Each year, the Charles L. Schepens Lecture during Retina Subspecialty Day is one of the highlights of the American Academy of Ophthalmology (AAO) annual meeting. The lecture is named in honor of Charles L. Schepens, MD (1912-2006), who has been called the “father of modern retina surgery.” During his career, Dr. Schepens invented numerous ophthalmic instruments, including the binocular indirect ophthalmoscope, and founded the Schepens Eye Research Institute, which remains a prominent center for research on the eye, vision, and blinding diseases.
Given Dr. Schepens’ background, it seems fitting that Steve Charles, MD, FACS, FICS, FASRS, was chosen to give the 2024 Schepens Lecture at AAO. Dr. Charles is a mechanical and electrical engineer as well as a vitreoretinal surgeon, who developed many techniques and devices currently used by retinal surgeons worldwide. During his long career, Dr. Charles has performed over 46,000 vitreoretinal surgeries and published numerous articles as well as the textbook Vitreous Microsurgery, now in its sixth edition. He has consulted with Alcon in research and development (R&D) for almost 34 years and has over 190 patents issued or pending. His many honors include the 2018 Laureate Recognition Award, the highest award given by AAO, and the first Founders Award given by the American Society of Retina Specialists.
During our conversation, which has been edited for length and clarity, Dr. Charles spoke about what it means to be invited to give this prestigious lecture and provided some insights into the intersection of technology and surgical technique.
You’ve received many awards and honors during your career. What does it mean to you to be asked to give the Charles L. Schepens Lecture at the American Academy of Ophthalmology’s meeting this year?
Dr. Charles: This is very meaningful for me on several levels. Representatives of the Retina Society, the Macula Society, the Club Jules Gonin, ASRS, the Retinal Research Foundation, and the Schepens Foundation are members of the selection committee, so that means every major national and international organization in retina made the choice. I also have a tremendous amount of respect for other people who have delivered that lecture in the past. It’s a great honor.
I knew Dr. Schepens personally. When I built the vitrectomy program at the National Institutes of Health [in the early 1970s], I got a phone call from the director that said Dr. Schepens wants to watch you operate. He was always very courteous to me and very professional — he usually sat in the front row of meetings and took notes. So, at the personal level, it is nice to have met him. I never had an opportunity to watch him operate, but he worked until his early 90s, as I remember.
In your lecture, you discuss systems engineering in ophthalmic surgery. Can you share some of the key insights?
Dr. Charles: First, the techniques and technologies are for the most part not independent of each other. They’re mutually dependent. So doing vitrectomy for retinal detachment got a lot better when I invented linear suction and when I pushed for faster and faster cutting rates because it made it much safer to remove vitreous. Technique and technology evolve together.
Second, the complexity of our machines has grown tremendously. We’ve gone from 3 functions in the vitrectomy machine to 13 functions. We've gone from no code at all, just a little motor drive and an integrated circuit, to 4.1 million lines of code in the newest Alcon machine with 32 processors and 49 printed circuit boards. The complexity has grown tremendously. The size of instruments has gotten much smaller — it’s gone from 17 gauge to 27 gauge. The cutting rates have gone from 200 cuts per minute to 30,000 cuts per minute. There’s been enormous progress over the 5 decades that I've been doing this, and that progress has come about from collaboration between engineers and surgeons.
Another theme of my talk is to give credit to the engineers involved. There are some doctors who take credit for things that they didn’t think of, but they were in the room when an engineer thought of it. That's inappropriate, so I want to honor the engineers.
When developing new instruments and devices, what are the most important considerations to balance between technology and the needs of the surgeon?
Dr. Charles: I'm about making complex systems that include many functionalities get better by continuing to work with the engineering team. The most important considerations are really to provide reliable, cost-effective performance that is available worldwide. If doctors all over the world continue to use your innovation, then it's the real deal, whether it's technique or technology.
I’m in a unique position, because when I entered medical school in Miami I decided to continue to study engineering. Many people go to medical school after engineering school, but immediately drop engineering as soon as they enter med school. I did engineering work as a medical student by working at Bascom Palmer, during internship, and during residency also at Bascom Palmer. That engineering was to help with surgery and with imaging.
For 51 years now I’ve been doing surgery and I’ve continued to learn more engineering. I’ve taught myself photonics, I’ve taught myself advanced electronics, field programmable gate arrays (FPGAs), and parallel processing architectures. Continuous learning in medicine and surgery is critical, and so is continuous learning in engineering.
You’ve helped develop many innovations over the years. Is there one that stands out to you as particularly transformative or that you’re most proud of?
Dr. Charles: I don’t have a favorite, quite honestly. I’m proud of the fact that I've been involved in developing 5 consoles, including the Accurus and the Constellation from Alcon, and now their new machine, Unity VCS. Instead of being a gadfly and floating around from idea to idea, I've continued to focus on making those better: faster fluidics performance, faster cutting speeds, better lasers, and more functions. The first 4 machines were the world market share leaders, and I think the new one will be as well.
What advice would you give to young ophthalmologists interested in working at the intersection of technology and surgical technique today?
Dr. Charles: People will come to me and say, “I want to start a company.” I say, “OK, what technology are you confident in? Are you a biotechnology person? Are you electronic or mechanical engineer? Systems engineer? Do you have a cohort of brilliant scientists and engineers that you work with?” If the answer is no, that's called “aspirational innovation,” and nothing’s going to happen.
Innovation isn’t about padding your resume or hanging plaques on your wall. I have nearly 200 patents, but if those products are not distributed globally to help patients all over the world it’s meaningless. My advice is, don’t focus on the fame game. Look at real-world problems and learn as much about technology as you can, so at least you know the language to communicate with the full-time engineers who are going to build a device that makes a difference. RP
