age from 14 to 77 years, were given anesthesia with standard preoperative medication and a peribulbar injection of a mixture of 2% mepivacaine hydrochloride and hyaluronidase. Only one of the 76 patients required an additional injection of anesthetic to achieve adequate anesthesia. No morbidity was associated with the peribulbar anesthesia. Local anesthesia, particularly retrobulbar anesthesia, has been used as an alternative technique in an attempt to reduce the morbidity and mortality associated with general anesthesia in ocular surgery, particularly in those patients with high-risk characteristics. Even with retrobulbar anesthesia, however, there is a risk of morbidity and, in rare cases, mortality. Our results suggest that the use of peribulbar anesthesia is a safe and effective means of anesthesia in strabismus surgery because of minimal associated morbidity.

Extracapsular cataract extraction under local anaesthesia without retrobulbar injection

Day-case cataract surgery and the need for local anaesthesia are likely to increase. Retrobulbar (and peribulbar) anaesthetic injection is a common technique in cataract surgery, but serious complications are persistently reported. Subconjunctival injection is an alternative that avoids these risks. This retrospective study compares two groups of patients that underwent extracapsular cataract surgery under local anaesthetic. One group (retrobulbar) had uncomplicated retrobulbar injection with bupivicaine and hyaluronidase. The other group (non-retrobulbar) had superior bulbar, subconjunctival infiltration with bupivicaine and hyaluronidase. The operative complications and postoperative visual outcomes were similar in both groups. These results may encourage the investigation and adoption of the subconjunctival alternative to retrobulbar anaesthetic injection in cataract surgery.

Local anaesthesia for eye surgery. The peri-ocular technique

A technique of peri-ocular infiltration of local anaesthetic for eye surgery is described. The ease of administration of this form of local blockade is highlighted and its low propensity for complication compared with retrobulbar blockade. The involvement of anaesthetists in the performance of local anaesthesia for ophthalmic surgery that utilises this technique is encouraged.

Complications of radial and transverse keratotomy

Radial keratotomy for myopia and transverse keratotomy for astigmatism are the most commonly performed refractive surgical procedures. A decade of experience with modern techniques has produced considerable literature on the complications of keratotomy. Vision-threatening complications (bacterial keratitis, traumatic rupture of the globe through weakened keratotomy scars, endophthalmitis, cataract formation from surgical trauma to the lens) are quite rare, occurring in less than 1% of eyes in published series. The most common side effects affect most patients in the first few months after surgery: pain for 24 to 48 hours, transient glare and light sensitivity, and fluctuating visual acuity. The most common persistent complications are overcorrection and undercorrection. Persistent irregular astigmatism occurs in almost all cases in the region of the incision scars, but it is rarely severe enough to reduce spectacle acuity. Most individuals have mild glare, but this is rarely disabling. Diurnal variation of refraction in visual acuity occurs commonly, but the magnitude of the fluctuation is seldom enough to require multiple pairs of spectacles. Longterm refractive stability occurs in approximately half of eyes by six months, but approximately one in four eyes will experience continued change over six months to four years. Complications, such as scarring from intersecting keratotomy incisions, irregular astigmatism resulting from multiple reoperations, and overcorrections with the attendant early onset of symptomatic presbyopia are becoming much less frequent.

Principles of ophthalmic anesthesia

Ophthalmic surgery presents the anesthesiologist with many unique challenges. The exigencies of this subspecialty include a comprehensive knowledge of ocular physiology and pharmacology and an understanding of the anesthetic implications intrinsic to a wide variety of ophthalmic procedures.

Regional anaesthesia for 12,000 cataract extraction and intraocular lens implantation procedures

Twelve thousand regional anaesthetics for cataract extraction and intraocular lens implantation surgery were administered by one anaesthetist over a period of 52 months in a free-standing outpatient surgical facility. The ophthalmologist, who did all the operations, assessed the quality of the blocks using an objective scoring system which is described. The first 3,595 patients had retrobulbar and seventh nerve blocks. The following 1,640 patients had higher volume retrobulbar blocking alone. The next 3,478 had peribulbar blocks, followed by 2,226 who had a modified form of peribulbar blocking. A final group of 1,061 had a combination of peribulbar and periorbital blocks with added retrobulbar injection if indicated. As the method of blocking evolved, the more closely was the goal of safe, painless and effective regional anaesthesia approached. The requirements for effective anaesthesia of this type are presented, the complications described and the importance of familiarity with the anatomy of the orbit and its contents stressed.

Ocular perforation from a retrobulbar injection

Proliferative vitreoretinopathy occurred in three of seven cases of ocular perforation from retrobulbar injection, resulting in a visual acuity of 20/200 or worse. Direct macular injury and macular pucker occurred in two cases each. Needle injury exit sites were in the posterior pole in all cases. Predisposing factors were not experimentally verified, but associated conditions included axial myopia, multiple injections, traditional superonasal gaze position, previous retinal buckling procedure, and enophthalmos.

Ocular complications associated with retrobulbar injections

The authors describe six complications, of retrobulbar injections documented by fundus photography and fluorescein angiography. These include (1) injection of corticosteroid into the posterior ciliary arterial circulation resulting in emboli in the vasculature of the choroid and the optic nerve head; (2) injection of corticosteroid into the ophthalmic artery resulting in emboli in both the choroidal and retinal circulations; (3) presumed injection of lidocaine and air into the optic nerve sheath adjacent to the globe with extension anteriorly into the subretinal space and the space between the posterior vitreous and the internal limiting membrane; (4) occlusion of the central retinal artery without an associated retrobulbar hemorrhage; (5) trauma to and partial injection of lidocaine in the central retinal artery with embolization into the retinal circulation; and (6) presumed injection of lidocaine into the optic nerve sheath producing a combined central retinal vein and artery occlusion. Alternative techniques that might decrease the incidence of complications associated with retrobulbar injections are discussed.

Respiratory arrest after retrobulbar block

We describe a patient who suffered respiratory arrest some minutes after retrobulbar block before cataract extraction. She was managed by artificial respiration for 20 min, and after the had recovered from this potentially fatal complication cataract extraction was performed without complications and without any neurological sequelae. Retrobulbar blocks, as well as other retrobulbar, injections, should be performed only in safe situations. Individuals trained in airway maintenance and ventilatory support should be immediately available, and the patient must be monitored for at least 10 min after the retrobulbar injection.

Life-threatening complication of retrobulbar block. A hypothesis

After routine retrobulbar injection of a 4-ml 1:1 mixture of 0.75% bupivacaine, and of 2% lidocaine and one ampule of hyaluronidase for cataract extraction, the patient sustained bilateral opthalmoplegia, blindness, central respiratory arrest, and loss of consciousness. Neurologic examination shortly thereafter suggests that this may be a result of accidental subarachnoid injection. Prompt recognition and treatment reversed a life-threatening situation.

Contralateral amaurosis after retrobulbar injection

Contralateral amaurosis after retrobulbar injection of local anesthetic agents occurred in two patients, a 64-year-old woman and a 57-year-old man. The amaurosis resulted from migration of the anesthetic agents to the optic chiasm and contralateral optic nerve via the subarachnoid space. In both cases visual acuity returned to preoperative levels within 90 minutes. A modified technique in which patients look straight ahead or slightly downward and outward during retrobulbar injection, as opposed to the traditional upward and inward positioning of the globe, avoids inadvertent piercing of the sheaths of the optic nerve and injection of substances into the subarachnoid space.

Contralateral decreased visual acuity and extraocular muscle palsies following retrobulbar anesthesia

Numerous complications resulting from retrobulbar injections in the injected eye and orbit have been reported. A rare complication of retrobulbar anesthesia is the occurrence of decreased visual acuity and extraocular muscle palsies in the contralateral eye. We report three cases of contralateral dysfunction of cranial nerves II and III, following retrobulbar anesthesia. None of the patients suffered permanent sequelae. Several methods of decreasing the probability of such an occurrence are discussed.

Current concepts in retrobulbar anesthesia

Recently there have been major advances in the field of retrobulbar anesthesia. New agents which allow prolonged anesthesia and akinesia have been introduced. Several new techniques to administer retrobulbar anesthesia have been developed. The toxicity of local anesthetics and the complications arising from such injections have been studied, and ways to avoid and manage them have been expanded.

The CT-topography of retrobulbar anesthesia. Anatomic-clinical correlation of complications and suggestion of a modified technique

The anatomic relationship of an injection needle as traditionally placed in retrobulbar anesthesia to optic nerve, orbital vessels and eye muscles is demonstrated by computed tomography. The clinical complications of retrobulbar injections are reviewed and correlated to the orbital topography in different positions of gaze, as analyzed in anatomic sections and CT images. The results indicate that with the transitional technique of retrobulbar injection the most important orbital structures are in the immediate neighbourhood of the needle. A different injection technique is discussed.