Topical Intracameral Anesthesia - Cataract Surgery, 3rd Edition

Cataract Surgery, 3rd Edition

PART II – Preparation

Chapter 9 – Topical Intracameral Anesthesia

Alan S. Crandall, MD

Contents

	•	Anesthesia
	•	Topical Anesthesia
	•	Additional Uses for Intracameral Anesthesia
	•	Parabulbar (Sub-Tenon's) Anesthesia
	•	Techniques for Topical Anesthesia

CHAPTER HIGHLIGHTS

	≫	Techniques for topical anesthesia
	≫	Pupillary dilation through intracameral lidocaine

Anesthesia

Modern intraocular surgery involves many new technologies. These include, among many others:

	•	phacoemulsification
	•	foldable intraocular lenses
	•	clear corneal incisions
	•	capsular tension rings (and Cionni variations).

This infusion of new techniques has forced a reevaluation of the anesthetic needs for anterior segment surgery.

In the 1985 survey of members of the American Society of Cataract and Refractive Surgeons (ASCRS),^[1] 76% of the responding ophthalmologists used a retrobulbar injection with a facial block; 4% used a periocular block, and 4% used general anesthesia. Thus, in 1985, 92% of the ophthalmologists who returned their survey used a retrobulbar anesthetic for cataract surgery. A similar survey conducted among members of the American Academy of Ophthalmology^[2] showed that in 1992, 71% of those responding used retrobulbar anesthesia for cataract surgery, whereas 28% used a peribulbar technique. Subsequent ASCRS surveys showed a steady decline in the number of respondents using retrobulbar anesthesia.^[3–11] By the 1998 survey, anesthesia preferences for cataract surgery had changed dramatically, with 32% of respondents using retrobulbar anesthesia; 27% using a periocular block; and 37% of respondents using topical anesthesia for cataract surgery, an anesthetic technique not even listed in the 1985 survey.

One might conclude from these data that topical anesthesia for cataract surgery is an entirely new notion. However, more correctly, one would say that topical anesthesia has been rediscovered. In 1884 Karl Koller first described the topical use of cocaine as an anesthetic agent for ocular surgery.^[12] Later that same year, Knapp^[13] described a method for enucleation using a retrobulbar injection of cocaine.^[12] Widespread acceptance of injected cocaine anesthesia for cataract surgery was limited, however, by the toxicity of the drug. Thus, at the turn of the century, topical instillation of cocaine was the standard for cataract surgery. Topical cocaine, however, was not without local toxicity. Tetracaine later became available and was less locally toxic than cocaine; therefore, it was commonly substituted for cocaine as a topical agent for cataract surgery. Tetracaine, however, did not provide the same depth of anesthesia for intraocular structures as did cocaine. This fact, along with the more complicated surgical techniques developed in the 1920s and 1930s, pushed many ophthalmologists away from topical anesthesia to rely more on retrobulbar procaine injections to provide adequate surgical anesthesia for cataract surgery.^[14] Infiltration of retrobulbar anesthetic was really the standard cataract surgery technique for decades thereafter. Ironically, it has been the complications associated with these infiltration anesthetic techniques that have led the ophthalmic community full circle, back to topical anesthesia for cataract surgery.

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Topical anesthesia

Topical anesthesia is not new. In fact, it was considered an important discovery when Karl Koller observed that a solution of cocaine applied to the eye could prevent pain during eye surgery. (Koller likely also introduced Sigmund Freud^[15] to cocaine.) With further advances in anesthesia and changes in ocular surgery, general anesthesia and injection techniques became the standard of care. The use of topical anesthesia was reintroduced by Fichman^[16] in the early 1990s. This technique used topical 0.5% tetracaine. Soon other agents also became acceptable because other drops (such as 0.75% Marcaine (Sanofi Winthrop Pharmaceuticals, New York) and 1% to 2% lidocaine) were less toxic to the corneal epithelium.

Initially, some patients were not completely comfortable with the use of topical anesthesia alone, so some surgeons used intravenous sedation and analgesics to give further comfort. However, in 1995 Gills, Cherchio, and Raanan^[17] introduced the use of nonpreserved lidocaine (1%) given intracamerally, which would provide further anesthesia. In an attempt to evaluate the new procedures, Patel et al.^[18] randomized patients to receive a retrobulbar block versus topical anesthesia. A visual pain analogue scale was used to assess pain during surgery. They concluded that topical anesthesia can be used safely and that patient discomfort was only marginally higher postoperatively. Furthermore, the same group then randomly allocated patients to receive topical plus balanced salt solution, versus topical plus intracameral lidocaine, and found very slight differences between the two groups. They also found slightly better patient cooperation in the group that received the intracameral lidocaine.^[19]

In routine small-incision cataract surgery, ocular anesthesia with topical anesthetics will usually suffice (Table 9-1). However, depending on the surgeon's experience^[20] there may be contraindications (relative and absolute) to the use of topical anesthesia (Table 9-2).

Table 9-1 -- Techniques of anesthesia for cataract surgery

General anesthesia

Retrobulbar

Peribulbar

Parabulbar

Topical

Table 9-2 -- Contraindications to topical anesthesia

Relative

Language barrier

Deafness

Uncooperative patients

Difficult surgery

Extended time for surgery

Nystagmus

Absolute

Allergy to the anesthetic

Coarse nystagmus

Currently, this author uses topical anesthesia for cataract surgery, combined cataract and glaucoma surgery, trabeculectomy, viscocanalostomy, secondary lens implants, sutured posterior chamber intraocular lens, and sutured Cionni rings.

Additional uses for intracameral anesthesia

Use of intracameral lidocaine for pupil dilation during cataract surgery

Cataract surgery papillary dilation is important; a standard regimen generally includes tropocaimide 1%, cyclogel 1% and neosynepherine 10%. Usually three sets of drops are applied over a 15–20min time frame (sets every 5min). Dilation with this combination is good but may last over many hours (patients are frequently still dilated on the day one visit). The multiple applications may also compromise the epithelial surface allowing abrasions to recur or reduce the clarity of the cornea making surgery more difficult.

Cionni et al^[24] reported the use of unpreserved lidocaine intracamerally to paralyze the sphincter muscle which led to adequate pupil dilation within 90s. They felt dilation was adequate and the pupil returned quickly to normal function.

To improve the speed of dilation we now use 1:1000 unpreserved epinephrine (Table 9-3); dilation is very rapid (Figure 9-1). The advantages of using intracameral techniques to dilate are:

	1.	the patients can be moved into the operating room quickly (not requiring three sets of drops separated by 5 min)
	2.	the corneas are subjected to fewer drops and are always pristine (especially valuable in diabetics or patients with anterior basement membrane disease)
	3.	the pupils return to normal function quickly
	4.	there is no risk for narrow angle closure.

Table 9-3 -- Formula for lidocaine/epinephrine

Lidocaine 1% preservative free 30 mL

Epinephrine 1:1000 mL amps (1cc)

Withdraw 0.3 mL Lidocaine 1% from vial, discard

Add back 0.3 mL Epinephrine to vial

Label: 24 h expires



Figure 9-1 Bupivacaine 0.75% drops administered initially every 10min three times.

Other regimens for intracameral dilation have proven helpful in patients with intraoperative floppy iris syndrome. Dr. Joel Shugar has found his intracameral solution^[25] to rapidly dilate and help prevent iris problems in patient with IFIS (especially patients on Flomax (tamsulosin)). This combination is known as “epi-Shugarcaine” (Table 9-4).

Table 9-4 -- Epi-Shugarcaine

	pH
1:1000 Epinephrine (American Reagent)	3.133
4% non-preserved lidocaine (Abbott Labs)	6.333
BSS Plus (Alcon Labs)	7.197
Shugarcaine	6.97
3:1 Shugarcaine/epinephrine	6.899

Parabulbar (sub-tenon's) anesthesia

Tenon's capsule is, of course, an anterior extension of dura. It fuses with conjunctiva near the surgical limbus. Therefore, it can provide access to the retrobulbar space. Hansen, Mein, and Mazzoli^[21] reported the use of sub-Tenon's surgery in 1990. Greenbaum^[22] designed a specific flexible cannula to deliver the anesthesia. In this procedure, a dissection is made through conjunctiva and Tenon's capsule down to bare sclera; the Greenbaum cannula (or other blunt cannula) is used; and, by making the incision small enough, the fluid can be forced to dissect posteriorly, and, usually, only a few milliliters of anesthesia are required. The anesthesia is of rapid onset, but the globe akinesia takes a few minutes to occur. A similar technique was described by Stevens;^[23] however, he used a blunt, curved, metal cannula and started his incision 5mm posterior to the limbus.

Techniques for topical anesthesia

	1.	In outpatients, drops with 0.5% proparacaine are initiated. Dilating drops and antibiotic plus Voltaren (Novartis Pharmaceutical Corp., East Hanover, NJ) are administered twice. Beginning with the third set and approximately 15 min before surgery, one more set of dilating drops and two sets of 0.75% bupivacaine drops are instilled (Figure 9-1). Next, two to three drops of half-strength Betadine (Purdue Frederick Co., Norwalk, Conn.) are instilled into the cul-de-sac (Figure 9-2).
	2.	Just before entering the operating room, viscous lidocaine is instilled into the cul-de-sac (Figure 9-3).
	3.	Once in the operating theater, one more drop is instilled and the patient has the sterile skin preparation administered. Another drop of anesthetic can be administered.
	4.	During draping, the patient's upper lid is held with a sterile 4 × 4 gauze bandage, and the patient is asked to look down. This usually allows application of the drape without difficulty (Figure 9-4). The patient can be told that there is an odd feeling during the process, especially when placing the lid speculum (Figure 9-5A and B). Most patients are quite comfortable once the speculum is in place. It is important that the lashes are covered with the drape to reduce the stimulus. The light source is very low and slowly raised as the patient becomes comfortable.
	5.	A stab incision is made, and 0.3mL of 1% unpreserved lidocaine is slowly injected. Patients can be warned that they may feel a slight sting, although most do not (Figures 9-6 and 9-7).
	6.	Versed (Roche Laboratories, Nutley, NJ), 0.5–1 mg, usually will be administered, although many patients require none*.



Figure 9-2 Betadine 5% drops administered before lidocaine gel.



Figure 9-3 Lidocaine 2% gel applied to ocular surface before preparation and draping of patient.



Figure 9-4 Drape applied after sterile prep as lids are retreated and patient looks down.



Figure 9-5 A and B, Lid speculum placed after incision of drape, ensuring adequate coverage of lid margin and lashes.



Figure 9-6 Nonpreserved lidocaine 1% injected into anterior chamber.



Figure 9-7 Thornton fixation ring used to stabilize globe for paracentesis.

* Supported in part by a grant from Research to Prevent Blindness, Inc., New York, NY, to the Department of Ophthalmology and Visual Sciences, University of Utah.

References

[1]. Leaming D.V.: Practice styles and preferences of ASCRS members – 1985 survey. J Cataract Refract Surg 1968; 12:380-384.

[2]. Schein O.D., Bass E.B., Sharkey P., et al: Cataract surgical techniques: preferences and underlying beliefs 1995; 113:1108-1112.

[3]. Leaming D.V.: Practice styles and preferences of ASCRS members – 1987 survey. J Cataract Refract Surg 1988; 14:552-559.

[4]. Leaming D.V.: Practice styles and preferences of ASCRS members – 1988 survey. J Cataract Refract Surg 1989; 15:689-697.

[5]. Leaming D.V.: Practice styles and preferences of ASCRS members – 1989 survey. J Cataract Refract Surg 1990; 16:624-632.

[6]. Leaming D.V.: Practice styles and preferences of ASCRS members – 1991 survey. J Cataract Refract Surg 1992; 18:460-469.

[7]. Leaming D.V.: Practice styles and preferences of ASCRS members – 1983 survey. J Cataract Refract Surg 1994; 20:459-467.

[8]. Leaming D.V.: Practice styles and preferences of ASCRS members – 1994 survey. J Cataract Refract Surg 1995; 21:378-385.

[9]. Leaming D.V.: Practice styles and preferences of ASCRS members – 1995 survey. J Cataract Refract Surg 1996; 22:931-939.

[10]. Leaming D.V.: Practice styles and preferences of ASCRS members – 1996 survey. J Cataract Refract Surg 1997; 23:527-535.

[11]. Leaming D.V.: Practice styles and preferences of ASCRS members – 1997 survey. J Cataract Refract Surg 1998; 24:552-561.

[12]. Altman A.J., Albert D.M., Fournier G.A.: Cocaine's use in ophthalmology: our 100-year heritage. Surv Ophthalmol 1985; 29:300-306.

[13]. Knapp H.: On cocaine and its use in ophthalmic and general surgery. Arch Ophthalmol 1884; 13:402-448.

[14]. Russell D.A., Guyton J.S.: Retrobulbar injection of lidocaine (Xylocaine) for anesthesia and akinesia. Am J Ophthalmol 1954; 38:78-84.

[15]. Karch S.B.: Coca java and the Southeast Asia coca industry. In: Karch S.B., ed. A brief history of cocaine, Boca Raton: CRC Press; 1997:71-81.

[16]. Fichman R.A.: Use of topical anesthesia alone in cataract surgery. J Cataract Refract Surg 1996; 22:612-614.

[17]. Gills J.P., Cherchio M., Raanan M.: Unpreserved lidocaine to control discomfort during cataract surgery using topical anesthesia. J Cataract Refract Surg 1997; 23:545-550.

[18]. Patel B.C.K., Burns T.A., Crandall A., et al: A comparison of topical and retrobulbar anesthesia for cataract surgery. Ophthalmology 1996; 103:1196-1203.

[19]. Crandall A.S., Zabriskie N.A., Patel B.C.K., et al: A comparison of patient comfort during cataract surgery with topical anesthesia versus topical anesthesia and intracameral lidocaine. Ophthalmology 1999; 1006:60-66.

[20]. Patel B.C.K., Clinch T.E., Burns T.A., et al: Prospective evaluation of topical versus retrobulbar anesthesia: a converting surgeon's experience. J Cataract Refract Surg 1998; 24:853-860.

[21]. Hansen E.A., Mein C.E., Mazzoli R.: Ocular anesthesia for cataract surgery: a direct sub-Tenon's approach. Ophthalmic Surg 1990; 21:696-699.

[22]. Greenbaum S.: Anesthesia in cataract surgery. In: Greenbaum S., ed. Ocular anesthesia, Philadelphia: WB Saunders; 1997:1-55.

[23]. Stevens J.D.: A new local anesthesia technique for cataract extraction by one quadrant sub-Tenon's infiltrations. Br J Ophthalmol 1992; 76:670-674.

[24]. Cionni R.J., Barros M.G., Kaufman A.H., Osher R.H.: Cataract surgery without preoperative eyedrops. J Cataract Refract Surg 2003; 29:2281-2283.

[25]. Shugar J.K.: Use of epinephrine for IFIS prophylaxis [letter]. J Cataract Refract Surg 2006; 32:1074-1075.

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Contents

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Cataract Surgery, 3rd Edition

PART II – Preparation Chapter 9 – Topical Intracameral Anesthesia

PART II – Preparation

Chapter 9 – Topical Intracameral Anesthesia