Ophthalmic Surgery
Natalia F. Callaway MD1
Darius M. Moshfeghi MD1
Richard A. Jaffe MD, PhD2
1SUGEONS
2ANESTHESIOLOGIST
CATARACT EXTRACTION WITH INTRAOCULAR LENS INSERTION
SURGICAL CONSIDERATIONSDescription: Cataract—the leading cause of treatable blindness in the world—is defined as opacification of the crystalline lens. Cataract surgery is the most common surgical procedure, with more than 3 million performed in the United States each year. Several approaches to cataract removal have evolved as a result of advances in both instrumentation and artificial intraocular lenses (IOL). Most modern cataract surgery is performed using a variation of the extracapsular technique, which involves removal of the crystalline lens through an opening made in the anterior lens capsule (known as a capsulectomy). Removal of the lens nucleus can then be accomplished intact, which requires an 8- to 10-mm corneal incision, or more commonly by phacoemulsification wherein ultrasound energy is used to fragment the lens, allowing aspiration of the lens material. The advantages of phacoemulsification are that the entire procedure can be performed through a much smaller, clear corneal incision (usually ˜3 mm in length) and is associated with fewer adverse events. With both approaches, the softer, more peripheral cortical lens material is then removed by aspiration, leaving the posterior capsular bag intact to support an IOL implant (Fig. 2-1). If the lens capsule is torn or is for any reason unable to support an IOL, the lens can be fixated with sutures in the posterior chamber (behind the iris), or an anterior chamber IOL can be placed in front of the iris. Presently, the most popular materials for IOL implants are polymethylmethacrylate, silicon, and acrylic. Only silicon and acrylic are foldable, which allows their insertion through a small corneal incision and, therefore, are the most commonly used. The wound is closed with nylon or Vicryl suture (9-0 or 10-0) to achieve a watertight seal, although when small incisions are used, the wounds are often self-sealing and do not require sutures.
Variant procedure or approaches: Intracapsular cataract extraction involves removal of the crystalline lens with its surrounding capsular bag intact. To accomplish this, the zonules that normally stabilize and center the lens must be broken, and a cryoprobe often is used to remove the lens from the eye through a large incision. This procedure is performed infrequently, given the superior visual outcomes of extracapsular techniques. It may be indicated in situations where capsular bag support has been compromised by either trauma, malignancy, or inherited disorders.
Usual preop diagnosis: Cataract
 Figure 2-1. A: Placement of intraocular lens into remaining capsular bag. B: “In-the-bag” insertion. |
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ANESTHETIC CONSIDERATIONSAt the present time in the United States, cataract surgery is most commonly performed using only topical anesthetic agents (e.g., preservative-free 2-4% lidocaine, levobupivacaine 0.75%, ropivacaine 1%, or oxybuprocaine 1%) to block trigeminal nerve endings in the cornea and conjunctiva. Iris and ciliary body anesthesia depend on local anesthetic penetration into the anterior chamber. Thus, in a few patients, there may be a need for supplemental anesthetic administration (e.g., intracameral, 1% lidocaine) and less commonly systemic analgesic and sedative drugs. Inadvertent eye and lid movement should be expected. Adverse reactions to topical anesthetics are extremely rare and typically allergic in nature. High concentrations or prolonged exposure to local anesthetics can be toxic to the corneal epithelium (delayed wound healing; corneal erosion), and to the retina. A prospective randomized double-blind series demonstrated that combining topical anesthesia with intracameral lidocaine anesthesia was safe and effective in phacoemulsification with intraocular lens implantation. This technique avoided potential sequelae of retrobulbar or peribulbar anesthesia for cataract surgery. However, in one study of patients undergoing cataract surgery using topical anesthesia reported greater intraoperative and postoperative discomfort than those given a sub-Tenon block. Use of intravenous sedation increased the incidence of adverse events as compared with topical anesthesia without
sedation. All local anesthetic techniques should be avoided in patients with uncontrolled movement disorders, or an inability to cooperate.
sedation. All local anesthetic techniques should be avoided in patients with uncontrolled movement disorders, or an inability to cooperate.
Anesthesia-trained personnel monitored most patients during cataract surgery, and the most commonly used local anesthetic was lidocaine. The anesthetic method associated with the lowest degree of pain, dissatisfaction, drowsiness, or nausea and vomiting was a regional block technique with administration of sedatives and diphenhydramine.
See Anesthetic Considerations for Ophthalmic Surgical Procedures under MAC (adult), p. 158, or for Pediatric Ophthalmic Surgery, p. 1199.
Suggested Readings
1. Ashwin PT, Shah S, Wolffsohn JS: Advances in cataract surgery. Clin Exp Optom 2009; 92(4):333-42.
2. Borazan M, Karalezli A, Akova YA, Algan C, Oto S: Comparative clinical trial of topical anaesthetic agents for cataract surgery with phacoemulsification: lidocaine 2% drops, levobupivacaine 0.75% drops, and ropivacaine 1% drops. Eye 2008; 22(3):425-9.
3. Chuang LH, Yeung L, Ku WC, et al: Safety and efficacy of topical anesthesia combined with a lower concentration of intracameral lidocaine in phacoemulsification: paired human eye study. J Cataract Refract Surg 2007; 33(2):293-6.
4. Coelho RP, Weissheimer J, Romão E, et al: Pain induced by phacoemulsification without sedation using topical or peribulbar anesthesia. J Cataract Refract Surg 2005; 31(2):385-8.
5. Eichel R, Goldberg I: Anaesthesia techniques for cataract surgery: a survey of delegates to the Congress of the International Council of Ophthalmology, 2002. Clin Experiment Ophthalmol 2005; 33(5):469-72.
6. Eke T, Thompson JR: Serious complications of local anaesthesia for cataract surgery: a 1 year national survey in the United Kingdom. Br J Ophthalmol 2007; 91(4):470-5.
7. Malik A, Fletcher EC, Chong V, Dasan J: Local anesthesia for cataract surgery. J Cataract Refract Surg 2010; 36(1):133-52.
8. Rogers GM, Goins KM: Cataract surgery in the patient that cannot lie flat. Curr Opin Ophthalmol 2010; 21(1):71-4.
9. Sanmugasunderam S, Khalfan A: Is fasting required before cataract surgery? A retrospective review. Can J Ophthalmol 2009; 44(6):655-6.
10. Srinivasan S, Fern AI, Selvaraj S, et al: Randomized double blind clinical trial comparing topical and sub-Tenon’s anaesthesia in routine cataract surgery. Br J Anaesth 2004; 93:683-6.
11. Tan CS, Au Eong KG, Kumar CM: Visual experiences during cataract surgery: what anaesthesia providers should know. Eur J Anaesthesiol 2005; 22(6):413-9.
12. Vann MA, Ogunnaike BO, Joshi GP: Sedation and anesthesia care for ophthalmologic surgery during local/regional anesthesia. Anesthesiology 2007; 107(3):502-8.
CORNEAL TRANSPLANT
SURGICAL CONSIDERATIONSDescription: Patients with corneal pathology who have failed stem-cell techniques may require corneal transplantation (penetrating keratoplasty [PKP] or lamellar keratoplasty). Corneal transplantation involves replacing a portion of the host cornea with tissue from a donor eye (allograft). The primary goals of this procedure are to both restore the integrity of the cornea and establish a clear visual axis. The ideal death-to-preservation time of the donor cornea is < 18 h, and the donor cornea can be stored for up to 2 wk before transplantation. The procedure often begins with the placement of a scleral fixation ring (Flieringa ring) just beyond the corneoscleral junction, which is secured with 7-0 Vicryl sutures. This provides additional scleral support that is especially helpful in children or patients who have undergone previous cataract surgery. The donor corneal button is removed from the surrounding corneoscleral rim with a trephine and kept in storage medium until the recipient bed is prepared. The host cornea is then trephined in a previously marked central location, using either manual or vacuum-assist techniques while the anterior chamber is maintained with viscoelastics. After the eye is opened, it is critical to avoid patient movement, coughing, bucking, or any Valsalva maneuvers to prevent expulsion of the intraocular contents through the wound. The size of the donor button is generally cut ˜0.25 mm larger than the host bed. The donor cornea is then sutured endothelial side down into place with 10-0 nylon sutures, which can be accomplished using 16 interrupted sutures (generally preferred with corneas that are inflamed, thinned, or vascularized), running sutures, or a combination, depending on a number of factors unique to each patient. Great care is taken during manipulation of the allograft to avoid trauma to the inner surface of the graft, as damage to the endothelial cells in this location can result in primary graft failure.
Variant procedure or approaches: PKP may be combined with cataract extraction or exchange of a previously placed intraocular lens (IOL). In addition, PKP may be combined with limbal stem-cell transplantation (autograft from less injured eye) in cases where the most superficial corneal epithelial layer is unable to regenerate following damage (e.g., chemical burn injuries) to the limbal stem cells. Partial-thickness transplants, called lamellar keratoplasty, also can be performed in certain clinical situations. PKP may be combined with glaucoma filtration procedure and retinal surgery.
Usual preop diagnosis: Persistent corneal edema; inherited corneal dystrophy; keratoconus; corneal scar; infectious keratitis; chemical injury
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ANESTHETIC CONSIDERATIONSCorneal transplants commonly require GA or a retrobulbar/peribulbar block to prevent movement of the eyelids or extraocular muscles that could lead to distortion of the globe during the procedure. However, in patients with significant coagulopathy, a history of perforated corneal ulcers, severe systemic disease, or other conditions that make the use of these forms of anesthesia less preferable, corneal transplant can be performed with topical anesthesia in cooperative patients.
See Anesthetic Considerations for Ophthalmic Surgical Procedures under MAC (adult), p. 158, or for Pediatric Ophthalmic Surgery, p. 1199.
Suggested Readings
1. Kallio H, Rosenberg PH: Advances in ophthalmic regional anaesthesia. Best Pract Res Clin Anaesthesiol 2005; 19(2):215-27.
2. Riddle HK Jr, Price MO, Price FW Jr: Topical anesthesia for penetrating keratoplasty. Cornea 2004; 23(7):712-4.
3. Tan DT, Dart JK, Holland EJ, Kinoshita S: Corneal transplantation. Lancet 2012; 379(9827):1749-61.
4. Yeung SN, Kim P, Lichtinger A, et al: Combined topical and intracameral anesthesia for Descemet’s stripping automated endothelial keratoplasty. Int Ophthalmol 2012; 32(3):273-6.
TRABECULECTOMY
SURGICAL CONSIDERATIONSDescription: Glaucoma is a chronic disorder characterized by progressive and irreversible optic neuropathy with visual field defect. Glaucoma can develop at any intraocular pressure (IOP), but most current treatments are targeted at decreasing IOP. It is the second most common cause of blindness in the United States and accounts for more than 5.1 million cases of blindness throughout the world. Trabeculectomy (glaucoma filtration procedure) is the most common surgical procedure used to reduce IOP and is often undertaken only after maximal medical therapy has failed. In trabeculectomy, a drainage fistula (ostium) is created from the anterior chamber to the subconjunctival space, allowing aqueous humor to drain from the eye. (Normal anatomy relevant for aqueous fluid production is shown in Fig. 2-2). First, a limbus-based or fornix-based incision is created in the conjunctiva and Tenon’s layer, exposing the underlying bare sclera. A partial-thickness (4-5 mm) scleral flap, hinged at the limbus, is then created. Because scarring (secondary to inflammation) is the most common cause of surgical failure, antimetabolites, such as mitomycin-C or 5-fluorouracil, are often applied to the surgical site to slow or prevent fibroblast proliferation. Next, an incision into the anterior chamber is created at the base of the scleral flap and converted to a sclerotomy by removing an approximate 1 × 4 mm piece of corneoscleral tissue. To prevent the iris from entering the ostium as well as to protect against future angle closure, an iridectomy is performed, followed by closure of the overlying scleral flap with 10-0 nylon sutures. Before closure, it is important to avoid coughing, bucking, or Valsalva maneuvers, which might cause suprachoroidal hemorrhage or expulsion of intraocular content. The conjunctiva is then reapposed, using running 8-0 or 9-0 absorbable or nylon sutures.
 Figure 2-2. Ocular anatomy concerned with control of IOP. (Reproduced with permission from Barash PG, Cullen BF, Stoelting RK, et al., eds: Clinical Anesthesiology, 7th edition. Lippincott Williams & Wilkins: 2013.) |
 Figure 2-3. Basic technique of inserting Molteno implant. Silicone tube is inserted into anterior chamber via needle track and is connected to a subconjunctival acrylic plate that is attached to the sclera near the equator. (Reproduced with permission from Allingham RR, ed: Shield’s Textbook of Glaucoma, 6th edition. Williams & Wilkins, Philadelphia: 2010.) |
Variant procedure or approaches: In patients for whom trabeculectomy has failed, a variety of drainage implants have been created to maintain the patency of the drainage ostium. These devices (e.g., Ahmed, Molteno, Krupin, Baerveldt) consist of plastic reservoirs that are placed in the sub-Tenon’s space and are connected to a tube that enters the anterior chamber (Fig. 2-3). These devices differ in implant size and whether or not there is an internal valve to prevent excessive drainage. Long-term IOP reduction with drainage implants is not as successful as trabeculectomy.
In infants and children with congenital glaucoma (see Pediatric Ophthalmic Surgery, p. 1198), the anterior chamber angle, which normally allows outflow of aqueous, develops abnormally and often requires surgical intervention. Goniotomy (opening Schlemm’s canal) is usually the initial procedure of choice. An alternative procedure is a trabeculotomy performed by exposing Schlemm’s canal (the drainage system) in a corneoscleral cutdown. A trabeculotome is then threaded into this canal and is rotated, creating a tear in the trabecular meshwork and allowing direct communication between the anterior chamber and Schlemm’s canal.
Usual preop diagnosis: Glaucoma
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ANESTHETIC CONSIDERATIONSTrabeculectomy is typically accomplished using sub-Tenon anesthesia, which allows monitoring of conjunctival mobility when selecting the surgical site. Alternatively, it can be done using topical anesthetics. GA is usually reserved for pediatric patients, patients unlikely or unable to cooperate during the procedure, or if low intraocular pressure from anesthesia is desirable.
Subconjunctival anesthesia at the bleb site may be associated with a poorer outcome, because it may stimulate fibroblasts to cause scarring due to hemorrhage and tissue damage. Peribulbar and retrobulbar injections in patients with advanced glaucoma may be associated with increased intraocular pressure, which can be prevented by decreasing anesthetic volumes and avoiding the use of orbital Honan balloons.
Topical and intracameral anesthesia are being increasingly employed for trabeculectomy to avoid injection pain and potential complications, such as conjunctival button holes and hemorrhage. However, topical agents have the following limitations: inferior duration and intensity of anesthetic effect and lack of ocular akinesia, which is necessary to prevent globe compression in patients with prominent eyelid squeezing. Intracameral lidocaine as a supplement to topical anesthesia has the theoretical advantage of increasing depth of anterior chamber, but it poses the risk of damaging the phakic lens and excessive iridectomy enlargement. To avoid these possible complications, intracameral acetylcholine or topical pilocarpine can be used in conjunction with intracameral lidocaine.
See Anesthetic Considerations for Ophthalmic Surgical Procedures under MAC (adult), p. 158, or for Pediatric Ophthalmic Surgery, p. 1199.
Suggested Readings
1. Edmunds B, Bunce CV, Thompson JR, et al: Factors associated with success in first-time trabeculectomy for patients at low risk of failure with chronic open-angle glaucoma. Ophthalmology 2004; 111:97-103.
2. Kumar CM, Eid H, Dodds C: Sub-Tenon’s anaesthesia: complications and their prevention. Eye (Lond) 2011; 25(6): 694-703.
3. Sauder G, Jonas JB: Topical anesthesia for penetrating trabeculectomy. Graefes Arch Clin Exp Ophthalmol 2002; 240:739-42.
4. Zabriskie NA, Ahmed IIK, Crandall AS, et al: A comparison of topical and retrobulbar anesthesia for trabeculectomy. J Glaucoma 2002; 11:306-14.
ECTROPION REPAIR
SURGICAL CONSIDERATIONSDescription: Ectropion is a malposition of the eyelid often due to laxity in the tarsoligamentous sling, in which the lid margin is everted away from the globe. The surgical approach depends on the underlying anatomic abnormality, which can be congenital, involutional, cicatricial (scarring), or due to mechanical traction from masses or facial nerve palsy. A lateral tarsal strip procedure is often used, with the lateral canthal tendon first released by performing a lateral canthotomy and cantholysis of the crus (Fig. 2-4). A lateral portion of tarsus is then dissected free of overlying skin, muscle, and conjunctiva. This strip of tarsus is trimmed to the appropriate length and is secured to the periosteum of the lateral orbital rim with suture. Excess skin is removed and the defect is closed. If punctal malposition is present, the tarsal strip procedure may be combined with a medial conjunctival spindle procedure.
Variant procedure or approaches: Cicatricial ectropion from a contracting scar can sometimes be released with a Z-plasty incision that releases vertical skin tension. Alternatively, a full-thickness skin graft may be required and can be harvested from the upper lid or the postauricular or supraclavicular regions.
Usual preop diagnosis: Ectropion of the eyelid
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ANESTHETIC CONSIDERATIONSSee Anesthetic Considerations for Ophthalmic Surgical Procedures under MAC (adult), p. 158, or for Pediatric Ophthalmic Surgery, p. 1199.
 Figure 2-4. In the tarsal strip procedure, the lower eyelid is incised laterally. The entire lower crus of the canthal tendon must be severed. (Redrawn with permission from Duane’s Ophthalmology, Williams & Wilkins, Philadelphia: 2013.) |
Suggested Reading
1. See Suggested Readings following Ophthalmic Surgery section, p. 176.
ENTROPION REPAIR
SURGICAL CONSIDERATIONSDescription: Entropion is a condition characterized by an inward rotation of the eyelid margin. The surgical approach depends on the underlying anatomic abnormality, which can be congenital, spastic, involutional, or cicatricial (scarring). For the more common involutional or age-related cases, the primary defect involves horizontal lid laxity, disinsertion of the lower lid retractors, and/or an overriding orbicularis muscle. Correction often involves use of the lateral tarsal strip procedure (see description under Ectropion Repair) to achieve tightening of the lower lid. Reattachment of the eyelid retractor muscles/aponeurosis may also be used in certain cases, either alone or in addition to a tarsal strip procedure.
Variant procedure or approaches: Cicatricial entropion results from a contracting scar of the tarsus and/or conjunctiva pulling the lid margin inward. Correction requires release of this tension and either a lid-splitting procedure with tarsal advancement, rotational grafts, or free mucosal grafts harvested from hard palate. In the latter case, nasal intubation will be required to allow access to the graft site. Quickert procedure involves the placement of 2-3 sutures under local anesthesia to evert the eyelid. Entropion frequently recurs after this procedure.
Usual preop diagnosis: Entropion of eyelid
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ANESTHETIC CONSIDERATIONSEntropion repair can usually be accomplished as an outpatient procedure using local anesthesia and MAC.
See Anesthetic Considerations for Ophthalmic Surgical Procedures under MAC (adult), p. 158, or for Pediatric Ophthalmic Surgery, p. 1199.
Suggested Reading
1. See Suggested Readings following Ophthalmic Surgery section, p. 176.
PTOSIS REPAIR
SURGICAL CONSIDERATIONSDescription: Ptosis (drooping of the upper eyelid margin) can be severe enough to obstruct the visual axis. Causes include congenital maldevelopment, mechanical traction, myogenic conditions (e.g., dystrophies, myasthenia gravis), neurogenic conditions (e.g., Horner’s syndrome, cranial nerve III palsy), actinic skin changes and aponeurotic dehiscence. The surgical approach depends primarily on the presence or absence of adequate levator muscle function that is responsible for elevating the upper eyelid. The most common etiology is age-related dehiscence or disinsertion of the levator aponeurosis from its normal attachment to the tarsus. Because levator muscle function is usually satisfactory in these patients, surgical correction involves reinserting the aponeurosis to the anterior tarsus alone or in combination with shortening of the aponeurosis by advancement or resection. Access is obtained by an incision in the upper eyelid crease. Removal of excess skin and orbicularis muscle (blepharoplasty) may be performed simultaneously. Although several formulas have been devised to determine the amount of aponeurotic shortening, intraop measurement usually is performed to ensure that the appropriate lid position and contour are achieved. This
requires that the procedure be performed under local anesthesia and that the patient be positioned and draped in a way that allows him/her to sit upright during surgery. Incisions are closed, and crease reformation can be performed if desired.
requires that the procedure be performed under local anesthesia and that the patient be positioned and draped in a way that allows him/her to sit upright during surgery. Incisions are closed, and crease reformation can be performed if desired.
 Figure 2-5. Frontalis sling (modified Crawford technique). Note location of brow and lid incisions and double rhomboid fascial slings. (Redrawn with permission from Duane’s Ophthalmology, Williams & Wilkins, Philadelphia: 2013.) |
Variant procedure or approaches: In patients with levator muscle function that is not adequate to achieve eyelid elevation, a frontalis sling procedure is performed to elevate the upper eyelid (Fig. 2-5). More commonly required in children with congenital ptosis, this allows the patient to open the eye by elevating the brow. A variety of materials can be used to accomplish this suspension, including silicon rods or fascia. In children < 3 yr, autologous fascia lata can be harvested from the outer thigh from hip to knee. The material is tunneled beneath the skin and muscle from the brow incisions to the anterior tarsal region of the eyelid using Wright needles. After appropriate contour and height are achieved, the sling is secured and incisions are closed. Frontalis suspension usually is performed under GA in both adults and children.
Usual preop diagnosis: Ptosis
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ANESTHETIC CONSIDERATIONSPtosis repair typically requires GA for infants and children and can be accomplished with local anesthesia (± subcutaneous epinephrine) and MAC as an outpatient procedure in adults. The need for patient cooperation during the surgery should be discussed with the surgeon and patient in advance. See Anesthetic Considerations for Ophthalmic Surgical Procedures under MAC, p. 158.
