Reprinted with permission from Dillman DM. Anesthesia for cataract surgery. Chapter 6. In: Wallace RB III, ed. Refractive Cataract Surgery and Multifocal IOLs. Thorofare, NJ: Slack; 2000.
The challenges surgeons face in lens/IOL surgery — to identify and obtain the elusive "state of the art" status — can be staggering. Many of these challenges are described in this tutorial.
The purpose of this section is to tell you how to dilate a pupil quickly and efficiently. I learned the technique from colleagues whom I believe learned it from Jim Gills, MD, at the 1999 American Academy of Ophthalmology meeting. However, the credit for the concept goes to Ken Rosenthal, MD. He developed the basic process in 1992 and presented it at the 1993 American Society of Cataract and Refractive Surgery meeting.
Following are the steps for your preoperative nursing staff to follow:
1. Create a dilating "cocktail." The ingredients of this concoction are a mixture of the preoperative drops you currently use. The exact amounts you will determine by trial and error. In my practice, I use:
These agents are mixed together to give a total of 7 cc of the mixture.
2. Soak small cotton balls in the mixture. We use prerolled dental pledgets (they are available in various sizes; we use size #3). Instead of cotton, you may also cut instrument wipes into small pieces.
3. Upon arrival at the surgery facility, place one or two drops of your preferred topical anesthetic (tetracaine, proparacaine, etc.) into the inferior conjunctival fornix.
4. Place a soaked cotton ball into the inferior conjunctival fornix. We try to line it up with the pupil.
5. Allow 30 minutes to achieve a dilated pupil without the inconvenience of repeated applications.
6. Once in the operating room, have the assistant who prepares the eye and skin remove the cotton ball and discard it.
I do not know who deserves the credit as the first cataract surgeon to use topical anesthesia. However, I know of at least two earlier reports that were brought to my attention by Charles H. Williamson, MD.1 In 1910, Julius Hirschberg, MD, reported the use of a 2% cocaine solution in thousands of cataract surgeries and "encountered only advantages, never a single disadvantage." Using a combination of topical anesthesia and superior subconjunctival lidocaine injection, R. Smith, MD, of London, performed planned extracapsular cataract extraction (ECCE) in 175 cases from 1985 to 1988.2
However, Richard Fichman, MD, is responsible for introducing topical anesthesia to small-incision cataract surgery. His foresight and courage to challenge tradition have had a positive impact upon my ability to deliver full impact, state-of-the-art cataract surgery to my patients. In a personal interview, he was willing to share with me the road he traveled to reach such a grand destination.
Dr. Fichman’s arrival at topical anesthesia was along a path paved with a series of "whys" and "why nots." In 1991, after performing small-incision, self-sealing cataract surgery, he was struck by the fact that his patients experienced little pain from the cataract surgery. However, many patients experienced pain with the regional block and/or had nausea and malaise from the accompanying intravenous (IV) medications. A problem with a batch of Wydase (hyaluronidase, Wyeth) started the cascade. It gave him the opportunity to challenge: "Is Wydase necessary? Why do we use it? Why not try the block without it?" He stopped administering Wydase and observed no intraoperative or postoperative differences.
Next was bupivacaine HCl. When Dr. Fichman was a resident, he had been taught to use bupivacaine when performing ECCEs. "Why do I use it now with my current technique? Is it really necessary? Why not try the block without it?" He stopped incorporating bupivacaine and observed only positive differences (e.g., faster return of acuity, lid movement, and ocular movement).
After switching to lidocaine HCl, Dr. Fichman began to see some of his patients a few hours after surgery (rather than waiting until the following day). Within that time frame, he noted that good visual function was returning and the patients were happier without the traditional overnight patch. He was only one step away.
Later in 1991, he took a radial keratotomy (RK) course that, ironically, changed the course of cataract surgery. He learned that a Russian-style (uphill) RK incision could be made with only topical anesthesia. In some regard, that struck him as being potentially more troublesome than his tightly controlled small-incision cataract surgery.
Subsequently, in his practice, Dr. Fichman decreased his required lidocaine HCl 2% block from 5 cc to 4 cc. Then decreased it to 3 cc, then 2 cc, and then 1 cc. Then came the final "why not?"
In September 1991, Dr. Fichman performed his first small-incision cataract surgery using only topical tetracaine HCl. Understandably, he performed his first "10 to 15 cases with his heart in his throat." But, to his delight, he found these patients to be positively "different in every aspect." As a group, they were happier and more enthusiastic than his previous cataract surgery patients were.
Later that year, at a small ophthalmology meeting, for the first time, he shared with colleagues his discovery and technique. The regional anesthesia, injection anesthesia paradigm was now officially shifted, and the path made available for others to follow.3
History of Intraocular Anesthesia
To the best of my knowledge, the first published description of purposely placing an anesthetic agent into the eye was by Dr. Fichman.4 James Gills, MD, popularized intracameral lidocaine at the 1995 American Academy of Ophthalmology meeting. Many surgeons, including myself, began using it soon thereafter.
Is Intraocular Anesthesia Necessary?
Many surgeons believe that intracameral lidocaine is not additive to the topical component and, therefore, it offers no added value. They may use it under special circumstances, but for most surgeries, they use only topical anesthesia. I am a strong proponent of intraocular lidocaine and use it in 100% of cases, even when I use a block. Topical and intraocular lidocaine are synergistic. From this point forward, I will present them as a team.
Disadvantages of Injection
Placing a needle within
the orbit and then blindly injecting a liquid anesthetic carries with it many
potential problems.5-8 Disadvantages that are potentially life
threatening or sight threatening include sequelae such as cardiopulmonary
arrest or globe perforation (Table 1).There is also a category of "nuisance" side effects associated
with injection (i.e., they may be a nuisance to our patients, but
ophthalmologists have come to accept them as being part and parcel of injection
anesthesia), for example, pain, fear, ptosis, diplopia (Table 2).
Advantages of Injection
Regional injection
anesthesia is the well-established tradition for cataract surgery in the United
States. That comfort and acceptance are primary advantages (Table 3).
Disadvantages of Topical/Intraocular Anesthesia
There are many disadvantages associated with performing phacoemulsification
using only topical/intraocular anesthesia (Table 4).
Advantages of Topical/Intraocular Anesthesia
All
potential systemic and ocular disadvantages associated with injection
anesthesia can be avoided (Table 1 and
Table 2). Additionally, topical/intraocular anesthesia
is the fastest modality by which patients can return to postsurgical vision (Table 5).
Table 1. Potential Life- and Vision-Threatening Side Effects From Injection Anesthesia
Life-threatening
Vision-threatening
Table 2. Potential "Nuisance" Disadvantages from Injection Anesthesia
Table 3. Perceived Advantages of Injection Anesthesia
Table 4. Potential Disadvantages of Topical/Intraocular Anesthesia
Table 5. Advantages of Topical/Intraocular Anesthesia
The main indication for topical/intraocular anesthesia is a routine phacoemulsification case. I define a routine case as one in which the density of the cataract, the size of the pupil, and the depth of the anterior chamber are such that the surgeon expects the case to go smoothly.
Relative contraindications would be nonroutine cases. A nonroutine case involves circumstances that conceivably can take a surgeon outside his or her comfort zone. The comfort zone is going to vary considerably from one surgeon to another. Potential examples are extremely dense, black cataracts, small pupils, and weak zonules.
The contraindications are the easiest to identify and include any circumstance that would prevent or disrupt intraoperative communication and/or cooperation between the surgeon and the patient.
Harry Grabow, MD, has packaged these contraindications into what he calls the "Six Ds."9 The first three are systemic in nature: deafness, dementia, and dysphasia (here meaning the inability of the patient to effectively verbally communicate because of either a neurological disorder or the speaking of another language). The second three are ocular and have in common the compromise of the patient’s ability to reliably see the fixation light (the microscope light): dense cataract, degeneration of the macula, and dysfunctional ocular motility.
Attempting to identify the "personality profile" of the good and bad candidates is virtually impossible. Patients who are timid, anxious, or do not want to be informed of the steps in the procedure usually do well with topical anesthesia. The "I can take anything, Doc!" kind of patient may be less cooperative than originally perceived.
I usually do not recommend topical/intraocular anesthesia for patients who are sensitive (semicombative) to the light of the indirect ophthalmoscope during the preoperative examination. If a patient cannot tolerate the light of the indirect ophthalmoscope, he or she may not be able to tolerate the operating microscope light.
I conduct the blood pressure cuff/lid speculum tests prior to commencing the case. If a patient complains about extreme pain and discomfort from either the inflated blood pressure cuff or inserted lid speculum, I will not attempt to proceed with topical anesthesia. A patient who is sensitive to touch or pressure, in my opinion, would not perceive topical/intraocular anesthesia to be a pleasant experience. In fewer than 1% of the cases in which I encountered this sensitivity, I decided to stop and administer a short-acting, low-volume peribulbar block.
The ideal agent for topical anesthesia would have the following characteristics: rapid onset, no toxicity, deep anesthetic, would last as long as the case, and could be instantly reversed if necessary. This ideal agent does not exist. Three agents are commonly used: tetracaine 0.5%, Xylocaine 4% (lidocaine, Astra), and Marcaine 0.75% (bupivicaine HCl, Abbott). Proponents of each often say that their preferred agent causes less corneal toxicity9 and works better than the others. I have used them all and do not endorse one over the other.
Because of my familiarity with Xylocaine 4% for topical anesthesia for refractive surgery, I use it as my routine agent for cataract surgery. However, liquid Xylocaine 4% is available in a topical and a systemic (injectable) preparation. The topical form is often used for mucous membrane surgery, as might be performed by oral, and ear, nose, and throat surgeons. Ophthalmologists who use the injectable form as a topical agent for ocular anterior segment procedures are often more comfortable with its sterility. I use topical Xylocaine 4%.
Some surgeons are switching from liquid topical agents to lidocaine 2% jelly. It can be obtained as a sterile preparation from at least two sources: Astra makes a lidocaine 2% jelly used by anesthesiologists for intubation, and Urojet makes a lidocaine 2% jelly for urological techniques. Astra’s jelly is available in a 30-oz tube that can be sterilely subdivided into smaller amounts, depending on its intended use. It also is available in smaller 5-cc to 10-cc aliquots that potentially can be used as one per patient. The Urojet product is available in a 20-cc glass syringe that also can be sterilely subdivided. I prefer the Astra preparation because it provides better visibility for the surgeon.
There is a variety of ways that jelly can be used. Some surgeons prefer to use it both in the holding area and as part of the preoperative preparation, some for the preoperative preparation only. I find the use of jelly makes draping more challenging, so I apply a generous amount immediately after inserting the speculum. Lidocaine jelly provides topical anesthesia and serves as an effective lubricant for the cornea (the Astra preparation also contains hydroxypropylmethylcellulose). Therefore, the surgical assistant will rarely, if ever, need to squirt the cornea.
The majority of surgeons using topical/intraocular anesthesia use sterile, nonpreserved lidocaine 1%. Because the pH of commercially available lidocaine is in the acidic range (6.4), some patients experience a burning or stinging sensation when it is first injected into the anterior chamber. For this reason, Joel Shugar, MD, formulated a preparation that he calls "Shugarcaine," in which one part lidocaine 4% is sterilely mixed with three parts BSS Plus (balanced salt solution, Alcon).10 This results in a lidocaine 1% formulation at a gentler pH and, perhaps, is gentler to the endothelial cells. However, to my knowledge, no data show that lidocaine 1% is toxic to living, human corneal endothelial cells. Dr. Gills11 showed a 3% incidence of endothelial cell loss in his masked randomized prospective parallel group study of phacoemulsification performed with sterile, nonpreserved lidocaine 1% — a number that is comparable to phacoemulsification performed without intraocular lidocaine.
Naysayers of topical/intraocular anesthesia believe that surgeons administering topical/intraocular anesthesia are "snowing the patients with systemic medications" and are really doing a form of semiconscious sedation. When topical/intraocular anesthesia is properly administered, nothing could be further from the truth.
The main contraindication to topical/intraocular anesthesia is the inability of the patient to cooperate during the surgery. Therefore, significant sedation is not only unnecessary, it also is counterproductive and potentially dangerous.
For that reason, I have added the seventh "D" to Dr. Grabow’s six Ds: "Drugs… just say no."11 If the surgeon can attempt topical anesthesia only by administering a lot of sedation, I recommend the surgeon continue to use regional anesthesia.
Now that is not to say that sedation of any kind can never be used. Topical anesthesia patients, like all cataract surgery patients, are about to undergo a new and different experience in unfamiliar surroundings involving their eye and their future vision. They are bound to be at least somewhat nervous and anxious. While much of that can be alleviated by the demeanor, attitude, and communication techniques employed by the preoperative and intraoperative teams, I am not opposed to slowly titrated sedation for topical anesthesia.
When needed, we have found that 0.5 mg to 1.0 mg of IV Versed (midazolam HCl, Roche) is sufficient in the majority of cases. Many surgeons who use topical anesthesia prefer 10 mg of propofol.
In the unusual situation in which more sedation is indicated, the medication should be titrated. Remember, the goal in topical anesthesia is for everyone involved to be relaxed, attentive, and cooperative.
One misconception about topical anesthesia is that corneal tunnel incisions are required. That is incorrect. When I first began using topical anesthesia, I was making more scleral tunnel incisions than clear corneal incisions. Although the corneal approach is now my preferred technique, I would not hesitate to use topical anesthesia with a scleral incision.
A cataract surgeon does not have to change any aspect of his or her current phacoemulsification technique to accommodate topical/intraocular anesthesia. Bridle sutures, conjunctival peritomies, cautery, suturing, peripheral iridectomies can be performed safely and comfortably with the topical anesthesia protocol I have outlined (see protocol section). Switching to topical anesthesia requires a true paradigm shift3 not only for the surgeon but also for the entire office and operating room staff.
Topical anesthesia is effective with scleral tunnel incisions, combined phaco trabeculectomy, and trabeculectomy alone; it works well with small incision, anterior segment surgery.
I have no experience with a planned ECCE and topical/intraocular anesthesia. Although it can be done,12 I am hesitant to use topical/intraocular anesthesia in a planned ECCE because of the significant amount of intraoperative control the surgeon abdicates to ECCE.
Preoperative Counseling for Topical/Intraocular Anesthesia
When observing the administration of topical/intraocular anesthesia for the first time, visiting ophthalmologists frequently ask, "How do you inform the patient that he or she is going to have surgery done with eyedrops only?" I know of no better response than that from Dr. Fichman himself:
"Patients in my practice are made aware of the fact that topical anesthesia will be used during their cataract surgery. The information is presented in a positive light, emphasizing the elimination of intravenous sedation and the general sense that the patients will be ‘up and at ‘em’ almost immediately after surgery without pain, grogginess, or cosmetic deformity.
"The patient is not encouraged to choose between topical anesthesia and regional blocks. The former is enthusiastically presented as the preferred method. Notably, many of the patients have sought out my services precisely to avoid retrobulbar or peribulbar blocks, or to regain vision immediately without the need of an eye patch.
"One of my initial concerns in adopting topical anesthesia to cataract surgery was how to ‘bring the patient along’ as a partner in the venture. It was my feeling at the time, and one that continues after more than 1,000 cases, that no purpose is served by telling an elderly patient that a controversial technique is about to be used requiring perfect fixation at the risk of substantial complications.
"The fact that fixation during this procedure is almost natural is a difficult concept for the majority of cataract surgeons to fathom; in fact, the procedure’s inexplicable ease is truly its beauty. If surgeons themselves are unable to fully appreciate the realities of cataract surgery under topical anesthesia, there is little reason to expect elderly patients, already apprehensive about the surgery, to assimilate the medical subtleties of the approach and feel comfortable in making an informed decision.
"What appears on the surface to be ethical (an exhaustive informed consent emphasizing the novelty of the procedure and a reliance on voluntary eye movement, potential complications from noncompliance) seems almost inhumane (i.e., expecting an emotionally charged patient to make a rational decision on this point). Just as a prolonged informed consent regarding the benefits and risks of phacoemulsification versus planned ECCE would be cumbersome and counterproductive, so also is a discussion of topical anesthesia versus local injection. The patient is not prepared to judge nor should the patient be asked to judge facets of surgery, such as phaco versus ECCE, two hands versus one hand, scleral flap versus corneal incision, one stitch versus no stitch, iris plane versus endocapsular, etc.
"The onus for these decisions falls to the surgeon. Once the surgeon is confident that a particular technique is beneficial in his or her hands, the details become elements of the overall technique. It is a typical aspect of surgical medicine that a patient readily accepts all facets of the surgeon’s regimen. Whatever circumstances brought the patient into the surgeon’s care, the relationship in the preoperative period is one based almost entirely on trust.
"Once I became convinced that cataract surgery with topical anesthesia was a superior technique, I naturally felt it imperative to communicate this belief to my patients. Our confidence in the overall quality of care we deliver — including the success and effectiveness of our anesthesia technique—permeates the patient’s experience at my practice, extending even to the attitude and body language of the physician and staff."
Although surgeons do not use the topical/intraocular anesthesia protocol, in my research, I have not found major variants. Following is my protocol for topical/intraocular anesthesia,13 as well as any interesting variations.
Preoperative/Holding Area
Tuberculin syringes (1
cc) are filled with topical Xylocaine 4%. A syringe is assigned to each
individual patient. The syringe itself serves as the dropper.
The patient’s family and friends are encouraged to remain with the patient throughout the preoperative routine. A heparin lock is placed. If indicated, 0.5 mg to 1.0 mg of IV Versed is administered. The pupil dilating process is outlined earlier in this tutorial.
No type of oculocompression device (e.g., Honan balloon, super-pinky, etc.) is used. Using topical/intraocular anesthesia has taught me that we create the need for these devices by placing a large volume of fluid into a closed space.
Operating Room
The patient is transported into the
operating room and placed onto the operating chair/table. Once the patient is
comfortable and the appropriate monitoring devices (e.g., blood pressure, pulse
oximeter, cardiac) are attached, the preparation procedure is begun. First, the
prep nurse, using the same Xylocaine 4% syringe used in the preoperative room,
places several drops of anesthetic onto the appropriate eye. From that point
forward, the preparation is identical to that which is used with injection
anesthesia, with one significant exception. The prep nurse must now communicate
with the patient so that the feelings, sounds, and smells are not a threat but
rather expected sensations. A drop of Betadine 5% (povidone-iodine) solution is
placed into the inferior conjunctival fornix. This is followed by a routine
Betadine skin prep of the lids, which is then removed with isopropyl alcohol
and allowed to dry.
Immediately after the patient is draped and the speculum inserted, we place a generous amount of Xylocaine 2% jelly onto the eye, attempting to cover all of the exposed area.
The operating microscope light is turned down to its lowest intensity. I then announce to the patient that the light is coming. I warn that "at first the light will seem very bright but I do not want you to be startled by it." I then bring the light onto the field slowly and gently over the eye. By the time I am ready for the capsulorrhexis, the patient is accustomed to the light and then I turn it up to normal intensity for the remainder of the procedure.
I am now ready to proceed with the surgery. First, I make a sideport incision. I then inject the Xylocaine 1% directly into the anterior chamber through the sideport incision. For some patients, Xylocaine causes a stinging or burning sensation. Therefore, so as not to startle the patient and put him or her on guard, before injecting the Xylocaine I warn the patient that I am instilling a medication that might tingle. How much should be injected? Everett Dirkson once offered these words: "I am a man of fixed and unbending principles, the first of which is to be flexible at all times." So it is with the Xylocaine. No set amount, just a few squirts will do the job nicely.
I then go through the following steps: exchange the aqueous with a viscoelastic agent, create the clear cornea phaco incision, perform the capsulorrhexis, and then do hydrodissection with the same sterile Xylocaine 1%.
From this point forward, I converse with the patient to: (1) remind him or her to look at the light, (2) acknowledge that he or she is doing a great job (he or she is a good partner), and (3) state that the procedure is going well. If I sense any level of discomfort, as might be indicated by a low groan, a little movement, etc, it is important to ask the patient directly, "Are you doing okay?" More often than not, what I learn is that either everything is just fine, that is just his or her normal breathing pattern/sounds, or that it is the inflated blood pressure cuff or pulse oximeter that is bothering him or her. If it is ocular discomfort, I employ "verbal anesthesia" to assure the patient that it is a normal sensation, that all is going well, and that it will soon pass. If indicated, we will slowly titrate IV sedation.
There may be some concern with using topical/intraocular anesthesia during a procedure in which a complication occurs such as cases in which the iris prolapses or the nucleus or IOL is dropped or when there is a need to enlarge the pupil, break the capsule, or perform a vitrectomy.
All of these circumstances can be treated in the same fashion as a case in which injection anesthesia had been employed. In my opinion, it is not a matter of what is being done, but how long it takes to do it.
With my protocol, I have found that I have about 30 minutes of working time. After 30 minutes, patients will usually experience pain. While theoretically it would be possible (and acceptable) to recreate a closed system using a viscoelastic material and taking advantage of the self-sealing incision (or sutures if necessary), one could always stop and administer a low-volume peribulbar block. Thus far, I have not found that to be necessary. I apply more topical drops or inject more Xylocaine. Be aware, however, that in certain situations (such as placing a secondary IOL in an aphakic eye, an eye that had a previous vitrectomy, or an eye with a broken posterior capsule) it is possible to have posterior diffusion of the intraocular Xylocaine that may lead to the anesthetizing of the neurosensory retina. This can give partial or profound loss of vision, which, fortunately, is transient.
When a technique such as topical/intraocular anesthesia for phacoemulsification comes along, I believe it is surgeons’ responsibility to study it, evaluate it, and judge as to whether it is serving, self-serving, or both. Can it represent a better routine approach to phacoemulsification for both the patient and the surgeon? Like so many other advances in small-incision cataract surgery, when properly understood, learned, and applied, topical/intraocular anesthesia offers many benefits to all parties involved.