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Extracapsular surgery in lens implantation
extracapsular surgery In lens implantation (Binkhorst Lecture) Part III. Lens Implantation; In Extracapsular Surgery ].G.F. Worst Groningen Holland Lens Implantation Binkhorst's original extracapsular technique for lens implantation requires that a certain amount of lens matter remain in the lens fornices for lens loop fixation. My technique differs from Binkhorst's original concept by making an effort at total removal of all cortical matter. In the potential absence of fixation of the posterior loops by lens remnants, another fixation is imperative. Therefore I have used my various intracapsular fixation techniques in extracapsular procedures too. The advantages of this approach are :
articles
1. The incidence of posterior capsule opacification can be lowered to about 8% by operating on nuclear cataracts intracapsularly. 2. The chances of lens matter occluding the pupil are reduced. 3. The advantage of lens stabilization by the posterior capsule is retained. 4. The large flaps of anterior lens capsule take over the function of lens fixation. S. The surgical routine used in intracapsular lens implantation and lens fixation can be transposed to the extracapsular situation. 6. The same indication for various lens types in intracapsular surgery are now applicable to extracapsular types of surgery. F.i. if a small pupil lens is required extracapsular surgery forms no obstacle, though no pupil centration is obtained by this lens. There is no danger of lens luxation in the immediate postoperative period with full pupil dilation as required in extracapsular surgery without lens implantation. The Following Lenses May Be Used: 1. The Platinum Transiridectomy Clip lens (The Platina). 2. The iris sutured Iris Medallion lens. (Steel, supramid, or polypropylene suture). 3. The Boomerang lens or small pupil lens. 4. The small incision supramid loop lens . S. The Titanium small incision, small pupil lens with transiridectomy clip fixation.
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The Binkhorst 2 loop lens is not recommended in combination with the above described extracapsular tech~ique as no cortical matter for lens fixation remams. The Platinum Transiridectomy Clip Lens This iris Medallion lens has two supramid loops directed towards 6 and 12 o'clock. The platinum clip is closed through an iridectomy and brought in contact with the posterior loop. The lens is introduced with an open sky technique at 12 o'clock after which the cornea is closed and a progress of the lens is observed through the cornea towards the 6 o'clock area. It is essential to "plough" the intact anterior capsule flaps away with the lower loop. It is essential to use a microscope for this operation. The 12 o'clock iris is lifted over the 12 o'clock loop with a wide forceps traction. If the iris is sufficiently dilated the loop can be placed without further forceps manipulation. Intraocular Pilocarpine or acetylcholine is administered. After careful centration the position of the platinum clip is noted on the iris and an iridectomy is made exactly under the extremity of the platinum clip. The haptic edge of the lens is now regrasped and the platinum clip is pushed through the iridectomy in contact with the posterior supramid loop. Great care must be taken not to overextend the platinum clip as this will lift the body of the lens forward. The lower loop is protected from luxation by its intracapsular fixation. The top part of the lens is fixed by the platinum clip system. This platinum clip lens, if properly applied in extracapsular cases, is the best and the easiest lens in our hands for primary implantation after extracapsular surgery. Likewise for secondary implantation it is an efficient lens after extracapsular implantation. The Iris Sutured Iris Medallion Lens Our second choice is the original sutured iris Medallion lens. To insert this lens the author's iris suture is placed through the iris. Contrary to the intracapsular technique where this suture is put in before lens extraction, in extracapsular surgery this suture is placed after the contents have been removed. The posterior capsule offers sufficient protection to permit insertion at a late stage of the operation. At this moment I use a steel suture for fixation of the iris Medallion lens. As the Binkhorst Iridocapsular lens was the original extracapsular lens a brief description of its insertion follows here.
1. The lens is grasped with a Binkhorst forceps. 2. The lens is inserted with its lower loop at the 6 o'clock position behind the iris. If the pupil is sufficiently wide the upper loop can be inserted under the iris with a backwards movement. If the pupil is too much contracted, the upper loop can be brought under the iris by means of the Binkhorst spatula and iris retraction hook. Insertion of this lens is extremely simple and effective providing that the intraocular movements are not executed with the forceps. 3. Fixation of the Binkhorst Iridocapsular lens. Method A.: An iridectomy is performed and a loose suture is passed through the iridectomy around the upper loop and through the iris stroma. This suture must be knotted loosely. Method B.: John Alpar's suture. s A double-armed suture must be used. The posterior loop of the Binkhorst lens is engaged with the suture outside the eye, both arms of the double-armed suture are now passed separately through the pupil and out through the iris stroma above. After inserting the lens, the suture is pulled up and knotted, affirming the posterior loop to the iris. The double-armed Alpar s suture is highly effective in fixation of any type of posterior loop to the upper iris.
The Slotted Iris Medallion Lens The author prefers the slotted Iris Medallion lens with a steel suture. The steel suture is passed through the iris after extracapsular lens extraction. A single knot is made and a circular loop of about 6 mm. diameter is formed. The suture ends must be cut short, for safety'S sake. After insertion of the slotted Iris Medallion lens the circular loop is slipped around the haptic part of the lens and into the slots. The suture is stretched and cut. This steel suture procedure has been adapted as perlon sutures do absorb in the course of several years. If polypropylene is as inabsorbable as claimed by its manufacturers, return to the original Iris Medallion suturing technique can be expected.
167
The Cloverleaf Loop Lens This lens has been specifically designed for extracapsular surgery with the T -shaped incision of the anterior capsule. . . The lens is inserted under microscope control WIth ItS lower feet under the two capsular flaps. The top loop is brought under the iris. After careful centration an iridectomy is made corresponding to the anterior hook closure: The superior posterior loop is exteriorized through the iridectomy and the metal clip is hooked over the posteri~r loop. After this the lens is pushed into the eye agam. Great care must be taken to determine the correct size and place of the iridectomy as the Cloverleaf loop lens an iridectomy supported lens and not a pupil supported lens. The Boomerang Lens The Boomerang lens has a single horizontal posterior loop with two points of insertion near to the center of the lens. Its technique of insertion is the same as the insertion of the slotted Iris Medallion lens. The function of this lens is to provide a small pupil. The Ridley-Worst-Alpar Posterior Chamber Lens The original idea of Ridley 6 to put an artificial lens in the posterior chamber resting against the posterior capsule failed only in one respect: The weight of the lenses was excessive, resulting in their frequent luxation. By redesigning the Ridley lens it has been possible to re-instate the brilliant idea of Ridley. After a number of variations have been used we have decided that the combination of capsule fixation and iris fixation is required for proper stabilization of a posterior chamber lens. Efforts to stabilize posterior chamber lenses by a suture only, have proven fruitless in our hands. It is by means of the Alpar suture, that the posterior chamber lens can be effectively stabilized, providing its lower edge is positioned in the capsular fornix. The lens has a special edge for lower capsule fornix fixation. After insertion of an artificial lens in extracapsular surgery it is important to wash the posterior chamber through the iridectomy in order to dislocate remaining cortical lens matter and pigment particles. A careful stream through the iridectomy will force these particles in the anterior chamber where they can be easily washed out. 168
Complications of Extracapsular Surgery with Lens Implantation Corneal edema and striate keratitis. Depending on the length of irrigation, the inherent vulnerability of the endothelium and the amount of mechanical contact made with the endothelium, moderate to severe corneal striate keratopathy may develop. With increased surgical experience with the cannula procedure, this corneal edema is always transient. Pigment loss. Damage to the pigment epithelium is frequent, but seems to be without clinical significance unless the pigment is not washed out and forms deposits on the artificial lens. Although I am unaware of clinical observations correlating pigment damage with cystoid macular edema, I have the clinical impression that extensive damage to the iris pigment epithelium is a contributing factor. A study of this possibility could be valuable. Capsule damage. The purpose of the extracapsular procedure is the prevention of cystoid macular edema, and manifest rupture of the posterior capsule is a fairly serious complication.
If vitreous is mixed with remammg lens cortex a serious situation has been created. This must be prevented at all costs, and for this reason it is advisable to remain on the safe side while removing cortex. However, even an apparently intact posterior capsule may be a clinically broken capsule. This is a frequent occurrence in phacoemulsification. Fold formations in the posterior capsule predominantly in one direction, indicate slackness and damage to the zonule perpendicular to the folds. If the pressure in the anterior chamber is made excessive during the washing procedure, breaks in the anterior hyaloid forming part of the rear wall of Petit's canal are frequent. Cystoid macular edema in these cases may occur. It is stressed here, that intactness of the visible part of the posterior capsule does not signify intactness of the capsule behind the iris. Some Complications of Lens Implantation in Extracapsular Surgery The sutured Iris Medallion lens. 1.
Loop luxation may occur.
2. Failure to engage one or both loops inside the capsular bag. This may lead to a later de centration of the lens due to unilateral traction of contracting capsule. 3. Decentration towards 12 o'clock. The Platinum transiridectomy clip lens The lower loop may luxate, if one fails to insert it between the capsular flaps. The Boomerang lens. Luxation may occur in case of failure to insert the loops between the capsular folds. The small incision supramid loop lens. In case of too much depression of the clip, the body of the lens may lift forward, risking corneal touch. The titanium small pupil lens with transiridectomy clip fixation. It is surgically difficult to close the clip properly. Therefore the incision must be made sufficiently large for maneuvering intraocularly.
All of the lenses mentioned may show sphincter erosion in case of excentric positioning. In some cases, 9 years after lens implantation (the Iris Medallion lens) in traumatic cases local iris atrophy has been observed due to ciccatricial retraction of the lens. All extracapsular cases may show considerable striate keratopathy if the surgery has been traumatic. Capsule opacification. The main late complication is capsule opacification due to metaplasia of germinal lens fibers .
Contrary to the general belief, these opacifications of the posterior capsule hardly ever need a capsule discision. A discision makes the eye vulnerable to cystoid macular edema and aphakic retinal detachment. It is therefore imperative to clean the posterior capsule without opening it. A simple technique exists using the author's irrigated capsule "plane". After making a step incision with a Superblade, the irrigating capsule plane is introduced and deposits on the posterior capsule are "shaved" off under microscopic control. Recurrence of opacification is rare on condition that a large part of the capsule is cleaned. In cases of secondary lens implantation there is less risk of this asymmetric retraction, as retraction phenomena have already taken place and cannot continue to exert this force on the superior posterior lens loop. Furthermore secondary lens implants tend to remain free of capsule flaps as these have already stuck together.
169
articles
1. The incidence of posterior capsule opacification can be lowered to about 8% by operating on nuclear cataracts intracapsularly. 2. The chances of lens matter occluding the pupil are reduced. 3. The advantage of lens stabilization by the posterior capsule is retained. 4. The large flaps of anterior lens capsule take over the function of lens fixation. S. The surgical routine used in intracapsular lens implantation and lens fixation can be transposed to the extracapsular situation. 6. The same indication for various lens types in intracapsular surgery are now applicable to extracapsular types of surgery. F.i. if a small pupil lens is required extracapsular surgery forms no obstacle, though no pupil centration is obtained by this lens. There is no danger of lens luxation in the immediate postoperative period with full pupil dilation as required in extracapsular surgery without lens implantation. The Following Lenses May Be Used: 1. The Platinum Transiridectomy Clip lens (The Platina). 2. The iris sutured Iris Medallion lens. (Steel, supramid, or polypropylene suture). 3. The Boomerang lens or small pupil lens. 4. The small incision supramid loop lens . S. The Titanium small incision, small pupil lens with transiridectomy clip fixation.
166
The Binkhorst 2 loop lens is not recommended in combination with the above described extracapsular tech~ique as no cortical matter for lens fixation remams. The Platinum Transiridectomy Clip Lens This iris Medallion lens has two supramid loops directed towards 6 and 12 o'clock. The platinum clip is closed through an iridectomy and brought in contact with the posterior loop. The lens is introduced with an open sky technique at 12 o'clock after which the cornea is closed and a progress of the lens is observed through the cornea towards the 6 o'clock area. It is essential to "plough" the intact anterior capsule flaps away with the lower loop. It is essential to use a microscope for this operation. The 12 o'clock iris is lifted over the 12 o'clock loop with a wide forceps traction. If the iris is sufficiently dilated the loop can be placed without further forceps manipulation. Intraocular Pilocarpine or acetylcholine is administered. After careful centration the position of the platinum clip is noted on the iris and an iridectomy is made exactly under the extremity of the platinum clip. The haptic edge of the lens is now regrasped and the platinum clip is pushed through the iridectomy in contact with the posterior supramid loop. Great care must be taken not to overextend the platinum clip as this will lift the body of the lens forward. The lower loop is protected from luxation by its intracapsular fixation. The top part of the lens is fixed by the platinum clip system. This platinum clip lens, if properly applied in extracapsular cases, is the best and the easiest lens in our hands for primary implantation after extracapsular surgery. Likewise for secondary implantation it is an efficient lens after extracapsular implantation. The Iris Sutured Iris Medallion Lens Our second choice is the original sutured iris Medallion lens. To insert this lens the author's iris suture is placed through the iris. Contrary to the intracapsular technique where this suture is put in before lens extraction, in extracapsular surgery this suture is placed after the contents have been removed. The posterior capsule offers sufficient protection to permit insertion at a late stage of the operation. At this moment I use a steel suture for fixation of the iris Medallion lens. As the Binkhorst Iridocapsular lens was the original extracapsular lens a brief description of its insertion follows here.
1. The lens is grasped with a Binkhorst forceps. 2. The lens is inserted with its lower loop at the 6 o'clock position behind the iris. If the pupil is sufficiently wide the upper loop can be inserted under the iris with a backwards movement. If the pupil is too much contracted, the upper loop can be brought under the iris by means of the Binkhorst spatula and iris retraction hook. Insertion of this lens is extremely simple and effective providing that the intraocular movements are not executed with the forceps. 3. Fixation of the Binkhorst Iridocapsular lens. Method A.: An iridectomy is performed and a loose suture is passed through the iridectomy around the upper loop and through the iris stroma. This suture must be knotted loosely. Method B.: John Alpar's suture. s A double-armed suture must be used. The posterior loop of the Binkhorst lens is engaged with the suture outside the eye, both arms of the double-armed suture are now passed separately through the pupil and out through the iris stroma above. After inserting the lens, the suture is pulled up and knotted, affirming the posterior loop to the iris. The double-armed Alpar s suture is highly effective in fixation of any type of posterior loop to the upper iris.
The Slotted Iris Medallion Lens The author prefers the slotted Iris Medallion lens with a steel suture. The steel suture is passed through the iris after extracapsular lens extraction. A single knot is made and a circular loop of about 6 mm. diameter is formed. The suture ends must be cut short, for safety'S sake. After insertion of the slotted Iris Medallion lens the circular loop is slipped around the haptic part of the lens and into the slots. The suture is stretched and cut. This steel suture procedure has been adapted as perlon sutures do absorb in the course of several years. If polypropylene is as inabsorbable as claimed by its manufacturers, return to the original Iris Medallion suturing technique can be expected.
167
The Cloverleaf Loop Lens This lens has been specifically designed for extracapsular surgery with the T -shaped incision of the anterior capsule. . . The lens is inserted under microscope control WIth ItS lower feet under the two capsular flaps. The top loop is brought under the iris. After careful centration an iridectomy is made corresponding to the anterior hook closure: The superior posterior loop is exteriorized through the iridectomy and the metal clip is hooked over the posteri~r loop. After this the lens is pushed into the eye agam. Great care must be taken to determine the correct size and place of the iridectomy as the Cloverleaf loop lens an iridectomy supported lens and not a pupil supported lens. The Boomerang Lens The Boomerang lens has a single horizontal posterior loop with two points of insertion near to the center of the lens. Its technique of insertion is the same as the insertion of the slotted Iris Medallion lens. The function of this lens is to provide a small pupil. The Ridley-Worst-Alpar Posterior Chamber Lens The original idea of Ridley 6 to put an artificial lens in the posterior chamber resting against the posterior capsule failed only in one respect: The weight of the lenses was excessive, resulting in their frequent luxation. By redesigning the Ridley lens it has been possible to re-instate the brilliant idea of Ridley. After a number of variations have been used we have decided that the combination of capsule fixation and iris fixation is required for proper stabilization of a posterior chamber lens. Efforts to stabilize posterior chamber lenses by a suture only, have proven fruitless in our hands. It is by means of the Alpar suture, that the posterior chamber lens can be effectively stabilized, providing its lower edge is positioned in the capsular fornix. The lens has a special edge for lower capsule fornix fixation. After insertion of an artificial lens in extracapsular surgery it is important to wash the posterior chamber through the iridectomy in order to dislocate remaining cortical lens matter and pigment particles. A careful stream through the iridectomy will force these particles in the anterior chamber where they can be easily washed out. 168
Complications of Extracapsular Surgery with Lens Implantation Corneal edema and striate keratitis. Depending on the length of irrigation, the inherent vulnerability of the endothelium and the amount of mechanical contact made with the endothelium, moderate to severe corneal striate keratopathy may develop. With increased surgical experience with the cannula procedure, this corneal edema is always transient. Pigment loss. Damage to the pigment epithelium is frequent, but seems to be without clinical significance unless the pigment is not washed out and forms deposits on the artificial lens. Although I am unaware of clinical observations correlating pigment damage with cystoid macular edema, I have the clinical impression that extensive damage to the iris pigment epithelium is a contributing factor. A study of this possibility could be valuable. Capsule damage. The purpose of the extracapsular procedure is the prevention of cystoid macular edema, and manifest rupture of the posterior capsule is a fairly serious complication.
If vitreous is mixed with remammg lens cortex a serious situation has been created. This must be prevented at all costs, and for this reason it is advisable to remain on the safe side while removing cortex. However, even an apparently intact posterior capsule may be a clinically broken capsule. This is a frequent occurrence in phacoemulsification. Fold formations in the posterior capsule predominantly in one direction, indicate slackness and damage to the zonule perpendicular to the folds. If the pressure in the anterior chamber is made excessive during the washing procedure, breaks in the anterior hyaloid forming part of the rear wall of Petit's canal are frequent. Cystoid macular edema in these cases may occur. It is stressed here, that intactness of the visible part of the posterior capsule does not signify intactness of the capsule behind the iris. Some Complications of Lens Implantation in Extracapsular Surgery The sutured Iris Medallion lens. 1.
Loop luxation may occur.
2. Failure to engage one or both loops inside the capsular bag. This may lead to a later de centration of the lens due to unilateral traction of contracting capsule. 3. Decentration towards 12 o'clock. The Platinum transiridectomy clip lens The lower loop may luxate, if one fails to insert it between the capsular flaps. The Boomerang lens. Luxation may occur in case of failure to insert the loops between the capsular folds. The small incision supramid loop lens. In case of too much depression of the clip, the body of the lens may lift forward, risking corneal touch. The titanium small pupil lens with transiridectomy clip fixation. It is surgically difficult to close the clip properly. Therefore the incision must be made sufficiently large for maneuvering intraocularly.
All of the lenses mentioned may show sphincter erosion in case of excentric positioning. In some cases, 9 years after lens implantation (the Iris Medallion lens) in traumatic cases local iris atrophy has been observed due to ciccatricial retraction of the lens. All extracapsular cases may show considerable striate keratopathy if the surgery has been traumatic. Capsule opacification. The main late complication is capsule opacification due to metaplasia of germinal lens fibers .
Contrary to the general belief, these opacifications of the posterior capsule hardly ever need a capsule discision. A discision makes the eye vulnerable to cystoid macular edema and aphakic retinal detachment. It is therefore imperative to clean the posterior capsule without opening it. A simple technique exists using the author's irrigated capsule "plane". After making a step incision with a Superblade, the irrigating capsule plane is introduced and deposits on the posterior capsule are "shaved" off under microscopic control. Recurrence of opacification is rare on condition that a large part of the capsule is cleaned. In cases of secondary lens implantation there is less risk of this asymmetric retraction, as retraction phenomena have already taken place and cannot continue to exert this force on the superior posterior lens loop. Furthermore secondary lens implants tend to remain free of capsule flaps as these have already stuck together.
169