Better Brain Health: UP Neurosurgeon Develops Non-invasive, Eye-based Method to Measure Intracranial Pressure
Prof Llewellyn Padayachy is pioneering work in non-invasive techniques to assess and measure raised pressure inside the skull.
Paediatric neurosurgeon Professor Llewellyn Padayachy, Head of the Department of Neurosurgery at the University of Pretoria’s (UP) Steve Biko Academic Hospital, is redefining how brain-related diseases are diagnosed and treated, especially in low-resource settings. He’s at the forefront of pioneering work in non-invasive techniques to assess and measure raised pressure inside the skull, known as intracranial pressure (ICP).
As part of his PhD 15 years ago, Prof Padayachy set out to find safer methods for earlier diagnosis of brain tumours in children, a patient group that often presented far too late, with tumours already dangerously large. This trend of delayed diagnosis shifted his research focus to detecting raised ICP, pressure within the skull – a critical marker when diagnosing life-threatening neurological conditions. Traditionally, assessing this pressure involves invasive procedures and highly specialised equipment, resources that are often unavailable in rural or primary care settings.
“Ultimately, this non-invasive system offers a ‘thermometer for the brain’ – a simple yet powerful diagnostic tool that enables earlier treatment, better outcomes and more equitable healthcare access,” Prof Padayachy explains. “This research provides a lifesaving bridge between innovation and accessibility, especially on a continent where neurosurgery is severely under-resourced.”
At the heart of this innovation is the concept of the eye as a window to the brain. Initially using ultrasound imaging to measure the optic nerve sheath – along with technologies like optical coherence tomography (which uses light waves to take cross-sectional images of eye tissue), intraocular tonometry (to measure pressure inside the eye) and retinal scanning – his team has refined methods for non-invasively assessing ICP, without radiation or surgical intervention. This offers a faster, safer and more portable method for diagnosing neurological diseases.
Prof Padayachy’s initial work has since expanded to include adult patients, and now plays a crucial role in
identifying a range of central nervous system disorders, including brain tumours, hydrocephalus, infections and intracranial bleeding, conditions where early detection is essential for effective treatment.
This non-invasive approach has major benefits for both patients and health systems.
Early detection of conditions like brain tumours and hydrocephalus allows for intervention when symptoms are still mild and treatment is most effective. Detecting tumours earlier is the best modifier of outcome.
This eye-based technique is designed for point-of-care diagnosis. It is a simple, rapid method that can be employed in GP practices, rural clinics or by assistant nurse, with minimal training. By analysing high volumes of data using machine-learning algorithms, a “traffic light” system has been developed to streamline diagnosis: green for normal, orange for uncertain and red for urgent intervention.
The reduced risk and cost of this approach eliminates the dangers of invasive testing and reliance on expensive imaging tools like magnetic resonance imaging (MRI) and computed tomography (CT) scans, which are often unavailable in rural areas.
It can support broader disease management by aiding in the diagnosis of not just tumours but various central nervous system disorders, including bleeds, infection, strokes and traumatic brain injuries. This technology is also being tested in countries like Norway and Germany, and is applicable to astronauts who experience raised intracranial pressure in microgravity.
A solution for Africa, with global impact
According to the World Health Organization (WHO), more than two billion people around the world lack access to safe surgical care, with low- and middle-income countries carrying the greatest burden. Africa faces immense challenges in neurosurgery, such as severe underfunding, a lack of training positions and a high burden of disease.
There is one neurosurgeon per four million people, far below the WHO’s recommendation of one per 200 000. This shortage, compounded by the lack of a central brain tumour registry and limited access to diagnostics, severely impacts patient outcomes. In South Africa alone, limited infrastructure and only a handful of neurosurgical training posts mean that even the brightest medical talent can be lost in the system.
“We have more than 70 applicants for a single registrar training post,” Prof Padayachy says. “This is completely inadequate. This research demonstrates how innovation born out of necessity can help us overcome these hurdles.”
This non-invasive technique isn’t just capable of transforming care in Africa; its application in diagnosing visual impairment due to raised intracranial pressure in astronauts, where a conventional tool like lumbar puncture is difficult to use, highlights its versatility. Ultrasound, which is portable and radiation-free, is the only imaging modality suitable for space. The same “thermometer for the brain” now being tested in orbit began in the clinics of South Africa.
“With the right support, we can create a self-sustaining model for research in Africa, by Africans,” Prof Padayachy says. “We certainly have the talent, and we can develop the tools to lead the world in non-invasive brain diagnostics.”
