Invention of the capsulorhexis
Development of the procedure highlighted in inaugural ESCRS Heritage Lecture
Prof Thomas Neuhann
Inspiration, perspiration and a small degree of good fortune were the key ingredients in the invention of the capsulorhexis, Prof Thomas Neuhann told a packed audience at the inaugural ESCRS Heritage Lecture during the 36th Congress of the ESCRS in Vienna.
“Like many inventions, the first capsulorhexis was the result of frustration with existing methods and a desire to find a better solution. There was also an element of chance in that I was faced with a special case on this particular day in 1984, which prompted me to try something different to access the lens material,” he said.
The invention of the capsulorhexis, and more precisely the continuous curvilinear capsulorhexis (CCC), is credited to both Prof Neuhann and Howard Gimbel MD, who both independently applied the same circular concept, albeit using slightly different techniques.
In the early 1980s, the state of the art in cataract surgery was the anterior capsulectomy for which three basis variants existed, noted Prof Neuhann: Charles Kelman’s “Christmas tree” technique, Cornelius Binkhorst’s “letter-box” opening and the more commonly used “can-opener” approach.
The other contentious element of cataract surgery at the time was deciding where the posterior chamber lens would be implanted, said Prof Neuhann.
The most common implantation site was the ciliary sulcus but a lot of debate focused on whether the lens might be better placed in the capsular bag
“While the capsular bag was clearly the best place for the lens, the can-opener technique meant that the lenses were frequently decentred and there was a tendency for the haptics to pop out postoperatively. When this kept happening to me, I decided that either I find a solution to this or I stay in the sulcus,” said Prof Neuhann.
Prof Neuhann’s eventual solution to the problem turned out to be the capsulorhexis, which he first performed on a young female patient with retinitis pigmentosa and loose zonules.
“The capsule material was particularly tenacious and elastic and I simply could not get the usual can-opener technique to work. In my despair, I stuck a blade in and cut the capsule and inserted some Healon viscoelastic, which was not widely available at the time. I then took my tying forceps and tried to tear the capsule – and miracle of miracles, the tearing was much less strenuous on the capsule than trying to nick it with the capsulotome,” he said.
The next step was to make the technique reproducible under conditions at the time, as viscoelastics were not generally available and Prof Neuhann had to use a tube-guided forceps with a chamber maintainer during surgery.
“We eventually evolved to a needle technique because it was as sharp as a scalpel, it was viscoelastic independent and mydriasis independent. With the needle I could pull the pupillary margin back, I could make a cut with smooth edges and create two points for initiating the tear. It departed from a single incision and then went 360 degrees around,” he said.
To more accurately describe the new technique and differentiate it from preceding techniques, Prof Neuhann coined the term “capsulorhexis”, which uses the Greek suffix “rhexis” meaning “to tear”.
At around the same time, Howard Gimbel was also experimenting with tearing out the capsule in arc-like sections, while leaving small bridges to stabilise the flap until the circle was mostly formed.
“The basic principle of tearing was the same but my version ultimately stood the test of time because it proved to be a little bit more practical,” said Prof Neuhann.
In recognition of the fact that they had both arrived at the same basic concept independently and around the same time, Drs Gimbel and Neuhann published a joint paper in 1990 that explained their respective contributions to the capsulorhexis breakthrough.
“It was the right thing to do. My mentor Dick Kratz told me at the time: ‘I have seen so many bitter fights over priority. I think that was one of the nicest examples of resolving a priority discussion with dignity that I have ever seen.’”
Professor Neuhann is the founder and current medical director of MVZ Prof Neuhann and of the ALZ Eye Clinic, and head of the eye department of the Red Cross Hospital, all in Munich, Germany. He played a key role in the development of modern cataract, refractive and glaucoma surgery techniques. He served as president of European Society of Cataract and Refractive Surgery (ESCRS) from 1998 to 2000