Extracapsular Cataract Surgery: Indications and Techniques

Cataract Surgery, 3rd Edition

PART III – Extracapsular Cataract Extraction

Chapter 10 – Extracapsular Cataract Surgery: Indications and Techniques

Jared Emery, MD,
Roger F. Steinert, MD

Contents

	•	Indications
	•	Techniques
	•	Preparation
	•	Conjunctival Incision
	•	Scleral Incision
	•	Anterior Capsulectomy
	•	Removal of the Nucleus
	•	Removal of the Cortex
	•	Implantation of the Intraocular Lens
	•	Wound Closure

CHAPTER HIGHLIGHTS

	≫	Standard technique for dense cataracts
	≫	Complication avoidance and management
	≫	Detailed illustrations of each surgical step

Extracapsular cataract surgery, strictly speaking, includes both phacoemulsification and planned extracapsular cataract extraction. By convention, the terms extracapsular and planned extracapsular refer to an operation in which the lens nucleus is delivered intact through a limbal incision of about 10 mm.

Since 1970, phacoemulsification and extracapsular cataract surgery have replaced intracapsular cataract extraction, except for rare instances, such as subluxated lenses or eyes in which a question of patient sensitivity to lens material exists. Phacoemulsification was used in about 15–20% of cataract cases in the United States from the mid-1970s through to 1987. Phacoemulsification then rapidly gained in popularity, becoming the procedure of choice for about 50% of surgeons by 1990, for 70% of surgeons by 1992,^[1] and nearly 100% of responding surgeon members of the American Society of Cataract and Refractive Surgery in a survey in 2000.^[2] However, the extracapsular cataract operation is still used by many surgeons in specific situations. In some cases, it is the procedure of choice. Every cataract surgeon should be skilled in extracapsular cataract surgery.

Indications

The extracapsular operation can be used successfully for almost any cataract. The method is not appropriate for luxated or subluxated lenses. Its main disadvantages compared with phacoemulsification include greater induced astigmatism,^[3–7] less stability of the postoperative refraction,^[3,][8,][9] more early postoperative inflammation,^[10,][11] and a higher rate of posterior capsular opacification.^[12] Its main advantage is that in some cases it can provide a greater margin of safety. In cases in which the nucleus is very dense, the pupil dilates poorly, posterior synechiae are present, or zonular integrity is in question (as in pseudoexfoliation syndrome or after pars plana vitrectomy), some surgeons have a greater margin of safety with the extracapsular procedure.

The surgeon should use the procedure that is likely to give the most successful result. For example, if the surgeon perseveres with phacoemulsification made difficult by poor exposure, he or she might face a higher likelihood of capsular rupture with vitreous loss than might have been the case had the surgery been converted to large-incision extracapsular extraction. The careful surgeon judges each case in advance and chooses phacoemulsification or planned extracapsular surgery based on his or her expectation that this will produce the best result for the patient. In the majority of cases, this decision can be made before surgery. For some cases, however, one might choose during surgery to switch from phacoemulsification to a planned extracapsular technique. The extracapsular technique of Emery (discussion to follow) allows the surgeon to switch readily from phacoemulsification to large-incision planned extracapsular surgery at any stage of the operation.

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Techniques

The best cataract surgical techniques give consistently reproducible results. The surgeon remains in control. The operation accomplishes removal of the nucleus with minimal stress on the zonules, secure placement of an intraocular lens (IOL) with an intact capsular bag, and closure with a watertight incision that gives minimal astigmatism. The procedure should be as simple as possible to promote success and should apply with minimal variations to all types of cases.

Preparation

After aseptic preparation of the operative site, dry the lid margins using cellulose sponges. Apply a large unperforated plastic drape (3M) to the open lids and incise (Figure 10-1).



Figure 10-1 Technique for incision of plastic drape.

Retract the upper and lower lids using the Jaffe wire lid speculum. Attach a rubber band to each speculum and use a hemostat to clip the rubber band to the drapes, applying the minimum amount of tension that will give adequate exposure of the globe. Place 4-0 black silk sutures beneath the insertions of the superior and inferior rectus muscles. Tuck in the flaps of the drape and attach the sutures to the rubber bands (Figure 10-2). Use only the necessary tension to produce adequate exposure above the superior limbus and maintain visibility of the inferior limbus.



Figure 10-2 Surgeon's view of placement of Jaffe wire lid specula and rectus sutures. Note that good exposure of the operative site is achieved while still allowing visibility of the inferior limbus.

Conjunctival incision

Make a fornix-based flap to expose the limbus using a 7 mm peritomy with oblique relaxing incisions extending from the limbus about 3 mm posteriorly, as illustrated (Figure 10-3).



Figure 10-3 Expose the superior limbus with a 7 mm peritomy and oblique relaxing incisions.

Apply light wet-field cautery to obliterate all visible surface vessels posterior to the intended incision site, which will be approximately 3 mm posterior to the anterior limbus (Figure 10-4). Clean the limbus with a Tooke knife to “squeeze” residual blood from vessels near the limbus. Avoid fraying the scleral surface with excessive scraping.



Figure 10-4 Cauterize surface vessels posterior to the incision site.

Scleral incision

Using calipers, measure a 10 mm chord length on the sclera, with the points positioned 3 mm posterior to the limbus (Figure 10-5). Make a 10 mm partially penetrating incision using a 30° disposable steel microsurgical blade. The incision groove will run parallel with the limbus and 3 mm posterior to the anterior limbal margin (Figure 10-6). The groove should be perpendicular to the scleral surface and to a depth of 50–75% of the scleral wall thickness.



Figure 10-5 Incision site: a 10 mm chord length 3 mm posterior to the limbus.



Figure 10-6 Place incision groove parallel with the limbus 3 mm posterior to the anterior limbal margin.

Make a lamellar scleral dissection using a disposable crescent blade. Begin this dissection at the base of the preplaced groove. Dissect the flap anteriorly, beginning at the apex of the groove. Continue tangential to the globe for about 1 mm along the entire length of the groove. Then extend the tunnel in one direction, wherever access is easiest (Figure 10-7). Gradually come anterior, being careful to depress the heel of the crescent blade to avoid premature penetration at the site where the corneoscleral curvature steepens. Bring the incision anterior into clear cornea just beyond (central) to the limbal arcade (Figures 10-7 and 10-8). About 4 mm of scleral-corneal dissection should extend to the point of anterior chamber entry. Keeping the blade fully inserted, as in Figure 10-7, gently extend the plane of dissection right and left to the full 10 mm width; stabilize the globe by grasping the sclera posterior to the groove. Avoid grasping the scleral flap because it might tear. Judge the depth of the scleral-corneal dissection by viewing the blade through the translucent sclera. Keep the sclera moist to give greater visibility of the blade (see Figures 10-7 and 10-8).



Figure 10-7 Dissection of scleral tunnel using crescent blade.



Figure 10-8 Cross-sectional view of cornea and sclera showing depth and extent of scleral tunnel.

Use a disposable phaco keratome to penetrate the anterior chamber, making an incision parallel to the iris plane. It helps to aim the point of the blade somewhat posteriorly until initial penetration is achieved to avoid sliding up along corneal lamellae and entering the anterior chamber more centrally than desired. After penetration of the blade point, level out the blade so that it remains parallel to the plane of the iris and then push in to make a 1.5 mm opening. You will extend this incision later after the anterior capsulectomy (Figure 10-9).



Figure 10-9 Plane three of the incision: penetration into the anterior chamber using a disposable phaco blade. Inset shows cross-sectional view of incisional planes.

Anterior capsulectomy

Fully inflate the anterior chamber with a viscoelastic such as sodium hyaluronate. Use a 27-gauge disposable needle with a small microhook at its tip to create a 6 or 7 mm circular anterior capsulectomy. Make very small bites directed parallel with the pupillary margin. Each bite after the first should begin on top of the anterior capsule about 1 mm from the adjacent capsular incision (Figure 10-10). A fluid movement of the microhook should first puncture the capsule with slight posterior pressure and then sweep parallel with the pupillary margin until the tear joins the adjacent incision.



Figure 10-10 Anterior capsulectomy. For this, bend a 27-gauge disposable needle into the configuration shown in the inset. Attach the needle to a small syringe, which serves as a handle.

The capsulectomy should be at least 6 mm in diameter. Smaller-diameter openings lead to rather large tears of the peripheral capsule that tend to destabilize the lens implant. An opening of 6–7 mm gives a reasonable margin of peripheral anterior capsule, while allowing the nucleus to prolapse with less pronounced radial tearing.

After completion of the circular anterior capsulectomy, reinsert the blade that was used to make the original entry into the anterior chamber and extend the entry site to about 3 mm. Inject additional viscoelastic before this step as needed. (The surgeon may make the initial entry 3 mm wide to skip this step. The 1.5 mm initial entry was suggested to help retain the viscoelastic and to maintain the depth of the anterior chamber throughout the capsulectomy.) Remove the fragment of anterior capsule using toothless forceps. Insert the crescent blade and extend the third plane of the incision parallel to the iris plane to the full 10 mm width of the previous flap dissection (Figure 10-11). Use pushing strokes of the crescent blade to cut the third plane; this helps make a watertight valve incision.



Figure 10-11 Extend plane three of the incision with the crescent blade.

Removal of the nucleus

Put three interrupted 8-0 Vicryl or 9-0 black silk sutures across the lips of the scleral groove, taking about a 1 mm bite on each side. Place them so that when they are tied they will be equally spaced across the wound, giving four 2.5 mm openings for passage of the irrigation–aspiration instrument (Figure 10-12). Loop the sutures around the margins of the groove, as shown in Figure 10-12.



Figure 10-12 Technique for placement of three interrupted 9-0 black silk sutures.

Using the McIntyre 26-gauge cannula attached to an irrigating cystotome handpiece, prolapse the superior lens nucleus into the anterior chamber. Pass the McIntyre 26-gauge cannula into the anterior chamber at the 12 o'clock position. Move the tip over to the 2 o'clock position and slide it beneath the margin of the anterior capsular leaflet. Retract the leaflet toward the lens equator rather firmly to allow the cannula to pass beyond the equator. Then, press slightly posterior with the whole shaft (not just the tip) of the cannula while gently irrigating with gravity flow through the handpiece. Maintain posterior pressure against the scleral wound while holding the shaft of the instrument parallel to the plane of the iris to help bring the nucleus forward. The lens nucleus begins to cleave from the posterior capsule, allowing the tip of the cannula to pass beneath the equator of the nucleus. After cleavage begins and irrigation forms a space between the edge of the nucleus and the posterior capsule, lift slightly on the edge of the nucleus to enhance the cleavage, slide the cannula slightly to the right in the cleavage, lift on the edge of the nucleus again, depress slightly and slide into the cleavage to the right again, lift again on the nucleus, and so on, repeating this movement slowly to allow the nucleus to cleave and lift away from the posterior capsule. The movement should be slow and deliberate to give the nucleus time to separate gently from the posterior capsule. Continue this movement until the superior quarter to half of the nucleus emerges through the pupil into the anterior chamber (Figures 10-13 and 10-14).



Figure 10-13 Technique for prolapse of superior nucleus into the anterior chamber using the McIntyre 26-gauge cannula with irrigation.



Figure 10-14 Prolapse of nucleus into anterior chamber is facilitated by infusion of balanced salt solution posterior to nucleus.

Attach a Knolle-Pearce irrigating lens loop (Storz E0631) in the irrigating handpiece and adjust the bottle height to get a rapid drip of fluid. Pass the lens loop through the incision and then gently beneath the nucleus, allowing time for the fluid to dissect ample space between the nucleus and the posterior capsule. Lift slightly on the nucleus, slide into the cleavage plane, lift slightly again, slide further into the cleavage plane, and so on. Repeat this sequence until the nucleus floats up away from the posterior capsule and toward the wound. The lens loop should now be positioned beneath the central nucleus. Hesitate until fluid builds up and pushes the nucleus against the internal lip of the wound. Then withdraw the loop while applying slight posterior pressure at the same time, lift slightly on the anterior scleral lip with forceps held in the free hand. Most nuclei come readily through a 10 mm incision, but an occasional large hard compact nucleus comes out more readily after extending the scleral incision to a width of 11 mm (Figures 10-15 and 10-16).



Figure 10-15 Extract the nucleus using a Knolle-Pearce irrigating lens loop.



Figure 10-16 The lens loop draws the nucleus through the wound.

Commonly, a rumpled shell of epinuclear cortex strips away from the nucleus as it passes out of the eye and remains adjacent to the internal lip of the wound. Irrigate this loose cortex from the anterior chamber using a Randolph cannula attached to a squeeze bottle of balanced solution.

Removal of the cortex

Tie the three preplaced sutures. Use either an automated irrigation-aspiration device, such as that found with equipment supplied for phacoemulsification or extracapsular surgery, or a manual irrigation–aspiration instrument. Insert the tip of the irrigation–aspiration device through any of the 2.5 mm wound segments between the sutures as needed for easy access. Insert the instrument with the aspiration hole aimed anteriorly.

Place the tip of the instrument gently into the capsular fornix while keeping close to the posterior capsule to avoid aspirating the free anterior capsular flap. This allows the cortex in the capsular fornix to occlude the opening as aspiration begins, helping prevent aspiration of the anterior capsular leaflet. About 1 s after initiating gentle aspiration, withdraw the tip of the aspiration device into the pupillary space to verify that cortex is attached to it. Once the surgeon confirms that the irrigation port is aspirating cortex and is free of other unwanted attachments, the aspiration vacuum can be increased to complete aspiration of the attached cortical fragment. Remove the cortex sequentially from adjacent sites until all has been removed. As each fragment is aspirated, slowly bring the tip of the instrument into the center of the pupil to strip cortex away from the posterior capsule and simultaneously to aspirate it.

Begin aspirating cortex at the 6 o'clock position and then remove it gradually as illustrated until cortex remains only adjacent to the wound. Usually cortex adjacent to the wound can be removed by inserting the aspiration tip at the far right side of the incision to remove cortex next to the left part of the incision, and vice versa. If cortex near the wound is adherent, irrigate it using a curved Binkhorst aspiration cannula attached to a syringe. This usually loosens it so that it can be more easily removed by the aspiration tip (Figures 10-17 to 10-20). If these maneuvers do not remove the cortex, aspirate it carefully using a curved Binkhorst cannula attached to a syringe containing balanced salt solution after inflating the capsular bag with a viscoelastic agent.



Figure 10-17 Remove residual cortex from posterior capsule using irrigation–aspiration instrument beginning at the 6 o'clock position (surgeon's view).



Figure 10-18 Cross-sectional view of cortical aspiration.



Figure 10-19 Cortex at 3 and 9 o'clock is removed after the inferior cortex.



Figure 10-20 Aspiration of cortex at 12 o'clock position is made easier by inserting the irrigation–aspiration instrument through the far right side of the incision to remove cortex at the 12 to 1 o'clock position (A) and through the far left of the incision to remove cortex at the 11 to 12 o'clock position (B).

Polish the posterior capsule with a capsule polishing instrument (Figure 10-21). Any cortex that can be readily removed will be rubbed off the capsule. If residual fibrotic material does not readily come off, this may be left for later neodymium:yttrium-aluminum-garnet laser capsulotomy. With an appropriate aspiration device that includes a “capsule vacuuming” mode, residual cortical material can be vacuumed away from the posterior capsule with reasonable safety (Figure 10-22).



Figure 10-21 Polish the posterior capsule with a Kratz scratcher.



Figure 10-22 Aspiration of residual cortical material using irrigation–aspiration instrument and “capsule vacuuming” mode.

Implantation of the intraocular lens

With a viscoelastic agent, fill the central anterior chamber and place additional viscoelastic beneath the anterior capsular flaps to inflate the capsule for in-the-bag intraocular lens (IOL) insertion. If the surgeon desires to place the lens implant into the ciliary sulcus, such as in a situation when the posterior lens capsule has ruptured, use viscoelastic beneath the iris to flatten the residual anterior capsule flap against the posterior capsule to inflate the space of the ciliary sulcus rather than inflating the lens capsule as described previously.

Remove the 11 o'clock and 12 o'clock temporary sutures in preparation for the lens insertion. Holding the lens with lens-insertion forceps (such as Bechert forceps), slide it into the anterior chamber. As the optic passes through the wound, tilt it to position the haptic to pass into the capsular bag (or sulcus, if desired). The inferior haptic should slide close to the posterior capsule and into the bag (or sulcus) as the optic passes through the wound incision (Figure 10-23). As the right hand releases the optic, the left hand, holding the superior haptic, pushes it in and to the left, thereby rotating the inferior haptic of the lens somewhat toward the 7 or 8 o'clock position.



Figure 10-23 Technique for implantation of intraocular lens using viscoelastic.

After releasing the optic, grasp the superior haptic of the lens at its midpoint. In the left hand, use a blunt iris hook (Katena K3-5422) (Figure 10-24). Grasp the residual margin of the anterior capsule along with the margin of the iris and retract slightly toward the wound, using the blunt iris hook in the left hand while passing the superior haptic into the anterior chamber and using the right hand with a vector of movement toward the position of the iris hook (Figure 10-25). This causes the lens to rotate into a horizontal position. The superior haptic is flexed sufficiently to clear the margin of the iris and the anterior capsule and to pass beneath the edge of the iris hook, which can, in effect, “shoe-horn” the superior haptic into the capsular bag by gliding the haptic beneath the hook. Once the superior haptic has been released into the capsule bag, a Sinskey hook may be used to rotate the lens slightly clockwise to settle it into a central position. Minimize manipulation of the lens to avoid dislocating a haptic from the bag into the ciliary sulcus.



Figure 10-24 An iris hook guides superior haptic into the capsular bag.



Figure 10-25 The iris hook can retract the anterior capsule and iris if necessary to allow accurate placement of the superior haptic into the capsular bag.

Wound closure

Place a corneal cover over the central cornea to block light from the microscope. Leave the temporary suture in place at the 1 o'clock position; close the incision to the right of that suture with a running 10-0 nylon suture placed in a shoelace fashion as illustrated. In Figure 10-26, the initial penetration point of each bite of the suture is labeled sequentially to demonstrate how the suture is placed. The first bite starts within the lips of the wound and passes through only the posterior lip; the final bite passes only through the anterior lip, thereby allowing the two suture ends to come together and to be tied within the wound. Begin each suture bite after the first, about 1 mm from the anterior lip of the incision.



Figure 10-26 Technique for placement for shoelace suture – each bite is numbered in order. Suture is tied with knot in wound.

Pass the needle though the flap, then intralamellarly along the bed of the scleral dissection and finally through intact sclera. Exit 1 mm posterior to the scleral groove. Bury the knot within the lips of the wound next to the remaining temporary suture.

Aspirate residual viscoelastic material by passing the irrigation–aspiration instrument through the incision remaining open to the left of the temporary suture (Figure 10-27). Inject an intraocular miotic agent to constrict the pupil. Close the remainder of the wound with a 10-0 nylon suture using a modified shoelace configuration, as indicated (Figure 10-28). Close the conjunctival flap by applying wet-field coaptation forceps in the usual fashion along the oblique cuts nasally and temporally (Figure 10-29).



Figure 10-27 Removal of viscoelastic through remaining unsutured part of wound. Inject intraocular carbachol 0.01% to constrict pupil after removal of viscoelastic.



Figure 10-28 Remove remaining 9-0 silk suture and place 10-0 nylon shoelace suture as indicated, with each bite numbered in order of placement.



Figure 10-29 Appearance showing constricted pupil (carbachol) and conjunctival flap in place.

References

[1]. Leaming D.V.: Practice styles and preferences of ASCRS members – 1992 survey. J Cataract Refract Surg 1993; 19:603.

[2]. Leaming D.V.: Practice styles and preferences of ASCRS members – 2000 survey. J Cataract Refract Surg 2001; 27:948-955.

[3]. Steinert R.F., Brint S.F., White S.M., et al: Astigmatism after small incision cataract surgery: a prospective, randomized, multicenter comparison of 4- and 6.5-mm incisions. Ophthalmology 1991; 98:417-423.

[4]. Hayashi K., Hayashi H., Nakao F., et al: The correlation between incision size and corneal shape change in sutureless cataract surgery. Ophthalmology 1995; 102:550-556.

[5]. Kohnen T., Dick B., Jacobi K.W.: Comparison of induced astigmatism after temporal clear corneal tunnel incisions of different sizes. J Cataract Refract Surg 1995; 21:417-424.

[6]. Oshika T., Nagahara K., Yaguchi S., et al: Three year prospective, randomized evaluation of intraocular lens implantation through 3.2 and 5.5 mm incisions. J Cataract Refract Surg 1998; 24:509-514.

[7]. Olson R.J., Crandall A.S.: Prospective randomized comparison of phacoemulsification cataract surgery with a 3.2-mm vs a 5.5-mm sutureless incision. Am J Ophthalmol 1990; 125:612-620.

[8]. Werblin T.P.: Astigmatism after cataract extraction: 6-year follow-up of 6.5- and 12-millimeter incisions. Refract Corneal Surg 1992; 8:448.

[9]. Watson A., Sunderraj P.: Comparison of small-incision phacoemulsification with standard extracapsular cataract surgery: postoperative astigmatism and visual recovery. Eye 1992; 6:626.

[10]. Laurell C.G., Zetterstrom C., Phillipson B., et al: Randomized study of the blood–aqueous barrier reaction after phacoemulsification and extracapsular cataract extraction. Acta Ophthalmol Scand 1998; 76:573-578.

[11]. Pande M.V., Spalton D.J., Kerr-Muir M.G., et al: Postoperative inflammatory response to phacoemulsification and extracapsular cataract surgery: aqueous flare and cells. J Cataract Refract Surg 1996; 22:770-774.

[12]. Minassian D.C., Rosen P., Dart J.K., et al: Extracapsular cataract extraction compared with small incision surgery by phacoemulsification: a randomized trial. Br J Ophthalmol 2001; 85:822-829.

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Contents

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Cataract Surgery, 3rd Edition

PART III – Extracapsular Cataract Extraction Chapter 10 – Extracapsular Cataract Surgery: Indications and Techniques

PART III – Extracapsular Cataract Extraction

Chapter 10 – Extracapsular Cataract Surgery: Indications and Techniques