|HISTORICAL/REMEMBERING THE PAST
|Year : 2018 | Volume
| Issue : 1 | Page : 45-50
Remembering Dr. Charles D. Kelman and Development of phacoemulsification
Consultant Ophthalmic Surgeon: R K Eye Care Centre, Rasipuram, Namakkal, Tamil Nadu, India
|Date of Web Publication||4-Jun-2018|
Dr R Vasumathi
18/A, G V R Mill Street, Rasipuram, Namakkal, Tamil Nadu
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Vasumathi R. Remembering Dr. Charles D. Kelman and Development of phacoemulsification. TNOA J Ophthalmic Sci Res 2018;56:45-50
“Never throughout history has a man who lived a life of ease left a name worth remembering.”
– Theodore Roosevelt.
Charles D. Kelman, MD, best known as the Father of Phacoemulsification, fought against all the odds and developed phacoemulsification which absolutely revolutionized cataract surgery. He had an epiphany in a dentist's chair that led to a radically simpler way for eye surgeons to remove cataracts.
Charles Kelman was born in Brooklyn, NY, on May 23, 1930. He graduated from Tufts University in Boston, Mass, and received his medical degree from the University of Geneva in Geneva, Switzerland. He returned to the United States for his internship at Kings County Hospital in Brooklyn and then completed his ophthalmology residency training at Wills Eye Hospital in Philadelphia, PA.
In 1960, when he finished his residency at Wills Eye Hospital, general anesthesia was common, no microscopes were used for any ophthalmic surgery anywhere in the world, a 180° incision was made, a large sector iridectomy was performed, the lens was grasped by a capsule forceps, and then the entire lens was pulled from the eye. Eight or more sutures closed the incision, and the patient remained hospitalized for 7–10 days. The eyes were red, the lids swollen, and irritated for up to 6 weeks.
Early in his career, Dr. Kelman sought new methods to facilitate cataract surgery. He was at the forefront in the use of cryosurgery for intracapsular cataract extraction. His contribution to the development of cryoextraction became widely accepted and conferred a greater degree of safety to cataract extraction. He did not stop with that. Dr. Kelman envisioned a small-incision cataract procedure that would permit a shortened hospital stay or perhaps no hospital stay at all, as well as the ability of a patient to resume normal and customary activities almost immediately.
He was in the process of writing a grant application to the John A. Hartford Foundation to investigate the effects of freezing on the eye. After finishing the final draft, he felt that the application seemed “boring.” He knew that the foundation looked to support breakthrough procedures, not boring scientific studies and that the application would be rejected. He needed something exciting but did not know what. Without knowing what he was doing, he put his subconscious mind to work and went to bed.
Sometime in the night, he got out of bed and wrote a phrase which would forever change his life and would forever change the practice of cataract surgery. That phrase was, “The author will also find a way to remove cataract through a tiny incision, eliminating the need for hospitalization, general anesthesia, and dramatically shortening the recovery period [Figure 1].” The Hartford Foundation Director, E. Pierre Roy, called him a few days later to tell him that he was not interested in the effects of freezing on the eye but that he would give the grant for the new cataract operation.
|Figure 1: Dr. Kelman (seated) and laboratory assistant Cheryl Jalbert (right) conducted research on laboratory animals at the Manhattan Eye, Ear, and Throat Hospital, before later performing the first phacoemulsification on a human subject in 1967. Source: https://www.eyeworld.org/|
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He had no idea how he would accomplish this feat. He was, however, confident that he could do so easily; this confidence sprang from three factors: (i) He had quite easily discovered cryoretinopexy and had published the first paper on that subject, (ii) he had quite easily codiscovered (Krwawicz, in Poland had also, independently discovered the same thing) cryoextraction of cataracts, and (iii) he was blissfully and naively unaware of the complexity of the task he had set out for himself. It is for this reason that often people outside of a particular discipline are able to make breakthroughs. Those more knowledgeable are too aware of the difficulties.
Development of phacoemulsification
The first “method” for removing the lens through a small incision revolved around a collapsible “butterfly net,” the net portion being made out of condom thin latex. The idea he had was to dilate the pupil, instill an enzyme to loosen the zonule, turn the patient over on his or her face, and vibrate his or her head with a manual vibrator, until the lens fell into the anterior chamber, then instill acetylcholine to constrict the pupil. Once the cataract would be trapped in the anterior chamber, the collapsed latex net would be introduced to trap the cataract, which would then be simply mushed up with a needle, until the net and the squashed cataract could be pulled through the small incision. It is important for the reader to note how far from the sophisticated phaco machines this original, naive idea was [Figure 2].
This “cat in the bag method” could not be made to work. All attempts with this device were made on animal and eye bank eyes. It was too traumatic to the cornea, the bag was too thick and took too much volume in the anterior chamber, the bag kept breaking, etc. It had taken 6 months to fabricate this “butterfly net” and to test it. He had used up one-sixth of his 3-year grant, and he began to worry.
He then began investigating devices which would break up a cataract so that it could be irrigated and aspirated from the eye. Various drills, rotary devices, and various types of microblenders were constructed and tried; each failed for several reasons. If the iris was touched with a rotating tip, it would immediately become completely ensnared and a total of 360 iridodialyses would inadvertently be performed. Usually, uncontrollable hemorrhage would ensue. Furthermore, the iris did not even have to be close to the rotating tip. The eddy currents set up within the chamber were enough to draw the iris to the rotating tip and instantaneously disinsert and remove it.
The second obstacle to fast-rotating devices was that the eddy currents set up in the anterior chamber would throw lens particles against the endothelium and completely denude it in a few seconds, leading to permanent opacification and vascularization. Third, the lens itself when caught on the rotating tip would also spin in the chamber with the consequent destruction of the endothelium. The microblender with needles rotating in opposite directions was intended to prevent the lens from spinning, but it was unsatisfactory. It also increased the chances of incarcerating the iris in the two rotating tips. Slow turning drills were designed, but these too were unable to prevent the lens from turning. Rocking vibrators still rubbed off endothelium. Steps were taken to fix the lens from the opposite side with the use of the prongs. The sharp tips, however, endangered the posterior capsule. Low-frequency vibrators were tried, but the lens merely vibrated with the tip. None of the aforementioned devices were ever used clinically as they were considered dangerous and ineffective. The solution of this problem had become more than a challenge – it had become an obsession to him.
In analyzing the difficulties he had so far, it became clear that the main problem was that the lens was moving, rotating, or vibrating inside of the anterior chamber and therefore rubbing against the endothelium. This realization eventually led to the solution only a few months before the expiration of the grant. At this time, it became obvious that to let the lens remain stationary in the chamber, the acceleration of the moving tip against it had to be high enough so that the standing inertia of the lens would not be overcome; in other words, high enough acceleration was required so that the lens could not back away, vibrate, or rotate with the tip. He imagined a sharp knife slowly punching against a punching bag. The punching bag would move with the knife. If, however, the knife is quickly plunged against the bag, the knife will enter and the bag will not move. In this analogy, the punching bag represents the lens, and the knife represents the tool used to enter the lens. The high acceleration could only be achieved with an ultrasonic frequency. Early experiments with a dental ultrasonic unit using irrigation only and a nonlongitudinal motion were encouraging but were clinically unsuccessful because of the high energy radiated and the relative inefficiency requiring many minutes of ultrasonic time in the anterior chamber. Substitution of a longitudinal motion at the tip was introduced to prevent disinsertion of the iris and to reduce radiation.
Once he had discovered the method of breaking up the lens, he thought the rest would be easy. It was not. There were three types of problems lurking ahead, which as they were discovered, had to be overcome: surgical problems, instrument problems, and political problems.
In the first attempt to do phacoemulsification, the pupil constricted during the surgery. There had to be new drugs and methods to maintain dilatation. In the early cases, the pupil constricted rapidly in the procedure because potent mydriatics were not available at that time. At first, he performed large sector iridectomies so that he could see behind the iris; however, in many cases, the iris became aspirated into the tip and became badly frayed. Because of this problem, he began to bring the lens into the anterior chamber before performing the phaco and before the pupil constricted. For several years, he then taught anterior chamber phaco, which he still believed a viable alternative to posterior chamber phaco, for those less skilled. There was a slight increase in the endothelial cell loss over the posterior chamber phaco, but not enough to be significant.
After a few years, mydriatics were placed in the irrigating solution, and anti-inflammatory drops were used on the cornea in combination with more powerful mydriatics. Once viscoelastics came into use, they too aided in pupillary dilation, and posterior chamber phaco became much easier. For those pupils that are fibrotic, several models of iris hooks are available.
A method of opening the anterior capsule had to be developed which would be consistent, exposing the lens, but not extending to the zonules. His first attempts to incise the anterior capsule in several directions, with crisscrossing lines taught him that these incisions in the capsule, if subjected to traction, could extend around the anterior surface of the lens into the zonule and perhaps even onto the posterior capsule. One day, he observed on an animal eye that if he used a dull cystotome rather than a sharp one, instead of cutting the capsule, the cystotome tore it. Moreover, that tear was always in the form of a triangle. He named this technique the Christmas Tree Opening. This became the forerunner of the continuous tear capsulorhexis. Once the triangular tear was made, the pie-shaped flap would be grasped with a forceps, gently extracted, and then cut at its base. This method was in general use until the “can opener technique” was introduced, and then finally, the continuous tear technique widely used today.
Using loupes (the standard method of magnification at that time), the magnification was not adequate. Using existing surgical microscopes gave no depth perception since the lighting was flat and there was no red reflex. The first microscopes he tried were tabletop dissecting microscopes, and they had inadequate side illumination. In examining other types of microscopes, he came upon an exciting discovery. Using an ear-nose-throat (ENT) microscope, the red reflex from the coaxial light gave him an incredible depth perception intraocularly. From then on, only ENT microscopes were used until Zeiss finally made one more suitable for ophthalmology.
The posterior capsule is not a strong membrane. Techniques had to be developed which would protect it during the lens removal. It became evident to him very early on that the big obstacle to phaco would be the rupture of the posterior capsule. The early phaco machines did not have the power or the suction that present models have, and the tip had to be pushed into a hard nucleus to emulsify it. This pushing often broke the capsule. One must remember that there were no viscoelastics at that time. To make the procedure safer for him, and especially for others learning it, he devised a technique for prolapsing the entire nucleus into the anterior chamber, where it could be emulsified at some distance from the capsule. This method remained in vogue until the equipment was improved, at which time phaco in the posterior chamber was reintroduced.
A technique of surgery had to be developed which would allow a surgeon to safely emulsify the nucleus without damaging the endothelium or the iris. In the early cases, the cornea collapsed many times against the vibrating needle, and the corneas had severe striate for sometimes up to 1 month. There was no method at this time of counting endothelial cells, but later studies showed up to 50% cell loss in these first cases. It is interesting to note that these corneas eventually cleared, giving the patients good vision.
A technique would be needed to safely pull the cortex out of the fornices of the capsule and then to aspirate it. In the early cases, the same phaco tip and sleeve were used to remove cortex, but it became obvious that this terminal opening endangered the capsule. He modified the tip so that it had a closed terminal end, with the lumen on the side, so that it could be directed away from the capsule.
An instrument powerful enough to emulsify all types of cataracts without damaging adjacent structures had to be developed. The first phacoemulsifier used on animals and patients consisted of a table with various parts and devices connected to each other. One of the parts was a dental apparatus used to remove tartar from the teeth. This was modified so as to add suction and irrigation. The ultrasonic stroke was not only too small to act on hard cataracts, but it also got dampened even further when a load (the cataract) was put on. He found that with piezoelectric crystals, rather than magnetostrictive stacks, a greater stroke could be achieved and that dampening could be prevented.
Ultrasonic frequencies build up sufficient heat to denature tissue. Cooling would have to be guaranteed. After actually cooking and denaturing the protein of the lens in some animal eyes, it became clear to him that constant irrigation of the vibrating tip had to be assured. His original idea of having a watertight, close-fitting incision was not going to work, since when the tip was occluded, the outflow through the tip was blocked, and since the incision was tight around the tip, no fluid could escape. It then became necessary to have the incision slightly larger than the tip so that fluid could always escape from the eye and also to insure that the amount of fluid flowing into the eye always exceeded the amount being aspirated. Once these concepts were put into effect, heat buildup ceased to be a problem.
Considerable suction was necessary to hold lens material onto the vibrating tip. Once this material was aspirated, in a few milliseconds, there was enough suction buildup to collapse the chamber. The result of this collapse was to see the cornea touching the vibrating tip, with the endothelium being emulsified. A method had to be found to prevent this. In order for the lens material (especially if it is hard nucleus) to remain fixed to the tip while that tip is vibrating, a fairly high level of vacuum must be achieved. He started with a high level of vacuum, with copious amounts of fluid entering and leaving the eye. However, if the capsule or iris were inadvertently engaged, these tissues would be more susceptible to damage than if the suction were lower.
Then, he realized that a peristaltic-type pump could apply minimum suction until such a time as the tip became occluded, at that time the suction would rise, holding the lens material onto the tip while it was being emulsified. The problem created with this system was that as soon as the lens material became suddenly aspirated, the high level of suction in the system would collapse the chamber. For the first 50 or so cases, he had no other solution to this problem, than that of trying to anticipate the collapse, and just before the morcel would be aspirated, he would take his foot off the foot pedal. This was very ineffective, and many times during the first cases, the cornea would collapse onto the vibrating tip. Although the endothelium was damaged, to his good fortune, those eyes always cleared after a few days, permitting him to continue developing the instrument and technique.
After much searching, he finally found a fluid control system which monitored flow in arteries by creation of an electrical current from the ions as they rushed through the arteries. He adapted this system so that the fluid flow through the aspiration line was monitored. When it stopped (tip occlusion), a valve was put into the alert position. Within a few milliseconds after flow started up again (aspiration of the morcel), this valve would open to the atmosphere, killing the suction. This was a very satisfactory system and was used for several generations of phacoemulsifiers.
Ophthalmic surgeons were used to tiny instruments which fit into the fingers. The early handpieces were extremely heavy and cumbersome. The original procedures took up to 4 h, with over 1 h of ultrasonic time. A special three-dimensional parallelogram had to be invented and constructed to hold the handpiece. He was willing to use it while he was developing the techniques, but he knew that no one else would be willing. While looking for ways to make the handpiece lighter and smaller, he developed the three-dimensional parallelogram to hold the handpiece, with all axes of rotation around the incision.
The original handpiece was magnetostrictive and had a frequency of 25,000 cycles. By substituting piezoelectric crystals for the heavy magnetostrictive plates, the size and weight were greatly reduced and the frequency was raised to 40,000 cycles.
The original handpiece was magnetostrictive and had to be water cooled. This cooling water had to be isolated from the sterile end of the handpiece. Nonsterile water flowed in, around, and out of the magnetostrictive plates. The first handpiece had a set of O-rings to isolate this nonsterile water from the sterile irrigation fluid, but in one instance, the O-rings failed, causing an infection. The interim solution was to add a second set of O-rings, but finally, when the piezoelectric crystal replaced the magnetostrictive, air cooling was sufficient and no O-rings were needed.
The original tips were steel, and flaking was a problem, with the possibility of leaving iron shavings inside the eye. Titanium is a completely inert metal and is silent in the tissue. It is also less friable than steel, and therefore, the steel tips were replaced with this metal, and there has not been any report of adverse effects from this material. It was extremely rare to see any particle in any operated eye.
The vibrating tip had to be insulated from the corneoscleral wound to prevent heating. Various materials were tried and the two best found were silicon and Teflon. Since silicon was softer, it was the final choice.
Since a fair amount of solution would be washing over the cornea during the procedure, it was important to find the best possible irrigating solution. Rather than embark on a scientific quest as to which solution would be the safest, he had observed in Barcelona that Joaquin Barraquer employed a solution, made in Spain, which closely approximated the fluid in the anterior chamber. He began importing and using this solution.
It was difficult enough for a serious scientist to introduce a dramatic change in a procedure which everyone thinks is already ideal. If he had known in advance how many problems there were, he might well never have started the project. The Chinese proverb is appropriate here, “The longest journey in the world begins with the first step.”
Although the surgical and instrument problems outlined above were difficult to solve, they were a constant challenge and their solution brought a great deal of satisfaction to him. Not so for the political problems! When he first introduced phacoemulsification and aspiration, it was met with more than scientific reserve. It was met with scorn. He recalled “How dare I, a young nobody presume to change what the University professors were proclaiming the safest and most sophisticated surgical procedure ever devised (intracapsular surgery)?” At meetings where he presented the concept, there were considerable derision, mockery, and hostility in the questions from the floor.
At Manhattan Eye and Ear Hospital where he was assistant attending surgeon, the hospital voted to allow only one case per week and this cut down on the number of cataract cases he could do. When he began doing phacoemulsification, the surgeon directors advised him that he would have to stop immediately if he had even one case of serious complications. When you put that sword of Damocles together with the problems outlined above with the technique and instrument, one can imagine the pressure involved in every procedure.
Once the technique had been taken up by several others in various parts of the country, each investigator was met with the same hostility that he had encountered. Once it began to be accepted by several dozen surgeons, the political forces against it had the operation declared “experimental” by Medicare, meaning that there would be no reimbursement for the procedure. It took several months, and letters from a thousand patients from all over the country to get this ruling by the government reversed.
The American Academy of Ophthalmology then commissioned one of the most vociferous antagonists to the procedure to do an “unbiased” study comparing the results of phaco to intracapsular surgery. He was put on the panel but was never allowed to see any of the results of this study until they were ready to be submitted. It came as no surprise to find that intracapsular surgery was found to be infinitely superior to phacoemulsification. Since the justification of this conclusion was rather suspect, he engaged the professor of statistics at Columbia Presbyterian University to examine the methods and conclusions drawn. His report was so scathing that the original report was discarded, and the final verdict submitted to the Academy was that phaco was at least as safe and effective as intracapsular surgery.
The increase in the percentage of cases done with phaco slowly increased over the years until foldable lenses were introduced. From that time, phaco cases increased dramatically.
We are grateful to him for devising a better way to remove a cataract, for persisting with his idea under contentious circumstances and when the technique was sufficiently refined for generously teaching it to his colleagues. His discovery has made impact on the lives of millions of people worldwide who have benefited from the genius of his procedure.
His accomplishments were also recognized outside of ophthalmology. He received the American Academy of Achievement Award in 1970. President George H. W. Bush presented him with the National Medal of Technology in 1992 [Figure 3]. Dr. Kelman was awarded the Inventor of the Year Award by the New York Patent, Trademark, and Copyright Law Association, New York, for his invention of phacoemulsification, and in May 2004, he was inducted into The National Inventors Hall of Fame – a crowning recognition of his outstanding contribution to ophthalmic surgery [Figure 4].
Neurosurgeons have adopted the Kelman phacoemulsification machine for use in dissecting tumors from delicate brain and spinal cord tissue in children. In this way, the device has saved hundreds of young lives.
His talents amazed all of them who were privileged to know him. He was an accomplished jazz saxophonist, a writer and composer, an avid golfer, and a helicopter pilot. He managed to devote equal measures of enthusiasm to his undertakings and mastered each of them. The common thread in all that Charlie touched was his ability to envision a solution to quandaries that others may not even have perceived. His innovative spirit pervaded all of his endeavors, and through his lectures and writings, he encouraged his colleagues to explore their hidden creativity.
In 2004, Kelman died of lung cancer in Boca Raton, Florida. He was survived by his wife, Ann, as well as five children, Lesley Kelman Koeppel, Jennifer, Evan, Jason, and Seth Kelman. A documentary was produced by New York metro area public television station which reveals the struggles Dr. Kelman went through to get his phacoemulsification recognized as a legitimate technique in cataract surgery. Executive Producer Roy A. Hammond of the documentary “Through My Eyes: The Charlie Kelman Story” has told in a press release that the program “finally pays homage to the man whose inventions have touched millions of lives worldwide and whose name should be a household name.”
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Agarwal A, Agarwal A, Jacob S. Phacoemulsification. 3rd
ed. Informa Healthcare; 2004.
[Figure 1], [Figure 2], [Figure 3], [Figure 4]