Advancing CVI research: NEI initiative and multidisciplinary collaboration

Video Transcript:

Editor's note: The below transcript has been lightly edited for clarity.

David Hutton:

I'm David Hutton of Ophthalmology Times. Joining me today is Dr. Lotfi Merabet, who recently had the chance to serve as co-chairman of a National Eye Institute initiative to promote research in cerebral visual impairment. Thanks for joining me. First, can you describe the primary goals of the NEI initiative on CVI and how it aims to advance research in this area?

Lotfi Merabet, OD, PhD, MPH:

Hello, David. Thank you very much for the opportunity to speak to you today. I would say there are really 3 main objectives for this recent NEI workshop. The first is to raise awareness for the condition of cerebral cortical visual impairment. And then the second, I would say, is to establish a series of definitions/diagnostic criteria that we can use for the care of individuals with CVI. Saying the third main initiative would be to establish a registry, a national registry, that will be important for identifying children or individuals with CVI, their criteria, the diagnostic criteria that was used, and at the same time follow these individuals over time to get a sense of the natural history of the condition as well.

David Hutton:

How will the initiative encourage collaboration between neuroscientists, ophthalmologists and other specialists to tackle the complex nature of CVI?

Lotfi Merabet, OD, PhD, MPH:

Well, I think it's a very important initiative, because, as you know, CVI is a very multidisciplinary field, not just in terms of understanding the basis of the condition, but also in terms of diagnosis and rehabilitation as well. So, my hope is that this initiative will bring together not only eye care providers, but other care providers involved as well. Neuroscientists have a better understanding of the underlying neurophysiology of the condition, and bringing in, as well, allied specialists, for example, teachers of the visually impaired, occupational therapists, physical therapists, orientation, mobility specialists. It really requires a multidisciplinary approach, not just in terms of the diagnosis, but I would also say, as well, an understanding of the underlying condition, and also to develop education and rehabilitative strategies as well.

David Hutton:

What role do you see public awareness and education playing in the success of this initiative, and how will outreach to patients and caregivers be integrated into the program?

Lotfi Merabet, OD, PhD, MPH:

I think it is extremely important, because I think we are seeing a fundamental shift in terms of visual impairment and blindness in children, particularly in pediatric populations. If you consider visual impairment and blindness in adults, typically, we're talking about acquired diseases or acquired issues that happen later in life, particularly at the level of the eye. When we're talking about visual impairments and blindness in children, we're talking about something happening very, very early in development, if not at birth. And at the same time, at the level of the brain, as opposed to the eye. So that's a very, very different shift in terms of our thinking, again, not only in terms of diagnosis, but also in terms of education and debilitation as well. So, I think it's extremely important to raise that issue. At the same time, from an epidemiological standpoint, it's important to realize that CVI is the main cause of visual impairment in children. And again, shifting our mindsets. The reason behind this is because many of these children are born with some sort of complication occurring at birth or shortly thereafter. Thirty, 40, 50 years ago, these children weren't surviving, but they are surviving today, and because of excellence in healthcare and as well as our recognition, we really need to be prepared for these children, as well as they as they grow older and so they can thrive to their fullest potential.

David Hutton:

Let's talk about diagnosis a little bit. What challenges do you see in diagnosing CVI, and how does the NEI initiative plan to address gaps in early detection and diagnosis?

Lotfi Merabet, OD, PhD, MPH:

Yeah, so I think the biggest challenge in terms of diagnosis, the fact that we really don't have a universal protocol or universal algorithm. A lot of that has to do with, not only sort of site specific effects, not just in the United States, but also around the world, but also at the same time, the tremendous heterogeneity of the condition as well. Children with CVI, or individuals with CVI, you know, are really, really diverse in their presentation. Some, for example, will have a lot of eye issues, for example, strabismus, or a problem at the level of the eye, or significant refractive error, which obviously has to be contended with. Other individuals may have extensive brain injury, which would reduce their visual acuity. Others, for example, may have injury at higher order areas or processing areas of the brain, where visual field and visual acuity may be within normal levels, and their visual impairment is more related to processing issues, as opposed to things like visual acuity or visual field. So ,coming up with an algorithm that can account for the. Broad heterogeneity, I think, is extremely challenging. The second issue, I would say, is what are the appropriate tools for the assessment as well? And that may again be limited by the resources available at a particular site or particular clinic, and I think we have to come find this sort of lowest common denominator that allows us to try to catch as many of these individuals as possible, so that one individual who diagnoses CVI in one part of the country uses the same sort of strategy as someone else we do in another part of the country. And again, we're trying to talk about the same people.

David Hutton:

Are there any emerging technologies or research methodologies that you believe hold promise improve improving our understanding and treatment of CVI?

Lotfi Merabet, OD, PhD, MPH:

Sure. I would say there's 2 that we are actually pursuing in our group, in our research initiative. One is using eye tracking, and there are a number of labs in the United States that are doing this. I think eye tracking is extremely useful because it allows for an objective characterization of how that individual uses their eyes and uses their vision when they interact with the world. At the same time, it doesn't require a verbal response, or it doesn't require necessarily a manual response. So it can be based solely in terms of eye movement. I think that that's very, very, very robust, and there's a lot of data that can be extracted. So, where an individual looks, how long they look where they don't look, tells me something about how they process that information and how they interact with the visual world. So I think that's very, very useful. The second arena that we're trying to explore is virtual reality, because I think it's extremely important to see how this individual uses their vision in the real world, and we call that functional vision. So, for example, how they read letters on an eye chart is certainly very, very useful and very, very informative, but it really doesn't tell me that much how they use their vision in the real world, which is much more complex than letters on a chart. So, virtual reality allows you to create these controlled environments where you can explore, for example, how that individual would search for a favorite toy or a family member or a particular individual in a crowd, for example. So, going beyond what we do in a classic eye exam to try to understand how that person uses their vision in the real world. And I think virtual reality could be a very, very promising platform to allow that.

David Hutton:

How does the initiative plan to support research on the development of rehabilitation strategies for patients with CVI, particularly in those pediatric, pediatric populations that you mentioned?

Lotfi Merabet, OD, PhD, MPH:

Well, I think the research, for 2 aspects, is the research can help understand the underlying neurophysiological basis of CVI. So, for example, if you have 1 particular type of injury, the timing of that injury, the location and the extent of that injury, and how that correlates to your visual function, and functional vision, I think, is an extremely important piece, because once that individual presents with a particular type of injury, we can make predictions about how that individual might use their vision, of the challenges that they may face, and what could be actually be helpful. At the same time, I think the research initiative, initiatives and times of understanding the longitudinal and the natural history of this condition is extremely important as well. So again, we can make correlations between the type of injury, the location of injury, the extent of that injury, and the type of outcomes that we can anticipate and correlate that with particular strategies that were implemented as well. So, I think it's extremely important to collect data in a large scale and an objective manner, so that we have a better understanding of what the natural history of this condition is and something that we have not had in the past, unfortunately.

David Hutton:

And lastly, what are the key takeaways from this for ophthalmologists and optometrists, and what are the next steps for this initiative?

Lotfi Merabet, OD, PhD, MPH:

So I would say as an optometrist myself, and one thing that I'd like to you, know, share with my colleagues is that you've probably seen this child at some point in your in your practice, and perhaps not even realized it. And what I would say is that an individual who presents, who has otherwise, say, visual acuity at a near normal level, and an eye health that looks, you know, normal as well, but yet has all these complex sorts of visual issues, like, you know, it's not safe to cross the street or I have trouble, you know, following what's happening in a classroom or something. It's not a psychological or psychiatric issue. It's a brain processing issue. So, what I would say to my colleagues, what's extremely important, is that do not dismiss these individuals because the eye itself looks healthy, or visual acuity seems to be within a normal range. There is a processing piece because the eyes connected to the brain and understanding what the brain component is to that visual impairment is extremely impairment is extremely important.