- Email: [email protected]
Pop-and-chop nucleofractis
techniques Pop-and-chop nucleofractis Rahul T. Pandit, MD, Thomas A. Oetting, MS, MD Horizontal chopping is effective for endocapsular nucleofractis. We describe pop and chop, a variant of chopping that enables an easy first crack and initial segment removal. It involves partial extracapsular prolapse of the nucleus prior to the initial chop. It is particularly useful when hydrodissection results in partial prolapse of the lens nucleus so that it is wedged into the anterior capsule opening. It is also helpful when beginning surgeons are learning phaco chop. J Cataract Refract Surg 2003; 29:2054–2056 2003 ASCRS and ESCRS
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haco chop was presented by Nagahara (K. Nagahara, MD, “Phaco Chop,” film presented at the 3rd American–International Congress on Cataract, IOL and Refractive Surgery, Seattle, Washington, USA, June 1993). It provides an effective method for nuclear fracturing within the capsular bag without requiring extensive ultrasound time for sculpting. Compared with divide and conquer,1 phaco chop appears to result in less ultrasound power and less endothelial cell damage.2 Phaco chop, however, can be difficult to master. One difficulty for beginners lies in the correct placement of the chopper in the periphery between the nucleus and epinucleus. This becomes especially difficult if the pupil is small and the nuclear edge cannot be visualized. Embedding the phaco tip deep enough to hold the nucleus still during chopping can be challenging at first. Finally, chopping provides little room for the nuclear pieces to move, the first of these pieces being the most challenging to remove.3 This difficulty was addressed
Accepted for publication March 18, 2003. From the Department of Ophthalmology and Visual Sciences, University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA. Neither author has a financial or proprietary interest in any material or method mentioned.
by Koch and Katzen4 using the stop-and-chop phacoemulsification technique, which allows for additional space so chopped sections can be removed. Supracapsular phacoemulsification, in which the nucleus is flipped out of the bag into the ciliary sulcus space, provides an alternative to endocapsular techniques. This technique, championed by Maloney and coauthors,5 takes advantage of the larger supracapsular space relative to the capsular bag, permitting easier nuclear disassembly. On the other hand, supracapsular phacoemulsification carries the potential for greater damage to the corneal endothelium and iris. To combine the benefits of these methods, we report a technique in which the nucleus is partially prolapsed or popped into the anterior chamber, intentionally or inadvertently, during hydrodissection. The nucleus is tilted up and held in place by the anterior capsule opening. With the nucleus tilted, the chopper can easily find the peripheral edge, the nucleus is held steady by the phaco tip and capsular bag, and adequate space is available to remove the chopped section. Normal endocapsular chopping is then continued as the remainder of the lens falls back into the capsular bag. This technique, which we refer to as “pop and chop,” is particularly useful for beginners attempting phaco chop and when the lens inadvertently prolapses halfway out of the bag.
Patricia Duffel, MA, assisted with illustrations for this paper. Reprint requests to Thomas A. Oetting, MS, MD, Department of Ophthalmology and Visual Sciences, University of Iowa Hospitals and Clinics, 200 Hawkins Drive, Iowa City, Iowa 52242, USA. E-mail: [email protected]. 2003 ASCRS and ESCRS Published by Elsevier Inc.
Surgical Technique The technique begins in the usual manner for temporal clear corneal phacoemulsification. The choice of an0886-3350/03/$–see front matter doi:10.1016/S0886-3350(03)00339-1
TECHNIQUES: PANDIT
Figure 1. (Pandit) Injection of BSS through a hydrodissection can-
Figure 2. (Pandit) After the chopper tip is placed behind the right-
nula causes prolapse of a portion of the lens nucleus anterior to the capsulorhexis edge.
most portion of prolapsed nucleus, the phaco tip is embedded in the central nucleus and the first chop is performed.
esthesia is the surgeon’s preference. A paracentesis port is made at the limbus. Dispersive viscoelastic material is injected into the anterior chamber to adequately coat the cornea, followed by a cohesive viscoelastic material centrally to further deepen the anterior chamber and flatten the anterior capsule. A beveled incision is made in the temporal clear cornea. After a 5.0 to 6.0 mm continuous curvilinear capsulorhexis is created, balanced salt solution (BSS威) is used to perform hydrodissection, separating the cortex from the capsule. Next, BSS is used to perform hydrodelineation. Enough fluid is injected to delineate the nucleus from the surrounding epinucleus and to prolapse half the nucleus out of the capsular bag (Figure 1). When using a straight cannula for hydrodelineation, the prolapsed nucleus is usually opposite the temporal corneal wound. If this is not the case, the nucleus is easily manipulated into this orientation. At this point, additional dispersive viscoelastic material may be injected into the region of the prolapsed nucleus to further protect the corneal endothelium and deepen the anterior chamber. The phacoemulsification tip is inserted into the anterior chamber through the main wound, followed by the chopping instrument through the paracentesis. The phaco tip is embedded near the center of the nucleus. Next, the chopper is placed posterior to the rightmost part of the prolapsed portion of the nucleus (Figure 2). The chopper is advanced toward the phaco tip while the latter is held stationary. Next, the chopper is placed posterior to the left part of the prolapsed portion of
the nucleus (Figures 3 and 4). Once again, it is advanced toward the phaco tip. The 2 cracks in the nucleus should meet in the center. The phaco tip is then embedded in the center of the cracked segment of nucleus, and this segment is phacoemulsified (Figure 5). The chopper is useful at this stage to help manipulate the free segment into the phaco tip. The remainder of the nucleus is
Figure 3. (Pandit) Top: Top view of chopper being placed posterior to the left-most portion of prolapsed nucleus while occlusion of the phaco tip embedded in the central nucleus is maintained. Bottom: Side view showing placement of chopper behind nucleus edge.
J CATARACT REFRACT SURG—VOL 29, NOVEMBER 2003
2055
TECHNIQUES: PANDIT
Figure 4. (Pandit) Placement of the chopper and phaco tip as de-
Figure 5. (Pandit) Phacoemulsification of the resulting nuclear
scribed in Figure 3.
segment.
then easily prolapsed back into the capsular bag, and rotation becomes easier. The remainder of the nucleus can be removed using conventional chopping techniques.
Discussion This variation of phaco chop is useful because it enables easy initial removal of a segment of nucleus. Once the first segment is removed, it is often easier to manipulate and rotate the remainder of the nucleus. Our variation of phaco chop is particularly useful when hydrodissection leads to inadvertent partial prolapse of the nucleus so that it is wedged into the anterior capsule opening. In addition, we have found our technique helpful in teaching beginners the correct placement of the chopper around the nuclear edge. With conventional chopping, it can be difficult to visualize the correct placement of the chopper. Furthermore, it can be difficult to embed the phaco tip deep enough to hold the nucleus still to create an adequate crack. These difficulties are more easily overcome using our technique. Certain precautions must be taken with this technique, especially by the beginning surgeon. During prolapse of the nucleus, BSS may be retained posteriorly in the capsular bag and increase pressure on the posterior capsule. This can be avoided by minimizing the amount of fluid used during hydrodelineation and by gently
2056
tapping the central nucleus to evacuate trapped BSS. When placing the chopper peripheral to the nucleus edge, care must be taken not to depress too far posteriorly so that peripheral anterior capsule is engaged and torn. One theoretical disadvantage of this technique is that during the initial use of phacoemulsification, phaco energy is directed more anteriorly. The surgeon should direct the tip posteriorly while embedding the prolapsed nucleus as well as minimize phaco power. It may be difficult to reproduce this technique in every eye. The ability to prolapse the nucleus will vary depending on capsulorhexis size and nuclear density. Despite these limitations, we believe that pop and chop can be useful.
References 1. Gimbel HV. Divide and conquer nucleofractis phacoemulsification: development and varations. J Cataract Refract Surg 1991; 17:281–291 2. Pirazzoli G, D’Eliseo D, Ziosi M, Acciarri R. Effects of phacoemulsification time on the corneal endothelium using phacofracture and phaco chop techniques. J Cataract Refract Surg 1996; 22:967–969 3. Vasavada A, Singh R. Surgical techniques for difficult cataracts. Curr Opin Ophthalmol 1999; 10:46–52 4. Koch PS, Katzen LE. Stop and chop phacoemulsification. J Cataract Refract Surg 1994; 20:566–570 5. Maloney WF, Dillman DM, Nichamin LD. Supracapsular phacoemulsification: a capsule-free posterior chamber approach. J Cataract Refract Surg 1997; 23:323–328
J CATARACT REFRACT SURG—VOL 29, NOVEMBER 2003
P
haco chop was presented by Nagahara (K. Nagahara, MD, “Phaco Chop,” film presented at the 3rd American–International Congress on Cataract, IOL and Refractive Surgery, Seattle, Washington, USA, June 1993). It provides an effective method for nuclear fracturing within the capsular bag without requiring extensive ultrasound time for sculpting. Compared with divide and conquer,1 phaco chop appears to result in less ultrasound power and less endothelial cell damage.2 Phaco chop, however, can be difficult to master. One difficulty for beginners lies in the correct placement of the chopper in the periphery between the nucleus and epinucleus. This becomes especially difficult if the pupil is small and the nuclear edge cannot be visualized. Embedding the phaco tip deep enough to hold the nucleus still during chopping can be challenging at first. Finally, chopping provides little room for the nuclear pieces to move, the first of these pieces being the most challenging to remove.3 This difficulty was addressed
Accepted for publication March 18, 2003. From the Department of Ophthalmology and Visual Sciences, University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA. Neither author has a financial or proprietary interest in any material or method mentioned.
by Koch and Katzen4 using the stop-and-chop phacoemulsification technique, which allows for additional space so chopped sections can be removed. Supracapsular phacoemulsification, in which the nucleus is flipped out of the bag into the ciliary sulcus space, provides an alternative to endocapsular techniques. This technique, championed by Maloney and coauthors,5 takes advantage of the larger supracapsular space relative to the capsular bag, permitting easier nuclear disassembly. On the other hand, supracapsular phacoemulsification carries the potential for greater damage to the corneal endothelium and iris. To combine the benefits of these methods, we report a technique in which the nucleus is partially prolapsed or popped into the anterior chamber, intentionally or inadvertently, during hydrodissection. The nucleus is tilted up and held in place by the anterior capsule opening. With the nucleus tilted, the chopper can easily find the peripheral edge, the nucleus is held steady by the phaco tip and capsular bag, and adequate space is available to remove the chopped section. Normal endocapsular chopping is then continued as the remainder of the lens falls back into the capsular bag. This technique, which we refer to as “pop and chop,” is particularly useful for beginners attempting phaco chop and when the lens inadvertently prolapses halfway out of the bag.
Patricia Duffel, MA, assisted with illustrations for this paper. Reprint requests to Thomas A. Oetting, MS, MD, Department of Ophthalmology and Visual Sciences, University of Iowa Hospitals and Clinics, 200 Hawkins Drive, Iowa City, Iowa 52242, USA. E-mail: [email protected]. 2003 ASCRS and ESCRS Published by Elsevier Inc.
Surgical Technique The technique begins in the usual manner for temporal clear corneal phacoemulsification. The choice of an0886-3350/03/$–see front matter doi:10.1016/S0886-3350(03)00339-1
TECHNIQUES: PANDIT
Figure 1. (Pandit) Injection of BSS through a hydrodissection can-
Figure 2. (Pandit) After the chopper tip is placed behind the right-
nula causes prolapse of a portion of the lens nucleus anterior to the capsulorhexis edge.
most portion of prolapsed nucleus, the phaco tip is embedded in the central nucleus and the first chop is performed.
esthesia is the surgeon’s preference. A paracentesis port is made at the limbus. Dispersive viscoelastic material is injected into the anterior chamber to adequately coat the cornea, followed by a cohesive viscoelastic material centrally to further deepen the anterior chamber and flatten the anterior capsule. A beveled incision is made in the temporal clear cornea. After a 5.0 to 6.0 mm continuous curvilinear capsulorhexis is created, balanced salt solution (BSS威) is used to perform hydrodissection, separating the cortex from the capsule. Next, BSS is used to perform hydrodelineation. Enough fluid is injected to delineate the nucleus from the surrounding epinucleus and to prolapse half the nucleus out of the capsular bag (Figure 1). When using a straight cannula for hydrodelineation, the prolapsed nucleus is usually opposite the temporal corneal wound. If this is not the case, the nucleus is easily manipulated into this orientation. At this point, additional dispersive viscoelastic material may be injected into the region of the prolapsed nucleus to further protect the corneal endothelium and deepen the anterior chamber. The phacoemulsification tip is inserted into the anterior chamber through the main wound, followed by the chopping instrument through the paracentesis. The phaco tip is embedded near the center of the nucleus. Next, the chopper is placed posterior to the rightmost part of the prolapsed portion of the nucleus (Figure 2). The chopper is advanced toward the phaco tip while the latter is held stationary. Next, the chopper is placed posterior to the left part of the prolapsed portion of
the nucleus (Figures 3 and 4). Once again, it is advanced toward the phaco tip. The 2 cracks in the nucleus should meet in the center. The phaco tip is then embedded in the center of the cracked segment of nucleus, and this segment is phacoemulsified (Figure 5). The chopper is useful at this stage to help manipulate the free segment into the phaco tip. The remainder of the nucleus is
Figure 3. (Pandit) Top: Top view of chopper being placed posterior to the left-most portion of prolapsed nucleus while occlusion of the phaco tip embedded in the central nucleus is maintained. Bottom: Side view showing placement of chopper behind nucleus edge.
J CATARACT REFRACT SURG—VOL 29, NOVEMBER 2003
2055
TECHNIQUES: PANDIT
Figure 4. (Pandit) Placement of the chopper and phaco tip as de-
Figure 5. (Pandit) Phacoemulsification of the resulting nuclear
scribed in Figure 3.
segment.
then easily prolapsed back into the capsular bag, and rotation becomes easier. The remainder of the nucleus can be removed using conventional chopping techniques.
Discussion This variation of phaco chop is useful because it enables easy initial removal of a segment of nucleus. Once the first segment is removed, it is often easier to manipulate and rotate the remainder of the nucleus. Our variation of phaco chop is particularly useful when hydrodissection leads to inadvertent partial prolapse of the nucleus so that it is wedged into the anterior capsule opening. In addition, we have found our technique helpful in teaching beginners the correct placement of the chopper around the nuclear edge. With conventional chopping, it can be difficult to visualize the correct placement of the chopper. Furthermore, it can be difficult to embed the phaco tip deep enough to hold the nucleus still to create an adequate crack. These difficulties are more easily overcome using our technique. Certain precautions must be taken with this technique, especially by the beginning surgeon. During prolapse of the nucleus, BSS may be retained posteriorly in the capsular bag and increase pressure on the posterior capsule. This can be avoided by minimizing the amount of fluid used during hydrodelineation and by gently
2056
tapping the central nucleus to evacuate trapped BSS. When placing the chopper peripheral to the nucleus edge, care must be taken not to depress too far posteriorly so that peripheral anterior capsule is engaged and torn. One theoretical disadvantage of this technique is that during the initial use of phacoemulsification, phaco energy is directed more anteriorly. The surgeon should direct the tip posteriorly while embedding the prolapsed nucleus as well as minimize phaco power. It may be difficult to reproduce this technique in every eye. The ability to prolapse the nucleus will vary depending on capsulorhexis size and nuclear density. Despite these limitations, we believe that pop and chop can be useful.
References 1. Gimbel HV. Divide and conquer nucleofractis phacoemulsification: development and varations. J Cataract Refract Surg 1991; 17:281–291 2. Pirazzoli G, D’Eliseo D, Ziosi M, Acciarri R. Effects of phacoemulsification time on the corneal endothelium using phacofracture and phaco chop techniques. J Cataract Refract Surg 1996; 22:967–969 3. Vasavada A, Singh R. Surgical techniques for difficult cataracts. Curr Opin Ophthalmol 1999; 10:46–52 4. Koch PS, Katzen LE. Stop and chop phacoemulsification. J Cataract Refract Surg 1994; 20:566–570 5. Maloney WF, Dillman DM, Nichamin LD. Supracapsular phacoemulsification: a capsule-free posterior chamber approach. J Cataract Refract Surg 1997; 23:323–328
J CATARACT REFRACT SURG—VOL 29, NOVEMBER 2003