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Lens bisector for silicone intraocular lens removal
Lens bisector for silicone intraocular lens removal Hans-Reinhard Koch, MD
ABSTRACT The lens bisector, designed to cut silicone intraocular lenses (IOLs) in the middle so they can be extracted through a 3.0 mm incision, consists of a disposable wire sling that can be pulled into a metal tube. After the IOL is moved into the anterior chamber, the sling is placed over its center and pulled completely into the tube, bisecting the lens atraumatically. The IOL halves are then extracted. A new IOL can be inserted through the same incision. J Cataract Refract Surg 1996; 22:1379-1380
T
he past 5 years have brought a gradual shift toward small incisions (3.0 to 3.5 mm wide) and implantation of foldable intraocular lenses (IOLs). The shift is largely the result of safer valve incision techniques such as clear corneal and posterior limbal incisions 1,2 and new 10L folding and injection devices. Until recently, the explantation of foldable lenses required substantial enlargement of the original incision or creation of a new, larger incision because adequate intraocular 10L folding techniques were not available. Neuhann 3 has shown that soft acrylic lenses can be easily folded within the eye for removal through the original incision. This paper shows a technique for cutting a silicone 10L in half, allowing extraction through a 3.0 mm wide incision.
The Instrument Intraocular lenses are extracted for many reasons including incorrect power calculation, intolerance of a multifocal 10L, anisometropia with aniseikonia, 10L damage during insertion, and intraoperative or postoperative 10L displacement. Volker Geuder and Hartmut Fath helped in the design of the lem bisector. Reprint requests to Ham-Reinhard Koch, MD, Klinik Dardenne, Friedrich-Ebert Strasse 23-27, Bonn D-53177, Germany.
The acrylic materials of AcrySof and loptex 10Ls are quite stiff at room temperature, although soft and flexible at body temperature. Thus, these lenses may be difficult to fold in the operating room before insertion. Once the lenses are warmed, they can be easily and gently folded (e.g., over a cyclodialysis spatula). These lenses are easier to handle when wet. On the other hand, silicone 10Ls are easier to fold in the operating room at room temperature if they are dry (i.e., not covered by water or viscoelastic). They have a lower refractive index and thus are thicker than acrylic 10Ls. Once in the eye, silicone 10Ls are slippery, resisting manipulation and folding attempts. Thus, to explant a silicone 10L, it must be cut into halves. I have tried to do this with a Vannas scissors and a manipulating instrument, nucleus rotator, or chopper. Because of the lenses' relative thickness and slippery surface, this was not easy,
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Figure 1. (Koch) The Koch lens bisector (A) consists of a disposable wire sling (0) that is introduced with its stem into a metal tube and fastened with a screw on the instrument handle. Once fastened, the sling can be drawn into the metal tube (B, C) by sliding the fastening screw on the handle toward the surgeon.
J CATARACT REFRACT SURG-VOL 22, SUPPLEMENT 2 1996
1379
LENS BISECTOR FOR SILICONE IOL REMOVAL
Figure 2. (Koch) Surgical technique. A: Viscoelastic is injected into the capsular bag to separate the anterior and posterior layers. B: The IOL has been moved into the anterior chamber and the first loop has been extracted through the clear corneal incision. C: The wire sling of the bisector is placed over the protruding haptic and inserted into the anterior chamber over the IOL. D: By holding the IOL by the protruding haptic, the IOL is maneuvered into the sling so that it is centrally placed. E: The wire is drawn into the tube and the IOL is deformed, resembling a cushion. F: Further pulling of the wire sling causes more deformation and, finally, bisection of the IOL. G: The bisected lens is seen in the anterior chamber. H: The first IOL half is extracted. I: The second IOL half is pushed out by the viscoelastic, with the push-pull hook depressing the posterior lip of the clear corneal incision.
especially with high-power lenses. The lenses tend to slip out of the branches of the scissors, resulting in a cut that is not central and requiring many manipulations until the lens is bisected. Such maneuvers can damage the endothelium and anterior chamber angle. To facilitate the cutting of silicone lenses, I designed an IOL bisecting instrument (Geuder GmbH) for easy and controlled cutting. I got the idea from Swiss cheese wmng. The IOL bisector (Figure 1) has a disposable, oblong 1.0 cm long wire sling that protrudes from a metal tube. It is pulled into the tube by sliding a button on the instrument's handle. The sling is placed over the center of the IOL. When the sling is pulled completely into the tube, it bisects the IOL. The sling (Figure 1, D) is inserted into the instrument before surgery and fastened with a screw on the instrument handle.
Surgical Technique Figure 2 shows an IOL explantation using the bisecting instrument. First, the IOL is removed from the
1380
capsular bag and both loops are moved into the anterior chamber. One loop is then pulled out through the 3.0 mm incision. The bisecting instrument is placed over the protruding loop and moved into the anterior chamber over the lens optic. By gently maneuvering the IOL by its haptic, the wire sling is placed exactly over the lens middle. When the sliding screw is moved toward the surgeon, the wire sling is pulled into the tube. The IOL is deformed and then cut exactly in the middle. The IOL halves are extracted. A new foldable IOL can be inserted through the incision.
References 1. Fine IH, Fichman RA, Grabow HB, eds. Clear-Corneal Cataract Surgery and Topical Anesthesia. Thorofare, NJ, Slack, 1993 2. Koch H-R. Phakotechnik mit Clear-Cornea-Inzision und Implantation von Silikonlinsen. OphthalmoChirurgie 1993; 5:117-130 3. Neuhann T. Intraocular folding of an acrylic lens for explantation through a small incision cataract wound. J Cataract Refract Surg 1996; 22:1383-1386
J CATARACT REFRACT SURG-VOL 22. SUPPLEMENT 21996
ABSTRACT The lens bisector, designed to cut silicone intraocular lenses (IOLs) in the middle so they can be extracted through a 3.0 mm incision, consists of a disposable wire sling that can be pulled into a metal tube. After the IOL is moved into the anterior chamber, the sling is placed over its center and pulled completely into the tube, bisecting the lens atraumatically. The IOL halves are then extracted. A new IOL can be inserted through the same incision. J Cataract Refract Surg 1996; 22:1379-1380
T
he past 5 years have brought a gradual shift toward small incisions (3.0 to 3.5 mm wide) and implantation of foldable intraocular lenses (IOLs). The shift is largely the result of safer valve incision techniques such as clear corneal and posterior limbal incisions 1,2 and new 10L folding and injection devices. Until recently, the explantation of foldable lenses required substantial enlargement of the original incision or creation of a new, larger incision because adequate intraocular 10L folding techniques were not available. Neuhann 3 has shown that soft acrylic lenses can be easily folded within the eye for removal through the original incision. This paper shows a technique for cutting a silicone 10L in half, allowing extraction through a 3.0 mm wide incision.
The Instrument Intraocular lenses are extracted for many reasons including incorrect power calculation, intolerance of a multifocal 10L, anisometropia with aniseikonia, 10L damage during insertion, and intraoperative or postoperative 10L displacement. Volker Geuder and Hartmut Fath helped in the design of the lem bisector. Reprint requests to Ham-Reinhard Koch, MD, Klinik Dardenne, Friedrich-Ebert Strasse 23-27, Bonn D-53177, Germany.
The acrylic materials of AcrySof and loptex 10Ls are quite stiff at room temperature, although soft and flexible at body temperature. Thus, these lenses may be difficult to fold in the operating room before insertion. Once the lenses are warmed, they can be easily and gently folded (e.g., over a cyclodialysis spatula). These lenses are easier to handle when wet. On the other hand, silicone 10Ls are easier to fold in the operating room at room temperature if they are dry (i.e., not covered by water or viscoelastic). They have a lower refractive index and thus are thicker than acrylic 10Ls. Once in the eye, silicone 10Ls are slippery, resisting manipulation and folding attempts. Thus, to explant a silicone 10L, it must be cut into halves. I have tried to do this with a Vannas scissors and a manipulating instrument, nucleus rotator, or chopper. Because of the lenses' relative thickness and slippery surface, this was not easy,
B -cc======-~
C-:=
--
~
Figure 1. (Koch) The Koch lens bisector (A) consists of a disposable wire sling (0) that is introduced with its stem into a metal tube and fastened with a screw on the instrument handle. Once fastened, the sling can be drawn into the metal tube (B, C) by sliding the fastening screw on the handle toward the surgeon.
J CATARACT REFRACT SURG-VOL 22, SUPPLEMENT 2 1996
1379
LENS BISECTOR FOR SILICONE IOL REMOVAL
Figure 2. (Koch) Surgical technique. A: Viscoelastic is injected into the capsular bag to separate the anterior and posterior layers. B: The IOL has been moved into the anterior chamber and the first loop has been extracted through the clear corneal incision. C: The wire sling of the bisector is placed over the protruding haptic and inserted into the anterior chamber over the IOL. D: By holding the IOL by the protruding haptic, the IOL is maneuvered into the sling so that it is centrally placed. E: The wire is drawn into the tube and the IOL is deformed, resembling a cushion. F: Further pulling of the wire sling causes more deformation and, finally, bisection of the IOL. G: The bisected lens is seen in the anterior chamber. H: The first IOL half is extracted. I: The second IOL half is pushed out by the viscoelastic, with the push-pull hook depressing the posterior lip of the clear corneal incision.
especially with high-power lenses. The lenses tend to slip out of the branches of the scissors, resulting in a cut that is not central and requiring many manipulations until the lens is bisected. Such maneuvers can damage the endothelium and anterior chamber angle. To facilitate the cutting of silicone lenses, I designed an IOL bisecting instrument (Geuder GmbH) for easy and controlled cutting. I got the idea from Swiss cheese wmng. The IOL bisector (Figure 1) has a disposable, oblong 1.0 cm long wire sling that protrudes from a metal tube. It is pulled into the tube by sliding a button on the instrument's handle. The sling is placed over the center of the IOL. When the sling is pulled completely into the tube, it bisects the IOL. The sling (Figure 1, D) is inserted into the instrument before surgery and fastened with a screw on the instrument handle.
Surgical Technique Figure 2 shows an IOL explantation using the bisecting instrument. First, the IOL is removed from the
1380
capsular bag and both loops are moved into the anterior chamber. One loop is then pulled out through the 3.0 mm incision. The bisecting instrument is placed over the protruding loop and moved into the anterior chamber over the lens optic. By gently maneuvering the IOL by its haptic, the wire sling is placed exactly over the lens middle. When the sliding screw is moved toward the surgeon, the wire sling is pulled into the tube. The IOL is deformed and then cut exactly in the middle. The IOL halves are extracted. A new foldable IOL can be inserted through the incision.
References 1. Fine IH, Fichman RA, Grabow HB, eds. Clear-Corneal Cataract Surgery and Topical Anesthesia. Thorofare, NJ, Slack, 1993 2. Koch H-R. Phakotechnik mit Clear-Cornea-Inzision und Implantation von Silikonlinsen. OphthalmoChirurgie 1993; 5:117-130 3. Neuhann T. Intraocular folding of an acrylic lens for explantation through a small incision cataract wound. J Cataract Refract Surg 1996; 22:1383-1386
J CATARACT REFRACT SURG-VOL 22. SUPPLEMENT 21996