Understanding Arthur Ho Discipline Hopping for the Sake of Vision Science

Think the world’s first silicone hydrogel contact lens, the development of contact lenses to treat myopia, and research to restore crystalline lens accommodation in presbyopic eyes. Professor Ho has been a major contributor to all of these efforts and more.

Recently acknowledged with a Member of the Order (AM) in the King’s Birthday Honours List, Prof Ho splits his time between the University of Miami in the United States, the University of New South Wales School of Optometry and Vision Science (UNSW SOVS) and the Brien Holden Vision Institute (BHVI) at UNSW.

For someone who “bores quickly”, these three engagements provide the perfect blend of research, education, and product development/commercialisation to keep his curious mind occupied.

There’s not much information publicly available about Arthur Ho. Born in Hong Kong to a Chinese father and an Australian-born Chinese mother, he emigrated to Australia with his family when he was just nine years old. Already a myope, he’d been prescribed his first pair of glasses in 1965, aged five.

“I got these horrible black glasses. I’ve actually still got the prescription, and a photograph of me wearing them, I don’t know why,” he laughs.

Noting the relatively recent but rapid rise in the incidence of myopia he said, “In Hong Kong in primary school in 1965, I was one of only two kids in the whole year of a hundred that had glasses… And it was great because at least in Hong Kong back then, there was a certain prestige in wearing glasses… they thought you were a smart kid.”

Coming to Australia presented a very different story. In 1967 the White Australian Policy had only just been dismantled, and so there was plenty of embedded racism within the community.

As one of just two Chinese families attending Ashfield Public School, young Arthur was the subject of taunting, not only with racially derogatory slurs but with comments about his “headlights” and “four eyes”.

Academically though, he had the advantage.

“In fourth grade in Hong Kong, we were already studying basic concepts of symbolic math, like algebra. But when I came over to Australia, they were still learning the 12 times table.”

At the end of primary school, Arthur was accepted into Fort Street High, a boy’s school at the time, in Sydney’s inner west. A selective public high school, he said Fort St was also responsible for the education of other leading optometrists, among them Professor Charles McMonnies, as well as the late Christine Craigie and Cecil Pye.

FINDING MULTI-STRAND SCIENCE

Prof Ho said he “hated primary school” and he “survived high school” however, the one thing he did get out of Fort Street High, that set him up for his career, was a love for multistrand science, an approach to education taken at the time by the Whitlam government.

“It wasn’t any one particular discipline, but it made you aware of how different things interact. Chemistry and physics and biology and geology all kind of interrelated. And that’s still the way that I work and think.

“Everyone’s after a specialist nowadays. Whereas I’m very much a spread-out generalist; I believe there’s actually a really important place for people who can gully hop between different disciplines and grab things from him, grab things from her. So, for example, beside optometrists and vision scientists, I work with engineering, biomed, and mechanical engineering students here. I work with biomedical engineering and ophthalmology people in Miami. And that’s what keeps me from becoming bored.”

AN ACCIDENTAL JOURNEY

Prof Ho’s journey into optometry was somewhat accidental. In fact, he said, it wasn’t until he walked through the school’s clinic in his second year of optometry study that he worked out what the profession did. And while it was slow to grow on him, he said he is forever grateful for the opportunities optometry has provided.

While the public’s concept of getting a pair of spectacles, of dispensing, may be simplistic, Prof Ho said it was the “humongous amount of clinical work” behind ‘merely’ dispensing glasses that initially captured his interest. “Understanding the anatomy, the physiology, and then, of course, the applied physics side, the optics, the vision, and how the vision – which is the human and the perception side – melds with the physics; the hard science part of optics, how a lens focusses… and how that’s applied into clinical work as an optometrist. I think this is what really drove me all the way through.”

That’s not to say that he took the knowledge gained from his optometry degree into practice immediately after graduation.

“As I said, I bore easy. So, I got bored – probably on day one (after graduating). I said, well, let’s go and enrol into a Master’s degree and see where I go from there. So, I ended up doing a Master of Optometry.”

While studying for his undergraduate degree, Arthur had worked part-time for (then) Dr Brien Holden and so, when a job as his research assistant came up, he jumped at the chance.

“Brien had established the Cornea and Contact Lens Research Unit in 1976 and, at a lecture before lunch, he said they wanted to start a big research project over the summer holidays, so he was looking for a student to help… I became the first research assistant for the unit. That was the best fun in the first few days, and it’s been the best fun for the past 45 years.”

In those early days, Prof Ho was working with well-known names in optometry. Alongside Dr Holden, he collaborated with David Pye, Lewis Williams, Steve Zantos, and Sue Green – on a study looking at what happens when you sleep overnight while wearing contact lenses.* Their research subjects included Debbie Sweeney, Arthur Back, Ian Cox, and Donna La Hood, all of whom went on to make massive contributions, especially to the field of contact lens innovation.

The findings eventually resulted in the publishing of an important paper, led by Prof Holden, on the minimum oxygen required for contact lenses.1 It also informed the development of the first silicone hydrogel contact lens material, which although enhanced, is still in use today.

“So you could say that the silicon hydrogel story started in 1978,” Prof Ho said.

LEANING IN TO MYOPIA

Having found the secret to a comfortable and safe contact lens material, Arthur Ho’s work with Dr Holden continued, and they eventually began working on myopia correction with Professor Earl Smith at the University of Houston in 2002.

“We started developing lenses that can actually bend the focus of light from the periphery in, to try and control myopia,” he explained. “Now, if you think about it, that really only works for optical devices that stays on axis with the eye and that’s a contact lens, not a spectacle lens. So, this is where we thought, first of all, we had something that optometrists can really get involved in and do something about. And secondly, contact lenses could be one of the ideal vehicles for actually delivering the (myopia) treatments.”

Prof Ho’s fascination with myopia continues today, because he said, despite learning so much about the condition, “we’re certainly not at the stage of having a complete understanding about how it works”.

“We know that myopic defocus works. We know that multi-focals work. We can leverage a traditional pair of bifocal lenses, spectacles, or contact lenses. And that’s been done for decades now. That’s been proven.

“And there are so many different variants to where we put plus microlenslets, or where we put peripheral plus power, or how we increase the depth of focus. All of that is playing with light in some way. We know it works, but I don’t think we know exactly how it works definitively yet. We need to get to the stage where we understand the mechanism.

“And then, of course, there are studies that show that if you drop contrast, you deescalate progression. Colour filters seems to have an effect. And weirdly, different studies show that red or blue light filters, may or may not have an effect… Genetics plays a part. The visual environment plays a part. “So, there’s a lot of stuff that’s going on, which is why I say we don’t know anything yet. And these are the sort of things that I get frustrated about. But I also get very curious about them too.”

STUDYING THE CRYSTALLINE LENS

In his effort to understand more about myopia progression, Professor Ho is working with a team of researchers at University of Miami headed by Professors Jean-Marie Parel and Fabrice Manns, and Professor Robert Augusteyn (who is Melbourne-based). Using the most sophisticated optical coherence imaging technology coupled with a laser ray-tracing system developed in Miami, they hope to gain an understanding of the relationship between the eye’s crystalline lens, axial growth, and refraction.

“I want to know how the crystalline lens might be relevant to myopia progression. We talk a lot about axial length, and flattening the cornea using orthokeratology, but not a lot is actually known about how the change in lens power or lens shape may actually affect the emmetropisation process,” he explained.

The team has observed that the thickness of a child’s crystalline lens decreases before slowly increasing, with the inflection point occurring at around six to 13 years of age.

“The eyeball is increasing in length at the same time the eye is growing, and the crystalline lens is decreasing in thickness, but increasing in diameter. And so, the lens power is actually dropping, and that – at least partially – compensates for the increase in axial length of the eye… which may be partially responsible for emmetropisation.”

However, there’s more to it.

“We know from a lot of the crystalline lens research around the world that the gradient refractive index of the crystalline lens is also changing. So as the lens flattens, the axial gradient is changing differently from the transverse radial gradient. And so, part of the power change is due to the refractive index gradient. We don’t know a lot about this in young children. So that’s my very esoteric, basic science interest in myopia.”

With so much going on in just one organ of a young person’s body, Prof Ho said “it’s worse than the first internal combustion engine… I’m amazed emmetropisation works!”.

A SHOTGUN APPROACH

Prof Ho believes that until we precisely understand myopia’s mechanism of action, the scientific world is doing the right thing by giving clinicians “a massive shotgun blast” of potential treatments.

“We’re trying colour filters, we’re trying light scattering, we’re trying defocus, we’re looking at the genes, we’re looking at lighting conditions, because we know that bright light also helps. We really have to tackle as many different aspects as we can until we can focus down and know exactly what the key combinations are that matter.”

Acknowledging the hundreds of lenses now touted worldwide as having potential to control myopia, along with the many lens designs currently being developed at BHVI, Prof Ho said there’s still room for more.

“The (available options) might not work a hundred percent, but because the problem is so big, while we’re waiting for an answer, even if it only works 10 or 20%, you would go for it. The continuous global research effort is also unearthing some unanticipated options, as we saw a few years back when BHVI’s extended depth of focus (EDOF) contact lens, designed for presbyopes, was found to be an effective control for myopia progression.

“We showed serendipitously, because there wasn’t really a mechanistic hypothesis behind it at the time, that it actually reduces myopia progression and is equal to the contact lenses that actually are intended to be myopia controlling,” Prof Ho said.

Additionally, choice is essential because different patients have different preferences due to comfort, fit, ease of use, etc.

“So, the more options, even if they have the same efficacy, the more options we give practitioners and patients, the better. So go for it. Four hundred, a thousand different designs. Let’s do it.

“Myopia to me, is primarily an opportunity. And certainly, I know that this was Brien’s interest, because he saw this as a massive opportunity to do something really important – as much from an optometrist’s perspective as from a commercial perspective.”

HOW LONG MUST WE WAIT?

While Prof Ho is unclear on how long it will be until we have a complete understanding of myopia – and the treatment panacea, he said innovations in technology are paving the way.

“Someone could have a major breakthrough tomorrow. It could be another 10 years. But I have great belief in the rapidity of technology development… It doesn’t take much for a sudden breakthrough to happen. So, we’re waiting for that.”

In the meantime, he said despite “receiving letters from the government suggesting it’s time for retirement” he has no intention of stepping back.

“I don’t think I’m the retiring type, because I bore easy. For as long as I think I’m useful and I can contribute, I would love to be involved in anything and everything. And not just myopia. I still have a very keen interest in presbyopia, and of course, along with presbyopia, intraocular lenses, and cataract… for example, we recently developed a design that can eliminate negative dysphotopsia in IOL patients.”

Clearly, there’s more to Prof Ho than meets the eye.

* In 1978, David Pye, already an MOptom, was a Research Officer at the CCLRU. He went on to become an Associate Professor. Sue Green was a research optometrist. Both Lewis Williams and Steve Zantos were undertaking their PhDs. At that time, Steve Zantos had just discovered ‘endothelial blebs’ using the ZantosHolden method for photographing the corneal endothelium.

Among many awards, in 1997 Dr Holden received a Medal of the Order of Australia (OAM) for outstanding contributions to eye care research and education. In 2001, he was recognised with the prestigious title of Professor Brien Holden OAM, Scientia Professor at University of New South Wales.

Reference

1. Holden, B.A., Mertz G. W., Critical oxygen levels to avoid corneal edema for daily and extended wear contact lenses. Invest Ophthalmol Vis Sci. 1984 Oct;25(10):1161-7. PMID: 6592160.