Considering the latest advances in cataract surgery anesthesia, it seems logical that surgeons would predominantly employ topical anesthetics. Avoiding needle injections reduces or eliminates various risks such as bruising, globe penetration, and retrobulbar hemorrhage. However, surgeons debate over which approach provides the greatest degree of patient comfort without causing anesthesia-related complications. What are the benefits of using one form of anesthesia over another? Cataract & Refractive Surgery Today asked several leading surgeons to share their thoughts.
INCISIONAL ANESTHESIA
During cataract surgery, Steven Dewey, MD, of Colorado Springs, Colorado, injects the eye with 0.2 cc of nonpreserved 2% lidocaine subconjunctivally and as far superiorly as possible. If this approach proves difficult in a particular patient, he notes that injecting the anesthesia inferiorly is acceptable. Prior to the injection, Dr. Dewey applies one drop of 0.75% bupivicaine and then waits at least 1 minute before administering the lidocaine.
“Typically, the patient will not feel the lidocaine injection at all, but the deeper placement of this agent will spread and provide coverage superior to topical alone or topical with intracameral lidocaine,” he says.
With the incisional regimen, more patients will require sedation for anxiety or claustrophobia than for pain, although 75% to 80% of patients will require none. Dr. Dewey tells his patients that they will experience 20 to 30 seconds of a deep stinging sensation near the end of the surgery as he irrigates viscoelastic from the chamber angle and states, “it is highly unusual for a patient to complain about this brief discomfort, either during or after the procedure. In the past, I tried administering topical and intracameral anesthesia, but I was disappointed by patients' delayed visual recovery due to the intracameral lidocaine. The patients felt that they needed to describe this problem to me in detail.” In a similar vein, Dr. Dewey was impressed that most patients still felt the “pinch” of the wound's stretching during IOL implantation. He explains that this sensation was worse with a forceps than with an injector due to the greater stretching of the incision.
“I decided to inject just enough nonpreserved 1% lidocaine into the walls of the incision to make the stroma a bit hazy,” Dr. Dewey comments. “In the unsedated patient, this very nicely avoids the ‘pinch' but, more importantly, keeps the patient from involuntarily responding to it at a rather critical step during the surgery.”
NO-NEEDLE SUBTENON'S RETROBULBAR
When surgeons ask patients what they expect from eye surgery, the foremost answer is improved vision, according to Christopher Connor, MD, from Hanover, New Hampshire. A close second, he says, is that the patient does not want to feel anything during the procedure. Anxiety skyrockets when patients experience even slight pain during ocular surgery; they do not know if it will worsen while they are “trapped under the drape.”
Like Dr. Dewey, Dr. Connor prefers not to administer much sedation to his patients. The reason that Dr. Connor is committed to subTenon's retrobulbar anesthesia is its level of pain control. He points out that an absence of pain markedly reduces anxiety levels for the patient as well as the staff. In addition, the patient requires minimal IV sedation.
Interestingly, Dr. Connor has completely abandoned topical/intracameral anesthesia because of its remnant pain and the IV sedation it requires to keep the patient still. He elaborates that “the benefits of topical such as ‘it is safer' and ‘the patient can see immediately following [surgery]' do not stand up to ‘no-needle retrobulbar.' Here's why: No needle is used, period. It is very safe.” At the beginning of the procedure, the surgeon makes a small buttonhole incision through the conjunctiva/subTenon's capsule using scissors under direct microscopic visualization. He then passes a curved cannula through the opening and along the sclera approximate to the equator. Next, the surgeon sprays the anesthetic under the subTenon's capsule, and the sensory block occurs immediately. As a result, the procedure can begin right away (Figures 1 through 3).
Dr. Connor explains that the surgeon has the ability to titrate the effect of the block. If the patient needs to see immediately following the case—for instance, a functionally one-eyed patient—1% lidocaine (instead of the standard 2%) may be used for the block, because it wears off faster. In more prolonged cases such as combined retinal/anterior segment procedures, a longer-acting block such as marcaine 0.75% may be added.
“IV sedation has its risks,” says Dr. Connor. “As surgery moves more and more out of the hospital/OR-based setting, the use of staff anesthesia coverage will lessen. [The use of] IV sedation will have to lessen if cataract surgery is going to remain ‘systemically safe.'” He claims that using no-needle subTenon's retrobulbar blocks can greatly reduce [the use of] IV sedation. More than half of his patients do not require sedation, and he prescribes just 1 to 2 mg of IV midazolam (Versed; Hoffmann-La Roche Inc., Nutley, NJ) to the others.
Dr. Connor has used this block for more than 6 years in thousands of patients without incurring any systemic or localized side effects. This approach may be used in all ophthalmic procedures, not just cataract surgery. According to Dr. Connor, the no-needle subTenon's retrobulbar block is the “wave of the future”—safe, fast, repeatable, titratable, and inexpensive.
NO-ANESTHESIA CATARACT SURGICAL TECHNIQUE
Interestingly, Amar Agarwal, MD, based in Chennai, India, uses a no-anesthesia cataract surgery technique that he instituted in 1998. Dr. Agarwal stresses the importance of using a solid speculum with a locking mechanism to tighten the blades. He uses a 26-gauge needle to inject a viscoelastic (Figure 4A) into the anterior chamber at a position between the lateral rectus and the vertical rectus (superior or inferior rectus). This action distends the anterior chamber and also provides an entry point into the eye through which to pass a globe-stabilization instrument.
Next, Dr. Agarwal makes the clear corneal incision between the lateral rectus and the other vertical rectus. He suggests creating a long incision in order to avoid iris prolapse. He uses his dominant (right) hand to make the clear corneal tunnel, while his left stabilizes the globe with the straight instrument (Figure 4B). Dr. Agarwal does not make the incision temporally at 180º, because, he says, “if the patient has a strong Bell's phenomenon, the eye will move upward, but, if the two incisions are separated by approximately 90º, the surgeon can keep the eye centered by using the two instruments, one in each hand.” Using a special 28-gauge chopper that he designed, Dr. Agarwal passes the instrument through the sideport incision without extending it (Figure 5A). He does not need a forceps to stabilize the eye, because the second instrument can act as a globe-stabilization tool during all the steps of surgery, including I/A and implantation of the foldable IOL (Figure 5B).
Dr. Agarwal has performed a study with David Apple, MD, from Charleston, South Carolina, and his colleagues in which they compared pain and other factors between topical, topical and intracameral, and no-anesthesia surgical methods, and they found no difference between the three groups. The point he makes is that instilling the topical anesthetic drops or intracameral injection does not make a patient more cooperative. Dr. Agarwal mentions that numerous surgeons in various parts of the world (such as the US, Germany, and Spain) have executed this technique, which indicates that racial factors are nonexistent. “The most important point,” he concludes, “is that the surgeon should rework the anatomy of the cornea.” Once surgeons can ascertain the actual reason for why no-anesthesia cataract surgery works, Dr. Agarwal believes that they will open a wide range of possibilities in ophthalmic surgery.
PERIBULBAR
William Fishkind, MD, of Tucson, Arizona, uses peribulbar anesthesia in 70% of his patients. Preoperatively, he enhances the block with systemic sedation using Versed 1 cc, Fentanyl 1 cc (Baxter Pharmaceutical Products Inc., New Providence, NJ), and Brevital (Jones Pharma Inc., St. Louis, MO) when the block is delivered. Recently, he has substituted Propofol injectable emulsion 1% (10 mg/mL, Baxter Pharmaceutical Products Inc.), because Brevital has been difficult to obtain.
Dr. Fishkind believes that the risks of topical anesthesia (eg, an errant capsulorhexis or a ruptured posterior capsule due to patient movement) are probably equal to the risks of a retrobulbar hemorrhage, although both are exceedingly rare. “What I most like about regional block anesthesia,” says Dr. Fishkind, “is that the patient does not need to cooperate. There is absolutely no pain. Many times the patient will sleep through the procedure.”
Postoperatively, Dr. Fishkind's patients tell him that the procedure was easy to tolerate and painless; this does not happen when he uses topical anesthesia. For that reason, he believes that a block with systemic augmentation is more comfortable for the patient. Dr. Fishkind adds, “the role of anesthesia is to make the patient comfortable, free from pain, and allow the operative procedure to progress safely.” He is in favor of regional block anesthesia because it best meets these goals. For those who request topical anesthesia, want to be more awake, have a fear of anesthesia, or are fully anticoagulated, Dr. Fishkind offers topical anesthesia, which accounts for the remaining 30% of his patients.
LEANING AWAY FROM TOPICAL
“I still use topical for a majority of my cases, but I am leaning away from it more and more, [which is] the opposite of what you would expect with [having] more experience,” states Iman Pahlavi, MD, from the Manhattan Eye, Ear & Throat Hospital. She has discussed this situation with many professionals, especially those who run surgical centers, and says that they seem to agree. According to Dr. Pahlavi, the essence of the argument is this: It is impossible to predict with accuracy which patients will be cooperative under the operating microscope. She comments, “the effects of sedation can often confuse a normally cooperative patient, and the real issue arises when he is contracting his abdominal muscles and ‘valsalva-ing,' which causes the posterior capsule to surge forward.”
“Patients, however, are impressed with topical anesthesia and ‘no-patch' surgery, so there are some techniques that can offer the advantages of both types of anesthesia,” continues Dr. Pahlavi. Because a patch is only necessary if a lid block is used (the patient cannot close his eyes), retrobulbar anesthesia alone can be administered, eliminating the need for a patch (the patch will only address eye movement during surgery, not eye squeezing). The surgeon may also elect to use only a limited amount of 1% plain lidocaine (without marcaine or bupivicaine). To avoid the bruising that can bother patients postoperatively, the surgeon may use peribulbar anesthesia or administer the retrobulbar anesthesia through the forniceal conjunctiva instead of the skin. Regardless of the anesthesia chosen, Dr. Pahlavi recommends always checking the patient's blink response at the end of the case, because, if the patient can successfully close his eyes, a patch is unnecessary.
Steven H. Dewey, MD, practices in Colorado Springs, Colorado, with the Colorado Springs Health Partners. Dr. Dewey may be reached at (719) 475-7700; deweys@prodigy.net.Christopher S. Connor, MD, is Assistant Professor at Dartmouth Medical School, Hanover, New Hampshire, and the Director of Clinical Services for the Dartmouth-Hitchcock Medical Center. Dr. Connor may be reached at (603) 650-5123; Christopher.S.Connor@Hitchcock.org.
William J. Fishkind, MD, is Clinical Professor of Ophthalmology at the University of Utah and Co-Director of Fishkind and Bakewell Eye Care and Surgery Center in Tucson, Arizona. Dr. Fishkind may be reached at (520) 293-6740; wfishkind@earthlink.net.
Amar Agarwal, MD, practices at Agarwal's Eye Hospital in Chennai, India. Dr. Agarwal may be reached at +91 44 811 2592; dragarwal@vsnl.com.
Iman Ali Pahlavi, MD, practices at the Manhattan Eye, Ear & Throat Hospital. Dr. Pahlavi may be reached at (212) 838-9200; Iman@dodick.com.
