1.1 Introduction

No modern treatise on intraocular lenses (IOLs) would be complete without at least a brief discussion on the evolution of today’s numerous IOL implants, which can be tailored to the patient’s specific pathologies and refractive desires. Although the history of cataract extraction dates back thousands of years, serious discussions about IOLs date back less than 75 years. ¹

Cataracts are the most commonly diagnosed condition in the field of ophthalmology. Today, about half of the estimated 180 million people in the world who are visually disabled have cataracts. As Dr. Norman Jaffe stated in his History of Cataract Surgery, ² “No other surgical specialty has been so dominated by a single surgery as has ophthalmology by cataract extraction.”

Numerous clinical advances in cataract surgery were made in the twentieth century, culminating in routine IOL implantation for simultaneous correction of aphakia. In examining the evolution of cataract treatment, from couching to extracapsular and intracapsular extraction techniques, then phacoemulsification, the use of the IOL, and now femtosecond laser use for cataract surgery, one can appreciate much of the evolution of ophthalmology itself; at every stage, knowledge gained about the anatomy, physiology, and pathology of the eye was used to improve the treatment of cataracts. This evolution did not come easily, and in many instances, “improvements” in the procedure were adamantly criticized by the leading, conservative practitioners of the day. It took thousands of years for cataract extraction to become the procedure that is performed today, and all these changes required great efforts of many luminaries in ophthalmology, working much of the time against great adversity to change the course of our specialty. No victory was harder fought or better deserved than the fight over the IOL.

1.2 Early Concepts in Cataract Surgery

There is a record of surgical treatment of cataracts in AD 37 by Celsius, the method of choice was couching, which was eloquently described by the Sushruta Samhita, the first textbook of surgery in India, which possibly dates to 1000 BC ³ :

The doctor chooses a bright morning and sits on a bench at knee height. Opposite is the patient who, after washing and eating, sits tied to the ground. The doctor palpates the impurity in the eye, then the patient stares at his nose while an assistant holds his head firmly. The surgeon holds a lancet with the index finger, long finger, and thumb, then draws it towards the pupil’s edge, half a finger width from the back and one fourth finger width from the outer eye corner. Next he draws it upward. He cuts in the left eye with his right hand, and in the right with his left hand. If he has cut properly, a sound is heard, and a drop of water comes out.

These Suttiahs (Hindu for oculist, or early eye surgeon no italic for this) continued couching in India into the 20th century. The Suttiah trade was passed down from father to son, requiring no formal training to practice.

During medieval times, the practice of medicine was conducted by various differentiated groups, including physicians, surgeons, barbers-surgeons, and “the irregulars,” especially the oculists and “cataract couchers,” most of whom had actually acquired a great deal of acumen with regard to eye operations. In fact, the regular medical community was so reluctant to practice eye surgery, because of its uncertain, often horrendous, outcomes, that it was compelled to endorse the irregulars as reasonable alternatives for eye care.

Riviere, a professor of medicine at Montpellier, ⁴ stated in 1640 that cataract surgery “should be left to the itinerant quacksalvers who practice it.” The London’s Company of Barber-Surgeons, the City of Worms in Rhineland, and the City of Florence all granted contracts to oculists for the practice of couching. These oculists remained active throughout the 18th and 19th centuries, well past the time when extraction of cataracts became the standard of care.

1.3 A Battle over the Etiology of Cataracts

In Latin and the modern-day Spanish language, the term “cataract” translates to “waterfall.” It is sometimes challenging to explain to patients why their natural lens, a normal ocular structure they have had their entire lives, becomes a “cataract” once it opacifies and negatively impacts their vision. The misuse of this term becomes more understandable once the history of our understanding of cataracts is known. Galen (AD 129–ca 199) and his contemporaries believed that cataracts were the result of corrupted humor from the brain solidifying behind the lens. Guy de Chauliac (1300–1368), often cited as the most distinguished surgical figure of the Middle Ages and one of the rare physicians who did partake in the treatment of cataracts before the 18th century, stated that cataracts were “skin-like spots in front of the pupil that interfere with vision due to an extensive moisture, which gradually penetrates into the eye and, in consequence of cold, coagulates.” ⁵ The crystalline lens was long considered to be the essential organ of sight. Thus removal of the lens seemed absurd because it was deemed essential for vision, and the problem of cataracts was considered separate from this structure.

From 1650 to 1660, the idea that cataracts resulted from opacification of the lens itself rather than a structure in front of it began to be taught by Robert Cook, Françoise Quarre, Pierre Lasnier, and Werner Rolfink. These views were largely discounted for the remainder of the century. The French surgeon Antoine Maitre-Jan confirmed, but did not publish, that the lens itself was opacified based on couching operations performed in 1685 and dissections performed in 1692. ⁶ On November 17, 1705, Michael Pierre Brisseau, another French surgeon, presented his findings to the Academie Royale des Sciences in Paris, against the advice of his mentors, that cataracts resulted from the opacification of the lens itself (discovered during the dissection of a dead French soldier). He maintained his point, with support from Maitre-Jean and others, against staunch opposition, and the dispute eventually cost Brisseau his faculty position at the French Academy.

The evidence for the opacification of the lens as the cause of cataracts continued to mount, and Charles St. Ives became the first person on record to extract a cataract from a living eye following a botched couching procedure in 1707. Jean Louis Petit followed with a similar report in 1708. The academy was eventually convinced that the lens was the cause of the cataracts.

1.4 First Extracapsular Cataract Extraction: Jacques Daviel (1696–1762)

Jacques Daviel was the first surgeon on record to remove a cataract using the extracapsular approach. In 1748, Daviel unsuccessfully attempted to couch the left lens of M. Garion, a local wigmaker. He had the same difficulty when he turned to the right eye: the lens broke into several pieces, which could not be dislocated out of the visual axis. He then decided to extract the lens fragments of the right eye by incising the lower segment of the cornea, folding the flap back, and eliciting the lens fragments from the posterior chamber with a needle. The eye healed well despite some vitreous loss. With this first extracapsular cataract extraction, Daviel revolutionized the practice of ophthalmology. In 1752 he published his results, which included 206 successful extractions with an 88% success rate. ⁷ These numbers improved to 354 cases with a 98% success rate in 1756. ⁵

Daviel’s procedure was effective but difficult, requiring numerous instruments and great clinical acumen; thus many of the prominent eye surgeons continued to couch cataracts. In 1753, George de la Faye of Paris and Samuel Sharp of London greatly simplified the procedure by requiring fewer instruments and less time to complete the operation. Thereafter, the majority of surgeons began the conversion from couching to extraction.

During the 19th century, the linear cataract extraction was developed by Albrecht von Graefe, ⁸ and this became the procedure of choice for extraction of senile cataracts during his lifetime (1828–1870). The procedure evolved to a more peripheral incision and then was combined with an iridectomy.

Daviel’s and Graefe’s cataract extractions were extracapsular, which involved removal of the lens without removing the lens capsule. Intracapsular extraction, which involves removal of both the lens capsule and the lens, began around the same time but was not popularized until much later.

Samuel Sharp completed the first intracapsular cataract extraction in 1753 ⁵ by making a puncture and counterpuncture and cutting downward through the limbus, and then using force with his thumb on the globe to expel the lens through the incision. Later on, various instruments were used to apply pressure on the eye while expulsing the lens, including a curette, spoon, and a strabismus hook.

Given the loss of vitreous caused by the pressure applied on the globe to expulse the lens, the pressure was soon replaced by traction, which continues to be of use with subluxed lenses. Traction evolved and was refined: Eugene Kalt (1861–1910) designed a smooth forceps especially for this purpose, then a suction cup was used (Paul Stoewer, 1902 and Vard H. Hulen 1910 and Ignacio Barraquer, 1917–24), and, in 1961, Tadeusz Krwawicz introduced a cryosurgical probe that facilitated the extraction of the lens and its capsule.

Other notable improvements in cataract surgery during the 19th and early 20th centuries included zonular destruction, sutures, local and regional anesthesia, motor akinesia, and the advent of a novel technique for cataract removal. Zonular destruction, which facilitates the removal of the lens by requiring less force for its expulsion from the globe, was first accomplished mechanically by Di Luca in 1866, and is now accomplished enzymatically with alpha-chymotrypsin, first discovered by Joaquin Barraquer in 1958. Sutures following cataract removal were first placed in 1849 by Henry W. Williams in New England, ⁵ who used a single corneoscleral suture, followed, in 1869, by conjunctival sutures, which resulted in more rapid healing and less suppuration at the operative site. Thirty years later, this suturing technique was introduced in Europe by Eugene Kalt in 1894 and Frederick Herman Verhoeff in 1916.

1.5 Correction of Aphakia following Cataract Surgery

One of the unavoidable complications of cataract surgery is a aphakia.

Linksz, International Ophthalmological Clinics, 1964 ²

This infirmity cannot be cured, it must be endured.

Dr. Alan C. Woods, Director of the Wilmer Eye Institute in Baltimore, who suffered from postsurgical aphakia

Aphakia results in loss of the ability to focus images, which renders the aphakic patient essentially blind without correction, except for the ability to perceive light/dark changes and shadowy images. Originally, aphakia was treated using spectacles and later with contact lenses. However, these devices were cumbersome: cataract spectacles necessitated a high magnification power to compensate for the distance from the retina; therefore, images seen through the spectacle lens were 25% larger than in the untreated eye, and this essentially obliterated binocular vision, resulting in loss of depth perception. This made simple daily tasks, such as pouring coffee and walking downstairs, difficult. Additionally, the spectacles could not restore peripheral vision.

Aphakic contact lenses, due to their location closer to the retina, resulted in a more tolerable 7% magnification of images and improved peripheral vision; however, contact lens use was quite difficult for elderly populations, which comprised the majority of aphakic patients. Dr. Jaffe, one of the earliest American ophthalmologists to use IOL implants, stated that “many patients became more handicapped after a technically perfect cataract operation than they were before the surgery.” ⁹ There was a need for a permanent functional replacement for the removed cataractous lens nearer its natural location.

1.6 Early Attempts at Intraocular Lens Implantation

Dr. Harold Ridley of Great Britain is credited with the first successful IOL implantation in 1949; however, some reports document much earlier attempts to replace the clouded lens following cataract surgery, the earliest of which comes from the memoirs of the infamous Giacomo Casanova, who reported in 1966 his meeting with Tadini, an Italian oculist who had a supply of polished crystals, which he claimed were to be placed inside the eye following cataract surgery to replace the removed lens. Tadini never followed through with his idea, but Casanova allegedly shared Tadini’s story with an Italian ophthalmologist named Cassamata, who attempted, with disastrous results, to replace the defective lens with a glass lens in 1795. ¹⁰

Another anecdote exists about a Russian ophthalmologist named A. Kh. Mikhailov, who experimented with intraocular implants in rabbits, and possibly humans, in the town of Sukhumi in the late 1930s and early 1940s. Unfortunately, all official records of these experiments were destroyed in a fire, thus their true nature remains speculative.

In light of the questionable authenticity of these early experiments, the work done by Harold Ridley in the 1940s is viewed as original and pioneering in the field of IOL implantation.