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Nucleus cryoinversion for extraction of highly complicated cataracts
Nucleus cryoinversion for extraction of highly complicated cataracts Joshua Ben-nun, MD, Yaniv Barkana, MD
We describe a technique for cataract extraction in vitrectomized eyes that uses secured removal of the nucleus with no manipulation of the capsular bag. After a large scleral tunnel is prepared and a capsulorhexis created, a 20-gauge retinal cryoprobe enveloped in a plastic or a silicone sleeve is introduced into the anterior chamber. The cryoprobe engages the nucleus by a “freeze-grip” and rotates it 180 degrees so that the nucleus is elevated into the anterior chamber with no force applied to the capsule and the cryoprobe supporting it from below. The cryoprobe is replaced by a vectis under the nucleus and with the help of another instrument from above, the nucleus is removed. Aspiration of cortical material under low-pressure fluid maintenance of the anterior chamber completes removal of the cataract. An intraocular lens is then implanted in the ciliary sulcus for maximum capsule support. J Cataract Refract Surg 2002; 28:1733–1736 © 2002 ASCRS and ESCRS
C
ataract development and progression are common after a pars plana vitrectomy, with rates of up to 80% when intraocular gases are used and 100% with silicone oil use.1–5 Cataract extraction in most of these eyes can be performed safely by phacoemulsification or extracapsular cataract extraction.6 – 8 In some cases, however, cataract surgery is highly challenging because of a combination of several pathologies that stretch the surgical capability to the limits. These eyes might have weak zonular support with noticeable phacodonesis, a narrow pupil, iridolental synechias, iris neovascularization, and occasionally structural distortion of the anterior chamber. In addition, the cataract has no vitreous support because of the previous vitrectomy. In such eyes, even the most careful surgical manipulations might lead to capsule rupture and a dropped nucleus into the vitreAccepted for publication January 7, 2002. From the Department of Ophthalmology, Assaf Harofe Medical Center, Zerifin, Israel. Neither author has a financial or proprietary interest in any material or method mentioned. Reprint requests to Yaniv Barkana, MD, Department of Ophthalmology, Assaf Harofe Medical Center, Beer Yaacov, Zerifin 70300, Israel. E-mail: [email protected]. © 2002 ASCRS and ESCRS Published by Elsevier Science Inc.
ous cavity. As there is no vitreous, the nucleus drops directly onto the macular area of the retina. We describe a technique that uses the advantages of totally secured nucleus removal via a scleral tunnel while avoiding manipulation of the capsular bag. Because a capsulorhexis is not mandatory with this technique, it is useful in cases with compromised capsule support or a capsule surface that cannot be manipulated. We named this technique after its most critical stage: nucleus cryoinversion
Surgical Technique An irrigation line is inserted at a 6 o’clock limbal position; the fluid height is kept no higher then 40 cm above eye level. A 7.0 mm scleral tunnel incision is made 1.5 mm from the limbus; a larger incision is made if a large nucleus is expected. A limbal entry is made with a 20-gauge knife to allow insertion of the capsulotomy needle. A wide capsulotomy (capsulorhexis or can opener) is performed under viscoelastic material. The goal is to avoid traction on the capsule during the procedure. The sharp tip of the capsulotome is also used to remove part of the soft anterior cortex to create a small crater, exposing the nucleus at its base; when pha0886-3350/02/$–see front matter PII S0886-3350(02)01272-5
TECHNIQUES: BEN-NUN
codonesis is advanced and obvious, this step is not performed. After the capsulotomy is created, the tunnel is opened with 3.2 mm knife (Xstar, Beaver). A standard 20-gauge retinal cryoprobe is enveloped by the plastic tubing of an 18-gauge intravenous cannula (Venflon 2, BOC Ohmeda AB) for thermal insulation; a sleeve made of any available plastic or silicone sterile tubing can be used. Only the last 1.0 mm of the cryoprobe is exposed. The cryoprobe is inserted into the anterior chamber through the open tunnel to touch, very gently, the nucleus surface at the crater base. If there is no crater, the
tip is placed on the exposed cortex. The freeze cycle is started and the cryoprobe is adhered to the cataract by a “freeze-grip.” The cryoprobe is rotated 180 degrees around its axis, elevating the nucleus to the anterior chamber without force applied on the opened capsule (Figure 1). The cryoprobe is now under the nucleus, securing it from accidentally dropping (Figure 2). The freezing cycle is stopped. If no crater was performed at the onset, a piece of anterior cortex will usually separate during the initial procedure. Thawing the tip will release it from the small cortical fragment. The tip is then returned to the small crater that was created with the nucleus in its base.
Figure 1. (Ben-nun) Intraoperative photograph and schematic showing a cryoprobe holding the anterior face of the nucleus via a freeze-grip in preparation for 180-degree nucleus inversion around the axis of the cryoprobe (IR ⫽ irrigation line; CP ⫽ cryoprobe, FG ⫽ freeze grip).
Figure 2. (Ben-nun) The nucleus (N) is inverted in the anterior chamber and supported underneath by the cryoprobe; the frozen tip of the cryoprobe is seen under the nucleus (IR ⫽ irrigation line; CP ⫽ cryoprobe, FG ⫽ freeze grip).
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J CATARACT REFRACT SURG—VOL 28, OCTOBER 2002
TECHNIQUES: BEN-NUN
the support available by the ciliary body–zonule–capsule diaphragm is used.
Results
Figure 3. (Ben-nun) A vectis (V) is inserted under the nucleus while it is supported by the cryoprobe (CP).
A metallic loop (vectis, MAKE) is inserted under the inverted nucleus to replace the cryoprobe; there is always an instrument supporting the nucleus from underneath, preventing a dropped nucleus and manipulation of the unstable capsule (Figure 3). A second instrument, usually an IOL manipulator (Sinskey, MAKE), is entered to hold the nucleus from above. Thus held, the nucleus is removed from the anterior chamber (Figure 4). Only at this stage is the fluid allowed to slowly fill the anterior chamber. Aspiration of the remaining cortex is done with an aspiration needle (McIntire, MAKE) through the limbal paracentesis. An intraocular lens (IOL) is implanted in the ciliary sulcus via the tunnel. The IOL is placed in the sulcus as these patients have poor zonular support; therefore, all
From 1998 to 2000, the nucleus cryoinversion technique was successfully used in 13 eyes. Ten eyes had a vitrectomy for diabetic retinopathy, 1 for central retinal vein occlusion (CRVO), and 2 for pseudoexfoliation and significant phacodonesis. Although all eyes had poorly dilating pupils with medication, no mechanical dilation of the pupil was done because of the risk of bleeding related to the underlying pathology. In all cases, an IOL was implanted in the posterior chamber in the ciliary sulcus with good capsular support. No late IOL dislocations occurred. All patients had worse than 20/200 visual acuity preoperatively, reflecting advanced cataract related to the reluctance to perform surgery in these eyes. In the 2 cases with phacodonesis, visual acuity improved to 20/40 or better. Some visual acuity improvement was documented postoperatively in 7 diabetic patients, who had a visual acuity between 20/100 and 20/200. In 3 diabetic patients and the patient with CRVO, vision did not improve after the cataract surgery. In this group, the primary and most significant factor affecting the postoperative visual acuity was the underlying retinal condition.
Figure 4. (Ben-nun) The nucleus is held between a vectis (V) from below and a Sinskey manipulator (H) from above and is removed through the scleral tunnel (IR ⫽ irrigation line).
J CATARACT REFRACT SURG—VOL 28, OCTOBER 2002
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TECHNIQUES: BEN-NUN
Discussion Relatively few patients present with very complicated eye conditions that make cataract surgery challenging. These patients might have an underling disease with vitreoretinal complications that required previous vitreoretinal surgery. As a result of the underlying disease or the unavoidable side effects of the surgery, cataract develops in addition to other pathologies. Unfortunately, most of these cases are bilateral because of the systemic nature of the underlying disease. In such cases, extreme effort is made to provide the patient with any amount of useful vision the eyes can provide. A major complication during cataract surgery in such eyes is the nucleus or cataract fragments dropping into the vitreous cavity. A narrow pupil and compromised visibility make the removal of the dropped particles significantly more difficult than in a normal eye. The use of the cryo technique for cataract removal was common practice during the era of intracapsular cataract extraction (ICCE), when the whole cataract was removed from the eye in 1 piece. The idea of a freeze-grip has been modified in the nucleus cryoinversion technique to a maneuver that secures nucleus removal without applying force on the lens capsule, avoiding rupture. We have found this method useful in cases that otherwise would need a large-sector iridectomy with ICCE using cryoextraction and a wide limbal incision. The nucleus cryoinversion technique is a useful tool in the
1736
hands of the cataract surgeon who must operate on patients with highly complicated cataract.
References 1. Melberg NS, Thomas MA. Nuclear sclerotic cataract after vitrectomy in patients younger than 50 years of age. Ophthalmology 1995; 102:1466 –1471 2. Thompson JT, Glaser BM, Sjaarda RN, Murphy RP. Progression of nuclear sclerosis and long-term visual results of vitrectomy with transforming growth factor beta-2 for macular holes. Am J Ophthalmol 1995; 119:48 –54 3. Cherfan GM, Michels RG, de Bustros S, et al. Nuclear sclerotic cataract after vitrectomy for idiopathic epiretinal membranes causing macular pucker. Am J Ophthalmol 1991; 111:434 –438 4. Blankenship GW, Machemer R. Long-term diabetic vitrectomy results; report of 10 year follow-up. Ophthalmology 1985; 92:503–506 5. Federman JL, Schubert HD. Complications associated with the use of silicone oil in 150 eyes after retina-vitreous surgery. Ophthalmology 1988; 95:870 –876 6. McDermott ML, Puklin JE, Abrams GW, Eliott D. Phacoemulsification for cataract following pars plana vitrectomy. Ophthalmic Surg Lasers 1997; 28:558 –564 7. Grusha YO, Masket S, Miller KM. Phacoemulsification and lens implantation after pars plana vitrectomy. Ophthalmology 1998; 105:287–294 8. Saunders DC, Brown A, Jones NP. Extracapsular cataract extraction after vitrectomy. J Cataract Refract Surg 1996; 22:218 –221
J CATARACT REFRACT SURG—VOL 28, OCTOBER 2002
We describe a technique for cataract extraction in vitrectomized eyes that uses secured removal of the nucleus with no manipulation of the capsular bag. After a large scleral tunnel is prepared and a capsulorhexis created, a 20-gauge retinal cryoprobe enveloped in a plastic or a silicone sleeve is introduced into the anterior chamber. The cryoprobe engages the nucleus by a “freeze-grip” and rotates it 180 degrees so that the nucleus is elevated into the anterior chamber with no force applied to the capsule and the cryoprobe supporting it from below. The cryoprobe is replaced by a vectis under the nucleus and with the help of another instrument from above, the nucleus is removed. Aspiration of cortical material under low-pressure fluid maintenance of the anterior chamber completes removal of the cataract. An intraocular lens is then implanted in the ciliary sulcus for maximum capsule support. J Cataract Refract Surg 2002; 28:1733–1736 © 2002 ASCRS and ESCRS
C
ataract development and progression are common after a pars plana vitrectomy, with rates of up to 80% when intraocular gases are used and 100% with silicone oil use.1–5 Cataract extraction in most of these eyes can be performed safely by phacoemulsification or extracapsular cataract extraction.6 – 8 In some cases, however, cataract surgery is highly challenging because of a combination of several pathologies that stretch the surgical capability to the limits. These eyes might have weak zonular support with noticeable phacodonesis, a narrow pupil, iridolental synechias, iris neovascularization, and occasionally structural distortion of the anterior chamber. In addition, the cataract has no vitreous support because of the previous vitrectomy. In such eyes, even the most careful surgical manipulations might lead to capsule rupture and a dropped nucleus into the vitreAccepted for publication January 7, 2002. From the Department of Ophthalmology, Assaf Harofe Medical Center, Zerifin, Israel. Neither author has a financial or proprietary interest in any material or method mentioned. Reprint requests to Yaniv Barkana, MD, Department of Ophthalmology, Assaf Harofe Medical Center, Beer Yaacov, Zerifin 70300, Israel. E-mail: [email protected]. © 2002 ASCRS and ESCRS Published by Elsevier Science Inc.
ous cavity. As there is no vitreous, the nucleus drops directly onto the macular area of the retina. We describe a technique that uses the advantages of totally secured nucleus removal via a scleral tunnel while avoiding manipulation of the capsular bag. Because a capsulorhexis is not mandatory with this technique, it is useful in cases with compromised capsule support or a capsule surface that cannot be manipulated. We named this technique after its most critical stage: nucleus cryoinversion
Surgical Technique An irrigation line is inserted at a 6 o’clock limbal position; the fluid height is kept no higher then 40 cm above eye level. A 7.0 mm scleral tunnel incision is made 1.5 mm from the limbus; a larger incision is made if a large nucleus is expected. A limbal entry is made with a 20-gauge knife to allow insertion of the capsulotomy needle. A wide capsulotomy (capsulorhexis or can opener) is performed under viscoelastic material. The goal is to avoid traction on the capsule during the procedure. The sharp tip of the capsulotome is also used to remove part of the soft anterior cortex to create a small crater, exposing the nucleus at its base; when pha0886-3350/02/$–see front matter PII S0886-3350(02)01272-5
TECHNIQUES: BEN-NUN
codonesis is advanced and obvious, this step is not performed. After the capsulotomy is created, the tunnel is opened with 3.2 mm knife (Xstar, Beaver). A standard 20-gauge retinal cryoprobe is enveloped by the plastic tubing of an 18-gauge intravenous cannula (Venflon 2, BOC Ohmeda AB) for thermal insulation; a sleeve made of any available plastic or silicone sterile tubing can be used. Only the last 1.0 mm of the cryoprobe is exposed. The cryoprobe is inserted into the anterior chamber through the open tunnel to touch, very gently, the nucleus surface at the crater base. If there is no crater, the
tip is placed on the exposed cortex. The freeze cycle is started and the cryoprobe is adhered to the cataract by a “freeze-grip.” The cryoprobe is rotated 180 degrees around its axis, elevating the nucleus to the anterior chamber without force applied on the opened capsule (Figure 1). The cryoprobe is now under the nucleus, securing it from accidentally dropping (Figure 2). The freezing cycle is stopped. If no crater was performed at the onset, a piece of anterior cortex will usually separate during the initial procedure. Thawing the tip will release it from the small cortical fragment. The tip is then returned to the small crater that was created with the nucleus in its base.
Figure 1. (Ben-nun) Intraoperative photograph and schematic showing a cryoprobe holding the anterior face of the nucleus via a freeze-grip in preparation for 180-degree nucleus inversion around the axis of the cryoprobe (IR ⫽ irrigation line; CP ⫽ cryoprobe, FG ⫽ freeze grip).
Figure 2. (Ben-nun) The nucleus (N) is inverted in the anterior chamber and supported underneath by the cryoprobe; the frozen tip of the cryoprobe is seen under the nucleus (IR ⫽ irrigation line; CP ⫽ cryoprobe, FG ⫽ freeze grip).
1734
J CATARACT REFRACT SURG—VOL 28, OCTOBER 2002
TECHNIQUES: BEN-NUN
the support available by the ciliary body–zonule–capsule diaphragm is used.
Results
Figure 3. (Ben-nun) A vectis (V) is inserted under the nucleus while it is supported by the cryoprobe (CP).
A metallic loop (vectis, MAKE) is inserted under the inverted nucleus to replace the cryoprobe; there is always an instrument supporting the nucleus from underneath, preventing a dropped nucleus and manipulation of the unstable capsule (Figure 3). A second instrument, usually an IOL manipulator (Sinskey, MAKE), is entered to hold the nucleus from above. Thus held, the nucleus is removed from the anterior chamber (Figure 4). Only at this stage is the fluid allowed to slowly fill the anterior chamber. Aspiration of the remaining cortex is done with an aspiration needle (McIntire, MAKE) through the limbal paracentesis. An intraocular lens (IOL) is implanted in the ciliary sulcus via the tunnel. The IOL is placed in the sulcus as these patients have poor zonular support; therefore, all
From 1998 to 2000, the nucleus cryoinversion technique was successfully used in 13 eyes. Ten eyes had a vitrectomy for diabetic retinopathy, 1 for central retinal vein occlusion (CRVO), and 2 for pseudoexfoliation and significant phacodonesis. Although all eyes had poorly dilating pupils with medication, no mechanical dilation of the pupil was done because of the risk of bleeding related to the underlying pathology. In all cases, an IOL was implanted in the posterior chamber in the ciliary sulcus with good capsular support. No late IOL dislocations occurred. All patients had worse than 20/200 visual acuity preoperatively, reflecting advanced cataract related to the reluctance to perform surgery in these eyes. In the 2 cases with phacodonesis, visual acuity improved to 20/40 or better. Some visual acuity improvement was documented postoperatively in 7 diabetic patients, who had a visual acuity between 20/100 and 20/200. In 3 diabetic patients and the patient with CRVO, vision did not improve after the cataract surgery. In this group, the primary and most significant factor affecting the postoperative visual acuity was the underlying retinal condition.
Figure 4. (Ben-nun) The nucleus is held between a vectis (V) from below and a Sinskey manipulator (H) from above and is removed through the scleral tunnel (IR ⫽ irrigation line).
J CATARACT REFRACT SURG—VOL 28, OCTOBER 2002
1735
TECHNIQUES: BEN-NUN
Discussion Relatively few patients present with very complicated eye conditions that make cataract surgery challenging. These patients might have an underling disease with vitreoretinal complications that required previous vitreoretinal surgery. As a result of the underlying disease or the unavoidable side effects of the surgery, cataract develops in addition to other pathologies. Unfortunately, most of these cases are bilateral because of the systemic nature of the underlying disease. In such cases, extreme effort is made to provide the patient with any amount of useful vision the eyes can provide. A major complication during cataract surgery in such eyes is the nucleus or cataract fragments dropping into the vitreous cavity. A narrow pupil and compromised visibility make the removal of the dropped particles significantly more difficult than in a normal eye. The use of the cryo technique for cataract removal was common practice during the era of intracapsular cataract extraction (ICCE), when the whole cataract was removed from the eye in 1 piece. The idea of a freeze-grip has been modified in the nucleus cryoinversion technique to a maneuver that secures nucleus removal without applying force on the lens capsule, avoiding rupture. We have found this method useful in cases that otherwise would need a large-sector iridectomy with ICCE using cryoextraction and a wide limbal incision. The nucleus cryoinversion technique is a useful tool in the
1736
hands of the cataract surgeon who must operate on patients with highly complicated cataract.
References 1. Melberg NS, Thomas MA. Nuclear sclerotic cataract after vitrectomy in patients younger than 50 years of age. Ophthalmology 1995; 102:1466 –1471 2. Thompson JT, Glaser BM, Sjaarda RN, Murphy RP. Progression of nuclear sclerosis and long-term visual results of vitrectomy with transforming growth factor beta-2 for macular holes. Am J Ophthalmol 1995; 119:48 –54 3. Cherfan GM, Michels RG, de Bustros S, et al. Nuclear sclerotic cataract after vitrectomy for idiopathic epiretinal membranes causing macular pucker. Am J Ophthalmol 1991; 111:434 –438 4. Blankenship GW, Machemer R. Long-term diabetic vitrectomy results; report of 10 year follow-up. Ophthalmology 1985; 92:503–506 5. Federman JL, Schubert HD. Complications associated with the use of silicone oil in 150 eyes after retina-vitreous surgery. Ophthalmology 1988; 95:870 –876 6. McDermott ML, Puklin JE, Abrams GW, Eliott D. Phacoemulsification for cataract following pars plana vitrectomy. Ophthalmic Surg Lasers 1997; 28:558 –564 7. Grusha YO, Masket S, Miller KM. Phacoemulsification and lens implantation after pars plana vitrectomy. Ophthalmology 1998; 105:287–294 8. Saunders DC, Brown A, Jones NP. Extracapsular cataract extraction after vitrectomy. J Cataract Refract Surg 1996; 22:218 –221
J CATARACT REFRACT SURG—VOL 28, OCTOBER 2002