VIRTUAL REALITY IN OPHTHALMOLOGY – REVIVE THE FUTURE DOCTORS
More detail in medical imaging
While the development of virtual reality is being used, and to a large extent, driven by the world of entertainment and training, immersive technologies are increasingly being recognised for their potential in the healthcare sector.
Dr Peter Maloca, a research fellow at Moorfields Eye Hospital in London is fascinated by the architecture of the eye and believes VR has the potential to transform working practices and telecommunication in ophthalmology. “The field of ophthalmology is particularly well placed to benefit from the VR revolution as it has been making use of three-dimensional information for many years”, he comments.
Peter has been championing the use of VR in healthcare by experimenting with virtual reality in his work as eye care specialist, most recently on a project that has seen him undertake a feasibility study of a novel and instant volume render technology to display optical coherence tomography data (OCT) and shadow ray casting into a VR environment.
New opportunities for VR
In his research work, Peter has years of experience of undertaking histological examinations on specimens, cutting tissue to get 2-D images of the sections. But this approach is limited. As Peter notes, “You can only do it once and you lose information when you look at 2D images. I always wanted to touch the image with my eyes.” This motivated him to investigate new and innovative techniques and look beyond the 2D to experimenting in 3D by using optical coherence technology. In turn, this has developed into a journey into the world of VR to discover how VR can potentially transform medical practice, research and training, as well as improve communication with patients.
Laser-derived optical coherence imaging technology
Optical coherence tomography (OCT) is one of the fastest adopted retinal imaging technologies. It is a non-touch laser imaging technology that uses low-coherence light to capture optical scattering from tissue without harming the patient. This results in an incredibly detailed image, on the level of micrometer being produced.
The integration of the OCT system into the operating microscope enhanced ophthalmic surgery and neurosurgery and has allowed OCT imaging of live surgery without disturbing a surgeons’ workflow. Yet, despite the benefits of OCT, the technology is limited through a lack of interactivity and spatial navigation.
Peter believes that these limitations can be addressed by harnessing VR technology to take real time imagery into the virtual space, in effect creating the next generation of OCT image display.
Virtual Reality clears the way to new OCT experiences
“This brand-new VR technology smoothly blurs the boundary between the physical world and computer simulation. As a doctor, I am no longer restricted to looking at my patient’s images from a bird’s eye view. Instead, I become part of the image and can move around in digital worlds to prepare myself, as a surgeon, for an operation in detail never seen before,” says Peter. Furthermore, an interactive experience can be offered to the patient who can take part of novel visualisations of his eye for a better understanding about his conditions.
In undertaking the feasibility research, Peter and his team created a VR program, written in C++/OpenGL to import and display volumetric OCT data using a high-end computer and a tethered head-mounted display. The advanced ray-casting system was implemented to render shadows cast in real-time with 180 frames per second (2 times 90 frames per second and eye) to provide high realism and clarity of the rendering.
An advanced high-end VR image display method was successfully developed to provide new views and interactions in an ultra-high speed projected digital scenery using point-cloud data, rather than polygon-based representations to produce a more photo-realistic and complex image.
A number of tasks were created for this VR application including manipulation of the VR model featured change of first-person view angle, change of model size, walk through-option, adjustment of ray casting light to highlight region of interest, VR cutting with a plane, display and cutting of original point-cloud in any direction, and stereotactic, bimanual manipulations. Adding to the sense of realism, using tethered head-mounted-display headsets enabled a “room scale” tracking technology, allowing the user to move in 3D space and use motion-tracked handheld controllers to interact with the VR model and VR environment.
Conclusions of the first Moorfields’ VR OCT feasibility study
The VR experience was user-tested by 57 people, including 35 ophthalmologists, 6 opticians and 14 other healthcare professionals, with the majority of users completing a survey about their views on the experience.
Among the results, over 70% of participants agreed that the system enhanced their understanding of the clinical case, increased their confidence, and whether the system improved their knowledge of eye disease. 60.9% agreed it could be used as a tool could help them anticipate potential problems and take appropriate action and 63.5% felt that the system might make them less likely to make errors. 89.5% of those questioned would recommend to others. The study supports the safety of the described VR system for a display of 3D OCT data and a immersed subjects reported an enjoyable VR OCT presence effect. (link to TVST)
Implications for the healthcare sector
“I have experienced that these new VR worlds are not like a medical textbook you have read. As soon as you close the book, the knowledge transfer seems to be finished. Instead, in our VR, the beautiful models have continued to accompany me to become a part of me, and have led to a reconnection of my neuro-sensory system, which has made me a better doctor. The winner is the doctor, his patient and students, who can all participate in this new kind of visual information. What I have learned from my patients and students is, that an excellently executed VR is not only the next logical evolution in medical image display and interaction, but also represents the key knowledge distributor and the conveyer of a new learning experience in medicine where ever you are, whoever you are and whenever you dive in.”
Peter believes that VR has the power to transform how healthcare practitioners work across a broad range of applications, from a new tool for patient engagement to medical education, professional training and consultation by a specialist. Indeed, this VR system is being recently introduced for medical teaching purposes at Moorfields Eye Hospital and at the University of Basel in Switzerland for preoperative planning for spinal surgeries and clipping of aneurysms of brain vessels.
“For students, or for patients, it is much easier, because they encounter an eye from inside, like they are walking in the mountains. You can then explain the issue to the patient and their understanding is very intuitive, because you are part of it” notes Peter.
Peter also highlights that as VR is a digital application, it has the potential to remove any barriers created by geographical location; in effect helping medical practitioners and researchers to collaborate effectively and efficiently on projects.
“The potential in VR in medical science is communications. We can now have an VR arena where different parties can join. I could show the data in a VR arena and invite my friend from New York or Paris and get instantaneous advice from people who are much brighter than we are for the benefit of the patient.”
Access the full version of the feasibility study