Category: Ophthalmology

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Closing the Gap on Eye Care Through Early Detection this World Optometry Week

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Uneven access to optometry services in South Africa puts pressure on prevention, but collaboration and technology are helping shift the dial.

Photo by Hush Naidoo Jade Photography on Unsplash

Access to good eye care in South Africa remains uneven, resulting in many conditions being diagnosed too late. World Optometry Week, observed from 22 to 28 March, shines a light on this reality, where one in 10 South Africans suffers from some form of vision loss, highlighting the importance of eye health and the role early detection plays in preventing avoidable vision loss.

This challenge is exacerbated by the fact that, while there are approximately 4 200 registered optometrists in South Africa, only a small proportion practise in the public sector. This limits access to care for many communities and delays diagnosis, particularly in under-resourced areas. As a result, prevention remains one of the most important, yet underutilised, tools in protecting eye health.

“The reality is that many serious eye conditions develop without noticeable symptoms early on,” says Dr Themba Hadebe, Clinical Executive at Bonitas. “By the time vision is affected, the condition may already be advanced. Regular eye tests are critical in detecting issues early and preventing avoidable vision loss.”

This year’s World Optometry Week theme, “A Shared Vision: Collaboration in Global Eye Care”, underscores the need for a coordinated approach to improve access, strengthen prevention and enable early diagnosis. This is one way to ease pressure on the broader healthcare system, since identifying conditions earlier reduces the likelihood of more complex interventions later, benefiting both patients and providers.

Why early detection matters

Conditions linked to chronic illnesses, particularly diabetes, remain a significant contributor to vision loss in South Africa. Diabetic retinopathy is among the leading causes of blindness in working-age adults, yet it often develops without pain or early warning signs.

Advances in optometric technology are beginning to shift how the risks of permanent damage are identified and managed. Developments highlighted by the American Optometric Association point to a growing role for AI-assisted diagnostics and enhanced imaging in improving both the speed and accuracy of screening. These tools support clinicians by flagging potential abnormalities during routine eye tests, enabling earlier referral for further assessment where needed.

Within this context, collaboration between medical schemes and provider networks plays a role in strengthening preventative care. Through its partnership with PPN, Bonitas provides members with access to diabetic retinopathy screening as part of the eye testing process at participating network practices.

The screening process uses AI-assisted technology to evaluate retinal images in real time, flagging any irregularities that could indicate early-stage disease. This allows clinicians to identify potential issues ranging from diabetic retinopathy to glaucoma or macular degeneration before they progress to more serious stages. Patients who require further assessment are referred for secondary care, ensuring timely intervention and reducing the risk of irreversible vision loss.

“This approach extends the reach of early detection by combining advanced technology with coordinated care and helps make the most of the limited number of specialists available,” says Hadebe. “Spotting problems early dramatically improves outcomes while reducing pressure on our healthcare system. In practice, it means a member could walk into a routine check-up and leave with peace of mind, or if something is flagged, a clear path to treatment.”

As World Optometry Week highlights, awareness must translate into action. In a healthcare environment where access is not equal, regular eye tests, particularly for those at higher risk, remain essential to safeguarding vision and improving long-term health outcomes.

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Scientists Engineer ‘Living Eye Drop’ to Support Corneal Healing

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Photo by Victor Freitas on Pexels

University of Pittsburgh School of Medicine researchers have developed an early-stage, experimental “living eye drop” that uses a naturally occurring eye bacterium to support corneal wound healing.

The proof-of-‑concept study, published in Cell Reports, demonstrates that the harmless eye-dwelling microbe Corynebacterium mastitidis can be genetically modified to secrete an anti-inflammatory therapeutic that promotes healing following corneal injury in a mouse model.

“This is the first demonstration that a microbe that lives on the ocular surface could be engineered to deliver a therapeutic that improves eye health,” said senior author Anthony St. Leger, associate professor of ophthalmology and of immunology and a faculty member of the UPMC Vision Institute. “It opens the door to the idea of ‘living medicine’ for the eye – something you apply once, and it stays, protects and helps the tissue heal.”

Because tears continually wash medications away, treating ocular surface disease often requires multiple daily applications of eye drops. This can limit the effectiveness of therapies for conditions such as corneal abrasions or dry eye disease.

To explore an alternative delivery method, the Pitt team engineered C. mastitidis, a benign bacterium that naturally resides under the eyelid, to continuously secrete cytokine interleukin10 (IL10). In mice, corneas that were gently scratched and treated with the engineered bacteria healed faster than those treated with regular bacteria or saline. When the IL10 receptor was blocked, this benefit disappeared – confirming the therapeutic effect was IL10-dependent.

The researchers also created a version of the microbe that releases human IL10, which improved wound closure in lab-grown cells that make up the outermost layer of human cornea and reduced inflammatory signaling in human immune cells. These studies offer an initial indication that the approach could eventually be adapted for use in people, though substantial development remains.

“What makes this exciting is that the system is modular,” St. Leger explained. “We built it so you can swap in different genes – different cytokines, growth factors or other proteins – to tailor the therapy to specific eye diseases.”

Though promising, the technology is still in early development. The researchers note that many steps must be completed before any clinical translation is possible, including developing built-in “off switches”  to safely and reliably remove or deactivate the engineered bacteria after they are no longer needed.

Source: University of Pittsburgh

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New Antenna Upgrade Boosts MRI Image Quality

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Photo by Mart Production on Pexels

Magnetic resonance imaging (MRI) is one of medicine’s most powerful diagnostic tools. But certain tissues deep inside the body – including brain regions and delicate structures of the eye and orbit that are of particular relevance for ophthalmology – are difficult to image clearly. The problem is not the scanner itself, but the hardware that sends and receives radio signals. 

Now, researchers at the Max Delbrück Center have developed an advanced materials-based MRI antenna that overcomes these limitations – delivering enhanced images more quickly and that can be used in existing MRI machines. The research, led by Nandita Saha, a doctoral student in the Experimental Ultrahigh Field Magnetic Resonance lab of Professor Thoralf Niendorf, was published in Advanced Materials.

Niendorf and his team worked closely with researchers at Rostock University Medical Center, combining expertise in MRI physics with clinical ophthalmology and translational imaging. The Rostock team is also supporting clinical validation of the technology.

“By using concepts from metamaterials, we were able to guide radiofrequency fields more efficiently and demonstrate how advanced physics can directly improve medical imaging,” says Niendorf, senior author of the paper. “This work shows a pathway toward faster, clearer MRI scans that could benefit patients in many clinical areas.” 

Rethinking MRI hardware with metamaterials

MRI works by sending radiofrequency (RF) signals into the body and detecting how tissues respond inside a strong magnetic field. The stronger the signal response, the better the image. Conventional MRI antennas – also called RF coils – often struggle to collect enough signal from deep or anatomically complex regions. This leads to images that lack detail and prolongs scan times.

The research team addressed this bottleneck by integrating metamaterials directly into the MRI antenna. Metamaterials are engineered structures that interact with electromagnetic waves in ways not found in natural materials. The engineered RF antenna increases signal strength from targeted tissues, improves spatial resolution and image sharpness and enables faster data acquisition. Crucially, the antenna fits into existing MRI systems, avoiding the need for new infrastructure. The team validated the technology by imaging the eye and orbit region in a group of volunteers at 7.0 Tesla.

MRI image of an eye, the eye socket and the brain.
© AG Niendorf, Max Delbrück Center

“Our research demonstrates clear relevance for ophthalmological applications as it can facilitate anatomically detailed, high-spatial resolution MRI of the eye,” says Professor Oliver Stachs, a co-author of the paper at University Medicine Rostock. “It offers the potential to open a window into the eye and into (patho)physiological processes that in the past have been largely inaccessible.” 

“Our goal was to rethink MRI hardware from the modern physics of antenna design,” adds Saha. This technology can also be tuned to protect sensitive areas of the body during MRI, for example, to reduce unwanted heating around medical implants, she adds. It could also be used to focus RF energy more effectively for MRI guided therapies for various cancer treatments, such as gentle heating of tumors (hyperthermia) or thermal ablation of tissue. 

Better diagnostics

For patients, MRI scans can be uncomfortable and time-consuming – even more so when images need to be repeated because important details are hard to see. Faster scans mean patients spend less time inside scanners. Clearer images mean doctors can make diagnoses with greater confidence. And because the new antenna is lightweight and compact, it can also be designed to better fit specific parts of the body, improving comfort even further.

The technology could also be adapted to support MRI systems running at magnetic field strengths lower or higher than 7.0T, to image target anatomy other than the eye, orbit or the brain or to track metabolism or drug movement inside the body, says Niendorf. Special MRI scans that use other atoms, such as sodium or fluorine, could also benefit from this technology by producing clearer signals and better images, he adds. 

“Innovations in imaging hardware have the potential to transform diagnostics, and this study is an important step toward next-generation MRI technology,” says Dr Ebba Beller, a co-author of the paper at Rostock University Medical Center.

The researchers are already planning larger studies at multiple hospitals and adapting the design for other organs, such as the heart and kidneys. The collaboration will continue to be strengthened by long-standing reciprocal visiting scientist appointments of Stachs and Niendorf. 

Source: Max Delbrück Center for Molecular Medicine

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Growing Evidence that Metformin Could Treat Age-related Macular Degeneration

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Retina showing reticular pseudodrusen. Although they can infrequently appear in individuals with no other apparent pathology, their highest rates of occurrence are in association with age-related macular degeneration (AMD), for which they hold clinical significance by being highly correlated with end-stage disease sub-types, choroidal neovascularisation and geographic atrophy. Credit: National Eye Institute

Doctors have found further evidence that metformin is associated with less progression of age-related macular degeneration (AMD), the most common cause of blindness in Western countries. In a study of over 2000 people with diabetes, people over the age of 55 years taking metformin were 37% less likely to develop the intermediate stage of AMD over five years compared to those not taking metformin. The results were published in BMJ Open Ophthalmology.

AMD is a disease which affects the central retina or macular at the back of the eye. It eventually causes the light-sensitive tissue to die off (geographic atrophy, a form of ‘dry’ AMD) or be damaged by abnormal blood vessel growth (‘wet’ AMD). Intermediate and advanced AMD affects 10-15% of people over 65 years of age (1.1 to 1.8 million people in the UK), and is the commonest cause of blindness in high-income countries.

The annual cost of AMD is estimated to be £11.1billion in the UK. Geographic atrophy has no treatment in the UK and Europe, while treatments for wet AMD are expensive and unpleasant (repeated injections into the eye).

The research from the University of Liverpool used pictures taken of the eyes of 2000 people attending the routine diabetic eye disease screening programme in Liverpool over 5 years. The researchers assessed whether AMD was present on the photographs and how severe it was, and then compared those taking metformin and those who were not. They also adjusted for factors which might bias the result, such as age, sex, and duration of diabetes. The odds of developing intermediate AMD over 5 years in the metformin group was 0.63 compared to the no metformin group (95% confidence range 0.43 to 0.92).

A potential benefit from metformin in AMD has been suspected before, but this is the first study to grade AMD from eye photographs. Previous studies on metformin have used secondary information on AMD such as GP diagnostic codes, or insurance claims in the US.

Dr Nick Beare, an eye doctor who led this research, says: “Most people who suffer from AMD have no treatment, so this is a great breakthrough in our search for new treatments. What we need to do now is test metformin as a treatment for AMD in a clinical trial. Metformin has the potential to save many people’s sight.”

Source: University of Liverpool

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Common Eye Ointment can Damage Glaucoma Implants, Study Warns

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Research shows that petrolatum-based eye ointments can cause the device to swell and potentially rupture, prompting an urgent update to clinical guidance.

Photo by Tima Miroshnichenko


Widely-used eye ointments can cause glaucoma implants to swell and potentially rupture, according to new research from Nagoya University in Japan. This study is the first to show, using clinical and experimental evidence, that petrolatum-based eye ointments can compromise the PRESERFLO® MicroShunt, an implant used in over 60 countries to treat glaucoma.

Glaucoma is an eye disease that damages the optic nerve and can lead to vision loss. It often results from increased intraocular pressure caused by blocked drainage of eye fluid. A recent study estimated that 76 million people globally are affected by glaucoma.

Progression of visual field loss (from left to right) due to glaucoma
(Credit: Ryo Tomita)

MicroShunt is a small filtration device implanted in the eye to improve fluid drainage in glaucoma patients. Compared to traditional surgeries, it lowers post-operative complications and reduces reliance on additional medications.

MicroShunt is made from a styrenic thermoplastic elastomer based on a polystyrene-block-polyisobutylene-block-polystyrene (SIBS) block polymer, which is highly biocompatible, flexible, and less likely to cause inflammation or scarring. However, this material is vulnerable when it comes into contact with hydrocarbon- and oil-based materials. Due to its high oil affinity, exposure to petrolatum-based eye ointments may allow oil components to penetrate the device, causing swelling and potential changes in its shape and flexibility.

The MicroShunt manufacturer’s instructions state that “the MicroShunt should not be subjected to direct contact with petrolatum-based (ie, petrolatum jelly) materials, such as ointments and dispersions.” But this precaution is not widely recognised or consistently followed in clinical practice.

“Swollen MicroShunts can be structurally fragile,” said ophthalmologist and Assistant Professor Ryo Tomita of Nagoya University Graduate School of Medicine, the study’s first author. “During surgery, I observed a rupture in a swollen MicroShunt. If more clinicians are aware of this risk, they will be able to prevent similar problems.”

Tomita and colleagues, including Assistant Professor Taiga Inooka and Associate Professor Kenya Yuki from Nagoya University Hospital and the Graduate School of Medicine collaborated with Dr. Takato Kajita and Junior Associate Professor Atsushi Noro from the Graduate School of Engineering to examine changes in the MicroShunt after exposure to a petrolatum-based eye ointment.

The medical team reviewed clinical cases, while the engineering team conducted laboratory analyses. The findings were published in Graefe’s Archive for Clinical and Experimental Ophthalmology.

Clinical evidence

The clinical study examined seven glaucoma patients whose MicroShunt implants were later removed for different reasons. The results revealed a clear pattern. In three cases, the MicroShunt was exposed outside the conjunctiva, and patients received a petrolatum-based eye ointment. All three explanted devices showed significant swelling, and two of them ruptured.

In three other cases, the MicroShunt remained covered by the conjunctiva, and no ointment was administered. These devices retained their original structure. Crucially, in one additional case, the MicroShunt was exposed outside the conjunctiva, but no ointment was applied. The device did not swell. This indicates that direct contact with the ointment, rather than conjunctival rupture alone, is the primary cause of swelling.

Photographic comparison of MicroShunt illustrating size changes
Top: MicroShunt explanted from a patient, exhibiting diffuse swelling with fracture and loss of one fin
Middle: MicroShunt explanted from another patient, showing localized swelling around the fin
Bottom: Unused MicroShunt (control)
Scale: 1 division = 1 mm   
(Credit: Ryo Tomita)

Laboratory confirmation

Laboratory experiments confirmed the clinical findings. The team immersed unused MicroShunts in petrolatum-based eye ointment to reproduce the swelling seen in clinical cases. Microscopic measurements showed significant changes. After 24 hours in the ointment, the MicroShunt’s outer diameter increased to 1.44 times its original size, and the fin-like portion widened to 1.29 times its initial value.

Chemical analysis identified the cause of this change. After 24 hours of immersion, oil components made up approximately 45% of the MicroShunt’s total weight, rising to 73% after three months. These results confirmed the primary cause of swelling to be the absorption of oil-based ointment constituents into the material.

Clinical implications

The research team emphasises that clinicians should avoid using petrolatum-based ointments on patients with MicroShunt implants, particularly when the device is exposed outside the conjunctiva. Alternative post-operative treatments should be considered, while further research is needed to assess whether swelling impacts MicroShunt performance even when rupture does not occur.

“Our study found that commonly used medical materials can cause unexpected complications if their chemical properties and usage environments are not fully understood,” Noro stated. “From both medical and engineering perspectives, we emphasise the importance of understanding the chemical properties of medical materials and appropriately managing their usage environments.”

Paper information:

Ryo Tomita, Taiga Inooka, Takato Kajita, Hideyuki Shimizu, Ayana Suzumura, Jun Takeuchi, Tsuyoshi Matsuno, Hidekazu Inami, Koji M. Nishiguchi, Atsushi Noro, and Kenya Yuki. (2026) Petrolatum-based ointment application induces swelling of the PRESERFLO MicroShunt. Graefe’s Archive for Clinical and Experimental Ophthalmology
DOI: 10.1007/s00417-025-07075-2

Categories : Ophthalmology PaediatricsTags :

Babies Learning to See After Being Born Blind

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Photo by Jeffrey Riley on Unsplash

A study conducted by University of Louvain (UCLouvain), published in Nature Communications, shows that part of the brain of babies born blind is permanently altered, while another part remains surprisingly intact. Babies’ brains are much more adaptable than previously thought: even if they cannot see at the very beginning of life, they can later learn to recognise the world around them.

Some babies are born with early blindness due to dense bilateral congenital cataracts, requiring surgery to restore their sight. This period of several months without vision can leave a lasting mark on how the brain processes visual details, but surprisingly little on the recognition of faces, objects, or words.

Using brain imaging, the researchers compared adults who had undergone surgery for congenital cataracts as babies with people born with normal vision. The results are striking: in people born with cataracts, the area of the brain that analyses small visual details (contours, contrasts, etc.) retains a lasting alteration from this early blindness. On the other hand, the more advanced regions of the visual brain, responsible for recognising faces, objects, and words, function almost normally. These “biological” results have been validated by computer models involving artificial neural networks. This distinction between altered and preserved areas of the brain paves the way for new treatments. In the future, clinicians may be able to offer visual therapies that are better tailored to each patient.

“Babies’ brains are much more adaptable than we thought,” explains Olivier Collignon, Professor at University of Louvain (UCLouvain). “Even if vision is lacking at the very beginning of life, the brain can adapt and learn to recognise the world around it even on the basis of degraded information.”

These findings also challenge the idea of a single “critical period” for visual development. Some areas of the brain are more vulnerable to early vision loss, while others retain a surprising capacity for recovery. “The brain is both fragile and resilient,” adds Olivier Collignon. “Early experiences matter, but they don’t determine everything.”

Source: Université catholique de Louvain

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Pioneering Retinal Implant Restores Reading Vision to Blind Eyes

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Study participant Sheila Irvine training with the device. Credit: Moorfields Eye Hospital

After being treated with an electronic eye implant paired with augmented-reality glasses, people with sight loss have recovered reading vision, reports a trial involving a UCL and Moorfields clinical researcher.

The results of the European clinical trial, published in The New England Journal of Medicine, showed 84% of participants were able to read letters, numbers and words using prosthetic vision through an eye that had previously lost its sight due to the untreatable progressive eye condition, geographic atrophy with dry age-related macular degeneration (AMD).

Those treated with the device could also read, on average, five lines of a vision chart; some participants could not even see the chart before their surgery.

The trial, with 38 patients in 17 hospital sites across five countries, was testing a pioneering device called PRIMA, with Moorfields Eye Hospital being the sole UK site. All patients had lost complete sight in their eye before receiving the implant.

Dry AMD is a slow deterioration of the cells of the macula over many years, as the light-sensitive retinal cells die off. For most people with dry AMD, they can experience a slight loss of central vision. Through a process known as geographic atrophy (GA), it can progress to full sight loss in the eye, as the cells die and the central macula melts away. There is currently no treatment for GA, which affects 5 million people globally. All participants in this trial had lost the central sight of the eye being tested, leaving only limited peripheral vision.

This revolutionary new implant is the first ever device to enable people to read letters, numbers and words through an eye that had lost its sight.

Mr Mahi Muqit, associate professor in the UCL Institute of Ophthalmology and senior vitreoretinal consultant at Moorfields Eye Hospital, who led the UK arm of the trial, said: “In the history of artificial vision, this represents a new era. Blind patients are actually able to have meaningful central vision restoration, which has never been done before.

“Getting back the ability to read is a major improvement in their quality of life, lifts their mood and helps to restore their confidence and independence. The PRIMA chip operation can safely be performed by any trained vitreoretinal surgeon in under two hours – that is key for allowing all blind patients to have access to this new medical therapy for GA in dry AMD.”

The procedure involves a vitrectomy, where the eye’s vitreous jelly is removed from between the lens and the retina, and the surgeon inserts the ultra-thin microchip, which is shaped like a SIM card and just 2mm x 2mm. This is inserted under the centre of a patient’s retina, by creating a trapdoor into which the chip is posted. The patient uses augmented-reality glasses, containing a video camera that is connected to a small computer, with a zoom feature, attached to their waistband.

Around a month or so after the operation, once the eye has settled, the new chip is activated. The video camera in the glasses projects the visual scene as an infra-red beam directly across the chip to activate the device. Artificial intelligence (AI) algorithms through the pocket computer process this information, which is then converted into an electrical signal. This signal passes through the retinal and optical nerve cells into the brain, where it is interpreted as vision. The patient uses their glasses to focus and scan across the main object in the projected image from the video camera, using the zoom feature to enlarge the text. Each patient goes through an intensive rehabilitation programme over several months to learn to interpret these signals and start reading again.

No significant decline in existing peripheral vison was observed in trial participants.

These findings pave the way for seeking approval to market this new device.

Sheila Irvine, one of Moorfields’ patients on the trial who was diagnosed with age-related macular degeneration, said: “I wanted to take part in research to help future generations, and my optician suggested I get in touch with Moorfields. Before receiving the implant, it was like having two black discs in my eyes, with the outside distorted.

“I was an avid bookworm, and I wanted that back. I was nervous, excited, all those things. There was no pain during the operation, but you’re still aware of what’s happening. It’s a new way of looking through your eyes, and it was dead exciting when I began seeing a letter. It’s not simple, learning to read again, but the more hours I put in, the more I pick up.

“The team at Moorfields has given me challenges, like ‘Look at your prescription’, which is always tiny. I like stretching myself, trying to look at the little writing on tins, doing crosswords.

“It’s made a big difference. Reading takes you into another world, I’m definitely more optimistic now.”

The global trial was led by Dr Frank Holz of the University of Bonn, with participants from the UK, France, Italy and the Netherlands.

The PRIMA System device used in this operation is being developed by Science Corporation (science.xyz), which develops brain-computer interfaces and neural engineering.

Mr Muqit added: “My feeling is that the door is open for medical devices in this area, because there is no treatment currently licensed for dry AMD – it doesn’t exist.

“I think it’s something that, in future, could be used to treat multiple eye conditions.”

More about the device:

The device is a novel wireless subretinal photovoltaic implant paired with specialised glasses that project near-infrared light to the implant, which acts like a miniature solar panel.

It is 30 micrometres/microns (0.03mm) thick, about half the thickness of a human hair.

A zoom feature gives patients the ability to magnify letters. It is implanted in the subretinal layer, under the retinal cells that have died. Until the glasses and waistband computer are turned on, the implant has no visual stimulus or signal to pass through to the brain.

In addition to practising their reading and attending regular training, patients on the trial were encouraged to explore ways of using the device. Sheila chose to learn to do puzzles and crosswords while one of the French patients used them to help navigate the Paris Metro – both tasks being more complex than reading alone.

Source: University College London

Categories : Implants and Prostheses OphthalmologyTags :

Oxford Researchers Develop Uniquely Shaped Microstent to Combat Glaucoma

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A schematic of the eye’s anterior segment, demonstrating the anatomical placement of the microstent. The stent diverts aqueous humour from the anterior chamber to the suprachoroidal space through the flexible tube, creating a subconjunctival bleb supported by the expanding element. Credit: Yunlan Zhang, Zhong You, Jared Ching.

A team of researchers at the University of Oxford have unveiled a pioneering ‘microstent’ which could revolutionise treatment for glaucoma, a common but debilitating condition. The study has been published in The Innovation, Cell Press.

Glaucoma is a leading cause of vision loss, second only to cataracts. Globally, 7.7 million people were blind or visually impaired due to glaucoma in 2020. The condition can cause irreversible damage to the optic nerve, due to increased pressure within the eyeball. Current treatment options – principally surgery to create openings in the eye or insert tubes to drain fluid – are highly invasive, carry risk of complications, and have limited durability.

‘Our deployable microstent represents a significant advancement in glaucoma treatment,’ said lead author Dr Yunlan Zhang (University of Oxford at the time of the study/University of Texas). ‘Current surgical implants for this type of glaucoma have been shown to have limited long-term effectiveness, being susceptible to failure due to fibrosis (scarring) in the eye.’ 

The new microstent features a unique structural shape that allows it to expand once in the eye. At 200µm, less than a quarter of a millimetre, the stent’s tiny diameter enables it to fit within the needle of a standard hypodermic syringe, for minimally-invasive insertion. Once in place and expanded, the microstent spans the fluid-filled space between the white of the eye and the membrane that covers it.

By supporting this space, the stent reduces the excessive fluid buildup and resulting intraocular pressure in the eye which is responsible for the most common type of glaucoma, primary open-angle glaucoma. Initial trials carried out in rabbits found that the microstents lowered eye pressure in less than a month with minimal inflammation and scarring. Furthermore, the microstent achieved a greater reduction of eye pressure than a standard tubular implant.

This development has the potential to transform the landscape of glaucoma therapy. By offering an enhanced solution in the minimally invasive glaucoma surgery field that combines mechanical innovation with biocompatibility, we hope to improve patient outcomes and quality of life.

Senior co-author Dr Jared Ching (Department of Engineering Science, University of Oxford).

Senior co-author, Professor Zhong You (Department of Engineering Science, University of Oxford) said: ‘Our microstent is made from a durable and super-flexible nickel-titanium alloy called nitinol, renowned for its proven long-term safety for ocular use. Its unique material and structural properties help prevent subsequent movement, improve durability, and ensure long-term efficacy.’

The research team used advanced modelling techniques to guide the microstent’s design and ensure compatibility with the anatomy of the eye. The device’s superelastic properties enable it to accommodate how the eye changes and stretches over time without permanent deformation, enhancing its durability and functionality.

Over half a million people in the UK have glaucoma – 2% of everyone over the age of 40 – and it is one of the most common causes of blindness worldwide. The introduction of this microstent could mark a pivotal step in enhancing treatment efficacy and accessibility.

The study ‘A Novel Deployable Microstent for the Treatment of Glaucoma has been published in The Innovation, Cell Press.

Source: Oxford University

Categories : OphthalmologyTags :

Blinking and Eyelid Function Is Enabled by Complex Control of Muscles

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Discovery could help pave the way for a prosthetic device to restore blink function lost to injury or disease

Muscle activation and movement patterns over time across the upper and lower eyelids, shown under different actions. Credit: Anatomical Engineering Group/UCLA

A blink of an eye is vital to protecting the eye by keeping it from drying out. This simple function seems natural and instantaneous, but is it?

Now, a team of UCLA biomechanical engineers and ophthalmologists has uncovered new details about the muscle that controls blinking, offering a pathway toward developing blink-assisting prostheses. Published in PNAS, the study found that the orbicularis oculi – the muscle that controls eyelid movement – contracts in complex patterns that vary by action and move the eyelid in more than just a simple up-and-down motion.

The researchers studied how this muscle behaves differently across various actions including spontaneous blinks, protective rapid closures and squeezed shut-eye motions.

“The eyelid’s motion is both more complex and more precisely controlled by the nervous system than previously understood,” said study corresponding author Tyler Clites, an assistant professor of mechanical and aerospace engineering at the UCLA Samueli School of Engineering. “Different parts of the muscle activate in carefully timed sequences depending on what the eye is doing. This level of muscle control has never been recorded in the human eyelid. Now that we have this information in rich detail, we can move forward in designing neuroprostheses that help restore natural eyelid function.”

In experiments with volunteers, the researchers looked at five different ways the eyes close:

  • Spontaneous blink: An automatic, unconscious blink that occurs regularly to keep the eye lubricated
  • Voluntary blink: An intentional blink, as when someone is asked to blink on command
  • Reflexive blink: A rapid, involuntary blink triggered to protect the eye from a collision
  • Soft closure: A gentle, slow eyelid descent, similar to the beginning of sleep
  • A forced closure: A deliberate squeezing of the eyelids tightly shut

To record activity in the orbicularis oculi with high precision, an ophthalmic surgeon inserted tiny wire electrodes into the eyelid. The researchers then used a motion-capture system to track eyelid movement in ultraslow motion. These tools allowed the team to measure subtle differences in eyelid movement, including speed, direction, and which part of the muscle initiated the action.

Video of spontaneous blink – dynamic muscle activation patterns and eyelid kinematics. Credit: Anatomical Engineering Group/UCLA

“People can lose the ability to blink due to a stroke, tumour, infection or injury. The condition is painful in the short term and can damage the eyes enough to cause vision loss,” said study co-author Dr Daniel Rootman, an associate professor of ophthalmology at the David Geffen School of Medicine at UCLA and director of the UCLA Orbital Disease Center. “We know that a small electric pulse can stimulate the orbicularis oculi muscle to move, but designing one that works well has been elusive. What we now have is a good roadmap to such a device, including where exactly to place electrodes, how to time them, and how strong the pulse should be. These guidelines could help pave the way for the development and clinical testing of such a device, with the ultimate goal of providing real relief for patients.”

With this fundamental knowledge of eyelid biomechanics in hand, the researchers can now work on refining a prototype neuroprosthesis to assist people with blinking.

“Understanding how the eyelid works is crucial to designing an accurate stimulation pattern for a prosthesis, as well as for diagnostic purposes,” said study first author Jinyoung Kim, a UCLA mechanical engineering doctoral student and member of Clites’ research group, the Anatomical Engineering Group at UCLA. “We are more than excited to bridge this gap and move forward to work with patients who have facial paralysis and help improve their lives.”

Source: UCLA Samueli School of Engineering

Categories : OphthalmologyTags :

Retinal Repair Work is Done by Microglia, not Neutrophils

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Findings have implications for understanding what goes wrong in retinal diseases

Photoreceptor cells in the retina. Credit: Scientific Animations

In a new study from the Flaum Eye Institute and Del Monte Institute for Neuroscience at the University of Rochester, researchers have discovered that the retina responds to damage differently than many other tissues in the body. When photoreceptor cells in the retina are damaged, microglia, or the brain’s immune cells, respond, and the neutrophils are not recruited to help despite passing through nearby blood vessels.

“This finding has high implications for what happens for millions of Americans who suffer vision loss through loss of photoreceptors,” said Jesse Schallek, PhD, associate professor of Ophthalmology and senior author of the study published in eLife. “This association between two key immune cell populations is essential knowledge as we build new therapies that must understand the nuance of immune cell interactions.”

Using adaptive optics imaging, a camera technology developed by the University of Rochester that allows the imaging of single neurons and immune cells inside the living eye, researchers studied the retinas of mice with photoreceptor damage. They found that while both neutrophil and microglia cells are present in the retina, only microglia cells respond to photoreceptor injury, and they do not call upon neutrophils to help repair the photoreceptor damage. Researchers believe this suggests a type of cloaking occurs during retinal injury to protect the retina from a rush of immune cells that could do more harm than good.

“What is remarkable here is that the passing neutrophils are so close to the reactive microglia, and yet they do not signal to them to assist in damage recovery,” said Schallek.

“This is notably different than what is seen in other areas of the body where neutrophils are the first to respond to local damage and mount an early and robust response.”

Source: University of Rochester Medical Center