A wish list for a nearly ideal IOL
The first IOL was implanted by Sir Harold Ridley on Nov. 29, 1949, at St. Thomas’ Hospital in London. Amazing to me, it was a monofocal posterior chamber lens, or PCL, manufactured by Rayner and implanted after large-incision extracapsular cataract extraction. Sixty years later, the procedure of PCLs implanted after small-incision ECCE with the nucleus removed by phacoemulsification in more affluent countries and manually in less affluent countries remains dominant.
Topical anesthesia was common and sutureless incisions standard in Ridley’s days following a Graefe knife incision with a large limbus-based conjunctival flap followed by hospitalization with immobilization (“sandbags”) for 10 to 14 days to allow the wound to seal. Sutureless incisions remain dominant today but are much smaller, allowing outpatient ASC or office-based surgery and immediate mobilization. It remains almost unbelievable to me that the first-ever IOL performed 70 years ago was a PCL implanted after ECCE with a sutureless incision under topical anesthesia.
I was blessed to meet and talk with Sir Harold Ridley during the American Society of Cataract and Refractive Surgery, European Society of Cataract and Refractive Surgeons and International Intra-Ocular Implant Club meetings in his later years. I found him to be a proper English gentleman of few words, yet kind, humble, approachable, still very sharp and British-style direct in his 80s. He was full of memories from those challenging and controversial days of early IOL implantation, and still a little wounded by the criticism his pioneering work elicited from many he once considered friends and colleagues. The late Charles Kelman, MD, when reminiscing about the early days of phacoemulsification, told a similar bittersweet story. Their stories are both worth remembering as we toil to pursue another generation of progress in our field.
Advances in IOL design and function continue unabated six decades after Sir Ridley and Rayner. Advances in the art and science of ophthalmic implantology remain a collaboration between clinicians and industry and still ignite spirited debate, challenging some friendships while strengthening others. Thanks to the high volume of IOL implants, nearly 4 million a year in the U.S. and approaching 28 million globally, the innovation cycle in the IOL field is well-funded.
This cataract/IOL field of invention has been and remains an area of special interest for me personally, and I will disclose that I have consulted widely in this field for more than 40 years. I “invented” my first PCLs, one sold by Iolab and the other by Surgidev, in 1979 and 1980, respectively. I was hired as chief medical officer by 3M Vision Care in 1980 and participated from day 1 in the development of the first diffractive multifocal IOL, later sold to Alcon. I remain active in the IOL research and development field with both start-up companies and major global strategic corporations.
On a personal note, I am also a potential patient in the next 5 years. My goal is to work toward an IOL implant that duplicates as closely as possible the vision of a pre-presbyopic phakic emmetrope.
I was one of those prior to age 40, and I would like to be one again. The vision I enjoyed was seamless and continuous from distance through intermediate to near, with a full field and good adaptation to photopic, mesopic and even moderately dark scotopic environments. My 40-year-old vision was minimally affected by forward light scatter, and symptoms of glare, starburst or halo were rare. I had no unwanted negative or positive dysphotopsia. I also did not need to be concerned about a secondary cataract developing in a few years and requiring laser therapy.
Today, we are making progress toward developing the IOL required to give me back the vision I enjoyed as a 40-year-old emmetrope. The first requirement, better biometry and IOL calculation formulas combined with an adjustable power IOL, is today a reality. My first goal is emmetropia with minimal higher-order aberrations. I want to see 20/12 or better without correction, as I did at age 40. I also want quality seamless vision back, from distance through intermediate to near, with no gaps and without correction. Trifocal IOLs and hybrid bifocal/EDOF lenses are a meaningful step in the right direction, but eventually I want an accommodating IOL with 3 D or more of accommodative amplitude. I see promise that an adjustable accommodating IOL is a possibility within 5 years, but if not, I want a power-, astigmatism- and higher-order aberration-adjustable full-range trifocal/quadrifocal/EDOF IOL that can closely duplicate the vision provided by the natural 40-year-old lens. I want the same IOL in both eyes to allow bilateral summation at every distance. I want my posterior capsule to remain clear forever, but at a minimum for 5 years. I believe more money needs to be invested in eliminating posterior capsular opacification, and some IOL designs are showing promise here. I want to function well in bright and dim light with minimal glare, starburst or halo and no positive or negative dysphotopsia. I would like a full range of color vision and perception and would favor a high-energy violet light blocker in my IOL over a full-range blue light blocker. I am OK wearing sunglasses in extreme environments. So, to my extraordinarily bright colleague clinician-scientists and my friends in industry, my “moon shot” 5-year request, while not simple, is possible. By 2025, please develop for me an adjustable accommodating (3 D or more of accommodative amplitude, please) PCL that will retain a clear capsule and produce no more forward light scatter with unwanted visual symptoms than the natural 40-year-old human lens that I so much enjoyed 32 years ago.
Disclosure: Lindstrom reports relevant financial disclosures for AcuFocus, Alcon, Bausch Health, Foresight 6, High Performance Optics, Johnson & Johnson Vision, Quest, RxSight and Zeiss.