Issue 2: Widefield Imaging and its Historic Connection

A Conversation with Dr. Charles Schepens

As many will know, Dr Schepens (Fig 1) was one of the greatest figures in ophthalmology - credited with pioneering many modern retinal surgical techniques. He was also the inventor of the binocular indirect ophthalmoscope (BIO) (Fig 2), a device that has done so much to make the understanding of retinal disease and the development of effective modern treatments a practical proposition.  Schepens believed that advances in treatments could only be attained through improved understanding of disease processes and correspondingly, enhanced diagnostics.

Fig 1) Dr Charles Schepens (Boston Globe Staff Photo / Mark Wilson)

Fig 2) Binocular Indirect Ophthalmoscope (BIO)

In a conversation with him at the American Academy of Ophthalmology (AAO) some 5 years before his death, I learned about a historic chapter of innovation at his institute 40 years earlier. As he unveiled the story, I was both surprised and moved to discover how seamlessly that work linked with my own entirely separate endeavours and closed the circle on my understanding of the evolution and drive to image the periphery. Up to that point I had always regarded my own efforts as being rather contrary and at odds with the mainstream, rather on the periphery (pun intended) of ophthalmology!

The Quest for More Than a “Glimpse” of the Retina

In 1992 I started my own widefield quest which, over a period of 10 years, led to the development of the imaging technology at the heart of Optos devices today. At the time, I had not heard of Dr Schepens nor did I know that the diagnostic techniques he pioneered had become the basis of so many advances in retinal surgery. However, I had seen his ophthalmoscope used on many occasions, often with difficulty, on my 5-year-old son.

As an industrial designer observing the process, it seemed to me that retinal examination on children was a very hit-or-miss affair, and ophthalmology lacked the level of sophisticated imaging tools available to practitioners in other fields such as cardiology. By the 1990s computed tomography (CT) and magnetic resonance imaging (MRI) had already made possible the most dramatic strides in medical understanding of disease progression and management. It seemed anachronistic that the ophthalmology field was still using a technique developed in the 1940s.

I observed that the process of manual ophthalmic examination was not only intrusive but its sensitivity highly dependent on the dexterity of the clinician and the inclination (or ability) of the patient to cooperate.  If done well there was only a very minimal capacity to record and compare findings over time, relying on drawing any findings on a piece of paper with a pencil - a process that struck me as horribly primitive in terms of accuracy and repeatability.

I felt that my son most often could not co-operate effectively enough for me to be satisfied about the completeness of the examination, nor could I see and compare the observations of previous visits. When I queried this, I recall the consultant saying “yes everything’s fine... but you’ve got to remember I am just getting a glimpse.”  I was taken aback..... “a glimpse”.......”A GLIMPSE”..... a glimpse is surely not enough for a conclusive medical opinion and certainly not a measure that will reassure a paranoid father! 

That experience set me off on a long and complex struggle to develop a retinal diagnostic technology that would offer doctors more than a glimpse and parents, a reliable understanding of the progression of their offspring’s disease for better or worse. My aspiration from the start was to design a device that would quickly and comprehensively capture a high resolution image of the whole retina - independent of the practitioner’s skill or patient’s ability to comply with instructions. In addition, the device would be practitioner- / patient-friendly in such a way that a 5-year-old would be more than happy to repeat the experience.

Non-compliance for follow up eye examinations is a very well recognised problem, particularly in the management of chronic conditions, such as diabetes, age-related macular degeneration (AMD) and glaucoma. So even if a patient is initially given a good comprehensive dilated manual examination, there is no guarantee they will return for follow-up if they subsequently decide they didn’t like the experience, as many do.

Concept Developments to Technology Design

In seeking a way to fulfill my self-imposed design brief, I had no allegiance to any particular technology, and I had no desire to invent something radical just for the sake of it. I started by forming a team of investigators who began reviewing all the technologies and techniques that were in common use to see if any could realistically be amended, extrapolated or developed toward my desired end. We looked at many possibilities including the auto-montage of fundus photos but found the techniques fundamentally flawed in our terms, either because of the need for dilation or skilled photographers.

We looked at the BIO and slit lamp and other entirely novel approaches. It was a long process and we went up many blind alleys. With all but one concept (using elliptical optics), we came up against some major compromise that undermined the fundamentals of our intent; so all these ideas were consigned to the waste bin.

The only workable concept (a large elliptical optic to couple light into the eye) offered a huge advantage from an ergonomic standpoint but had one major practical drawback in that no one in the world seemed to know how to make such a thing. For a while, the idea was set aside for us only to come back to it much later when we were staring into the abyss of abject failure.

One of the concepts we reviewed along the way was a device called the Equator-plus camera that had been invented by Oleg Pomerantzeff (Fig 3), a professor of engineering based at the Schepens Eye Institute.

Fig 3) Oleg Pomerantzeff

The Equator-plus was capable of very widefield imaging, but by the time we discovered it had already failed in the market, allegedly because of high levels of artefact and poor resolution.  After Pomerantzeff’s retirement, those who took his work forward went in a quite different direction and developed the Rodenstock Confocal Scanning Laser Ophthalmoscope (RcSLO). The device was breakthrough in many senses but it was narrow field and did not address the original challenges identified with the BIO.

 By 1993, technology had moved on, so we felt well able to sort these issues. What we could not sort was the fact that in order to reach the retinal periphery, Pomerantzeff’s technique made it necessary to couple the camera’s lens in contact with the cornea. This feature alone made it an unacceptable approach as no child (and few adults) would willingly allow such intrusion.

Having no design avenues untried and running out of money for the fourth time, we finally returned to the idea of using elliptical optics to couple a wide angle laser scanning into the eye. After overcoming many technical setbacks, we produced the first optomap®. By 1999, we had a device that met our patient-friendly objectives, and by 2002, we had made refinements and some 100 Panoramic200 devices (Fig 4) were in the hands of early users.

A Visit from the Influential Ophthalmologist

Fig 4) The Panoramic200 - one of Optos’ first patients (aged 6yrs)

It was at this point that Charles Schepens arrived with a huge entourage into our exhibition stand at the AAO congress. By this time I knew Dr Schepens was truly venerated by the profession for his lifetime of outstanding contribution to ophthalmology (not least as inventor of the BIO).   So I was proud and delighted that Dr Schepens had taken the time to come deliberately to our stand. I explained to him the workings of our system and why the design was the way it was – to achieve an image of the whole retina and be 5-year-old friendly.

He appeared fascinated and looked at me with great curiosity and then exclaimed... “This is exactly the machine that my good friend Pomerantzeff was trying to build.” Dr Schepens went on to close the circle for me by describing how in the early days he had excitedly examined Pomerantzeff with his new BIO. To his discomfort, he did not receive the applause he expected. Instead Pomerantzeff observed that the process was intrusive and seemed difficult. Pomerantzeff would immediately embark upon the design of a better approach. Some years later the Equator -plus camera emerged.

From Pioneers’ Wisdom to Improved Diagnostics

With the benefit of the works of Schepens and Pomerantzeff, we avoided some pitfalls and built on the inherent advantages of laser scanning that they had pioneered. By solving the problem of making elliptical optics, we eventually succeeded in producing an image of the retina reaching the far periphery without contact, dilation or high light levels.

Optos’ technology has progressed in leaps and bounds since those early days. However, we still have more to achieve and are well on the way, thanks in part to the works of Oleg Pomerantzeff and Dr. Schepens who shared our vision and the importance of the periphery. We are proud to be associated with Dr Schepens’ ambition to improve diagnostics and of our new technology developments that are increasing the understanding of disease processes today. They will hopefully help advance treatments of tomorrow.

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