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Lenses Suitable for Use after Phacoemulsification
LENSES SUITABLE FOR USE AFTER PHACOEMULSIFICATION JOHN H. SHEETS, MD ODESSA, TEXAS
THE author has retrieved computer statistics on 2000 lens implants after using phacoemulsification of cataract. The minimum follow-up of these patients is nine months. The various types and number of lenses used is shown in Table 1.
Other lenses have been used, but because the numbers are small they have been excluded. Furthermore, some lenses have been used almost exclusively for intracapsular surgery and are not included here. Such lenses include the Binkhorst 4-loop and Fiederov styles.
The lens implants were done using a closed chamber technique, air to maintain the corneal dome, and the lens glide to introduce the intraocular lens (except in the case of Copeland and Shearing lenses). A discission was performed primarily in 11% of the cases.
RESULTS
Improved vision ranged from 95% using the Binkhorst 2-loop to 87% using the Choyce lens (Table 2). Secondary discissions were required (Table 3).
TECHNIQUE
In general, the first 1200 cases were done using a standard Kelman phacoemulsification; the last 800 cases were done employing a posterior chamber emulsification. Perhaps some adjustment in results should be made when comparing the two; however, time limitations prevent this. Suffice it to say, there have been no basic differences except in endothelial cell counts, early postoperative appearance, and slightly less corneal edema (statistically insignificant). A longer time period may be required to ascertain a definite difference.
COMPLICATIONS
Primary complications considered here are retinal detachment, macular edema (CME) unresolved for six months, corneal edema, and dislocations (Table 4). LENSES MOST SUITABLE FOR USE WITH KPE
For practical purposes, any intraocular lens style is suitable for use with phacoemulsification. This author, however, has eliminated totally iris-supported lenses with anterior and posterior loops. It is felt that the extra size and weight of these lenses make them impractical when a posterior capsule exists to allow for capsular fixation.
Submitted for publication Nov 17, 1978. Reprint requests to PO Box 7016, Odessa, TX 79760 (Dr Sheets).
Through experience with many lenses, others have been eliminated
2034
VOLUME R6 NOVEMBER 1979
LENSES AFTER PHACOEMULSIFICATION
TABLE 1 TYPES AND NUMBER OF LENSES IMPLANTED
Binkhorst 2-loop Platina style Copeland style Choyce Single loop Medallion suture Shearing posterior chamber Kelman Total
%WITH VISION IMPROVED
Binkhorst 2-loop Platina Single loop Kelman Shearing Copeland Medallion suture Choyce
95 92.5 91 90 90
89 88 87
LENS STYLE Choyce Binkhorst 2-loop Platina Copeland Kelman Shearing Medallion suture Single loop Overall average =
551 1019 180 106 60 52 30 20 2018
TABLE 2 VISUAL RESULTS WITH VARIOUS LENSES
LENS STYLE
TABLE 3 SECONDARY DISCISSIONS
NUMBER IMPLANTED
LENS TYPE
2035
% OF DISCISSIONS 2 7 7.5 8 10 10 13 16.5 8%
by trial and error. Examples of these include the Medallion suture lens, single loop lens and Copeland lens. The Medallion suture lens has several reasons for being impractical: it requires a suture to the iris which frequently breaks or frays, causing dislocation, and it has one of the highest percentages of corneal edema (constant motion) as well as unresolved macular edema. The single loop lens does exceedingly well when good capsular fixation exists. However, the metal
TABLE 4 COMPLICATIONS WITH VARIOUS LENSES LENS STYLE Binkhorst 2-loop Platina Copeland Choyce Single loop Medallion suture Shearing Kelman
% CME >6 MO
%RETINAL DETACHMENT
0.9 0.6 8.0 12.0 1.7 4.0 2.0 20.0
0.75 1.0 0.5 7.0 1.7 0 5.0 0
%CORNEAL EDEMA 0 1.5 0 3.0 1.7 8.0 0 0
% DISLOCATIONS 2.5 2.0 1.0 0 15.0 10.0 15.0 5.0
2036
JOHN H. SHEETS
loops readily dislocate, frequently totally lacerating the iris. A 15% dislocation rate and exceptionally severe problems occurred in many of these patients. The Copeland lens is essentially eliminated due to less than good final visual acuity, due primarily to a relatively high unresolved macular edema, especially when a discission is required. The Choyce lens has certainly had its share of controversy, and due to relatively less good results than some others, it is eliminated from routine use with KPE. While the Kelman lens showed some improvement over the Choyce lens, results again were less than spectacular. Again, macular edema was a frequent complication, as well as dislocation of the single sharp haptic above, passing through the iris and into the ciliary body. Ideally, a good lens for KPE should be one that could easily gain capsular fixation, fit through a very small incision, and maintain proper centering. It appeared that the Shearing lens met most of these requirements. While those patients that do well, do very well, those that do poorly, do very poorly. A moderately high unresolved macular edema rate is present, as well as axis instability causing a partial luxation through the pupil. This lens,
OPHTH AAO
in this author's experience, does not fixate to the posterior capsule. This leaves two lenses most suitable to use. The Platina and the Binkhorst 2-loop. Except for corneal edema and CME somewhat higher with the Platina lens, the results have been essentially identical. The corneal edema rate may still increase further as time lapses. Experience has shown us that metal-looped lenses produce more macular edema and corneal problems. Perhaps the more recent Platina styles that substitute a Prolene stave for the metal and eliminate the upper haptic will do much to make the two lenses more nearly equivalent in results. The final problem remains in the extra manipulation required to fasten the Platina clip and this is certain to produce a small percentage of corneal trauma. Thus, again we are left with the Binkhorst 2-loop lens. It is the simplest to insert and produces the least complications and the best visual results. Perhaps, when the problem of a clouding posterior capsule is solved, and a posterior chamber lens that is stable and remains fixed to the capsule is developed, a new era will be entered.
THE author has retrieved computer statistics on 2000 lens implants after using phacoemulsification of cataract. The minimum follow-up of these patients is nine months. The various types and number of lenses used is shown in Table 1.
Other lenses have been used, but because the numbers are small they have been excluded. Furthermore, some lenses have been used almost exclusively for intracapsular surgery and are not included here. Such lenses include the Binkhorst 4-loop and Fiederov styles.
The lens implants were done using a closed chamber technique, air to maintain the corneal dome, and the lens glide to introduce the intraocular lens (except in the case of Copeland and Shearing lenses). A discission was performed primarily in 11% of the cases.
RESULTS
Improved vision ranged from 95% using the Binkhorst 2-loop to 87% using the Choyce lens (Table 2). Secondary discissions were required (Table 3).
TECHNIQUE
In general, the first 1200 cases were done using a standard Kelman phacoemulsification; the last 800 cases were done employing a posterior chamber emulsification. Perhaps some adjustment in results should be made when comparing the two; however, time limitations prevent this. Suffice it to say, there have been no basic differences except in endothelial cell counts, early postoperative appearance, and slightly less corneal edema (statistically insignificant). A longer time period may be required to ascertain a definite difference.
COMPLICATIONS
Primary complications considered here are retinal detachment, macular edema (CME) unresolved for six months, corneal edema, and dislocations (Table 4). LENSES MOST SUITABLE FOR USE WITH KPE
For practical purposes, any intraocular lens style is suitable for use with phacoemulsification. This author, however, has eliminated totally iris-supported lenses with anterior and posterior loops. It is felt that the extra size and weight of these lenses make them impractical when a posterior capsule exists to allow for capsular fixation.
Submitted for publication Nov 17, 1978. Reprint requests to PO Box 7016, Odessa, TX 79760 (Dr Sheets).
Through experience with many lenses, others have been eliminated
2034
VOLUME R6 NOVEMBER 1979
LENSES AFTER PHACOEMULSIFICATION
TABLE 1 TYPES AND NUMBER OF LENSES IMPLANTED
Binkhorst 2-loop Platina style Copeland style Choyce Single loop Medallion suture Shearing posterior chamber Kelman Total
%WITH VISION IMPROVED
Binkhorst 2-loop Platina Single loop Kelman Shearing Copeland Medallion suture Choyce
95 92.5 91 90 90
89 88 87
LENS STYLE Choyce Binkhorst 2-loop Platina Copeland Kelman Shearing Medallion suture Single loop Overall average =
551 1019 180 106 60 52 30 20 2018
TABLE 2 VISUAL RESULTS WITH VARIOUS LENSES
LENS STYLE
TABLE 3 SECONDARY DISCISSIONS
NUMBER IMPLANTED
LENS TYPE
2035
% OF DISCISSIONS 2 7 7.5 8 10 10 13 16.5 8%
by trial and error. Examples of these include the Medallion suture lens, single loop lens and Copeland lens. The Medallion suture lens has several reasons for being impractical: it requires a suture to the iris which frequently breaks or frays, causing dislocation, and it has one of the highest percentages of corneal edema (constant motion) as well as unresolved macular edema. The single loop lens does exceedingly well when good capsular fixation exists. However, the metal
TABLE 4 COMPLICATIONS WITH VARIOUS LENSES LENS STYLE Binkhorst 2-loop Platina Copeland Choyce Single loop Medallion suture Shearing Kelman
% CME >6 MO
%RETINAL DETACHMENT
0.9 0.6 8.0 12.0 1.7 4.0 2.0 20.0
0.75 1.0 0.5 7.0 1.7 0 5.0 0
%CORNEAL EDEMA 0 1.5 0 3.0 1.7 8.0 0 0
% DISLOCATIONS 2.5 2.0 1.0 0 15.0 10.0 15.0 5.0
2036
JOHN H. SHEETS
loops readily dislocate, frequently totally lacerating the iris. A 15% dislocation rate and exceptionally severe problems occurred in many of these patients. The Copeland lens is essentially eliminated due to less than good final visual acuity, due primarily to a relatively high unresolved macular edema, especially when a discission is required. The Choyce lens has certainly had its share of controversy, and due to relatively less good results than some others, it is eliminated from routine use with KPE. While the Kelman lens showed some improvement over the Choyce lens, results again were less than spectacular. Again, macular edema was a frequent complication, as well as dislocation of the single sharp haptic above, passing through the iris and into the ciliary body. Ideally, a good lens for KPE should be one that could easily gain capsular fixation, fit through a very small incision, and maintain proper centering. It appeared that the Shearing lens met most of these requirements. While those patients that do well, do very well, those that do poorly, do very poorly. A moderately high unresolved macular edema rate is present, as well as axis instability causing a partial luxation through the pupil. This lens,
OPHTH AAO
in this author's experience, does not fixate to the posterior capsule. This leaves two lenses most suitable to use. The Platina and the Binkhorst 2-loop. Except for corneal edema and CME somewhat higher with the Platina lens, the results have been essentially identical. The corneal edema rate may still increase further as time lapses. Experience has shown us that metal-looped lenses produce more macular edema and corneal problems. Perhaps the more recent Platina styles that substitute a Prolene stave for the metal and eliminate the upper haptic will do much to make the two lenses more nearly equivalent in results. The final problem remains in the extra manipulation required to fasten the Platina clip and this is certain to produce a small percentage of corneal trauma. Thus, again we are left with the Binkhorst 2-loop lens. It is the simplest to insert and produces the least complications and the best visual results. Perhaps, when the problem of a clouding posterior capsule is solved, and a posterior chamber lens that is stable and remains fixed to the capsule is developed, a new era will be entered.