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Capsular tension ring use in a patient with congenital coloboma of the lens
Capsular tension ring use in a patient with congenital coloboma of the lens Hidenobu Mizuno, MD, Jun Yamada, MD, PhD, Masatoshi Nishiura, MD, Hiroaki Takahashi, MD, Yasukazu Hino, MD, Hirofumi Miyatani, MD Cataract surgery was performed in a 63-year-old man with bilateral coloboma of the lens. There was no traumatic history, but the patient had lower zonule deficiency and zonular weakness in both eyes, leading us to suspect congenital coloboma of the lens. In the first eye having cataract surgery, it was impossible to rotate the cataractous lens and place the intraocular lens (IOL) centrally in the capsular bag because the lens capsule was not round. The second eye had similar problems, and capsular tension ring implantation improved cataract lens rotation and phacodonesis, enabling central IOL implantation in the capsular bag. The visual acuity recovered to 20/20 in both eyes. Capsular tension ring implantation can facilitate cataract surgery in coloboma of the lens, even in long-term and continuous lens capsule deformity. J Cataract Refract Surg 2004; 30:503–506 2004 ASCRS and ESCRS
T
he development of phacoemulsification and continuous curvilinear capsulorhexis (CCC) has made it possible to remove cataracts through a small incision and implant an intraocular lens (IOL) in the capsular bag.1,2 Intraocular lens centration and stability in the capsular bag are critical to maintain an optimal visual outcome. An IOL in the capsular bag may be insecure in some cases, such as in coloboma of the lens with zonular dialysis and capsular bag deformity. In 1991, the use of an equator ring to maintain the capsular bag’s circular contour was presented by Hara and coauthors.3 After this, rings made of various materials were developed.4,5 The insertion of a capsular tension ring (CTR) in the capsular bag to maintain its circular contour
Accepted for publication June 24, 2003. From the Department of Ophthalmology, Kyoto Second Red Cross Hospital (Mizuno, Yamada, Nishiura, Takahashi, Hino, Miyatani), the Department of Ophthalmology, Meiji University of Oriental Medicine (Yamada), and the Department of Ophthalmology, Kyoto Yosanoumi Hospital (Nishiura), Kyoto, Japan. None of the authors has a financial or proprietary interest in any material or method mentioned. Reprint requests to Dr. Jun Yamada, MD, PhD, Department of Ophthalmology, Meiji University of Oriental Medicine, 6-1 Hinotani, Honoda, Hiyoshi-cho, Funai-gun, Kyoto, 629-0392, Japan. 2004 ASCRS and ESCRS Published by Elsevier Inc.
has visual outcome and surgical safety benefits.6–9 We describe our successful experience using a CTR during cataract surgery in a patient with bilateral coloboma of the lens.
Case Report A 63-year-old man who presented to our clinic in October 2001 for visual deterioration in both eyes had high myopia and had been aware of his poor vision since childhood. The patient had no history of oculopathy, ophthalmic surgery, trauma, or disease. On initial examination, the manifest refraction was ⫺6.00 diopters (D) with a best corrected visual acuity (BCVA) of 4/200 in the right eye and ⫺10.00 D with a BCVA of 4/200 in the left eye; intraocular pressure was 21 mm Hg in the right eye and 18 mm Hg in the left eye. Slitlamp examination with mydriasis revealed corticonuclear cataract and bow-shaped partial coloboma of the lens from 5 to 7 o’clock, where Zinn’s zonule was lacking (Figure 1). Fundoscopy showed a tessellated fundus and no coloboma of the retina, choroids, or optic nerve. A-scan biometry demonstrated an axial length of 25.15 mm in the right eye and 27.30 mm in the left eye. In November 2001, the procedures were done in the left eye by 1 surgeon (J.Y.) according to standardized protocol. Under sub-Tenon’s anesthesia, a 2.80 mm sclerocorneal incision, paracentesis at the 10 o’clock and 2 o’clock positions, CCC with a bent 25-gauge needle, and hydrodissection were performed uneventfully. Despite phacodonesis, the lens 0886-3350/04/$–see front matter doi:10.1016/S0886-3350(03)00585-6
CASE REPORTS: MIZUNO
Figure 2. (Mizuno) A CTR is inserted in the capsular bag through a side-port incision.
Figure 1. (Mizuno) Anterior segment of the right eye with mydriasis. Top: A coloboma of the lens is minimally observed at the lower position of the corticonuclear cataract. Bottom: After infraduction of same eye, a bow-shaped lack of inferior equator of lens with zonular dialysis is observed from 5 to 7 o’clock.
was normally located. Although phacoemulsification was done in the bag using a phaco-chop technique, the nucleus could not be rotated easily in the bag. This was solved by dividing the nucleus into many parts, and phacoemulsification was then completed. Subsequently, an injection of high-viscosity sodium hyaluronate could not expand the lens capsule completely because the hyaluronate moved to the posterior cavity due to the lack of the lower zonule. Lens capsule collapse 504
resulted in IOL decentration (821T, Pharmacia, ⫹14.0 D, 13.5 mm overall, 6.0 mm optic). This required sulcus IOL placement without suture fixation. Detailed information was given to the patient regarding cataract treatment for the right eye, and informed consent for CTR implantation was obtained. Capsular tension ring implantation was also approved by the ethics committee and review board of Kyoto Second Red Cross Hospital. In December 2001, the same surgeon performed the same procedure in the right eye using a single-piece poly(methyl methacrylate) incomplete circular ring (Ophtec type 13/11). The CTR was implanted through a side-port incision using a lens-positioning hook during the nucleus emulsification process (Figure 2). Capsular tension ring implantation improved the capsular bag deformity (Figure 3) and phacodonesis and enabled easy rotation of the cataract lens in the capsular bag. Subsequently, phacoemulsification in the bag could be completed. After removal of cortex material, the IOL (821T, Pharmacia, ⫹19.0 D) was placed centrally in the capsular bag (Figure 4). No pseudophacodonesis or IOL
J CATARACT REFRACT SURG—VOL 30, FEBRUARY 2004
CASE REPORTS: MIZUNO
Figure 3. (Mizuno) Through CTR insertion, the capsular bag defor-
Figure 4. (Mizuno) After CTR implantation, an IOL is located cen-
mity is repaired.
trally in the capsular bag. The CTR can be seen at the equator of the capsular bag.
dislocation occurred postoperatively and anterior chamber inflammation was minimal. At 1 month postoperatively, the visual acuity was 20/20 in both eyes. At 1 year postoperatively, the IOLs were centrally positioned in both eyes and no secondary problems were present.
CTR implantation helps reduce surgical complications in coloboma of the lens. There are several choices for treating cataract with coloboma of the lens. The IOL can be positioned in the sulcus as we did in the patient’s left eye. However, IOLs inserted in the sulcus rotate after surgery and may drop into the vitreous cavity through the zonular gap. Thus, the size of the zonular gap must be monitored; otherwise, sulcus placement of the IOL may lead to complications. Second, contact lens wear in the aphakic eye is also a good choice for this surgery. This is the safest choice for secondarily induced eye abnormalities, although patient satisfaction is poor. Finally, CTR implantation is another choice, as we did in the patient’s right eye. Standard use of a CTR is not recommended because the potential postoperative complications are unknown. Capsular tension ring rotation after surgery
Discussion The use of CTRs may be beneficial for cataract surgery. When a zonular defect is present and a CTR is inserted at any stage of the procedure to reestablish the capsule’s contour, the CTR protects against capsular fornix aspiration, consecutive zonular dialysis extension, irrigation fluid flow behind the capsule, vitreous herniation into the anterior chamber, IOL decentration, and closure of the capsular opening.9 In our experience,
J CATARACT REFRACT SURG—VOL 30, FEBRUARY 2004
505
CASE REPORTS: MIZUNO
has not been reported. If an implanted CTR rotates and the lens capsule loses its symmetry, the IOL can slide from the center to the side, resulting in serious complications for the patient and making successful treatment difficult. Because this patient had coloboma of the lens in both eyes, the zonular dialysis was likely congenital. Congenital coloboma of the lens resulting from failure of embryonic fissure closure is characterized by the lack of a lens inferior equator with zonular dialysis or weakness.10 Closure defect can sometimes involve the iris, ciliary body, retina, choroid, or optic nerve. The patient did not have other defects and acquired 20/20 visual acuity after surgery, demonstrating that small zonular dialysis may not cause amblyopia, although the asymmetrical lens induces irregular astigmatism. The use of a CTR in this patient with coloboma of the lens was successful. Further information on longterm CTR presence in the capsular bag may improve its potential use in cataract surgery.
References 1. Kelman CD. Phaco-emulsification and aspiration; a new technique of cataract removal; a preliminary report. Am J Ophthalmol 1967; 64:23–25
506
2. Gimbel HV, Neuhann T. Development, advantages, and methods of the continuous circular capsulorhexis technique. J Cataract Refract Surg 1990; 16:31–37 3. Hara T, Hara T, Yamada Y. “Equator ring” for maintenance of the completely circular contour of the capsular bag equator after cataract removal. Ophthalmic Surg 1991; 22:358–359 4. Nagatomo T, Bissen-Miyajima H. A ring to support the capsular bag after continuous curvilinear capsulorhexis. J Cataract Refract Surg 1994; 20:417–420 5. Hara T, Hara T, Sakanishi K, Yamada Y. Efficacy of equator rings in an experimental rabbit study. Arch Ophthalmol 1995; 113:1060–1065 6. Cionni RJ, Osher RH. Endocapsular ring approach to the subluxed cataractous lens. J Cataract Refract Surg 1995; 21:245–249 7. Sun R, Gimbel HV. In vitro evaluation of the efficacy of the capsular tension ring for managing zonular dialysis in cataract surgery. Ophthalmic Surg Lasers 1998; 29: 502–505 8. Gimbel HV, Sun R, Heston JP. Management of zonular dialysis in phacoemulsification and IOL implantation using the capsular tension ring. Ophthalmic Surg Lasers 1997; 28:273–281 9. Menapace R, Findl O, Georgopoulos M, et al. The capsular tension ring: designs, applications, and techniques. J Cataract Refract Surg 2000; 26:898–912 10. Duke-Elder WS. Text-Book of Ophthalmology. Vol 2: Clinical Methods of Examination, Congenital and Developmental Anomalies, General Pathological and Therapeutic Considerations, Disease of the Outer Eye. St Louis, MO, CV Mosby, 1938; 1237–1414
J CATARACT REFRACT SURG—VOL 30, FEBRUARY 2004
T
he development of phacoemulsification and continuous curvilinear capsulorhexis (CCC) has made it possible to remove cataracts through a small incision and implant an intraocular lens (IOL) in the capsular bag.1,2 Intraocular lens centration and stability in the capsular bag are critical to maintain an optimal visual outcome. An IOL in the capsular bag may be insecure in some cases, such as in coloboma of the lens with zonular dialysis and capsular bag deformity. In 1991, the use of an equator ring to maintain the capsular bag’s circular contour was presented by Hara and coauthors.3 After this, rings made of various materials were developed.4,5 The insertion of a capsular tension ring (CTR) in the capsular bag to maintain its circular contour
Accepted for publication June 24, 2003. From the Department of Ophthalmology, Kyoto Second Red Cross Hospital (Mizuno, Yamada, Nishiura, Takahashi, Hino, Miyatani), the Department of Ophthalmology, Meiji University of Oriental Medicine (Yamada), and the Department of Ophthalmology, Kyoto Yosanoumi Hospital (Nishiura), Kyoto, Japan. None of the authors has a financial or proprietary interest in any material or method mentioned. Reprint requests to Dr. Jun Yamada, MD, PhD, Department of Ophthalmology, Meiji University of Oriental Medicine, 6-1 Hinotani, Honoda, Hiyoshi-cho, Funai-gun, Kyoto, 629-0392, Japan. 2004 ASCRS and ESCRS Published by Elsevier Inc.
has visual outcome and surgical safety benefits.6–9 We describe our successful experience using a CTR during cataract surgery in a patient with bilateral coloboma of the lens.
Case Report A 63-year-old man who presented to our clinic in October 2001 for visual deterioration in both eyes had high myopia and had been aware of his poor vision since childhood. The patient had no history of oculopathy, ophthalmic surgery, trauma, or disease. On initial examination, the manifest refraction was ⫺6.00 diopters (D) with a best corrected visual acuity (BCVA) of 4/200 in the right eye and ⫺10.00 D with a BCVA of 4/200 in the left eye; intraocular pressure was 21 mm Hg in the right eye and 18 mm Hg in the left eye. Slitlamp examination with mydriasis revealed corticonuclear cataract and bow-shaped partial coloboma of the lens from 5 to 7 o’clock, where Zinn’s zonule was lacking (Figure 1). Fundoscopy showed a tessellated fundus and no coloboma of the retina, choroids, or optic nerve. A-scan biometry demonstrated an axial length of 25.15 mm in the right eye and 27.30 mm in the left eye. In November 2001, the procedures were done in the left eye by 1 surgeon (J.Y.) according to standardized protocol. Under sub-Tenon’s anesthesia, a 2.80 mm sclerocorneal incision, paracentesis at the 10 o’clock and 2 o’clock positions, CCC with a bent 25-gauge needle, and hydrodissection were performed uneventfully. Despite phacodonesis, the lens 0886-3350/04/$–see front matter doi:10.1016/S0886-3350(03)00585-6
CASE REPORTS: MIZUNO
Figure 2. (Mizuno) A CTR is inserted in the capsular bag through a side-port incision.
Figure 1. (Mizuno) Anterior segment of the right eye with mydriasis. Top: A coloboma of the lens is minimally observed at the lower position of the corticonuclear cataract. Bottom: After infraduction of same eye, a bow-shaped lack of inferior equator of lens with zonular dialysis is observed from 5 to 7 o’clock.
was normally located. Although phacoemulsification was done in the bag using a phaco-chop technique, the nucleus could not be rotated easily in the bag. This was solved by dividing the nucleus into many parts, and phacoemulsification was then completed. Subsequently, an injection of high-viscosity sodium hyaluronate could not expand the lens capsule completely because the hyaluronate moved to the posterior cavity due to the lack of the lower zonule. Lens capsule collapse 504
resulted in IOL decentration (821T, Pharmacia, ⫹14.0 D, 13.5 mm overall, 6.0 mm optic). This required sulcus IOL placement without suture fixation. Detailed information was given to the patient regarding cataract treatment for the right eye, and informed consent for CTR implantation was obtained. Capsular tension ring implantation was also approved by the ethics committee and review board of Kyoto Second Red Cross Hospital. In December 2001, the same surgeon performed the same procedure in the right eye using a single-piece poly(methyl methacrylate) incomplete circular ring (Ophtec type 13/11). The CTR was implanted through a side-port incision using a lens-positioning hook during the nucleus emulsification process (Figure 2). Capsular tension ring implantation improved the capsular bag deformity (Figure 3) and phacodonesis and enabled easy rotation of the cataract lens in the capsular bag. Subsequently, phacoemulsification in the bag could be completed. After removal of cortex material, the IOL (821T, Pharmacia, ⫹19.0 D) was placed centrally in the capsular bag (Figure 4). No pseudophacodonesis or IOL
J CATARACT REFRACT SURG—VOL 30, FEBRUARY 2004
CASE REPORTS: MIZUNO
Figure 3. (Mizuno) Through CTR insertion, the capsular bag defor-
Figure 4. (Mizuno) After CTR implantation, an IOL is located cen-
mity is repaired.
trally in the capsular bag. The CTR can be seen at the equator of the capsular bag.
dislocation occurred postoperatively and anterior chamber inflammation was minimal. At 1 month postoperatively, the visual acuity was 20/20 in both eyes. At 1 year postoperatively, the IOLs were centrally positioned in both eyes and no secondary problems were present.
CTR implantation helps reduce surgical complications in coloboma of the lens. There are several choices for treating cataract with coloboma of the lens. The IOL can be positioned in the sulcus as we did in the patient’s left eye. However, IOLs inserted in the sulcus rotate after surgery and may drop into the vitreous cavity through the zonular gap. Thus, the size of the zonular gap must be monitored; otherwise, sulcus placement of the IOL may lead to complications. Second, contact lens wear in the aphakic eye is also a good choice for this surgery. This is the safest choice for secondarily induced eye abnormalities, although patient satisfaction is poor. Finally, CTR implantation is another choice, as we did in the patient’s right eye. Standard use of a CTR is not recommended because the potential postoperative complications are unknown. Capsular tension ring rotation after surgery
Discussion The use of CTRs may be beneficial for cataract surgery. When a zonular defect is present and a CTR is inserted at any stage of the procedure to reestablish the capsule’s contour, the CTR protects against capsular fornix aspiration, consecutive zonular dialysis extension, irrigation fluid flow behind the capsule, vitreous herniation into the anterior chamber, IOL decentration, and closure of the capsular opening.9 In our experience,
J CATARACT REFRACT SURG—VOL 30, FEBRUARY 2004
505
CASE REPORTS: MIZUNO
has not been reported. If an implanted CTR rotates and the lens capsule loses its symmetry, the IOL can slide from the center to the side, resulting in serious complications for the patient and making successful treatment difficult. Because this patient had coloboma of the lens in both eyes, the zonular dialysis was likely congenital. Congenital coloboma of the lens resulting from failure of embryonic fissure closure is characterized by the lack of a lens inferior equator with zonular dialysis or weakness.10 Closure defect can sometimes involve the iris, ciliary body, retina, choroid, or optic nerve. The patient did not have other defects and acquired 20/20 visual acuity after surgery, demonstrating that small zonular dialysis may not cause amblyopia, although the asymmetrical lens induces irregular astigmatism. The use of a CTR in this patient with coloboma of the lens was successful. Further information on longterm CTR presence in the capsular bag may improve its potential use in cataract surgery.
References 1. Kelman CD. Phaco-emulsification and aspiration; a new technique of cataract removal; a preliminary report. Am J Ophthalmol 1967; 64:23–25
506
2. Gimbel HV, Neuhann T. Development, advantages, and methods of the continuous circular capsulorhexis technique. J Cataract Refract Surg 1990; 16:31–37 3. Hara T, Hara T, Yamada Y. “Equator ring” for maintenance of the completely circular contour of the capsular bag equator after cataract removal. Ophthalmic Surg 1991; 22:358–359 4. Nagatomo T, Bissen-Miyajima H. A ring to support the capsular bag after continuous curvilinear capsulorhexis. J Cataract Refract Surg 1994; 20:417–420 5. Hara T, Hara T, Sakanishi K, Yamada Y. Efficacy of equator rings in an experimental rabbit study. Arch Ophthalmol 1995; 113:1060–1065 6. Cionni RJ, Osher RH. Endocapsular ring approach to the subluxed cataractous lens. J Cataract Refract Surg 1995; 21:245–249 7. Sun R, Gimbel HV. In vitro evaluation of the efficacy of the capsular tension ring for managing zonular dialysis in cataract surgery. Ophthalmic Surg Lasers 1998; 29: 502–505 8. Gimbel HV, Sun R, Heston JP. Management of zonular dialysis in phacoemulsification and IOL implantation using the capsular tension ring. Ophthalmic Surg Lasers 1997; 28:273–281 9. Menapace R, Findl O, Georgopoulos M, et al. The capsular tension ring: designs, applications, and techniques. J Cataract Refract Surg 2000; 26:898–912 10. Duke-Elder WS. Text-Book of Ophthalmology. Vol 2: Clinical Methods of Examination, Congenital and Developmental Anomalies, General Pathological and Therapeutic Considerations, Disease of the Outer Eye. St Louis, MO, CV Mosby, 1938; 1237–1414
J CATARACT REFRACT SURG—VOL 30, FEBRUARY 2004