Eyeworld

EW CATARACT 26 July 2011 Innovations and advice from Claes Dohlman, M.D. Dr. Henderson: When and how did you come up with the idea to work on a keratoprosthesis? Dr. Dohlman: I want to point out that it has never been a question of a "single, sudden idea" that opened up the field. The concept of an artifi- cial cornea is an obvious one—as ob- vious as putting a window on a house to be able to see out. This oc- curred to surgeons at the time of the French revolution. The trick has been to develop a long-term, safe procedure—very difficult indeed. Dr. Henderson: If it is that difficult, why don't we simply stay with the time-tested penetrating kerato- plasty? Dr. Dohlman: There are several rea- sons for that: 1. For cultural, religious, or ad- ministrative reasons, many parts of the world still lack eye banks and donor material. In China, for in- stance, only a hundred keratoplas- ties are performed per year in spite of having a waiting list of about 4 million patients. 2. Expense is a factor. In the U.S. a donor cornea costs $2,500-3,000 because of all the necessary testing and accompanying administration. Even if cost is less in the developing world, it can still be an issue. 3. The long-term outcome of keratoplasty is much worse than normally believed. Even more im- portant, a very large segment of pa- tients with severe corneal disease are never offered keratoplasty because it is considered hopeless in their cases. Of 8 million people with bilateral corneal blindness worldwide (1.5 million children), only about 100,000 transplants are performed per year globally. This is why we need a simple, safe, and inexpensive artificial cornea. Dr. Henderson: So what have you done to transform a very high-risk concept into a practical, accepted procedure? Dr. Dohlman: My co-workers and I have spent several decades on this, taking small steps at a time. Of course we built on top of earlier con- tributions that were often very use- ful. The development of what is now called the Boston Keratoprosthesis has involved design and material changes, but even more, it has been a question of protecting the sur- rounding corneal tissue and preventing melting, infection, and inflammation, as well as glaucoma, retinal detachment, etc. Thus it is more biology than bioengineering. Dr. Henderson: Have you patented these improvements? Dr. Dohlman: I have not bothered to patent anything. When that ques- tion has come up, we are usually deep into new developments, mak- ing the previous patentable version obsolete. Dr. Henderson: How do you find a company to market your devices? Dr. Dohlman: We have chosen not to go that route. We have handled the manufacturing, marketing, and sell- ing of the devices ourselves, under the auspices of the Massachusetts Eye and Ear Infirmary. Thus, we work on a non-profit, academic basis. The income from the sales goes partly to paying our bills, partly to a robust research program, and the rest is given to our cornea serv- ice. This arrangement has an advan- This month's cover feature is on femtosecond laser refractive cataract surgery. This new technology has the potential of dramatically changing the manner in which cataract surgery is performed. How are such innovative ideas developed? Many ophthalmolo- gists may have a new idea for an in- strument but do not know how to pursue the idea. I interviewed Claes Dohlman, M.D., professor of ophthal- mology, Harvard Medical School, and chair emeritus, Massachusetts Eye and Ear Infirmary, Boston, who pioneered numerous innovations in cataract and corneal surgery, including a well-func- tioning keratoprosthesis. He shared some advice on how to take an idea and develop it into a product. Bonnie An Henderson, M.D., cataract editor Cataract editor's corner of the world The Boston Keratoprosthesis in situ Source: Massachusetts Eye and Ear Infirmary Principles of assembly of the Boston Keratoprosthesis into a carrier corneal graft Source: Massachusetts Eye and Ear Infirmary continued on page 27

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