Eyeworld

EW NEWS & OPINION 18 Michael E. Snyder, M.D., Cincinnati Eye Institute, Blue Ash, Ohio, describes how surgeons can successfully perform the difficult task of a capsulorhexis in patients with zonulopathy W hether related to Marfan's syndrome, Weill-Marchesani, simple ectopia, or microspherophakia, zonulopathy results in decentration of the crystalline lens, becoming symptomatic or in younger children potentially amblyogenic. This is the threshold at which surgical interven- tion is required. What to look for In some cases, the zonular defi- ciency can be highly asymmetric. Sometimes the loose zonules are markedly stretched and lax; in oth- ers they appear absent or lysed. A misshapen lens with flattening of the equatorial edge on the side where the zonules are weakest typi- cally indicates that the opposing zonules have greater integrity than when the lens remains perfectly round. Beware of the round lens, es- pecially when it appears decentered inferiorly. Changing the head posi- tion during examination and observing if the lens remains de- pendent based on gravitational forces can identify this sign of pro- found circumferential laxity. The most difficult part A complete capsulorhexis is the cru- cial step in preserving the capsular bag complex for IOL fixation and thereby eliminating or minimizing the need for manipulation or re- moval of vitreous gel. It is uniformly required for an ACIOL, iris-sutured PCIOL, or scleral-sutured PCIOL. Even for a skilled and highly experi- enced surgeon, this is often the most difficult part of an ectopia lentis case. As with most intraocular manip- ulations, the capsulorhexis requires a balance of forces. In normal cases, the anteroposterior force required to penetrate a needle or cystotome through the anterior pressure is op- posed by the taut capsulo-zonular apparatus. In ectopic lens cases, the capsule is lax and the zonules are unable to counteract any posteriorly directed forces (Figure 1). Accord- ingly, attempts to open the capsule with a cystotome can be met by fu- tile posterior movement of the lens and/or elastic indentation of the un- derlying soft cortical material with- out capsule perforation. This is particularly challenging in younger pediatric cases in which the capsule has a more durable, elastic nature. The crossed-swords, capsule pinch technique was developed to over- come these difficulties. The crossed-swords, capsule pinch technique In this technique, two 30-gauge nee- dles penetrate the peripheral limbus, each directed toward the center of the crystalline lens and toward each other. As the tips of the needles ap- proach, the anterior capsule is tan- gentially pinched by each needle tip, thereby creating an anterior dim- October 2011 by Michael E. Snyder, M.D. Performing a capsulorhexis in patients with ectopia lentis P erforming an intact capsu- lorhexis in eyes with ectopia lentis is one of the more chal- lenging and important steps in these cases. Once the rhexis has been cre- ated, the remainder of the procedure will usually proceed straightforwardly. An extremely useful method for begin- ning the capsulorhexis, especially in the presence of extreme zonular laxity, is the crossed-swords maneuver. In this month's column, Mike Snyder reviews his crossed-swords technique and touches on some tips and pearls for performing a capsulorhexis in the pres- ence of ectopia lentis. His article is sharp and to the point, and I am confi- dent that you will find it useful for your next subluxed lens. Richard Hoffman, M.D., tools and techniques editor Or view the video of Dr. Snyder's procedure at www.eyeworld.org/replay.php. Watch this video on your smartphone or iPad using your QR code reader. (Scanner available for free at your app store.) Figure 2 Source: Michael E. Snyder, M.D. Figure 1 Source: Michael E. Snyder, M.D. Tools and techniques

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