- Email: [email protected]
Hydro-chop technique for soft lenses
J CATARACT REFRACT SURG - VOL 32, JANUARY 2006
Hydro-chop technique for soft lenses Rosa Braga-Mele, MEd, MD, FRCS(C), Baseer U. Khan, MD
Chopping techniques were initially developed to expend the least amount of phacoemulsification power inside the eye to remove a lens and to improve efficiency. Soft nuclei are not generally conducive to traditional chopping techniques and have required alternate, energy-consuming techniques, such as sculpting, to be removed. We describe a modified chopping technique that can be used to mechanically cleave soft nuclei into distinct fragments before phaco power is required, reducing total power and energy expended in the eye. J Cataract Refract Surg 2006; 32:18–20 Q 2006 ASCRS and ESCRS
The driving force in advancing technologies and techniques in phacoemulsification lies in reducing the amount of ultrasound power and energy used within the eye. Reducing the power delivered intracamerally diminishes the damage that can occur to the endothelium, trabecular meshwork, and other intraocular structures. Chopping techniques have been shown to reduce the required phaco time to remove nuclear material1,2 by using mechanical force for nuclear disassembly, thereby minimizing the amount of phacoemulsification required. The quick-chop technique described by Nagahara (K. Nagahara, MD, ‘‘Phaco Chop,’’ film presented at the ASCRS 3rd American–International Congress on Cataract, IOL and Refractive Surgery, Seattle, Washington, USA, May 1993.) is most appropriate for moderate to hard lens only as it is very difficult, if not impossible, to achieve the vacuum occlusion required to quick chop a very soft lens. The stop-and-chop method3 may be used for soft lens, but phaco power and time are required to create the initial groove. Alternatively, flipping techniques4 have been described to remove soft lenses; however, this maneuver represents a certain risk to the endothelium, particularly in eyes with shallow anterior chambers. We are proposing a hydro-chop technique that reliably results in the first crack of a soft nucleus without the expenditure of phaco power in the eye.
Accepted for publication May 20, 2005. From the Department of Ophthalmology, University of Toronto, Ontario, Canada. Neither author has a financial or proprietary interest in any material or method mentioned. Reprint requests to Rosa Braga-Mele, MEd, MD, FRCS(C), Associate Professor, University of Toronto, Director of Cataract Unit and Surgical Teaching, Mount Sinai Hospital, Toronto 245 Danforth Avenue, Suite 200, Toronto, Ontario M4K 1N2, Canada. E-mail: [email protected]. Q 2006 ASCRS and ESCRS Published by Elsevier Inc.
18
SURGICAL TECHNIQUE
After a continuous curvilinear capsulorhexis is performed, cortical cleavage hydrodissection is carried out in the usual fashion using a curved Gimbel hydrodissection cannula (Storz).5 However, before exiting the eye, the hydrodissection cannula is used to create a central groove within the nucleus. Irrigation occurs through the cannula as it moves back and forth to create the groove so as not to impale the nucleus. The groove is extended for the length of the diameter of the capsulorhexis to a depth of one half to two thirds of the nucleus. The irrigation through the cannula cleaves the nucleus in half through the central plane (Figure 1). The phaco needle is then introduced into the anterior chamber along with a second instrument capable of chopping such as a Koch chopper or Sweeny nucleus manipulator (Storz). While only irrigating, the tip of the phaco needle is buttressed against the proximal aspect of the lens within this newly created thin central groove. The second instrument is then placed in the groove at the junction of the distal limit of the groove and the edge of the capsulorhexis (Figure 2). The tip of the second instrument is buried within the groove and pulled centrallydthe resistance to this movement is so little that the phaco tip buttressed against the proximal surface of the lens provides enough counter traction. A small lateral movement by the second instrument once the center of the lens has been reached is enough to generate a crack that can be propagated by reapposition of the phaco tip against the shelf of the newly created groove (Figure 3). A reverse-chopping technique can be used to further divide the nuclear half distal to the side-port incision. The second instrument is inserted within the crack such that the elbow of the second instrument is facing posteriorly and the tip is parallel to the capsular bag. The tip of the second instrument is then slid between the posterior epinucleus and the nucleus, so that it is directly underneath 0886-3350/06/$-see front matter doi:10.1016/j.jcrs.2005.11.023
TECHNIQUES: HYDRO CHOP FOR SOFT LENSES
the nucleus (Figure 4, A). The second instrument should be oriented such that it bisects the heminculeus to be chopped (Figure 4, B). The phaco tip is then placed on the surface of the nuclear half just proximal to the position of the second instrument. The second instrument is then moved vertically through the nucleus from a posterior to anterior direction with the phaco tip providing leverage and resistance, breaking the heminucleus further into halves. DISCUSSION
Figure 1. The hydrodissection cannula is passed in an arcuate fashion through the lens to a depth of one half to two thirds.
This technique provides a safe and reliable way of chopping a soft lens within the capsular bag. This minimizes the phaco power required to remove the lens and preempts possible damage to intracameral structures by phaco power used anterior to the iris plane as necessitated by flipping and supracapsular techniques. This technique could be likened to the use of a prechopper, as initially described
Figure 2. The chopper is placed in the groove created by the hydrodissection cannula while the proximal lens is buttressed by the phaco needle for counter traction. The chopper is then moved centrally.
Figure 3. Once the chopper has reached the center of the lens, the phaco needle tip is then buttressed against the inside surface of the cracked nucleus. The chopper then engages the opposite inner nuclear surface and is moved laterally to propagate the crack.
Figure 4. A: The chopper is rotated so that the arm is directed posteriorly and the chopping tip is parallel to the posterior capsule, just below the posterior margin of the nucleus. B: The chopper is oriented so that it bisects the heminucleus to be cleaved. The phaco needle tip is placed just beside where the chopper is stationed on the surface of the heminucleus. This provides the counter force to the movement of the chopper as it is moved vertically through the heminucleus, thereby halving the segment.
J CATARACT REFRACT SURG - VOL 32, JANUARY 2006
19
TECHNIQUES: HYDRO CHOP FOR SOFT LENSES
by Akahoshi,6 to mechanically cleave the nucleus into halves prior to insertion of the phaco needle, without the financial and practical considerations of having a prechopper as part of one’s surgical set.
REFERENCES 1. Sebban H. Phaco one-chop nucleotomy. J Cataract Refract Surg 2002; 28:1325–1329
20
2. DeBry P, Olson RJ, Crandall AS. Comparison of energy required for phaco-chop and divide and conquer phacoemulsification. J Cataract Refract Surg 1998; 24:689–692 3. Koch PS, Katzen LE. Stop and chop phacoemulsification. J Cataract Refract Surg 1994; 20:566–570 4. Fine IH. The chip and flip phacoemulsification technique. J Cataract Refract Surg 1991; 17:366–371 5. Fine IH. Cortical cleaving hydrodissection. J Cataract Refract Surg 1992; 18:508–512 6. Akahoshi T. Phaco prechop: manual nucleofracture prior to phacoemulsification. Operative Tech Cataract Refract Surg 1998; 1:69–91
J CATARACT REFRACT SURG - VOL 32, JANUARY 2006
Hydro-chop technique for soft lenses Rosa Braga-Mele, MEd, MD, FRCS(C), Baseer U. Khan, MD
Chopping techniques were initially developed to expend the least amount of phacoemulsification power inside the eye to remove a lens and to improve efficiency. Soft nuclei are not generally conducive to traditional chopping techniques and have required alternate, energy-consuming techniques, such as sculpting, to be removed. We describe a modified chopping technique that can be used to mechanically cleave soft nuclei into distinct fragments before phaco power is required, reducing total power and energy expended in the eye. J Cataract Refract Surg 2006; 32:18–20 Q 2006 ASCRS and ESCRS
The driving force in advancing technologies and techniques in phacoemulsification lies in reducing the amount of ultrasound power and energy used within the eye. Reducing the power delivered intracamerally diminishes the damage that can occur to the endothelium, trabecular meshwork, and other intraocular structures. Chopping techniques have been shown to reduce the required phaco time to remove nuclear material1,2 by using mechanical force for nuclear disassembly, thereby minimizing the amount of phacoemulsification required. The quick-chop technique described by Nagahara (K. Nagahara, MD, ‘‘Phaco Chop,’’ film presented at the ASCRS 3rd American–International Congress on Cataract, IOL and Refractive Surgery, Seattle, Washington, USA, May 1993.) is most appropriate for moderate to hard lens only as it is very difficult, if not impossible, to achieve the vacuum occlusion required to quick chop a very soft lens. The stop-and-chop method3 may be used for soft lens, but phaco power and time are required to create the initial groove. Alternatively, flipping techniques4 have been described to remove soft lenses; however, this maneuver represents a certain risk to the endothelium, particularly in eyes with shallow anterior chambers. We are proposing a hydro-chop technique that reliably results in the first crack of a soft nucleus without the expenditure of phaco power in the eye.
Accepted for publication May 20, 2005. From the Department of Ophthalmology, University of Toronto, Ontario, Canada. Neither author has a financial or proprietary interest in any material or method mentioned. Reprint requests to Rosa Braga-Mele, MEd, MD, FRCS(C), Associate Professor, University of Toronto, Director of Cataract Unit and Surgical Teaching, Mount Sinai Hospital, Toronto 245 Danforth Avenue, Suite 200, Toronto, Ontario M4K 1N2, Canada. E-mail: [email protected]. Q 2006 ASCRS and ESCRS Published by Elsevier Inc.
18
SURGICAL TECHNIQUE
After a continuous curvilinear capsulorhexis is performed, cortical cleavage hydrodissection is carried out in the usual fashion using a curved Gimbel hydrodissection cannula (Storz).5 However, before exiting the eye, the hydrodissection cannula is used to create a central groove within the nucleus. Irrigation occurs through the cannula as it moves back and forth to create the groove so as not to impale the nucleus. The groove is extended for the length of the diameter of the capsulorhexis to a depth of one half to two thirds of the nucleus. The irrigation through the cannula cleaves the nucleus in half through the central plane (Figure 1). The phaco needle is then introduced into the anterior chamber along with a second instrument capable of chopping such as a Koch chopper or Sweeny nucleus manipulator (Storz). While only irrigating, the tip of the phaco needle is buttressed against the proximal aspect of the lens within this newly created thin central groove. The second instrument is then placed in the groove at the junction of the distal limit of the groove and the edge of the capsulorhexis (Figure 2). The tip of the second instrument is buried within the groove and pulled centrallydthe resistance to this movement is so little that the phaco tip buttressed against the proximal surface of the lens provides enough counter traction. A small lateral movement by the second instrument once the center of the lens has been reached is enough to generate a crack that can be propagated by reapposition of the phaco tip against the shelf of the newly created groove (Figure 3). A reverse-chopping technique can be used to further divide the nuclear half distal to the side-port incision. The second instrument is inserted within the crack such that the elbow of the second instrument is facing posteriorly and the tip is parallel to the capsular bag. The tip of the second instrument is then slid between the posterior epinucleus and the nucleus, so that it is directly underneath 0886-3350/06/$-see front matter doi:10.1016/j.jcrs.2005.11.023
TECHNIQUES: HYDRO CHOP FOR SOFT LENSES
the nucleus (Figure 4, A). The second instrument should be oriented such that it bisects the heminculeus to be chopped (Figure 4, B). The phaco tip is then placed on the surface of the nuclear half just proximal to the position of the second instrument. The second instrument is then moved vertically through the nucleus from a posterior to anterior direction with the phaco tip providing leverage and resistance, breaking the heminucleus further into halves. DISCUSSION
Figure 1. The hydrodissection cannula is passed in an arcuate fashion through the lens to a depth of one half to two thirds.
This technique provides a safe and reliable way of chopping a soft lens within the capsular bag. This minimizes the phaco power required to remove the lens and preempts possible damage to intracameral structures by phaco power used anterior to the iris plane as necessitated by flipping and supracapsular techniques. This technique could be likened to the use of a prechopper, as initially described
Figure 2. The chopper is placed in the groove created by the hydrodissection cannula while the proximal lens is buttressed by the phaco needle for counter traction. The chopper is then moved centrally.
Figure 3. Once the chopper has reached the center of the lens, the phaco needle tip is then buttressed against the inside surface of the cracked nucleus. The chopper then engages the opposite inner nuclear surface and is moved laterally to propagate the crack.
Figure 4. A: The chopper is rotated so that the arm is directed posteriorly and the chopping tip is parallel to the posterior capsule, just below the posterior margin of the nucleus. B: The chopper is oriented so that it bisects the heminucleus to be cleaved. The phaco needle tip is placed just beside where the chopper is stationed on the surface of the heminucleus. This provides the counter force to the movement of the chopper as it is moved vertically through the heminucleus, thereby halving the segment.
J CATARACT REFRACT SURG - VOL 32, JANUARY 2006
19
TECHNIQUES: HYDRO CHOP FOR SOFT LENSES
by Akahoshi,6 to mechanically cleave the nucleus into halves prior to insertion of the phaco needle, without the financial and practical considerations of having a prechopper as part of one’s surgical set.
REFERENCES 1. Sebban H. Phaco one-chop nucleotomy. J Cataract Refract Surg 2002; 28:1325–1329
20
2. DeBry P, Olson RJ, Crandall AS. Comparison of energy required for phaco-chop and divide and conquer phacoemulsification. J Cataract Refract Surg 1998; 24:689–692 3. Koch PS, Katzen LE. Stop and chop phacoemulsification. J Cataract Refract Surg 1994; 20:566–570 4. Fine IH. The chip and flip phacoemulsification technique. J Cataract Refract Surg 1991; 17:366–371 5. Fine IH. Cortical cleaving hydrodissection. J Cataract Refract Surg 1992; 18:508–512 6. Akahoshi T. Phaco prechop: manual nucleofracture prior to phacoemulsification. Operative Tech Cataract Refract Surg 1998; 1:69–91
J CATARACT REFRACT SURG - VOL 32, JANUARY 2006