The Evolution of the Intraocular Lens - Cataract Surgery, 3rd Edition

Cataract Surgery, 3rd Edition

PART VI – Intraocular Lenses

Chapter 35 – The Evolution of the Intraocular Lens

Kenneth J. Hoffer, MD, FACS

Contents

	•	Prehistory
	•	Ridley Era
	•	Strampelli Era
	•	Choyce Era
	•	Binkhorst Era
	•	The Revolution: 1970s
	•	The 1980s Anterior Chamber Lens Disaster
	•	Phakic Intraocular Lenses to Correct Ametropia
	•	Small Incision Era
	•	Viscosurgical Agents
	•	Device and Material Developments
	•	YAG Laser and Lens Design
	•	Multifocal Intraocular Lenses
	•	Lens Implant Societies
	•	First Intraocular Lens Power Calculations
	•	Conclusion

CHAPTER HIGHLIGHTS

	≫	Personal view of the key developments in intraocular lenses (IOLs)
	≫	The role of Casanova in IOLs
	≫	Sir Harold Ridley and the RAF pilot
	≫	The Giants

In a short book chapter, it is impossible to cover every aspect and personality in the history of the intraocular lens (IOL). Therefore, this synopsis is limited by the historical materials at my disposal and my personal recollections.

Prehistory

The history of implanting a lens in the human eye to eliminate the “first complication of cataract surgery” – aphakia – dates back to Casanova^[1–3] (1725–1798). In his memoirs he related that in 1764 the Italian oculist Tadini had mentioned to him the idea of implanting a lens after cataract surgery. Casanova passed the idea to Casaamata^[2] of Dresden in 1795, and he attempted to introduce a glass lens into the eye after removing a cataract and watched it immediately slide back toward the fundus. Choyce^[4] stated that in 1939, John Foster of Leeds, England, made a jocular reference to the possibility of artificial lens implantation in an after-dinner speech at the Leeds Medical Society. Strampelli^[5] told of the unpublished fruitless attempts of Marchi to fixate quartz lenses with platinum wires in the anterior chambers of animals in 1940.

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Ridley era

In the autumn of 1948, a medical student was observing Harold Ridley extract a cataract at St. Thomas's Hospital in London. The student asked him why he was not going to replace the lens he had just removed. This simple question was the direct stimulus for Ridley to consider implanting an IOL. Ridley was born in Leicestershire, the eldest son of a Navy eye surgeon, and attended Cambridge. He was the head of his surgical division and a well-respected eye surgeon of his time. Fortunately, in August of 1999 (before his death on May 25, 2001), I had the opportunity to visit him and his charming wife Elizabeth at their home (Figure 35-1). I asked him if this story of the medical student was apocryphal, he said that it was absolutely true. In addition, he told me that the medical student was a woman. As it turns out, that was not the case and the student's name was Stephen Perry. Sir Ridley told me that he had asked John Pike of Rayners (Rayner & Keeler, Choleywood, England) to fashion a lens of polymethylmethacrylate (PMMA [from International Chemical Industries]) because he had noted no ill effects from stationary particles of PMMA in the eyes of Royal Air Force pilots (especially Gordon Cleaver, a Battle of Britain pilot) who had sustained injuries from shattered Spitfire canopies during World War II. The lens (Figure 35-2B) that they made was shaped like the human lens with a diameter of 8.35mm weighing 112mg, and it was sterilized using 1% cetrimide solution.



Figure 35-1 Sir Harold and Lady Elizabeth Ridley with the author at their home near Salisbury, England, on August 30, 1999. (Photo by Marcia Hoffer.)



Figure 35-2 A, Sir Harold Ridley. B, Original Ridley posterior chamber lens implant circa 1949.

History was made on November 29, 1949, when Ridley implanted the first lens in a 42-year-old woman after an extracapsular cataract extraction. The surgery went well, but unfortunately, lens-power calculation became of utmost importance when her postoperative refractive error was −18.00 to 6.00 × 120° (a −21.0diopter [D] overcorrection). I had assumed that Sir Harold (see Figure 35-2A) had removed the lens and replaced it with a proper power, but he told me that he was not able to do anything to correct the situation, and that a second lens was implanted 9 months later with the same result. Needless to say, the method of predicting the correct IOL power was changed. After Ridley's first public report at Oxford in 1951, many others followed his example, such as Arruga, Barraquer, Epstein, and Pafique, as well as Warren Reese of Philadelphia (the first American to implant an IOL, on St. Patrick's Day in 1952). The first paper published on IOLs was by Ridley in 1951.^[6–][7] The major complications were severe hyphema, downward decentration, iris atrophy, glaucoma, and anterior and posterior (6%) dislocation and inflammation. The cetrimide molecule was found to cling to the IOL and later to be released, which caused inflammation. In 1956, Cornelius Binkhorst^[8] of Terneuzen, Holland, suggested sterilizing the IOLs using ultraviolet (UV) (253.7 nm) radiation, which was used by some surgeons (Cox-Uphoff) in America in the 1970s. In 1958, Strampelli placed IOLs into the patient's earlobes for 3–4 months to humanize them before implanting them into the eye. Precipitates on the implants did not occur. In 1957, Frederick Ridley^[9] of England (no relation) introduced the sodium hydroxide sterilization method (Figure 35-3A) (soak in 10% NaOH for 1h at 30°C, store in 0.1% NaOH, neutralize on use with 0.5% NaHCO₃, rinse with saline). This method was embraced and used universally until 1978 when the U.S. Food and Drug Administration (FDA) mandated ethylene oxide sterilization, which had been introduced by American manufacturers.



Figure 35-3 A, Sodium hydroxide/bicarbonate sterilization method. B, An eye with a Ridley posterior chamber IOL (implanted by Sir Harold Ridley in 1951) with uncorrected 20/20 vision in 1979. (Photo by Kenneth J. Hoffer, in 1979.)

Overall, Ridley implanted about a thousand of these lenses. I had the opportunity to examine one of his patients (see Figure 35-3B) in Santa Monica in 1979. The 85-year-old woman had received the implant in 1951 (at age 57) and had an uncorrected visual acuity of 20/20 with a perfectly placed lens for over one-quarter of a century. Although these lenses weren't all bad, because of complications 15% of the Ridley designs were removed, and the implant was beginning to lose favor with those who were using it. Because of this, the pioneers looked for a better place to put Ridley's invention.

For a thorough description of the life of this incredible pioneer, see the book on Ridley's life by David Apple, MD.

Strampelli era

The next site considered for IOL placement was the anterior chamber; the aim being to prevent posterior dislocation and to enable its use in intracapsular and extracapsular surgery. The first to carry out this technique was Baron^[10] of France on May 13, 1952. He designed a huge convexo-concave piece of plastic (Figure 35-4A) that was 1mm thick centrally and rested in (filled) the angle. It came into contact with the corneal endothelium and had the expected results. He, therefore, changed the design to one of plano-convex (Figure 35-4B), but to no avail. Scharf^[11] of Germany was next with his quadripodal design, which he first implanted on September 26, 1953. Then 2 days later, Strampelli^[12] of Rome implanted the first of his designs (Figure 35-5), which looked like an Iolab Azar lens (B&L, San Dimas, Calif.) but was of solid plastic. Because of his early success and Choyce's later modifications of his original design, Strampelli has been credited with originating the anterior chamber IOL. Many got into the act after this; Schrek and Bietti, and even Sir Harold with his own tripod design. It was Dannheim^[13] of Germany who came up with the idea of a closed-loop haptic (Figure 35-6) using elastic-supporting loops made of supramide (similar to the Leiske lens [Surgidev] of the late 1970s and 1980s). Over 650 of these IOLs were implanted. Lieb and Guerry followed with a lens using three closed loops. Barraquer^[14] of Barcelona removed half of each loop (Figure 35-7) of the Dannheim lens (giving it an S shape), creating the first open-loop lens, which was later used by Shearing of Las Vegas to create the first flexible-loop, posterior-chamber lens in the late 1970s. However, we're jumping ahead. The primary result of all these early forays into the anterior chamber was bullous keratopathy, dissolving of supramide loops, and chronic inflammation, but the lenses did not dislocate into the vitreous.



Figure 35-4 A, Original Baron anterior chamber lens, the very first anterior chamber lens. B, Baron plano-convex anterior chamber lens design.



Figure 35-5 A, Original Strampelli tripod anterior chamber lens design. B, Phakic eye containing an original Strampelli anterior chamber lens.



Figure 35-6 Original Dannheim closed-loop anterior chamber lens design.



Figure 35-7 Original Barraquer open-loop anterior chamber lens design.

Choyce era

Peter Choyce (Figure 35-8) (died August 8, 2001), who assisted Sir Harold in London, took up the Strampelli concept and implanted his first Choyce Mark I anterior-chamber lens (Rayner) in 1956 (Figure 35-9A). The Mark II–VIII (Figure 35-9B) (including the final Mark IX) (Figure 35-9C) designs modified the optic curvature and the form of the haptic feet and tips. He perfected the Strampelli design such that it became the very first IOL (Coburn Optical, Ind.) to receive FDA approval in the United States, for which he was justifiably proud. Jerrold Tennant of Dallas, Texas, patented the Choyce Mark VIII design in the United States and helped popularize the lens in America as an alternative to the American-made metal-looped prepupillary lenses (Figure 35-10), which were causing so many problems for intracapsular surgeons. Choyce never benefited financially from the success of his IOL designs and I believe resented the fact that others benefited financially from his design (Tennant). In the early 1980s, Charles Kelman took the Choyce design a step further to the Multiflex designs we use today.



Figure 35-8 Mr. Peter Choyce, MD.



Figure 35-9 A, Choyce Mark I tripod anterior chamber lens design. B, Choyce Mark VIII quadripod anterior chamber lens design. C, Final Choyce Mark IX anterior chamber lens design.



Figure 35-10 First patient ever to receive an American-made (McGhan) metal-loop intracapsular iris clip lens design by Dennis Shepard in 1976. The eye ultimately became blind after several years.

Edward Epstein (Figure 35-11A) of Johannesburg, South Africa, had fairly good success with the original Ridley implant, but because of dislocations, he changed the design to fixate the lens using the pupil. He called this the Collar-Stud lens (see Figure 35-11B) and implanted the first one in June 1953. After noting pigmentary glaucoma in a high percentage of the 40 eyes he had given implants, he switched to some anterior-chamber designs and then developed the Maltese-Cross lens (see Figure 35-11C). This lens had four plates (blades) extending from the optic. The anterior two were fenestrated, and the posterior two were solid. The pupil was woven around the plates such that the lens was held in the pupil. In America, at the instigation of Richard Troutman and Cornelius Binkhorst's brother Richard, the same design with four solid plates was produced by an optician named Michael Copeland, becoming known as the Copeland–Binkhorst lens. This lens was used prominently by many American surgeons such as Jaffe, Galin, Osher, and Hamdi. Epstein was never given credit for his design by his American copiers.



Figure 35-11 A, Dr. Edward Epstein. B, Epstein Collar-Stud pupil-fixated lens design. C, Epstein Maltese-Cross pupil-fixated lens design.

Binkhorst era

Things were not looking good for lens implants in the late 1950s and 1960s, and many of the pioneers were abandoning their designs. The bad results led prominent ophthalmologists, especially in America, to deride and ridicule the entire concept. Statements such as “implanting such a foreign body is malpractice,” “recklessness,” “viciousness” (Derrick Vail, publicly to Ridley on the podium at the American Academy of Ophthalmology (AAO) after Ridley gave his invited lecture [Vail's remarks are published in the Transactions of the American Academy of Ophthalmology and Otolaryngology, January/February 1953]) and “intraocular time bomb” (Richard Troutman) caused many potentially interested surgeons to be wary of joining this merry band. Sir Stewart Duke-Elder of London hated Ridley for what he had done, and he and Vail were very close friends. This public ridicule of his new idea caused Ridley a great deal of psychological pain, and led to his suffering from depression for some time.

It was the integrity, pioneering perseverance, and intellectual and surgical acumen of one man that kept this subject alive to herald in the modern era. Cornelius Binkhorst (Figure 35-12A), of Terneuzen, Holland, had learned about lens implantation from Sir Harold in London, and gradually came to believe that there had to be a better way. He came up with a totally different design that he thought would prevent corneal decompensation, as well as posterior dislocation. He designed the prepupillary iris clip lens (see Figure 35-12B) in 1957 and implanted the first one on August 11, 1958. They were manufactured by both Rayner and Kurt Morcher (Bad Cannstatt, Ebitzweg, Germany). He first presented this lens publicly in Middelburg on the Isle of Walcheren on October 3, 1958. The term “pseudophakia” to indicate the presence of an IOL was inaugurated by Binkhorst at Oxford in 1959. The 5 × 0.6mm biconvex lens had two pairs of flexible supramide wire loops. The posterior pair was drilled into the posterior surface of the optic and bent at right angles to extend peripherally. They were inserted through the pupil and came to lie against the posterior surface of the iris, but they did not touch the ciliary body. The distance, loop tip to loop tip, was 7mm, and they prevented the lens from moving forward. After being constricted, the pupil took the shape of a square with a diagonal length of 4mm. The anterior loops were parallel to the posterior, but 0.75mm anterior to them. They were mounted on the equator of the optic and were adjacent to the anterior surface of the iris a safe distance from the anterior chamber angle. The lens weighed 6mg, compared with the Ridley lens at 112mg.



Figure 35-12 A, Dr. Cornelius D. Binkhorst. B, Binkhorst Iris Clip pupil-fixated lens design (side view). C, Iris-clip lens (front view).

In 1963, Syvyateslav Fyodorov^[15] (Figure 35-13) of Archangel, Russia, changed the relationship of the anterior and posterior loops from parallel to perpendicular. This was subsequently known as the Binkhorst–Fyodorov lens and it became quite popular in America. He also published the first IOL power formula in 1967.



Figure 35-13 A, Dr. Syvataslav Fyodorov as a young surgeon in Archangel, Russia. B, Fyodorov-Zakharov pupil-fixated Sputnik lens design. C, Fyodorov in later life.

Few realize that in 1967 the biconvex lens shape for IOLs was changed by Binkhorst to a simple convexo-plano shape at the suggestion of his brother Richard (New York) for the purpose of decreasing obstruction of aqueous flow through the pupil, thus, increasing the accuracy of the IOL power calculation, and, theoretically, lessening spherical aberration. By the 1970s, this became the shape of all IOLs until the American manufacturer Coburn Optical (later Storz, now Bausch & Lomb) came out with their first PMMA biconvex lens designs in the late 1980s. Although there were really no accounts of optical aberrations with the convexo-plano design, Holladay championed the biconvex design for the company, based on theoretical grounds, and it was soon to become the shape of all IOLs by all manufacturers. Later, several reports (including one by Atchison^[16]) establishing that for PMMA lenses the convexo-plano was the best optically, and that biconvex was only superior in lenses made of silicone. Nothing changed however, the die had been cast. In 1968 Fyodorov,^[17] working with Zakharov, replaced the anterior loops with three equidistant small prongs (pintles) and changed the posterior loops from two to three. Because of its “antennae” appearance, it was called the Fyodorov Sputnik lens (see Figure 35-13B). With the increase of posts in the pupil from four to six, the pupil took on a rounder shape when constricted. The lens only weighed 0.9mg in aqueous and the design was quite successful for intracapsular and extracapsular implantation, but it was difficult to obtain them in America during the Cold War years. To meet the demand, American manufacturers copied it, but they used heavier metal posterior loops and pintles that, because of their weight, caused tearing of the iris sphincter, chronic cystoid macular edema (CME), and dislocation, and the lens fell in popularity.

Various other changes were made in the iris clip lens from 1961 to 1971, but what really created the IOL revolution in the early 1970s was the change made by Binkhorst^[18] to his iridocapsular design (Figure 35-14), and the change made by Jan Worst, his Dutch protégé, to his Medallion sutured lens (Figure 35-15A).



Figure 35-14 A, Eye containing a Binkhorst two-loop iridocapsular lens implant circa 1976. B, Binkhorst two-loop iridocapsular lens design.



Figure 35-15 A, Worst Medallion sutured pupil-fixated lens design. B, Worst Platina iridectomy clip pupil-fixated lens design.

Binkhorst originally designed the iridocapsular lens for use in children in 1965, but soon realized that it was the lens of choice for all eyes. The anterior loops of the iris clip lens were removed, and the posterior loops were changed to 0.15mm platinum–iridium wire because they were to be imbedded in iris and capsule tissue (he feared supramide could biodegrade over time like the Dannheim lenses.) This increased the lens weight to 15.1mg. He implanted the first style with supramide loops on September 16, 1965, and with metal loops on October 27, 1965. The two-loop lens became his lens of choice for all cataract cases by 1973. What is most interesting in the evolution of IOLs is that as a result of the 1974 American revolution in IOL surgery, Binkhorst advocated extracapsular surgery and the use of the two-loop lens. His successes were the basis for the rapid increase in interest in IOLs in America, but Americans ignored Binkhorst's advice and proceeded with intracapsular designs, such as the iris clip and Copeland lenses. Phacoemulsification was completely ignored by most IOL surgeons because the “incision had to be extended to get the lens in.”

Jan Worst, of Groningen, Holland, attempted to eliminate the anterior loops and replaced them with a flat, thin, superior plate extension of the optic with two holes to allow the lens to be sutured to the superior iris. It was called the Worst Medallion lens (Medical Workshop, Groningen, Holland) (see Figure 35-15A), and he implanted the first one on December 18, 1970. His success added to the enthusiasm and excitement in America in 1974. Worst made several other designs with iridectomy clipping devices^[19] (see Figure 35-15B) and recommended stainless-steel sutures for fixation. These ideas were not as popular in America.

So far this chapter has liberally relied on the first textbook on IOLs by Marcel Nordlohne^[20] (Figure 35-16) in 1975 for many of its historical facts and has subsequently relied on the excellent textbook on IOLs by David Apple.^[21]



Figure 35-16 The cover of the first intraocular lens textbook by Nordlohne (Junk Publishers) in 1975.

The revolution: 1970s

The 1970s was a decade of revolution and change in IOL surgery. It began with the use of lenses such as the Copeland, Binkhorst iris clip, Sputnik, iridocapsular, and Choyce Mark VIII, and it ended with the Simcoe and Shearing posterior chamber lenses.

Posterior chamber era

Through most of the 1970s, two camps of lens implanters developed: those performing intracapsular surgery and using their favorite IOL design (90%), and those (including myself) using phacoemulsification and implanting the iridocapsular lens (10%). In 1975, John Pearce^[22] (Figure 35-17A) of England took the lead back into the posterior chamber with his one-piece PMMA tripod lens (see Figure 35-17B). James Little of Oklahoma City and Eric Arnott of London followed suit with their design and later so did William Harris of Dallas in 1977. Things were rather quiet until 1977, when Shearing^[23] of Las Vegas advocated implanting a flexible-loop Barraquer anterior chamber lens into the posterior chamber and called it “ciliary body” (later ciliary sulcus) fixation. Several prominent phacoemulsification trainers in California, such as Richard Kratz and Robert Sinskey, began using the Shearing lens (Model 101, Iolab Corp.) (Figure 35-18A) and teaching it in their courses. The loops were stiff and in the shape of the letter J. Often the lens would become trapped in the pupil, so at the suggestion of Kratz (Iolab ignored Shearing's previous request to do this^[24]), the loops were angulated 10° anteriorly to keep the optic posterior to the pupil. This was the very first modification of this posterior-chamber IOL and was given the name Model 101K because Kratz refused to attach his name to it. What many will find surprising is that the next modification ever to be made to this posterior-chamber IOL was the addition of the Hoffer^[25] ridge to the optic, and for the same reason it was called the Model 101H (see Figure 35-29C).



Figure 35-17 A, Mr. John L. Pearce, MD. B, Original Pearce tripod posterior chamber lens design.



Figure 35-18 Shearing flexible-loop posterior chamber lens designs. A, Original Shearing stiff J loop. B, “Sinskey” soft J loop. C, Kratz-Johnson crimped J loop.



Figure 35-29 A, First mechanical drawing by Iolab of the Hoffer ridge lens. B, Graphic depiction of the increased pressure caused at the edge of the lens by the ridge. C, An eye with an Iolab ridge lens demonstrating the blockage of Elschnig pearls at the edge of the lens optic.

Through the early and mid-1980s, it became increasing evident that the posterior chamber lens should be implanted completely in the capsular bag to eliminate all contact with uveal tissue. The stiffness of the loops and the jagged “can-opener” capsulotomy made this technically difficult. In the same year as Shearing (1977) (or perhaps earlier), William Simcoe of Tulsa designed long sweeping loops (Figure 35-19A) that came off the lens optic at a very low angle rather than perpendicular, so that they were very flexible and could be “dialed” into the capsular bag. Simcoe and others later recommended shortening the loops so that they took on the shape of the letter C (see Figure 35-19B and C).



Figure 35-19 Simcoe flexible-loop posterior chamber lens designs. A, Original Simcoe wide C loop. B, Modified short C loop. C, One-piece PMMA C-loop lens.

Shearing had obtained a method patent for his design and, in attempting to protect his intellectual property, filed legal actions against all the manufacturers making a posterior-chamber lens that was not licensed. In their defense, these manufacturers relied on Simcoe's claim of having really been the first to implant a posterior-chamber lens when he cut off the posterior loops, snipped the anterior loops of an iris clip lens, and implanted them into the capsular bag, which he did before Shearing's patent. These court battles were notorious and contentious, and even led to an Academy meeting podium fistfight, as well as the exhumation of the body of a patient in whom Simcoe claimed to have inserted such an implant (the family was paid to exhume the body).^[24] The claimed lens was not found, but Simcoe states that the hospital records were in disarray and that it would be impossible to know which patients had received these initial lenses. Perhaps we will never know who was first.

All posterior-chamber lenses had loops of supramide and latter Prolene. In the mid-1980s, Wayne Callahan⁎ used computer lathes (Cilco, Huntington, WVa; now Alcon Surgical, Ft. Worth, Tex.) to fashion the first all-PMMA one-piece, posterior-chamber lenses. Early models were stiff and thick, but as development proceeded, they became thin and flexible. The Jaffe, Arnott,^[26] and Bechert designs (with Hoffer ridges) became popular throughout the 1980s (Figure 35-20).



Figure 35-20 A, Jaffe short, encircling loop, all-PMMA one-piece lens with Hoffer ridge. B, Arnott large, encircling loop, all-PMMA one-piece lens. C, Bechert all-PMMA one-piece 7mm lens design with Hoffer ridge.

In 1980, Kratz asked Iolab to make a crimp in the J loop (to decrease its stiffness), but refused to allow his name to be used on the lens model, so Iolab called it the Sinskey lens^[24](see Figure 35-18B). Later, other manufacturers copied this “soft-J” design, and they were called the Kratz and Kratz–Johnson lenses (see Figure 35-18C). Other posterior-chamber designs, such as the Anis lens (Figure 35-21A) and the Galand disc lens (Figure 35-21B) were defining the future direction of lens design until the foldable lenses caused their demise.



Figure 35-21 Later “Ridleyesque” posterior chamber lens designs.A, Anis large closed-circle lens. B, Galland disc lens design.

The 1980s anterior chamber lens disaster

The use of anterior chamber lenses continued throughout the 1980s and became extremely popular with intracapsular surgeons, especially when problems with American-manufactured iris-supported lenses (with metal loops [see Figure 35-10]) became an issue. Choyce slimmed down the Mark VIII to the Mark IX in 1978. American manufacturers copied the Mark VIII lens, and most were poorly made and poorly polished, leading to the Ellingson uveitis–glaucoma–hyphema syndrome.^[27] In 1977, Robert Azar of New Orleans came out first with a copy of the Strampelli lens with the letters of his last name embossed as molded projections on the surface of the optic, lest someone forget who designed it. He later (1982) changed the design to one with closed loops, called the Azar 91Z (Iolab) (Figure 35-22A), to compete with the Leiske closed-loop lens (Figure 35-22B), both of which became extremely popular in the United States.



Figure 35-22 The troublesome closed-loop anterior chamber lenses. A, Azar 91Z lens (1982). B, Leiske lens (1978). C, Hessberg lens (1981). D, Stableflex lens (1983). E, Shepard lens (1979). F, Dubroff lens (1981). G, Copeland anterior chamber lens (1982).

Other surgeons designed closed-loop designs (see Figure 35-22) fashioned after the original Dannheim lens. History was repeating itself by those unfamiliar with it or totally unwilling to learn its lessons. Lens designs such as the Leiske (1978, Surgidev), Shepard (1979), Hessberg (1981, Intermedics), Dubroff (1981), Optiflex (1981), Feaster (1982), Stableflex (1983, Optical Radiation Corp.), and the Copeland anterior-chamber lens (see Figures 35-22B–G) were being implanted in great numbers throughout the United States. Many of these lenses ultimately led to multiple complications and had to be removed, often during a corneal transplantation for bullous keratopathy. These designers were all committed to the concept that a one-size, anterior-chamber lens that could fit eyes of all sizes, which was to the detriment of many patients.

During this period, Charles Kelman^[28] of New York (Figure 35-23H), the inventor of phacoemulsification, refrained from implanting IOLs. He finally gave in and designed an anterior-chamber lens tripod (by “cutting the plastic out of it” [similar to the attempt by Boberg-Ans in 1961]). It was made of solid PMMA lathe-cut in the shape of a “pregnant 7,” with an optic of 4.5mm and special foot plates to impinge in the angle that he first implanted in 1978. The first to make this lens was Precision-Cosmet of Minnesota (Figure 35-23A). A slight modification was later made by Heyer-Schulte (Irvine, Calif. [later AMO]), and they improved it to the Omnifit in 1981 (see Figures 35-23B and C). Collaborating with Wayne Callahan at Cilco, Kelman designed the extremely flexible Quadriflex (1981) quadripodal design, which later was modified to the Multiflex I (1982) (see Figures 35-23D and E). Both had four-point angle fixation with the haptics coming off the same side of the lens optic. The former looked like a “pregnant E,” but the haptics of the Multiflex were unique in that their design allowed internal flexion in the same plane as the haptics without forward movement of the optic. This was the answer and is now the basis for all safe anterior-chamber lens implantation used today. When a high incidence of optic entrapment by the pupil was noted, Kelman directed that the haptics should exit the lens optic from opposite sides, and these became the S-flex and the Multiflex II (see Figure 35-23F). The most unique attribute of the Multiflex II was that Cilco originally made the lens in seven different sizes (see Figure 35-23G), from 11.5–14.5mm (in 0.5mm steps), so that any size of eye could be fitted safely without making the eye withstand the constant pressure of an oversized lens. This was never repeated by any other company. It has always been my theory that if this had been done with all the closed-loop anterior-chamber lenses, the disasters they caused might have been prevented. The “one-size-fits-all” anterior-chamber lens goal of the surgeons who experimented with it was the cause of untold loss of sight.



Figure 35-23 The successful Kelman all-PMMA anterior chamber lens designs. A, Original Precision-Cosmet “pregnant-7” tripod lens (1978). B, Heyer–Schulte tripod design. C, AMO Omnifit tripod lens. D, Cilco Quadriflex lens (1981). E, Cilco Multiflex I lens. F, Cilco Multiflex II lens (1982). G, Six (of seven) different sizes of the Cilco Multiflex II lens (note difference in design between the shortest and the longest). H, Charles D. Kelman, MD.

Kelman always strongly advocated precise horizontal corneal diameter measurement and intraoperative gonioscopy to ensure proper sizing during the procedure. This advice was ignored by most implanting surgeons to their peril. For intracapsular cataract extraction (ICCE), secondary and backup implantations, I switched from the Rayner Choyce Mark VIII to the Cilco Kelman Multiflex II in 1983 and (following Kelman's teachings) have not had to remove a personally implanted Multiflex II for any reason.

Phakic intraocular lenses to correct ametropia

Jan Worst designed his iris plane Lobster Claw lens for aphakia in 1976, which sat on the surface of the iris and was fixated by two haptic claws that imbricated the anterior stroma of the iris in the nondilating midperiphery portion. This lens was used extensively in Europe, India, and Pakistan for aphakia and today is being used in a different version as a phakic IOL for the correction of refractive errors (Artisan Lens, Ophtec, Fla.) This lens has received FDA approval for use in the US and is called the Verisys (AMO, Irvine, CA) (Figure 35-24A). Undeterred by the failures of Strampelli, Barraquer, and many other early pioneers who attempted to use anterior chamber lenses in phakic eyes, Georges Baikoff of Marseilles, France, modified the Multiflex II lens for the same purpose, beginning with the Domilens ZB lens (see Figure 35-24B). This was later changed to the B&L Nuvita lens (see Figure 35-24C) and ultimately the CIBA Vision Vivere lens, which has PMMA haptics but an acrylic foldable optic that is multifocal (see Figure 35-24D). All such ICLs have been removed from the market due to chronic ongoing endothelial cell loss. In the 1980s, Fyodorov and Zuev were working on phakic IOLs for the posterior chamber, starting with the Mushroom pupillary centering lens, which ultimately led to the Staar ICL (Collamer) (see Figure 35-25A), and the Medennium PRL (Silicone) (Figures 35-25B and C), which was developed by Dimitrii Dementiev, MD (see Figure 35-25D) of Milano, Italy. The Staar lens has received FDA approval, while the US studies of the PRL have been suspended.



Figure 35-24 Phakic lens implant designs. A, Eye containing the Ophtec Artisan Worst “lobster claw” iris-supported lens. B, Original Baikoff Domilens ZB anterior chamber lens. C, Baikoff B&L Nuvita anterior chamber lens. D, Latest Baikoff foldable-optic acrylic/PMMA CIBA Vision Vivere anterior chamber lens.



Figure 35-25 Phakic posterior chamber lens implant designs. A, Staar ICL. B, Medennium myopic (upper) and hyperopic (lower) PRL lenses. C, Eye containing myopic Medennium PRL. D, The author (Dr. Kenneth Hoffer) with Dr. Dimitrii D. Dementiev (designer of PRL) in Milano, Italy in 1997.

Small incision era

Phacoemulsifiers always disliked enlarging their small, 3.5mm incision to implant a 6–7mm solid PMMA optic IOL. What was needed was a lens optic that could be folded and enter the 3.5mm incision.

In the mid-1970s, Keiki Mehta^[29] (Figure 35-26) of Bombay, India, fabricated iris clip lenses using silicone for the optic with no intention of folding them. He told me what he was doing at that time and, 10 years later, how they had all turned yellow over time and that he had, therefore, abandoned their use. In the early 1980s, Edward Epstein started making posterior-chamber IOLs of silicone with the intention of folding them. However, once Thomas Mazzacco (Healdsburg, Calif.) (see Figure 35-26) began folding and implanting plate haptic silicone IOLs (Staar Surgical, Covina, Calif.) through a 3.5mm phaco incision, the world of lens implantation changed forever. From this point on, the popularity of phacoemulsification went from 40 to 95%. At first, they didn't ensure that the lenses were entirely in the capsular bag, and complications ensued. Around 1981, Calvin Fercho^[30] of Fargo, ND (see Figure 35-27A), invented the complete circular capsulorrhexis (later to be popularized by Thomas Neuhann [Munich, Germany] and Howard Gimble [Calgary, Canada] while Fercho was undergoing prostate cancer treatment) (see Figure 35-27B). It soon became apparent that the plate haptic silicone lens worked best if placed entirely in the capsular bag with an intact, round central capsulorrhexis of adequate size. The FDA only approved it with this stipulation.



Figure 35-26 The silicone pioneers. Left to right: Drs. Keiki Mehta, Kenneth Hoffer (the author), Edward Epstein, and Thomas Mazzacco.



Figure 35-27 Cataract surgery innovators. A, Dr. Calvin Fercho. B, Ocular Surgery News article (November 15, 1986) first to describe circular capsulotomy. C, Dr. Michael McFarland.

Viscosurgical agents

Endre Balazs^[31] began the research on using hyaluronic acid as a replacement for vitreous. Soon David Miller (Boston) and Roger Stegman (South Africa) began talking about its use for anterior segment surgery. Balazs presented his work at the 1979 AAO meeting in San Francisco. It just so happened that the AAO had asked me to be the discussant for that paper. After giving a presentation, in which the idea was cautiously lauded, I recommended that it be supplied in a preset syringe ready for use in all cataract surgery. I also warned of the potential for antigenicity and intraocular pressure rise. After sitting down, two gentlemen from Pharmacia (of Sweden) approached and asked if I would be interested in doing some research with their new product called Healon. When I agreed, I soon received vials of Healon and performed the first phacoemulsification/IOL viscosurgery in America in November 1979. I was soon using it for every cataract surgery I performed. After 6 months of excellent results (except for temporary rises in intraocular pressure), I warned the company that they had better be well prepared with a huge supply before they bring it to the market because I believed that it would become the standard in cataract surgery immediately. They did not follow my advice, and 6 months after its introduction, they were back-ordered on the product for almost 1 year. In that intervening period, many surgeons looked for ways to bring about the same result without the expense of Healon. Needless to say, everyone is aware of the profound effect Healon and subsequent viscosurgical agents have had on the safety and ease of lens implant surgery.

Device and material developments

Probably the most important development in cataract and lens implant surgery was the introduction of the Zeiss motorized zoom microscope in 1965, which allowed surgeons to see the red reflex while operating. The first motorized zoom, focus, and X–Y controls were introduced in 1970. This has had a great effect on the increasing use of extracapsular surgery.

Based on the experience of James Gills of Tarpon Springs, Florida, many surgeons abandoned the routine use of a peripheral iridectomy with posterior-chamber lenses during the 1980s. Michael McFarland (see Figure 35-27C) of Pinebluff, Arkansas, first proposed the concept of self-sealing sutureless incisions, and Howard Fine popularized making the incision in clear corneal surgery. In 1990, John Shepherd^[32] of Las Vegas invented the in-the-bag fracturing, hydration, and quartering of the nucleus for phacoemulsification, later popularized by Gimble and others. All these advances made the surgery simpler and safer, as well as shortening the recovery time for the eye dramatically.

One of the most interesting developments was the elimination of retrobulbar injections. R.M. Redmond^[33] of Belfast, Northern Ireland, had written a paper in April 1990 about performing extracapsular cataract surgery using local anesthesia without a retrobulbar injection (Figure 35-28A). After reading the paper, I invited him to present his experience at my IOL Course^[34] at the AAO Meeting in October 1991 (Figure 35-28B). Many prominent cataract surgeons were also lecturing at, or attending this course, and Redmond's presentation drew excited interest. Soon there followed many surgeons attempting topical anesthetics for IOL surgery, especially with clear corneal incisions. Redmond Smith of London had also eliminated retrobulbar injections since April of 1985. He also eliminated O'Brien lid akinesia in June 1987 and used a locking speculum to prevent the patient from blinking. Gills recommended intraocular xylocaine in addition to the topical anesthetic.



Figure 35-28 A, Article by Mr. R.M. Redmond, MD, on topical anesthesia in the British Journal of Ophthalmology in April 1990. B, Academy course where Redmond first presented topical anesthesia in America.

In 1979 Barasch and Poler^[35] tried making IOL optics out of glass. This was done by Lynell, Inc., and they used a new polymer, Elastimide, to fashion haptics to hold the glass optic. Because of the increased index of refraction of glass, the lenses were very thin. When the yttrium-aluminum-garnet (YAG) laser caused several of these lenses to crack inside the eye, the FDA recalled them. Staar Surgical used the Elastimide material for the haptics of their three-piece silicone posterior chamber lenses.

Acrylic lenses were the next logical offshoot from research into optical-quality materials that could be folded like silicone. The edge architecture of the original popular models caused persistent haloes (because of acrylic's higher index of refraction) in a sporadic but persistent number of extremely unhappy patients. After many years of ignoring the issue, Alcon finally made changes in the edge design in the newer acrylic lens styles, but there are still reports of this nagging phenomenon.

Yag laser and lens design

The challenging and sometimes complicated surgical posterior capsulotomy became outdated when Aron-Rosa^[36] of Paris, France, and Fankhauser^[37] of Switzerland independently introduced the YAG laser in the early 1980s. Aron-Rosa began clinical trials in October 1978 and did 5000 eyes over a period of 4 years. Fankhauser did his first YAG capsulotomy in November 1980. Soon reports of IOL damage from the laser began to appear. Contrary to common belief, the Hoffer laser ridge optic^[38] was designed in 1978 for two equally important purposes. The first was to increase the pressure at the edge of the optic to create an increased barrier to the migration of lens epithelial cells onto the posterior capsule (Figures 35-29B and C). The second was to create a space between the back surface of the IOL and the posterior capsule to prevent damage to the IOL during the performance of a posterior capsulotomy. Iolab made the first ridge lenses (Figure 35-29A), but they were soon followed by Cilco, CooperVision (Bellevue, Wash.) and then most other companies. The stimulus for its popularity was the increased use of the YAG laser, which was causing severe pitting in lens optics without the spacing. Other ideas for spacing ensued, such as a meniscus optic (William Myers, CooperVision), Prolene riders (Lawrence Castleman, MD, Ioptex, San Leandro, Calif.), and partial ridges (Kratz-Johnson, AMO). For the Hoffer ridge to block Elschnig pearl formation and prevent posterior capsule opacification (PCO), the haptics had to be angled anteriorly (to increase posterior pressure) and the lens had to be placed entirely in the capsular bag (uniform pressure on entire ridge). Because neither of these rules was adhered to during the lenses' popular period from 1983 to 1989, reports of the effects of the ridge on PCO were conflicting, although several studies showed a definite positive effect.^[39] No adverse effects of this lens modification have been reported after 18 years of use. After the disastrous recall of the Azar 91Z, Iolab claimed that it was the Hoffer ridge lenses that kept them afloat. As studies began to show that convex-surface-posterior lenses decreased PCO, and with the increased production of more-accurate lasers, most surgeons turned toward biconvex IOLs without the ridge in the 1990s. The Hoffer ridge optic was successfully made on biconvex PMMA IOLs (Coburn Optical) and with silicone (AMO), but never brought on the market. Today, many IOLs use a sharp edge design based on this barrier concept.

UV protection was also an issue strongly advocated by Diana Langley in the 1980s and soon it became a standard in IOL fabrication.

Multifocal intraocular lenses

In 1982, after seeing a patient referred with severely decentered Shearing lenses bilaterally (Figure 35-30B), I postulated a concept^[40] of multifocality for IOLs. The patient had 20/20 vision without correction but was also correctable to 20/20 with an aphakic spectacle correction. I concluded that the only way this could be possible would be if her brain were selecting the clearest image of the two being presented by the pseudophakic and aphakic zones of her pupil. I immediately attempted to patent the concept, but Jack Hartstein had applied for this with contact lens in 1975 (Figure 35-30A). I pressured Iolab into fabricating a 50/50 split bifocal IOL for research purposes. After they made five such lenses (see Figure 35-30C) for me in their research and development division, they lost interest in the idea while they turned their attention to research with partial-depth positioning holes. Frustrated, I was able to get Ioptex to clean, polish, verify the powers, and sterilize these lenses. With thorough informed consent, I implanted them in three patients, uniocularly. They worked, but I had to remove one because of annoying images. Three years later, I learned that John Pearce, working with Iolab, was implanting central bullet bifocal IOLs by Iolab in England. This was soon followed by the diffractive multifocal (3M) and the various other manufacturer designs, including the Array lens by Allergan (AMO). After Alcon purchased the 3M IOL division, they abandoned the multifocal because of the strict FDA testing asked of them. Allergan persisted, and they ultimately received FDA approval. All the other designs gradually faded away. Ironically, I do not implant multifocal IOLs.



Figure 35-30 A, Harstein bifocal intraocular lens patent application, December 8, 1975. B, Chart of patient with bilateral dislocated posterior chamber lenses, November 18, 1982. C, Original 1983 Hoffer split bifocal intraocular lens.

Today there a number of approved methods to provide multifocality including so-called “accommodating IOLs.” How this all shakes out will be known in the future.

Lens implant societies

It is impossible to relate the history of IOLs without touching on the societies that sprang up to deal with them. Choyce^[4] came up with the idea of setting up an organization for the study of lens implants in 1964. It took a couple of years for him to convince Ridley, but they did it in 1966 and held their first meeting as the Intraocular Implant Club (IIC) on Wednesday, July 14, 1966, in Oxford, England. Ridley was the first president, followed by Strampelli in 1970. It was the Paris meeting on Saturday, June 1, 1974, at the Meridien Hotel adjoining the Palais des Congres after the close of the Twenty-second International Congress of Ophthalmology, that saw the tremendous surge of interest in IOLs. Forty-four members and 88 nonmembers attended; most were from America. After the formation of the American society and other national implant societies, they changed the name to the International IIC (IIIC).

In March 1974, I conceived of the idea of an American society for lens implantation to bring together the disparate factions then present in the implant world here in the United States. I had not yet heard of the IIC. I wanted the society to hold educational meetings and publish a scientific journal because at that time there was no forum for presenting or publishing reports on the subject. I persuaded three colleagues to help me (Drs. John Darin, Jeremy Levenson, and Stephen Cooperman). Together we organized and incorporated the society as the American Intra-Ocular Implant Society (AIOIS) in August 1974, whose name was changed to the American Society of Cataract & Refractive Surgery (ASCRS) in 1983 (Figure 35-31). After 1 year, Dr. Cooperman went on to other things including a stint in jail for fraudulent art theft in the late 90s.



Figure 35-31 Past presidents of the American Society of Cataract & Refractive Surgery (ASCRS) (in chronological order of holding office). Bottom row: Kenneth J. Hoffer (1974–1975), Norman S. Jaffe (1975–1977), Robert C. Drews (1977–1979), Miles A. Galin (1979–1980), Henry M. Clayman (1980–1983), Manuc C. Kraff (1983–1985). Top row: Guy E. Knolle (1989–1991), Jack M. Dodick (1991–1993), John D. Hunkeler (1993–1995), Charles D. Kelman (1995–1997), David Karcher (Executive Vice President 1981–present), Spencer P. Thornton (1997–1999), Robert M. Sinsky (1999–2000).

When I visited Cornelius Binkhorst in Terneuzen, Holland, in November 1974, he was very kind to me, but expressed his great concern about this “American Implant Society” he had heard I had founded. I reassured him that we had no intention of overshadowing the IIC, of which he was then president.

I don't think he completely believed me, but he finally dropped the subject. Needless to say I was disconcerted because I never thought of the little society I had started as trying to take over for the IIC, but looking back on it now, he was right; it did. One year later, to quell his continued fears about AIOIS, I urged him to create a European Implant Lens Council, which would be an amalgamation of European national implant societies over which he could preside. As president, he ultimately did just that, and the European Council later became the European Society of Cataract & Refractive Surgery (ESCRS).

First intraocular lens power calculations

As proven by Sir Harold's first two cases, correct calculation of the IOL power is essential and a vital part of the history of IOLs. When I learned in 1974 that Jan Worst was using A-scan ultrasound axial length for IOL power calculation, Karl Ossoinig's (Figure 35-32A) (Iowa City) A-scan lectures^[41] (1972) were brought to mind prompting me to call him regarding the instrument to be used. Santa Monica Hospital agreed to purchase the recommended Kretz 7200-MA unit from Austria and a keratometer and to provide a facility where I could perform the tests. The new facility was called the “Eye Lab.”



Figure 35-32 A, Karl C. Ossoinig, MD, of Iowa City. B, The first intraocular lens power specific A-scan ultrasound unit in 1975 (Sonometrics DBR-100).

Before inserting my first IOL (Medallion ICCE) on April 22, 1974, I performed the first A-scan IOL power calculation in the Western Hemisphere.^[42] Dr. Ossoinig was on the telephone from Iowa talking me through the calibration of the Kretz unit and the measurement of the photographs. For his willingness to help me, I will be eternally grateful. It worked!

Before this time, American lens implanters used a standard 18.0-D prepupillary lens for all eyes, expecting the patient to be as myopic or hyperopic as he or she was before surgery. In the mid-1970s, Dennis Shepard (Santa Maria, Calif.) devised a nomogram based on the patient's preoperative refractive error. After the word spread about the Eye Lab, many other ophthalmologists sent their patients to the Eye Lab for IOL power calculation, including Dr. Henry Hirschman, who sent his patients by limousine to Santa Monica from Long Beach. After months of personally performing the exam myself, I finally decided to train a technician. The Eye Lab's photographer, Don Allen, was the closest at hand, and after 2 months he picked it up easily and became the first IOL power-calculation technician in America. Don died several years ago, and I honor him here.

Working with Lou Katz of Sonometrics, I designed the first A-scan ultrasound unit (see Figure 35-32B) specific for IOL power calculation (DBR-100).^[42] It ushered in the era of automatic measuring gates and the applanation technique, of which the latter turned out to be less accurate than the Ossoinig immersion technique but became and remains the standard to this day. In 1974, I programmed the Colenbrander and Hoffer IOL formulas on a Hewlitt-Packard programmable calculator. It took hundreds of presentations at the AAO and ASCRS meetings, as well as numbers of “9diopter surprises” to make A-scan the standard of care nationwide. The efforts of formula developers such as Tom Lloyd, Don Sanders, John Retzlaff, Manus Kraff, Thomas Olsen, Jack Holladay, and Wolfgang Haigis cannot be left unmentioned.

Conclusion

One thread runs clear through this history of IOLs. Since Jaques Daviel^[43] (Paris) performed the first intentional intracapsular cataract extraction on April 8, 1747, most, if not all, of the steps of innovation (and mistakes) leading to what we do today were devised and carried out by individual, private, practitioner, cataract surgeons throughout the world without university or government research funding. To all of them, we owe a debt of gratitude.

Ridley lived long enough (94 years) to have his invention implanted into his own eyes, realize the benefit to humanity he had provided, and be knighted by his Queen (Figure 35-33). For that we can all be grateful; what a unique and lucky man he was.



Figure 35-33 Queen Elizabeth II knighting Sir Harold Ridley in London, March 2000.

With the passing of four giants, Ridley, Choyce, Binkhorst, and Fyodorov, I dedicate this chapter to their memory. I am grateful for having known them.

References

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[19]. Platina, 1973.

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[24]. Shearing S.P.: The genesis of the posterior chamber lens. In: Kwitko M.L., Kelman C.D., ed. The history of modern cataract surgery, The Hague, Netherlands: Kuglen Publications; 1998:139-146.

[25]. Hoffer K.J.: Five Year's Experience with the ridged laser lens implant. In: Emery J.M., Jacobson A.C., ed. Current concepts in cataract surgery (eighth congress), New York: Appleton-Century Crofts; 1983:296-299.

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[28]. Kelman C.D.: Anterior chamber lens design concepts. In: Rosen E.S., Haining W.M., Arnott E.J., ed. Intraocular lens implantation, St Louis: Mosby; 1984:239-245.

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[39]. Westliing A.K., Calissendorff B.M.: Factors influencing the formation of posterior capsular opacities after extracapsular cataract extraction with posterior chamber lens implant. Acta Ophthalmol 1991; 69:315-320.

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