October 2018

CATARACT

Presentation spotlight
Peribulbar anesthesia in patients with axial myopia for phacoemulsification


by Stefanie Petrou Binder, MD, EyeWorld Contributing Writer

“Using peribulbar local anesthesia for phacoemulsification in patients with axial myopia is an effective technique.”
—Theodora Stavropoulou, MD

 

Peribulbar anesthesia provided adequate analgesia, sensory anesthesia, and akinesia in highly myopic patients with no serious complications

The choice of ocular anesthesia for cataract surgery largely depends on the surgeon’s personal preference, skills, and the patient’s cooperation. Akinesia and anesthesia of the globe, lids, and adnexa need to be achieved, as well as adequate postoperative analgesia. Local anesthesia of the eye is divided into topical, intracameral, and infiltration (regional), the last of which includes retrobulbar block, peribulbar block, sub-Tenon’s block, and subconjunctival block. Topical anesthesia is today’s mainstay, however, in patients in whom topical anesthesia may not do the trick, cataract surgeons need to consider more reliable approaches. A new study attests to the safety and efficacy of the peribulbar approach in patients with axial myopia.
The aim of this study was to evaluate the efficacy of peribulbar anesthesia for phacoemulsification in 40 patients with axial myopia. The patients were monitored for major or minor complications and both surgeon and patient satisfaction was assessed.
According to Theodora Stavropoulou, MD, Department of Ophthalmology, Athens University Clinic, Athens, Greece, who was the first author of the study that was presented as an e-poster at the 2017 ESCRS Congress, peribulbar anesthesia is an important tool for the eye surgeon to have for highly myopic patients. “Peribulbar anesthesia provides immobility of the eye, something needed in more complicated surgeries, as surgery in the high myopic can be. In our clinic, we recommend this type of anesthesia for more demanding cataract surgeries, although the majority of surgery happens under eye drop anesthesia,” Dr. Stavropoulou said.
The study included 40 patients with axial myopia. Dr. Stavropoulou and her team used lidocaine and ropivacaine 1:1, 4 ml in total, through a 23-gauge, 0.5 mm needle. Anesthesia was administered by the same surgeon, who was experienced with peribulbar injections.
The results showed that adequate akinesia developed within 15 minutes in 70% of the patients. Adequate analgesia developed in almost all patients, except for two in which intracameral anesthesia was added. The cataract surgeries were otherwise uneventful, involving IOL implantation, and no globe perforations or other major complications from the anesthetic injection. Dr. Stavropoulou noted 25/40 patients with posterior staphylomas.

Axial myopia: Risk factor

Regional anesthesia of the eye, such as peribulbar block, is generally safe and reliable, however, complications can include needlestick injuries to the globe, which can be sight-threatening. A study that examined the charts of 23 patients who experienced needle perforations from retrobulbar or peribulbar injections reported that risk factors for globe penetration included high myopia, previous scleral buckling procedures, injection by a non-ophthalmologist, and poor patient cooperation during the injection. They showed that 70% of perforations were from sharp needles, and 30% were from blunt needles.1
In another, unrelated series of 20 eyes in which there was inadvertent perforation of the globe during retrobulbar or peribulbar anesthesia, investigators calculated that needle damage in patients with high myopia of equal to or greater than 26 mm axial length was 30 times more common with an inferior temporally placed peribulbar block, compared with eyes that had normal axial lengths of 23 mm or less.2
Peribulbar anesthesia generally involves two injections roughly 20 minutes before surgery, placed above and below the orbit. It blocks the ciliary nerves, which prevent movement of the globe, but not the optic nerve. “Peribulbar is not complicated to place, indeed we use the inferior temporal approach,” Dr. Stavropoulou said. “The biggest risk is perforation of the eye, especially in eyes with high axial length. The surgeon needs to be experienced and proceed carefully while administrating the injection.”

Other options

Overall, infiltration anesthesia is contraindicated in uncooperative patients. The retrobulbar approach involves injection of anesthetic into the intraconal eye compartment, while peribulbar anesthesia is injected into the extraconal eye compartment, which helps in avoiding most of the complications associated with the retrobulbar approach, such as ocular perforation, retrobulbar hemorrhage, oculo-cardiac reflex, and optic nerve damage, among others. Peribulbar is technically easier to place, is less painful, and is associated with less IOP rise than retrobulbar anesthesia. It is more difficult to achieve the same complete anesthesia as with retrobulbar anesthesia, but it is still widely used given its lower complication rate.
Some of the complications associated with peribulbar block include spread of local anesthetics to the contralateral eye, periorbital ecchymosis, and transient blindness.
According to Dr. Stavropoulou, even the small setbacks of surgery that she experienced with this approach were easy to overcome. “The rise of the intraocular pressure was not a problem, since after the injection we put some pressure over the globe, so the majority of the liquid was absorbed. We usually wait about 20 minutes before proceeding to the operation,” she explained. “Also, in the group of patients without adequate ocular immobility, the surgery continued as per normal, with some cooperation from the patients.”
Other options to achieve adequate anesthetic and analgesic effects for this patient group include topical and intracameral anesthesia. A study that compared the level of pain during phaco and IOL implantation in 301 eyes using three different types of anesthesia, topical, intracameral, and sub-Tenon’s, found that while intracameral lidocaine provided sufficient pain suppressive effects in eyes without high myopia, sub-Tenon’s anesthesia was found to be better in eyes with high myopia.3 This study substantiated that a deeper, more far-reaching anesthetic approach might be required in highly myopic eyes.
The majority of patients presenting for cataract surgery are older than 70 years of age, and many have preexisting medical conditions. Regional anesthesia may therefore be preferable, allowing good eye immobilization and pain blocking effects, while still allowing minimal disruption to patients’ daily routine. “Using peribulbar local anesthesia for phacoemulsification in patients with axial myopia is an effective technique. It causes immobility, which is important in complicated cases,” Dr. Stavropoulou said.

References

1. Hay A, et al. Needle penetration of the globe during retrobulbar and peribulbar injections. Ophthalmology. 1991;98:1017–24.
2. Duker JS, et al. Inadvertent globe perforation during retrobulbar and peribulbar anesthesia. Patient characteristics, surgical management, and visual outcome. Ophthalmology. 1991;98:519–26.
3. Hosoda Y, et al. A comparison of patient pain and visual outcome using topical anesthesia versus regional anesthesia during cataract surgery. Clin Ophthalmol. 2016;10:1139–44.

Editors’ note: Dr. Stavropoulou has no financial interests related to her comments.

Contact information

Stavropoulou
: stavropouloudora1@gmail.com

Peribulbar anesthesia in patients with axial myopia for phacoemulsification Peribulbar anesthesia in patients with axial myopia for phacoemulsification
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