Scientists at Nanyang
Technological University, Singapore (NTU), with clinicians from
the Singapore Eye Research
Institute (SERI), have invented
a new 'pen camera' that makes it easier for doctors to diagnose patients with
glaucoma.
Glaucoma is an eye disease, where the high fluid pressure
within the eye damages the delicate fibres of the optic nerve, which carry visual
impulses from the eye to the brain. It is a leading cause of blindness in
the world. It has no early symptoms, but a build-up of pressure inside the eye
can be an indicator. In Singapore, around three per cent of people over the age
of 40 years – or over 65,000 people – have glaucoma. This percentage rises with
age.
High pressure within the eye is caused by an imbalance
between fluid production and its drainage out of the eye, typically due to
clogged drainage channels.
An eye specialist determines the type of glaucoma through a
gonioscope, a hand-held lens placed in direct contact with the eye. The
specialist then peers through a microscope paired with the lens to make a
visual diagnosis. Each type of glaucoma requires a different form of treatment.
The drawback of this method of peering through a lens is that the doctor cannot
review the image of the eye at a later date. Machines are available on the
market that can capture images of the angle with or without any direct contact
with the eye, but they are very expensive, ranging from US$25,000 to US$120,000
(S$33,000 to S$158,000).
The new 'pen camera', called the GonioPEN, provides the ability to
detect the type of glaucoma in a faster and cheaper manner. It combines a
high-resolution camera and LEDs for illumination to take a high-quality image
of the human eye. The prototype pen camera, estimated to cost S$5,000, is
connected to a computer via a USB cable. The camera captures images of the eye
from four different perspectives and saves it to the computer, which can then
be magnified several times for a better diagnosis by an eye doctor. A
software is then used to analyse the images, helping doctors and eye
specialists with their diagnosis.
The device causes negligible discomfort, unlike the current
gonioscopes, which are glass scopes that must be pressed against the eyeball of
the patient. In a recent pilot study by Assistant Professor Baskaran Mani from SERI, all 20 patients
found the GonioPEN more comfortable than the conventional hand-held lens used
with a microscope.
The prototype device is portable and digital, allowing a
trained technician to capture images of the eye quickly with minimal training. Its
ease of use means it can be used by primary, secondary or private eye care
physicians, while its compact size makes it portable for all healthcare
set-ups. The cost is also kept low by eliminating the need for a microscope.
Moreover, the current gonioscopy method takes up to 15
minutes to perform and requires a skilled specialist's expertise to diagnose
the problem on the spot, and hence, it is not done in clinics as a routine. Consequently,
nearly half the patients do not go through the test in clinics, leaving
glaucoma undiagnosed.
The GonioPEN addresses these problems by capturing high-resolution digital
images of the eye from the side of the cornea. in just three minutes. The
images, which could be taken by a technician, are reviewed separately by the
eye specialist, shortening the time the patient's eye needs to be under the
microscope as the specialist makes his diagnosis as in the existing
method.
The pen camera was developed over the last two years by a joint
research team led by NTU Associate Professor Murukeshan Vadakke
Matham, Director of NTU's Centre for Optical and Laser Engineering,
in collaboration with Professor
Aung Tin, the Executive Director of SERI. The team also includes NTU
researchers Dr Sandeep Menon P, Dr Shinoj VK and Mr Hong Xun Jie, Jesmond.
The research is supported by grants from the National
Medical Research Council and the National Research Foundation (NRF)Singapore. Patents
have been filed for the GonioPEN by NTU's innovation and enterprise arm,
NTUitive.
The press release states that innovative devices such as the
GonioPEN, developed on campus, are aligned with NTU's Smart
Campus vision
of harnessing the power of digital technology and tech-enabled solutions to
support better learning and living experiences, the discovery of new knowledge,
and the sustainability of resources.
Asst Prof Mani said, "With GonioPEN, the diagnosis can
be generated with an automated software, instead of only relying on a doctor's
expertise. This saves time for both doctors and patients involved in eye care,
allowing more patients to be examined in clinics. Clinically, patients found
the GonioPEN more comfortable than a gonioscope."
Assoc Prof
Murukeshan, who is from NTU's School of Mechanical and Aerospace
Engineering, said, "With the GonioPEN, a digital camera image of a higher
resolution can now be stored for future reference and retrieved easily. A
technician could perform the gonioscopy before a specialist reviews the images
to give an in-depth diagnosis or a second opinion. Doctors can also better
track the changes in their patients' condition over time.
Prof Aung Tin,
who is also Deputy Medical Director (Research) at the Singapore National Eye
Centre, said that in the digital era of healthcare and future teleophthalmic
care possibilities, such a device will enable advancement in the standard of
medical care.
"The GonioPEN, with its compactness and integration to
our electronic medical records, will achieve such goals for the future eye care
model in Singapore," he commented.
