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Intraoperative management of posterior capsule tears in phacoemulsification and intraocular lens implantation1
Intraoperative Management of Posterior Capsule Tears in Phacoemulsification and Intraocular Lens Implantation Howard V. Gimbel, MD, MPH, Ran Sun, MD, Maria Ferensowicz, BSc, MA, Ellen Anderson Penno, MD, MS, Aasim Kamal, MD Objective: This paper presents the incidence, causes, and management of posterior capsule (PC) tears and their postoperative outcomes in a large series of eyes that underwent cataract removal and intraocular lens (IOL) implantation, operated on by one surgeon. Design: Retrospective, noncomparative case series. Participants: Eighteen thousand four hundred seventy consecutive eyes (1992–1999) were reviewed with the assistance of electronic medical records for incidence of PC tears in patients seeking treatment at an outpatient cataract surgery clinic. Intervention: Eyes in this series underwent continuous curvilinear capsulorrhexis (CCC), nucleofractis phacoemulsification, and IOL implantation under topical anesthesia. Different intraoperative surgical strategies such as posterior continuous curvilinear capsulorrhexis (PCCC) were used in the management of PC tears. Main Outcome Measures: Routine preoperative and postoperative visual and refractive outcomes were recorded, including incidence of lens capsule tears, IOL position, and postoperative complications. Results: Posterior capsule tears occurred in 83 of 18,470 eyes, resulting in an overall incidence of 0.45%. Of these 83 eyes with PC tears, 49% received vitrectomy. Fifty-one of 83 PC tears (61.4%) were amenable to be converted to PCCC. Of these 51 procedures, 50 eyes had PC IOL in-the-bag fixation. One eye had PCCC with optic capture. There were no eyes with dropped nuclei or nuclear fragments requiring pars plana vitrectomy. Seventeen eyes (20.5%) had Neuhann anterior capsule rhexis fixation with the haptics placed in the sulcus and IOL securely in the bag. Ten eyes (12.1%) had the IOL placed in the sulcus, and 5 eyes (6.0%) required anterior chamber IOL fixation. None of the 83 PC tears resulted in clinically evident cystoid macular edema, retinal detachment, or endophthalmitis. Conclusions: With an intact CCC and with conversion of PC tears to PCCC, in-the-bag fixation of IOLs can be achieved in most eyes. Ophthalmology 2001;108:2186 –2192 © 2001 by the American Academy of Ophthalmology. The objective of this paper is to present the incidence, causes, and management strategies of posterior capsule (PC) tears and their postoperative outcomes. Phacoemulsification is now the favored procedure for cataract extraction. With the development of better phacoemulsification techniques, new instrumentation, and new intraocular lenses (IOLs), the incidence of complications in cataract surgery with IOL implantation has continued to decrease. Posterior capsule tears, an intraoperative complication, although rare, can cause serious operative and postoperative complica-
Originally received: October 22, 2000. Accepted: April 23, 2001. Manuscript no. 200546. From the Gimbel Eye Centre, Calgary, Alberta, Canada. Presented in part at the annual meeting of the American Academy of Ophthalmology, Dallas, Texas, October 2000. The authors have no propriety or financial interest in the research or instruments described in this article. Correspondence to Howard V. Gimbel, MD, MPH, Gimbel Eye Centre, 4935 40th Avenue NW, Suite 450, Calgary, Alberta, Canada T3A 2N1. E-mail: [email protected].
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© 2001 by the American Academy of Ophthalmology Published by Elsevier Science Inc.
tions. Therefore, the intraoperative management of PC tears is vital in the maximization of in-the-bag IOL implantation and minimization of sequelae related to other IOL implantation positions.
Materials and Methods Study Design With the assistance of on-line medical records, 18,470 consecutive eyes that underwent phacoemulsification and IOL implantation from 1992 through 1999 were analyzed for incidence of PC tears.
Main Outcome Measures Routine preoperative and postoperative visual and refractive outcomes were recorded, as were intraoperative and surgical parameters, including IOL position, description of any capsule tears, and postoperative complications. ISSN 0161-6420/01/$–see front matter PII S0161-6420(01)00716-3
Gimbel et al 䡠 PCCC for PC Tears Surgical Technique All surgeries were performed by one surgeon (HVG). Under topical anesthesia, continuous curvilinear capsulorrhexis (CCC) and nucleofractis phacoemulsification were performed. Posterior capsule tears were managed through the application of CCC principles to the PC when possible.
Posterior Curvilinear Capsulorrhexis With the liberal use of viscoelastics, posterior continuous curvilinear capsulorrhexis (PCCC) is initiated by grasping the advancing tear in the PC with forceps, applying CCC principles.1 It is extended and completed into a circle that encompasses the extent of the tear and is blended from the periphery to the center as the circle is completed. Alternatively, one or both ends of a linear tear may be rounded and blunted. The best control of the progressing tear in the PC is achieved using the elongated Kelman-McPherson or Kraff-Utrata forceps, grasping the capsule flap near one point of tearing and turning the tear in the desired direction. The PCCC is kept as small as possible so as to preserve the maximum integrity of the PC. This technique is performed to avoid an anticipated extension of the inadvertent linear or triangular tear during such maneuvers as a required vitrectomy or lens placement.
Posterior Continuous Curvilinear Capsulorrhexis with Optic Capture Primary PCCC with posterior capsular optic capture is a technically challenging procedure that requires skill to avoid peripheral tears in the PC and loss of the capsular bag.2,3 Posterior continuous curvilinear capsulorrhexis is used to convert the PC tear. The PC opening must be smaller than and concentric with the IOL optic. Although the PC is thin, the PCCC appears to have the same stretching capacity as the anterior CCC. With liberal use of viscoelastics and under high magnification of the operating microscope, a cannula is used to vault the IOL optic through the PCCC, first superiorly and then inferiorly.
Neuhann Rhexis Anterior Capsule Fixation A similar technique of capturing the optic through the anterior capsulorrhexis opening has been described in patients with posterior capsular tears and loss of capsular bag support of an IOL. For these patients, Neuhann and Neuhann described a technique of placing the IOL in the sulcus and then placing the optic of the IOL through the anterior capsulorrhexis opening to achieve capture and stable fixation (Neuhann T, Neuhann TH. The rhexis-fixation lens. Film festival entry at the American Society of Cataract and Refractive Surgery (ASCRS), Boston, Massachusetts, April 1991).
Figure 1. Yearly incidence of posterior capsule tears, 1992 to 1999.
one had PC optic capture. In the remaining 32 eyes where PCCC was not possible, anterior capsule (AC) rhexis fixation was used in 17 eyes (53.1%) where the CCC was intact and small enough to capture the optic (Fig 4). Ten eyes underwent sulcus placement because the AC rim was not intact and anterior CCC capture was not possible. Five eyes required AC IOL implantation because of inadequate capsule support. No scleral suture fixation IOLs were used. Seventy-six eyes with tears (91.57%) achieved 20/40 or better best-corrected visual acuity compared with 91.70% without tears (P ⫽ 0.98).
Discussion Various strategies have been described for the management of PC tears.4 –13 Avoiding any PC tears is the goal of every cataract surgeon. If a tear does occur, management techniques and skills are required for successful in-the-bag PC IOL placement or at least capsule fixation of the IOL by being partly in the bag and partly outside the bag, with the optic captured by the anterior or posterior capsulorrhexis. A strong CCC maximizes safe and uneventful phacoemulsification and PC IOL implantation because it is pivotal in avoiding extensions of equatorial tears to the PC. In phacoemulsification cataract surgery with IOL implantation, early suspicion and detection of PC tears is of vital importance. Beginner or advanced phacoemulsification surgeons realize
Results Eighty-three PC tears occurred in 18,470 consecutive surgeries, for an overall incidence of 0.45%. The yearly incidence of PC tears for 1992 through 1999 is presented in Figure 1. Of the 83 eyes with PC tears, 42 (50.6%) occurred during phacoemulsification (Fig 2). Of these, 38 (90.5%) required vitrectomy. Thirty-three PC tears (39.7%) occurred during irrigation and aspiration, and of these, 14 (42.4%) required vitrectomy. Ten percent of tears occurred at other stages of surgery, such as IOL placement or hydrodissection. There were no eyes with dropped nuclei or nuclear fragments requiring pars plana vitrectomy or posterior assisted levitation Fifty-one PC tears (61.5%) were amenable to be converted to PCCC (Fig 3). Of these, 50 eyes had in-the-bag IOL fixation and
Figure 2. Frequency of posterior capsule tears and vitreous presentation.
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Figure 3. Posterior capsule tears converted to posterior continuous curvilinear capsulorrhexis and intraocular lens position.
that PC tears may occur at any time during cataract surgery.14 –17 Figure 5 shows the relative thickness of the AC and PC. The periequatorial capsule is the thickest part of the lens capsule (approximately 21–23 ). The central anterior lens capsule is approximately 14 , but the central posterior lens capsule is the thinnest (approximately 4 ). Although the PC is thinner, one can apply the principles of anterior continuous curvilinear capsulorrhexis to the PC for optimizing capsular bag integrity in cases where small discrete tears occur. Like the AC, the PC also has plastic properties. Plasticity is defined as the ability to retain a shape attained by pressure deformation. The PC is also more elastic than the AC. The force required to tear the PC is greater than the force required to tear the AC. The smooth circular opening does not leave V-shaped tears that easily extend to the equator with minimal stress. The capsulorrhexis margin maintains its integrity, and the molecules at the cut margin behave as a continuous chain. However, a sharp notch at the margin of the capsulorrhexis breaks this continuous chain and forms a radial tear. A CCC made in the PC thus behaves like a CCC and is resistant to radial tears. Posterior continuous curvilinear capsulorrhexis prevents small linear or triangular tears from extending to further damage the lens capsule. This prevents small linear or triangular tears from extending to the equator and stabilizes the capsule, especially during IOL implantation or vitrectomy. Posterior capsule tears at the equator or extending to the equator are not amenable to PCCC. Assia et al18 found a highly significant correlation between the circumference at rupture and the circumference of
Figure 4. Intraocular lens position when posterior continuous curvilinear capsulorrhexis was not possible.
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Figure 5. Schematic of adult human lens capsule showing relative thickness of capsule in different zones. (From American Academy of Ophthalmology. Lens and Cataract: Basic and Clinical Science Course, Section 11. San Francisco: American Academy of Ophthalmology, 2000 –2001. Adapted with permission. Illustration by Christine Gralapp.)
the capsulorrhexis: Cr ⫽ 1.6 Cc, where Cr is the circumference at rupture and Cc is the circumference of capsulorrhexis. This shows that the capsulorrhexis can stretch extensively before it is torn. Castaneda et al19 demonstrated that the pressure needed to disrupt a PCCC is actually greater than that which tears the zonules. This facilitates safe endolenticular phacoemulsification, irrigation and aspiration, and in-the-bag IOL implantation. In-the-bag implantation stabilizes the IOL, minimizes decentration and dislocation, and also reduces contact between the uveal tissue and the IOL. This decreases the incidence of postoperative complications such as pigment dispersion, transillumination iris defects, glaucoma, and uveitis. In 1992, Castaneda and Apple19 demonstrated, in an experimental study, the effectiveness of PCCC in preventing PC radial tears. By extending CCC principles to the PC, IOL in-the-bag placement is maximized. Posterior continuous curvilinear capsulorrhexis was described previously in pediatric cataract and IOL surgery for PC plaque removal. The smooth continuous tear of circular capsulorrhexis meets all the demands of advanced cataract and lens implantation surgery techniques. Posterior continuous curvilinear capsulorrhexis is especially advantageous in sustaining the integrity of the capsular bag when a vitrectomy is required. A previous paper detailed our experience with PC tears and conversion to PCCC in adult cataract surgery.1 In that review of 7174 consecutive eyes, the incidence of PC tears was similar at 36 (0.5%; Fig 6). Nineteen tears (52.7%) occurred during irrigation and aspiration (I/A), and 9 (25%) occurred during phacoemulsification, compared with 39.7% and 50%, respectively, in this series. Evaluating new instrumentation, new fluidic parameters, new surgical adjuvants, and new phacoemulsification techniques add to the risk of developing capsule tears during phacoemulsification in this series, whereas polished I/A tips, enhanced cortex removal techniques, and developments in the silicone I/A tip have decreased the incidence of PC tears during I/A. The placement of new IOLs accounted for two of six PC tears during IOL placement in this series.
Gimbel et al 䡠 PCCC for PC Tears
References
Figure 6. Summary of results from 1987 to 1989 posterior capsule tear study.
For these reasons and others, this has meant that the risk of PC tears during phacoemulsification and IOL implantation was not eliminated in this series. However, strategies and techniques like PCCC can be used routinely to manage tears to achieve excellent outcomes in most of these cases.20 Posterior capsule tears, if small enough, should always be converted to a PCCC to achieve in-the-bag IOL fixation safely. Compared with the 1987 to 89 series, in which in-the-bag fixation was observed in 69.4% of eyes with PC tears,1 PCCC, PCCC with optic capture, and Neuhann AC rhexis have increased the capsule fixation of the IOL to 81.9%, if the PC tear is too large and peripheral to convert to a PCCC. Anterior or posterior rhexis fixation stabilizes the IOL to the capsule and maintains a seal, thus creating a physical barrier between anterior and posterior segments. One can still use the originally planned IOL, as the AC depth and A-constant remain relatively status quo. Also, there is no need for longer haptics, as is necessary for sulcus fixation.
Conclusions In our experience, PC tears can occur at many different stages of cataract removal. Small or short tears in the PC occurring near the end of phacoemulsification or during I/A can often be blunted or converted to a PCCC, allowing for in-the-bag and capsule fixation of the IOL. Obtaining and maintaining an intact CCC leaves the option open to use anterior rhexis fixation in the event of a large PC tear. Complication management techniques are as important and essential as complication prevention measures to achieve satisfactory outcomes in cataract surgery. Our study shows that there are several potentials for PC tears. Even with a low PC tear rate, management techniques and skills are required. Modeled on the principle of anterior CCC, the PCCC technique allows safe and secure in-the-bag IOL placement and therefore enhances visual rehabilitation while reducing intraoperative and postoperative complications in cases where inadvertent PC tears occur.
1. Gimbel HV. Posterior capsule tears using phaco-emulsification: causes, prevention and management. Eur J Implant Refract Surg 1990;2:63–9. 2. Gimbel HV. Posterior continuous curvilinear capsulorhexis and optic capture of the intraocular lens to prevent secondary opacification in pediatric cataract surgery. J Cataract Refract Surg 1997;23:652– 6. 3. Gimbel HV. Posterior capsulorhexis with optic capture in pediatric cataract and intraocular lens surgery. Ophthalmology 1996;103:1871–5. 4. Blumenthal M, Assia E, Neumann D. The round capsulorhexis capsulotomy and the rationale for 11.0 mm diameter IOL. Eur J Implant Refract Surg 1990;2:15–9. 5. Lim ASM, Chiang C, Chew PTK. How serious is posterior capsule rupture? Eur J Implant Refract Surg 1990;2:57– 61. 6. Lischetti P. New technique for posterior capsulotomy. Eur J Implant Refract Surg 1990;2:77–9. 7. Mackool RJ, Sirota MA. Intracapsular foldable posterior chamber lens implantation in eyes with posterior capsule tears or zonular fiber instability. J Cataract Refract Surg 1998;24: 739 – 40. 8. Meucci G, Gini GP. The anterior capsule as a support for posterior chamber IOLs in case of posterior capsule rupture. Eur J Implant Refract Surg 1990;2:229 –32. 9. Michelson MA. Managing torn posterior capsule during phacoemulsification. Ophthalmic Pract 1992;10:66 –72. 10. Ng DT, Rowe NA, Francis IC, et al. Intraoperative complications of 1000 phacoemulsification procedures: a prospective study. J Cataract Refract Surg 1998;24:1390 –5. 11. Osher RH, Cionni RJ. The torn posterior capsule: its intraoperative behavior, surgical management, and long-term consequences. J Cataract Refract Surg 1990;16:490 – 4. 12. Galand A, van Cauwenberge F, Moosavi J. Posterior capsulorhexis in adult eyes with intact and clear capsules. J Cataract Refract Surg 1996;22:458 – 61. 13. Koch PS. Managing the torn posterior capsule and vitreous loss [review]. Int Ophthalmol Clin 1994;34:113–30. 14. Prasad S. Phacoemulsification learning curve: experience of two junior trainee ophthalmologists. J Cataract Refract Surg 1998;24:73–7. 15. Van Cauwenberge F, Rakic JM, Galand A. Complicated posterior capsulorhexis: aetiology, management, and outcome. Br. J Ophthalmol 1997;81:195– 8. 16. Natchiar G, Robin AL, Nalgirkar AR, Krishnadas R. Posterior capsule tears during extracapsular cataract surgery in India. Arch Ophthalmol 1993;111:706 – 8. 17. Osher RH, Yu BCY, Koch DD. Posterior polar cataracts: a predisposition to intraoperative posterior capsular rupture. J Cataract Refract Surg 1990;16:157– 62. 18. Assia, EI, Apple DJ, Tsai JC, Lim ES. The elastic properties of the lens capsule in capsulorhexis. Am J Ophthalmol 1991; 111:628 –32. 19. Castaneda VE, Legler UFC, Tsai JC, et al. Posterior continuous curvilinear capsulorhexis. An experimental study with clinical applications. Ophthalmology 1992;99:45–50. 20. Consultation section. How would you handle a tear in the posterior capsule detected at the end of phacoemulsification, with cortex intact and no vitreous loss? [review]. J Cataract Refract Surg 1997;23:12– 8.
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Originally received: October 22, 2000. Accepted: April 23, 2001. Manuscript no. 200546. From the Gimbel Eye Centre, Calgary, Alberta, Canada. Presented in part at the annual meeting of the American Academy of Ophthalmology, Dallas, Texas, October 2000. The authors have no propriety or financial interest in the research or instruments described in this article. Correspondence to Howard V. Gimbel, MD, MPH, Gimbel Eye Centre, 4935 40th Avenue NW, Suite 450, Calgary, Alberta, Canada T3A 2N1. E-mail: [email protected].
2186
© 2001 by the American Academy of Ophthalmology Published by Elsevier Science Inc.
tions. Therefore, the intraoperative management of PC tears is vital in the maximization of in-the-bag IOL implantation and minimization of sequelae related to other IOL implantation positions.
Materials and Methods Study Design With the assistance of on-line medical records, 18,470 consecutive eyes that underwent phacoemulsification and IOL implantation from 1992 through 1999 were analyzed for incidence of PC tears.
Main Outcome Measures Routine preoperative and postoperative visual and refractive outcomes were recorded, as were intraoperative and surgical parameters, including IOL position, description of any capsule tears, and postoperative complications. ISSN 0161-6420/01/$–see front matter PII S0161-6420(01)00716-3
Gimbel et al 䡠 PCCC for PC Tears Surgical Technique All surgeries were performed by one surgeon (HVG). Under topical anesthesia, continuous curvilinear capsulorrhexis (CCC) and nucleofractis phacoemulsification were performed. Posterior capsule tears were managed through the application of CCC principles to the PC when possible.
Posterior Curvilinear Capsulorrhexis With the liberal use of viscoelastics, posterior continuous curvilinear capsulorrhexis (PCCC) is initiated by grasping the advancing tear in the PC with forceps, applying CCC principles.1 It is extended and completed into a circle that encompasses the extent of the tear and is blended from the periphery to the center as the circle is completed. Alternatively, one or both ends of a linear tear may be rounded and blunted. The best control of the progressing tear in the PC is achieved using the elongated Kelman-McPherson or Kraff-Utrata forceps, grasping the capsule flap near one point of tearing and turning the tear in the desired direction. The PCCC is kept as small as possible so as to preserve the maximum integrity of the PC. This technique is performed to avoid an anticipated extension of the inadvertent linear or triangular tear during such maneuvers as a required vitrectomy or lens placement.
Posterior Continuous Curvilinear Capsulorrhexis with Optic Capture Primary PCCC with posterior capsular optic capture is a technically challenging procedure that requires skill to avoid peripheral tears in the PC and loss of the capsular bag.2,3 Posterior continuous curvilinear capsulorrhexis is used to convert the PC tear. The PC opening must be smaller than and concentric with the IOL optic. Although the PC is thin, the PCCC appears to have the same stretching capacity as the anterior CCC. With liberal use of viscoelastics and under high magnification of the operating microscope, a cannula is used to vault the IOL optic through the PCCC, first superiorly and then inferiorly.
Neuhann Rhexis Anterior Capsule Fixation A similar technique of capturing the optic through the anterior capsulorrhexis opening has been described in patients with posterior capsular tears and loss of capsular bag support of an IOL. For these patients, Neuhann and Neuhann described a technique of placing the IOL in the sulcus and then placing the optic of the IOL through the anterior capsulorrhexis opening to achieve capture and stable fixation (Neuhann T, Neuhann TH. The rhexis-fixation lens. Film festival entry at the American Society of Cataract and Refractive Surgery (ASCRS), Boston, Massachusetts, April 1991).
Figure 1. Yearly incidence of posterior capsule tears, 1992 to 1999.
one had PC optic capture. In the remaining 32 eyes where PCCC was not possible, anterior capsule (AC) rhexis fixation was used in 17 eyes (53.1%) where the CCC was intact and small enough to capture the optic (Fig 4). Ten eyes underwent sulcus placement because the AC rim was not intact and anterior CCC capture was not possible. Five eyes required AC IOL implantation because of inadequate capsule support. No scleral suture fixation IOLs were used. Seventy-six eyes with tears (91.57%) achieved 20/40 or better best-corrected visual acuity compared with 91.70% without tears (P ⫽ 0.98).
Discussion Various strategies have been described for the management of PC tears.4 –13 Avoiding any PC tears is the goal of every cataract surgeon. If a tear does occur, management techniques and skills are required for successful in-the-bag PC IOL placement or at least capsule fixation of the IOL by being partly in the bag and partly outside the bag, with the optic captured by the anterior or posterior capsulorrhexis. A strong CCC maximizes safe and uneventful phacoemulsification and PC IOL implantation because it is pivotal in avoiding extensions of equatorial tears to the PC. In phacoemulsification cataract surgery with IOL implantation, early suspicion and detection of PC tears is of vital importance. Beginner or advanced phacoemulsification surgeons realize
Results Eighty-three PC tears occurred in 18,470 consecutive surgeries, for an overall incidence of 0.45%. The yearly incidence of PC tears for 1992 through 1999 is presented in Figure 1. Of the 83 eyes with PC tears, 42 (50.6%) occurred during phacoemulsification (Fig 2). Of these, 38 (90.5%) required vitrectomy. Thirty-three PC tears (39.7%) occurred during irrigation and aspiration, and of these, 14 (42.4%) required vitrectomy. Ten percent of tears occurred at other stages of surgery, such as IOL placement or hydrodissection. There were no eyes with dropped nuclei or nuclear fragments requiring pars plana vitrectomy or posterior assisted levitation Fifty-one PC tears (61.5%) were amenable to be converted to PCCC (Fig 3). Of these, 50 eyes had in-the-bag IOL fixation and
Figure 2. Frequency of posterior capsule tears and vitreous presentation.
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Ophthalmology Volume 108, Number 12, December 2001
Figure 3. Posterior capsule tears converted to posterior continuous curvilinear capsulorrhexis and intraocular lens position.
that PC tears may occur at any time during cataract surgery.14 –17 Figure 5 shows the relative thickness of the AC and PC. The periequatorial capsule is the thickest part of the lens capsule (approximately 21–23 ). The central anterior lens capsule is approximately 14 , but the central posterior lens capsule is the thinnest (approximately 4 ). Although the PC is thinner, one can apply the principles of anterior continuous curvilinear capsulorrhexis to the PC for optimizing capsular bag integrity in cases where small discrete tears occur. Like the AC, the PC also has plastic properties. Plasticity is defined as the ability to retain a shape attained by pressure deformation. The PC is also more elastic than the AC. The force required to tear the PC is greater than the force required to tear the AC. The smooth circular opening does not leave V-shaped tears that easily extend to the equator with minimal stress. The capsulorrhexis margin maintains its integrity, and the molecules at the cut margin behave as a continuous chain. However, a sharp notch at the margin of the capsulorrhexis breaks this continuous chain and forms a radial tear. A CCC made in the PC thus behaves like a CCC and is resistant to radial tears. Posterior continuous curvilinear capsulorrhexis prevents small linear or triangular tears from extending to further damage the lens capsule. This prevents small linear or triangular tears from extending to the equator and stabilizes the capsule, especially during IOL implantation or vitrectomy. Posterior capsule tears at the equator or extending to the equator are not amenable to PCCC. Assia et al18 found a highly significant correlation between the circumference at rupture and the circumference of
Figure 4. Intraocular lens position when posterior continuous curvilinear capsulorrhexis was not possible.
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Figure 5. Schematic of adult human lens capsule showing relative thickness of capsule in different zones. (From American Academy of Ophthalmology. Lens and Cataract: Basic and Clinical Science Course, Section 11. San Francisco: American Academy of Ophthalmology, 2000 –2001. Adapted with permission. Illustration by Christine Gralapp.)
the capsulorrhexis: Cr ⫽ 1.6 Cc, where Cr is the circumference at rupture and Cc is the circumference of capsulorrhexis. This shows that the capsulorrhexis can stretch extensively before it is torn. Castaneda et al19 demonstrated that the pressure needed to disrupt a PCCC is actually greater than that which tears the zonules. This facilitates safe endolenticular phacoemulsification, irrigation and aspiration, and in-the-bag IOL implantation. In-the-bag implantation stabilizes the IOL, minimizes decentration and dislocation, and also reduces contact between the uveal tissue and the IOL. This decreases the incidence of postoperative complications such as pigment dispersion, transillumination iris defects, glaucoma, and uveitis. In 1992, Castaneda and Apple19 demonstrated, in an experimental study, the effectiveness of PCCC in preventing PC radial tears. By extending CCC principles to the PC, IOL in-the-bag placement is maximized. Posterior continuous curvilinear capsulorrhexis was described previously in pediatric cataract and IOL surgery for PC plaque removal. The smooth continuous tear of circular capsulorrhexis meets all the demands of advanced cataract and lens implantation surgery techniques. Posterior continuous curvilinear capsulorrhexis is especially advantageous in sustaining the integrity of the capsular bag when a vitrectomy is required. A previous paper detailed our experience with PC tears and conversion to PCCC in adult cataract surgery.1 In that review of 7174 consecutive eyes, the incidence of PC tears was similar at 36 (0.5%; Fig 6). Nineteen tears (52.7%) occurred during irrigation and aspiration (I/A), and 9 (25%) occurred during phacoemulsification, compared with 39.7% and 50%, respectively, in this series. Evaluating new instrumentation, new fluidic parameters, new surgical adjuvants, and new phacoemulsification techniques add to the risk of developing capsule tears during phacoemulsification in this series, whereas polished I/A tips, enhanced cortex removal techniques, and developments in the silicone I/A tip have decreased the incidence of PC tears during I/A. The placement of new IOLs accounted for two of six PC tears during IOL placement in this series.
Gimbel et al 䡠 PCCC for PC Tears
References
Figure 6. Summary of results from 1987 to 1989 posterior capsule tear study.
For these reasons and others, this has meant that the risk of PC tears during phacoemulsification and IOL implantation was not eliminated in this series. However, strategies and techniques like PCCC can be used routinely to manage tears to achieve excellent outcomes in most of these cases.20 Posterior capsule tears, if small enough, should always be converted to a PCCC to achieve in-the-bag IOL fixation safely. Compared with the 1987 to 89 series, in which in-the-bag fixation was observed in 69.4% of eyes with PC tears,1 PCCC, PCCC with optic capture, and Neuhann AC rhexis have increased the capsule fixation of the IOL to 81.9%, if the PC tear is too large and peripheral to convert to a PCCC. Anterior or posterior rhexis fixation stabilizes the IOL to the capsule and maintains a seal, thus creating a physical barrier between anterior and posterior segments. One can still use the originally planned IOL, as the AC depth and A-constant remain relatively status quo. Also, there is no need for longer haptics, as is necessary for sulcus fixation.
Conclusions In our experience, PC tears can occur at many different stages of cataract removal. Small or short tears in the PC occurring near the end of phacoemulsification or during I/A can often be blunted or converted to a PCCC, allowing for in-the-bag and capsule fixation of the IOL. Obtaining and maintaining an intact CCC leaves the option open to use anterior rhexis fixation in the event of a large PC tear. Complication management techniques are as important and essential as complication prevention measures to achieve satisfactory outcomes in cataract surgery. Our study shows that there are several potentials for PC tears. Even with a low PC tear rate, management techniques and skills are required. Modeled on the principle of anterior CCC, the PCCC technique allows safe and secure in-the-bag IOL placement and therefore enhances visual rehabilitation while reducing intraoperative and postoperative complications in cases where inadvertent PC tears occur.
1. Gimbel HV. Posterior capsule tears using phaco-emulsification: causes, prevention and management. Eur J Implant Refract Surg 1990;2:63–9. 2. Gimbel HV. Posterior continuous curvilinear capsulorhexis and optic capture of the intraocular lens to prevent secondary opacification in pediatric cataract surgery. J Cataract Refract Surg 1997;23:652– 6. 3. Gimbel HV. Posterior capsulorhexis with optic capture in pediatric cataract and intraocular lens surgery. Ophthalmology 1996;103:1871–5. 4. Blumenthal M, Assia E, Neumann D. The round capsulorhexis capsulotomy and the rationale for 11.0 mm diameter IOL. Eur J Implant Refract Surg 1990;2:15–9. 5. Lim ASM, Chiang C, Chew PTK. How serious is posterior capsule rupture? Eur J Implant Refract Surg 1990;2:57– 61. 6. Lischetti P. New technique for posterior capsulotomy. Eur J Implant Refract Surg 1990;2:77–9. 7. Mackool RJ, Sirota MA. Intracapsular foldable posterior chamber lens implantation in eyes with posterior capsule tears or zonular fiber instability. J Cataract Refract Surg 1998;24: 739 – 40. 8. Meucci G, Gini GP. The anterior capsule as a support for posterior chamber IOLs in case of posterior capsule rupture. Eur J Implant Refract Surg 1990;2:229 –32. 9. Michelson MA. Managing torn posterior capsule during phacoemulsification. Ophthalmic Pract 1992;10:66 –72. 10. Ng DT, Rowe NA, Francis IC, et al. Intraoperative complications of 1000 phacoemulsification procedures: a prospective study. J Cataract Refract Surg 1998;24:1390 –5. 11. Osher RH, Cionni RJ. The torn posterior capsule: its intraoperative behavior, surgical management, and long-term consequences. J Cataract Refract Surg 1990;16:490 – 4. 12. Galand A, van Cauwenberge F, Moosavi J. Posterior capsulorhexis in adult eyes with intact and clear capsules. J Cataract Refract Surg 1996;22:458 – 61. 13. Koch PS. Managing the torn posterior capsule and vitreous loss [review]. Int Ophthalmol Clin 1994;34:113–30. 14. Prasad S. Phacoemulsification learning curve: experience of two junior trainee ophthalmologists. J Cataract Refract Surg 1998;24:73–7. 15. Van Cauwenberge F, Rakic JM, Galand A. Complicated posterior capsulorhexis: aetiology, management, and outcome. Br. J Ophthalmol 1997;81:195– 8. 16. Natchiar G, Robin AL, Nalgirkar AR, Krishnadas R. Posterior capsule tears during extracapsular cataract surgery in India. Arch Ophthalmol 1993;111:706 – 8. 17. Osher RH, Yu BCY, Koch DD. Posterior polar cataracts: a predisposition to intraoperative posterior capsular rupture. J Cataract Refract Surg 1990;16:157– 62. 18. Assia, EI, Apple DJ, Tsai JC, Lim ES. The elastic properties of the lens capsule in capsulorhexis. Am J Ophthalmol 1991; 111:628 –32. 19. Castaneda VE, Legler UFC, Tsai JC, et al. Posterior continuous curvilinear capsulorhexis. An experimental study with clinical applications. Ophthalmology 1992;99:45–50. 20. Consultation section. How would you handle a tear in the posterior capsule detected at the end of phacoemulsification, with cortex intact and no vitreous loss? [review]. J Cataract Refract Surg 1997;23:12– 8.
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