AMERICAN JOURNAL OF OPHTHALMOLOGY VOLUME 88

NUMBER 5

NOVEMBER, 1979

T H E CHANGING SCENE O F INTRAOCULAR IMPLANT L E N S SURGERY T H E 31ST BEDELL LECTURE N O R M A N S. J A F F E , M.D. Miami Beach,

On Nov. 29,1949, Ridley implanted the first modern intraocular lens, a posterior chamber lens. In 1979, nearly 30 years later, about 80,000 intraocular lenses are implanted annually in the United States. What happened in between was a techno­ logic explosion that resulted in lens im­ plants supported by the angle of the ante­ rior chamber, lens implants supported by the iris or the iris and posterior capsule, and lens implants placed in the posterior chamber. When did all this happen? The basic techniques and methods for intraoc­ ular lens implantation were developed during a four-year period between 1949 and 1953. The original Ridley posterior cham­ ber lens has currently been replaced by those of Pearce, Shearing, and others. The Dannheim and Strampelli anglesupported lenses have been replaced by those of Choyce, Kelman, and others. Epstein's iris-supported lens has been succeeded by many styles, including those of Binkhorst, Copeland, Fyodorov, and Worst. Ophthalmic surgeons started lens im­ plant surgery with an extracapsular cataFrom the Bascom Palmer Eye Institute of the University of Miami School of Medicine, Miami Beach, Florida. This study was supported in part by the Miami Eye Foundation. This study was pre­ sented at the 31st Annual Wills Eye Hospital Clini­ cal Conference, March 2, 1979, Philadelphia, Penn­ sylvania. Reprint requests to Norman S. Jaffe, M.D., 1680 Michigan Ave., Miami Beach, F L 33139.

Florida

ract extraction that Ridley used to support the lens. Many lens implant surgeons have started using extracapsular cataract extraction again as a result of Binkhorst's clinical experience. Binkhorst first used the extracapsular cataract extraction to reduce the incidence of dislocations by using the posterior capsule for more sta­ ble fixation. He then maintained that the principal advantage of the extracapsular cataract extraction was protection of the cornea because implants without loops in the anterior chamber could be used. However, what has attracted many im­ plant surgeons is his current hypothesis that the posterior capsule protects the retina by lessening the possibility of cystoid macular edema and retinal detach­ ment. These premises, although accepted by many, have not yet been clinically proven. Despite this, Binkhorst's reason­ ing together with the clinical studies of Kelman and others, has influenced many surgeons to use extracapsular cataract ex­ traction for cataract surgery with or with­ out a lens implant. These technologic advances have influ­ enced American ophthalmology greatly, where the number of cataract operations performed per capita population consid­ erably exceeds that of any other country in the western world. 1 A much more liber­ al approach to the indication for cataract surgery has developed. This has resulted in some criticism from those who main­ tain that this more liberal interpretation is

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not medically, socially, and economically justified. The controversy has placed oph­ thalmology in the "eye" of a surgical storm. 2 For example, there has been such a proliferation of lens implants that a family tree of intraocular lenses can be constructed based on the three locations of fixation within the eye. 3 This changing scene of technologic ad­ vances has created a dilemma for every responsible ophthalmologist. The lay press, on the one hand, has heightened public expectation by making the most heroic surgical procedures appear con­ ventional. Consumer groups, on the other hand, label new advances as bordering on human experimentation. The heated de­ bate resulting from all this has divided ophthalmology into two camps: (1) lens implant surgeons who claim that the intraocular lens is a miracle, and (2) nonimplant surgeons who consider it a men­ ace. The reasonable ophthalmologist con­ siders neither of these points of view to be accurate. As stated by Shoch, 4 "The final word then, is, we are dealing not with a miracle, not with a menace, but with a reasonable advance in cataract surgery for certain selected patients." We can best face this dilemma by examining the changing scene of lens implant surgery and developing attitudes based on proven clinical trials.

NOVEMBER, 1979

Fig. 1 (Jaffe). Pearce posterior chamber lens in situ. The superior haptic is sutured to the iris (arrow).

these intraocular lenses are used with an extracapsular cataract extraction. Based on the particular bias of the surgeon, a long list of advantages and disadvantages can be cited for the three categories of intraocular lenses. Those cited in this paper include those I consid­ er to be least controversial.

POSTERIOR CHAMBER LENSES

Two of the popular posterior chamber lenses currently available are those of Pearce 5 and Shearing. 6 The Pearce poste­ rior chamber lens is sutured to the iris (Fig. 1). It has a tripod shape (Fig. 2). The Shearing lens, which is an outgrowth of the Barraquer anterior chamber, anglesupported lens of the 1950s, is placed in the posterior chamber with two incom­ plete haptic loops inserting into the re­ gion of the ciliary sulcus at two opposite points in the eye (Figs. 3 and 4). Both of

Fig. 2 (Jaffe). Pearce posterior chamber tripod lens.

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INTRAOCULAR IMPLANT LENS SURGERY

Fig. 3 (Jaffe). Shearing posterior chamber lens in situ.

Advantages of the posterior chamber lens include the following: 1. Best physiologic position—Its posi­ tion more closely parallels that of the crystalline lens than other intraocular lenses. 2. Greatest separation from the cornea and anterior chamber angle—This reduc­ es the likelihood of corneal edema or the uveitis, glaucoma, hyphema syndrome. 3. Easiest intraocular lens to insert without making contact with the cornea. 4. Free mobility of the pupil—This is a significant advantage because it permits adequate dilation of the pupil for ophthalmoscopic examination. The pupil re­ sponds physiologically in conditions of light and dark. 5. Cosmesis—The pupil appears nor­ mal. This is a minor advantage. 6. Less pseudophakodonesis—The im­ portance of this in preventing inflamma­ tion and cystoid macular edema has not been proven. 7. Less danger of corneal contact with postoperative abnormalities of anterior chamber depth—This is a significant ad­ vantage.

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8. Less glitter, dazzle, flutter, and edge glare—Patients with prepupillary lenses occasionally complain of reflections, im­ age duplication, halos, and the like. This has been virtually eliminated with posterior chamber lenses. Disadvantages of the posterior chamber lens include the following: 1. No long-term results—No long-term experience, favorable or unfavorable, ex­ ists of the intraocular tolerance of posteri­ or chamber lenses. 2. The Shearing posterior chamber lens depends on the capsule and ciliary sulcus for fixation—This may prove to be inade­ quate in the long run. 3. The Pearce posterior chamber lens requires a fixation suture—This compli­ cates the procedure. 4. Can only be used with an extracapsular cataract extraction—This is a signif­ icant disadvantage for those who must radically change their method of cataract surgery and for those who are not con­ vinced of the advantage of the extracapsular cataract extraction. 5. Impingement on ciliary body

Fig. 4 (Jaffe). Same eye as Figure 3. Pupil dilated.

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NOVEMBER, 1979

structures—This particularly involves the Shearing lens. If it is intended that the two loops of the implant rest in the ciliary sulcus, the insertion must be considered a blind procedure. The long-term tolerance of ciliary body structures of contact with the loops is unknown. 6. Difficult to remove—The Shearing lens is probably the most difficult implant to remove. The Pearce lens can be re­ moved more easily but still with greater difficulty than other types of intraocular lenses. ANTERIOR CHAMBER ANGLE-SUPPORTED LENSES

The most popular currently used ante­ rior chamber angle-supported lens is the Choyce Mark VIII lens and the ChoyceTennant variation. These are usually im­ planted at the time of cataract extraction (Fig. 5) and occasionally secondarily (Fig. 6). Choyce 7 recently introduced his Mark IX lens, which can be implanted through a smaller incision than the Mark VIII lens. Kelman 8 has also used an angle-supported lens, which can be intro­ duced into the eye through an incision as

Fig. 6 (Jaffe). Choyce Mark VIII lens in situ after a secondary implantation.

Fig. 5 (Jaffe). Choyce Mark VIII lens in situ.

small as 3 mm (Fig. 7). Advantages of the anterior chamber angle-supported lens include the follow­ ing: 1. Ease of insertion—The ease of inser­ tion is comparable to that of the Shearing lens. However, as stated previously with the Shearing lens, the insertion is some­ what of a blind procedure because the

Fig. 7 (Jaffe). Kelman anterior chamber lens in situ. Pupil dilated.

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INTRAOCULAR IMPLANT LENS SURGERY

surgeon cannot visualize the exact loca­ tion in the anterior chamber angle where the ends of the haptic are supposed to be placed. 2. Dilatable pupil—This advantage is significant and has been previously dis­ cussed. 3. Least pseudophakodonesis—When properly inserted, this type of implant gives the least pseudophakodonesis of all the types of implants. The advantage of this is still unknown. 4. Little risk of dislocation—This is a true advantage shown clinically. 5. Cosmesis—The pupil appears to be nearly normal. Occasionally, there is an oval-shaped pupil in the direction of the long axis of the implant. This is not a significant advantage. 6. Best intraocular lens for secondary implantation—This is one of its most im­ portant advantages. However, it should not be considered a stimulus for a more liberal interpretation of the indication for secondary lens implantation. 7. Can be used with either an intra- or extracapsular cataract extraction—This is a significant advantage because it re­ quires the surgeon to change his method of cataract extraction. Disadvantages of the anterior chamber angle-supported lens include the follow­ ing: 1. Dimensions of the implant are critical—There are significant disadvan­ tages to a too-short or too-long implant. Therefore, dependence on accurate esti­ mation of the width of the anterior cham­ ber and the manufacturer's designation of the length of the implant is a disadvan­ tage. 2. Controversy over manufacture— This implant has created more controver­ sy over quality of manufacture than any other implant. The sharp edges of injec­ tion molded lenses in particular have re­ sulted in serious problems. 3. Sputtering hyphema—Ellingson 9 re­

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ported the association of uveitis, glauco­ ma, and hyphema. This has resulted in the removal of many of these lens im­ plants after successful surgery, which ap­ pears to be related to the quality of the manufactured product. This complication is rare with other types of intraocular lenses. 4. Placement is a blind procedure—It is impossible to visualize the structures of the anterior chamber angle where the ends of the haptics are intended to insert. 5. Eyes are tender—This complication tends to diminish with time but it may be annoying to some patients. This does not occur with other intraocular lenses. 6. Late uveitis—This is usually not dif­ ficult to manage and it also occurs with other intraocular lenses. 7. Few long-term results—With the ex­ ception of Choyce, there have been few long-term clinical studies of anterior chamber angle-supported lenses. I R I S OR IRIS AND C A P S U L E SUPPORTED LENSES

Epstein was the first to use an irissupported lens. There are now many iris or iris and capsule supported intraocular lenses. Among these are the Binkhorst iris clip, Binkhorst iridocapsular, Worst Me­ dallion, Worst vertical clip, FyodorovBinkhorst, Fyodorov Sputnik, and Copeland-Epstein. Advantages of the iris or iris and cap­ sule supported lens include the follow­ ing: 1. Angle structures are spared—The ends of the haptics are separated by a comfortable distance from the anterior chamber angle structures. 2. Widely separated from the cornea— There is less danger of corneal touch than with an anterior chamber angle-sup­ ported lens but much greater than with a posterior chamber lens. 3. Consistency of manufactured prod­ uct—Small changes in model design by

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different manufacturers seem to have little influence on the safety of this type of lens. 4. Long history of good ocular tol­ erance—This lens has probably had the greatest number of observed series of any type of lens implant. The long-range tolerance seems to be satisfactory at this time. 5. No ocular tenderness—There is no tenderness of the eyeball on palpation. 6. May be used with an intra- or extracapsular cataract extraction—This advan­ tage is shared with the anterior chamber angle-supported lens. Disadvantages of the iris or iris and capsule supported lens include the fol­ lowing: 1. Iris fixation required—With the ex­ ception of the Copeland lens and possibly the Fyodorov-Binkhorst lens, this type of lens must have some form of fixation to the iris when used with an intracapsular cataract extraction. This makes the sur­ gery more complex. 2. Capsule fixation required—Most of the lenses in this group that are used with an extracapsular cataract extraction re­ quire some form of capsule fixation. This is not always achieved. 3. Dislocations more frequent—These lens implants have the highest frequency of dislocations of any type of implant. Iris or capsule fixation does not ensure against a dislocation. One or more haptic ele­ ments of the implant may dislocate. Con­ tact with the cornea is not infrequent. Those implants in this group that are not fixated with a suture present the addition­ al risk of dislocation into the vitreous. 4. The easier to insert lens implants cause more complications—The Copeland and Fyodorov-Binkhorst implants that are not sutured to the iris often cause more complications. The more sophisti­ cated implants in this group are more difficult to insert but are associated with less postoperative complications. 5. Pseudophakodonesis—These lenses

NOVEMBER, 1979

cause the greatest amount of pseudophak­ odonesis. They are supported by the iris, which is a movable part of the eye and therefore their additional weight increas­ es this motion. 6. Square pupil—This is an unimpor­ tant cosmetic blemish that is usually not obvious. 7. Difficulty in dilating the pupil—Iris synechiae to the implant often prevent adequate dilation for ophthalmoscopic examination. DISCUSSION

Each lens style and each technique for their implantation has its advocates; how­ ever, there may be little difference in the results with each when done by the same surgeon. Of importance is the re-emergence of the extracapsular cataract extraction. This is primarily the result of the clinical research of Binkhorst as well as the introduction of phacoemulsification by Kelman in 1967. The operation varies between the classic technique of Binkhorst and the highly sophisticated technique of Kelman. Many surgeons in the United States perform a planned ex­ tracapsular cataract extraction in which the lens nucleus is expressed and the remaining cortical material is removed by a variety of methods which extend from the most primitive to the most sophisti­ cated. The extracapsular method has gained favor because of certain alleged advantag­ es over the intracapsular technique. The following advantages are those most fre­ quently cited: 1. Retention of an avascular membrane between the vitreous and the anterior chamber; this presumably lowers the in­ cidence of retinal tears. 2. There is less likelihood of a redetachment in patients who have had previ­ ous retinal detachment surgery who re­ quire cataract extraction. Presumably the posterior capsule (even

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INTRAOCULAR IMPLANT LENS SURGERY

with a capsulotomy) keeps the vitreous from bulging forward, thus lessening vit­ reous shock. No valid statistics are availa­ ble to support this premise currently, but it appears to warrant further investiga­ tion. 3. Greatly reduced endophthalmodonesis. 4. Preservation of a barrier between the aqueous and vitreous and the protection of the retina from the possible toxic con­ stituents of the aqueous. Two advantages have been cited as a protection of the retina against the devel­ opment of cystoid macular edema. Endophthalmodonesis refers to the rel­ ative mobility of certain intraocular struc­ tures such as the iris or an intraocular lens compared to immobile structures such as the cornea and sclera. The greatest degree of endophthalmodonesis occurs with an iris-supported intraocular lens in con­ junction with an intracapsular cataract extraction. An anterior chamber anglesupported lens with an intracapsular cata­ ract extraction is associated with much less endophthalmodonesis. A difference in the incidence of cystoid macular edema between an iris-supported and an angle-supported lens implant has not yet been shown. As to a barrier protecting the retina from toxic constituents of the aqueous, these constituents have not yet been posi­ tively identified and it is not known whether the intact posterior capsule and surrounding zonular apparatus are imper­ meable to them. 5. Operative loss of vitreous is likely. This is an advantage that may be valid but it will not be realized until the surgeon becomes fully familiar with the technique of the extracapsular cataract extraction. 6. Preservation of membrane anterior to the vitreous in the event a secondary lens implant is indicated. If a routine cataract extraction is performed in antici­ pation of postoperative contact lens wear, and if the management of the contact lens

825

proves unsuccessful, then a secondary implant is much less hazardous. This is an advantage that should appeal to many cataract surgeons. 7. In corneal dystrophy, the endothelium may be protected from vitreous touch by preservation of the posterior capsule. This is undoubtedly true but this be­ comes less of an advantage when one considers that an extracapsular cataract extraction probably causes more endothelial cell loss than an intracapsular cataract extraction, according to most studies. 8. Aphakic penetrating keratoplasty is safer and technically easier with an intact posterior capsule. Most corneal surgeons would consider this an advantage. I have had extensive experience with different lens implant styles and different methods of cataract extraction. As a result of close patient follow-up and carefully kept records a comparison of these styles and techniques is possible. This includes the following series: 1. Intracapsular cataract extraction with a Binkhorst four-loop implant— 1,000 consecutive cases. 2. Extracapsular cataract extraction with a Binkhorst two-loop of four-loop implant—200 consecutive cases. 3. Extracapsular cataract extraction with a Shearing posterior chamber im­ plant—200 consecutive cases. 4. A prospective cystoid macular ede­ ma study comparing the incidence of angiographic-proven edema in some of the patients in Series 1 and 2 and in patients undergoing a routine intracapsu­ lar cataract extraction with a lens implant. 5. A comparison of 500 consecutive extracapsular cataract extractions with a Binkhorst lens implant performed by C. D. Binkhorst and 500 intracapsular cataract extractions with a Binkhorst lens implant performed by me. Both Binkhorst series began in Novem­ ber 1973 and the Shearing series began in March 1978. The follow-up was much greater for both Binkhorst series (six to 64

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TABLE 1 VISUAL ACUITY R E S U L T S *

Visual Acuity

ICCE Lens Binkhorst Implant (1,000 Cases)

E C C E Lens Binkhorst Implant (200 Cases)

E C C E Lens Shearing Implant (200 Cases)

88.0% 4.6% 5.8% 1.6% 6-64

89.5% 4.5% 4.5% 1.5% 6-64

90.5% 4.0% 3.0% 1.0% 3-12

(6/4.5 (20/15) - 6/12 (20/40) 6/15 (20/50) - 6/21 (20/70) 6/24 (20/80) - 6/120 (20/400) 6/120 (20/400) Follow-up (mos.)

*ICCE designates intracapsular cataract extraction; E C C E , extracapsular cataract extraction.

months) than for the Shearing series (three to 12 months). The visual acuity results are shown in Table 1. The percent­ age of cases achieving a final visual acuity of 6/12 (20/40) or better was strikingly similar in all three series. The reasons for failure to achieve visual acuity of 6/12 (20/40) are shown in Table 2. The four most commonly cited causes are con­ sidered: cystoid macular edema, retinal detachment, corneal edema, and senile macular degeneration. The two Binkhorst series with long follow-up show that there is a higher incidence of cystoid macular edema with an intracapsular cat­ aract extraction and a higher incidence of corneal edema with an extracapsular cata­ ract extraction. The rate of retinal detach­ ment is similar in both methods of cata­ ract extraction. Presumably the low rate

of retinal detachment in these series is directly related to case selection for lens implant surgery; that is, eyes with moder­ ate to severe myopia and young patients were not accepted for lens implant sur­ gery in these series. The conclusions that are apparent from these series are that, given a capable and experienced surgeon, the visual acuity results are similar to currently available lens implant styles and both intracapsular and extracapsular methods of cataract extraction. Addition­ ally, there is a higher rate of cystoid macular edema with an intracapsular cat­ aract extraction and a higher rate of corne­ al edema with an extracapsular cataract extraction. The details of the cystoid macular edema study have been reported else­ where. 1 0 The results of this study are

TABLE 2 C A U S E S VISUAL ACUITY L E S S T H A N 6/12

Condition Cystoid macular edema Retinal detachment Corneal edema Senile macular degeneration

(20/40)*

ICCE Lens Binkhorst Implant

E C C E Lens Binkhorst Implant

E C C E Lens Shearing Implant

3.1% 0.9% 0.5%

1.5% 0.5% 2.5%

1.0% 0.5% 1.0%

4.7%

4.0%

3.0%

*ICCE designates intracapsular cataract extraction; E C C E , extracapsular cataract extraction.

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INTRAOCULAR IMPLANT LENS SURGERY

TABLE 3 INCIDENCE OF ANGIOGRAPHIC-PROVEN CYSTOID MACULAR EDEMA*

4 Mos ICCE, Implant ECCE, Implant ICCE, No Implant

8 Mos

14/114 24/140 (17%) (12%) 4/48 3/51 (8%) (6%) 16/113 13/87 (14%) (15%) Total Angiograms 812

16-24 Mos 18/117 (15%) 2/48 (4%) 8/94 (9%)

*ICCE designates intracapsular cataract extrac­ tion; ECCE, extracapsular cataract extraction.

shown in Table 3. Intracapsular cataract extractions with a Binkhorst four-loop implant and intracapsular cataract extrac­ tions without an implant show compara­ ble rates of angiographic-proven cystoid macular edema during the three postoper­ ative time periods studied (four months, eight months, and 16 to 24 months). Extracapsular cataract extractions with a Binkhorst implant showed a lower incidence of cystoid macular edema than both of these groups during all three time periods. The difference was most significant at 16 to 24 months postoperatively. Binkhorst 11 justified his changing from an intracapsular to an extracapsular cata­ ract extraction by comparing a series of 500 consecutive extracapsular implant cases with an earlier series of 505 consec­ utive intracapsular implant cases. The latter showed a much higher rate of cys­ toid macular edema, corneal edema, and dislocations. The validity of this compari­ son is questionable because the Binkhorst four-loop implant underwent many modi­ fications in design because of corneal edema and dislocation. I analyzed my first consecutive intracapsular cases with a Binkhorst four-loop implant and com­ pared them with Binkhorst's extracapsu­ lar series. Of Binkhorst's patients, 360 were over 60 years old and all 500 of my patients were over 60 years old. The

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average age of patients older than age 60 years was 75 years for my series and 71 years for Binkhorst's series. However, Binkhorst's patients had a longer followu p (80% followed u p for nine to 59 months and 20% followed u p for more than 59 months) than my patients (100% followed u p for eight to 55 months). Eighty-seven percent of my patients and 80% of Binkhorst's patients achieved vis­ ual acuity of 6/12 (20/40) or better. Of those patients who failed to achieve 6/12 (20/40) or better visual acuity, there was a higher rate of cystoid macular edema in my series (2.8%) than in Binkhorst's (1.2%). However, the incidence of corneal ede­ ma was higher in Binkhorst's series (1.6%) than in mine (0.6%). The rate of retinal detachment was 1.0% in Bink­ horst's series and 0.6% in my series. A comparison of these two series does not justify the conclusion that the extracapsu­ lar cataract extraction with an implant gives superior results than an intra­ capsular cataract extraction with an im­ plant. The changing scene of intraocular lens implant surgery has witnessed numerous innovations in lens implant design and methods of cataract extraction. A modern attitude toward this technologic explo­ sion insists more than ever on conven­ tional points of view regarding patients' needs. The surgeon must assess the visual needs of his patients and not yield to pressure disseminated by the media, de­ mands of the patient or the temptation of economic reward. The need for the "art of medicine" has never been greater. Intraocular lens implant surgery carries a greater risk of complications than a routine cataract extraction. In the hands of a skilled, experienced surgeon, the risk is only slightly greater according to pres­ ent knowledge. 1 2 It can be much greater during the early experience of the surgeon or with those less surgically talented. The surgeon, therefore, is faced with a person-

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al assessment of his own capabilities. Another moral judgment faces the sur­ geon: even if he can achieve a successful surgical result in a high percentage of his cases, is he justified in performing this procedure in relatively young persons? There are as yet no well-documented clin­ ical studies spanning more than 20 years of follow-up observations with intraocu­ lar lenses. These issues are receiving the attention of national ophthalmologic organizations as well as the House Commerce Commit­ tee. Investigations of unnecessary opera­ tions are attractive to the mass media and often result in erroneous interpretation of the physicians' motives. Faced with the excitement of today's technologic advanc­ es, the ophthalmologist would do well to adopt a modern attitude based on oldfashioned values. SUMMARY

A review of lens implant surgery using different implant styles and both methods of cataract extraction revealed that there is little difference in the final visual acuity regardless of which implant or cataract technique is used. There appears to be a higher rate of cystoid macular edema with the intracapsular technique and a higher rate of corneal edema with the extracapsular technique. A modern attitude toward this techno­ logic explosion insists more than ever on

NOVEMBER, 1979

conventional points of view regarding patients' needs. ACKNOWLEDGMENTS

J. L. Pearce, M.D., provided the photographs for Figures 1 and 2; D. P. Choyce, M.D., provided the photograph for Figure 6; and C. D. Kelman, M.D., provided the photograph for Figure 7.

REFERENCES 1. Jaffe, N. S.: Cataract surgery. A modern atti­ tude toward a technologic explosion. N. Engl. J. Med. 299:235, 1978. 2. Blodi, F. C : A surgical storm. Arch. Oph­ thalmol. 96:427, 1978. 3. Roper-Hall, M. J.: The history of intraocular lenses. Symposium. Intraocular lenses. Trans. Am. Acad. Ophthalmol. Otolaryngol. 81:67, 1976. 4. Shoch, D.: The intraocular lens. Miracle or menace? Sight Sav. Rev. 46:51, 1976. 5. Pearce, J. L.: Sixteen months' experience with 140 posterior chamber intraocular lens implants. Br. J. Ophthalmol. 61:310, 1977. 6. Shearing, S. P.: A practical posterior chamber lens. Contact and IOL Lens Med. J. 4:114, 1978. 7. Choyce, D. P.: The evolution of the anterior chamber implant up to, and including, the Choyce Mark IX. Ophthalmology. 86:197, 1979. 8. Moses, L.: Kelman anterior chamber lens a preliminary report. Am. IOL Implant Soc. J. 4:54, 1978. 9. Ellingson, F. T.: The uveitis-glaucomahyphema syndrome associated with the Mark VIII anterior chamber lens implant. Am. IOL Implant Soc. J. 4:50, 1978. 10. The Miami Study Group: Cystoid macular edema in aphakic and pseudophakic eyes. Am. J. Ophthalmol. 88:45, 1979. 11. Binkhorst, C. D.: Five hundred planned extracapsular extractions with irido-capsular and iris clip lens. Ophthalmol. Surg. 8:37, 1977. 12. jaffe, N. S., Eichenbaum, D. M., Clayman, H. M., and Light, D. S.: A comparison of 500 Bink­ horst implants with 500 routine intracapsular cata­ ract extractions. Am. J. Ophthalmol. 85:24, 1978.

The changing scene of intraocular implant lens surgery.

AMERICAN JOURNAL OF OPHTHALMOLOGY VOLUME 88 NUMBER 5 NOVEMBER, 1979 T H E CHANGING SCENE O F INTRAOCULAR IMPLANT L E N S SURGERY T H E 31ST BEDELL...
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