The risk is almost 5 times higher with Wegovy than it is with Ozempic, and 3 times greater in men than it is in women, the analysis indicates.

Ischaemic optic neuropathy, or ION for short, is caused by inadequate/interrupted blood flow to the optic nerve, resulting in sudden vision loss in one or both eyes.

Although rare, ION has recently been linked to GLP-1 receptor agonists, particularly semaglutide, marketed as Wegovy, Ozempic, and Rybelsus, and variously used to treat obesity, diabetes, and to reduce cardiovascular disease risk, explain the researchers. 

To pinpoint whether the risks of ION might be associated with particular drugs, the researchers analysed alerts of unintentional and harmful side effects associated with medicines submitted to the US Food and Drug Administration (FDA) Adverse Event Reporting System (FAERS) between December 2017 and December 2024.

The researchers focused on ION associated with up to 2 mg of weekly injectable Ozempic for type 2 diabetes; up to 2.4 mg of weekly injectable Wegovy for obesity—the highest approved dose–and a daily tablet of Rybelsus for type 2 diabetes.  

They also included a once weekly injection of tirzepatide, a dual GLP-1/GIP agonist for the treatment of obesity and diabetes, which was analysed as a combined category and by indication: Mounjaro (for type 2 diabetes); Zepbound (for obesity).

Out of 30,668,520 unintentional and harmful side effect reports, 31,774 involved semaglutide; recipients had an average age of 56, and over half (54%) were female.

Of these reports, 3070 were attributed to Wegovy, originating from 6 countries in 3 continents, and 20,608 to Ozempic, originating from 11 countries in 4 continents.

Ozempic generated about 7 times more reports than Wegovy owing to its earlier approval in 2017; Wegovy was launched in 2021.

Yet despite this difference in volume, Wegovy was most strongly associated with ION (28 reports; higher odds of nearly 75), exceeding Ozempic (47 reports; higher odds of nearly 19) and generic forms of semaglutide (85 reports; higher odds of 21).

ION wasn’t reported in association with Rybelsus. And there was no signal—possible causal association between a medicine and an unintended side effect—with the comparator drugs.

When stratified by sex, the highest signal was for Wegovy in men (116 greater odds) and for Ozempic in women (nearly 27 greater odds).

And further analysis indicated that the odds of ION were nearly 5 times higher with Wegovy than with Ozempic, and more than 3 times higher in men than in women.

Injectables are faster acting than tablets, and differences in route, dose, and indication “may influence prescribing patterns and safety signals, with high-dose Wegovy probably driving the stronger association by predisposing to optic nerve hypoperfusion [low blood supply] through intravascular volume contraction, hypotension [low blood pressure] with nocturnal dips and autonomic instability, although no direct clinical link has been established,” point out the researchers.

“In contrast, the limited absorption and slower uptake of Rybelsus probably explain the absence of a detectable signal,” they add.

Media attention may have influenced reporting for Wegovy, they suggest, emphasising that the FDA reporting system precluded the ability to determine true incidence or assess whether reports clustered following regulatory recognition. And there was no information on co-existing conditions or disease severity either.

Nevertheless, “This study provides the first evidence of a formulation-and dose-dependent ION risk, with the strongest association observed for Wegovy,” write the researchers, concluding: “These findings highlight a potential dose-dependent safety concern that warrants urgent prospective evaluation to guide prescribing and regulatory policy.”

The authors of a linked commentary agree. “These findings add to an emerging body of growing literature reporting ocular complications with [anti-obesity medications] which warrants further scrutiny and urgent clarification for ophthalmologists,” they write.

The use of these drugs is set to grow, they suggest, highlighting that: “The UK has the highest level of obesity in Western Europe (29% of adults are obese, and 64% are overweight or obese).”

And research shows that anti-obesity medications “are also beneficial for cardiovascular diseases, such as stroke as well as dementia, which has led to [them] being considered first-line options for some of these conditions, further increasing their potential use,” they add. 

“To complicate matters further, the growing use of [anti-obesity medications] in children, typically over the age of 12, has caused considerable debate, likely increasing the risks of ocular complications in later life,” they suggest.

Recent clinical studies on these drugs “seem to offer new hope for some conditions, such as age related macular degeneration and uveitis,” they highlight, “but with potential risks of severe, though rare, ocular complications, such as ION, for others.”

Uveitis

Uveitis is an umbrella term for inflammation affecting the uvea, the middle layer of the eye. Patients can present with pain, photophobia, blurred vision and floaters. Uveitis can be caused by infections but can also be associated with auto-immune inflammatory diseases such as rheumatoid arthritis, Crohn’s disease or Behcet’s disease. If untreated, uveitis can impair vision permanently; “There is potential for vision loss from this inflammation and the damage that it causes. It can induce macular oedema, which is leaky fluid in the eye and if that fluid accumulates at the macula, which is responsible for your central vision, then it can impact your vision temporarily, but if left untreated can lead to permanent vision loss”, explains Ms Goacher.

Treatment of uveitis

The primary goal of treatment is the control of inflammation to prevent damage such as macular oedema. The clinical approach to uveitis is determined by the anatomical site of the inflammation. Anterior uveitis, affecting the front of the eye, is typically managed with topical steroid or anti-inflammatory drops. However, topical treatments cannot penetrate deeply enough for intermediate, posterior, or panuveitis, and systemic steroids are the standard first-line treatment. “If we can’t control patients on systemic steroids or …. if you can’t get patients off the steroids without them flaring back up with their uveitis you would then move on to secondary immunosuppressive medications. So, commonly we’d use mycophenolate or azathioprine”, says Ms Goacher. The biological, adalimumab is available as a third-line treatment, she adds.  Immunosuppressive treatment is steroid-sparing and can enable patients to transition off systemic steroids and avoid long-term side effects. Despite these options, an unmet need persists for patients who do not tolerate immunosuppressants, those who require maximal treatment but still experience flares, or those for whom systemic steroids are contraindicated.  Fluocinolone acetonide intravitreal implants (Iluvien ®), which provide local treatment, can be useful in these situations.

Fluocinolone intravitreal implants

The fluocinolone acetonide implant is a miniature device, measuring only 3.5 mm in length and 0.37 mm in diameter—roughly the size of a grain of rice. It is designed to be injected into the vitreous (the jelly-like part of the eye), where it slowly elutes the medication over a period of up to three years.

The implantation is performed as an outpatient procedure.  After the administration of numbing drops, the device is injected; the process typically takes 10 to 20 minutes, followed by a course of antibiotic drops. Once implanted, the patient cannot feel the device, and the polymer shell remains in the eye after the drug has been fully eluted.

Real-world clinical outcomes

Ms Goacher conducted an evaluation of 45 eyes (34 patients) treated with fluocinolone implants since 2019. The study group included patients with associated systemic inflammatory diseases, such as rheumatoid arthritis or Crohn’s disease. The findings highlighted several key clinical benefits:

• Visual acuity: 58% of patients experienced an improvement in visual acuity.
• Macular oedema resolution: At the six-month mark, 80% of patients with macular oedema saw the condition resolve.
• Systemic treatment reduction: 84% of patients taking systemic immunosuppressive medication were able to reduce their dosage, and three patients were able to stop systemic treatment entirely.
• Topical treatment reduction: There was a 20% reduction in the need for topical drops among the study group.

While the implant is designed to last three years, the audit found the average time to treatment failure (defined as the need for rescue therapy, such as increased drops or additional implants) was approximately 15 months. However, not all the patients had reached the three-year time point, notes Ms Goacher. Nevertheless, one-third of the patients in the study did reach the three-year mark without requiring further intervention, she says.

Managing complications

The use of local steroids in the eye is associated with known complications, primarily cataract development and increased intraocular pressure (IOP). In this audit,16% of patients developed cataracts post-insertion, with the average time to surgery being 12 months. Furthermore, 11% of patients experienced an IOP rise at the three-month mark. While three patients required surgery to manage this pressure, most cases were manageable with glaucoma drops.

From a clinical perspective, these complications are often viewed as a necessary trade-off; as Ms Goacher notes, cataract surgery is a routine, “bread and butter” procedure, whereas uncontrolled inflammation can lead to permanent, irreversible blindness.

Conclusion and future directions

The real-world data suggests that fluocinolone implants offer a robust option for stabilising uveitis and reducing the systemic medication burden on patients. Current efforts are focused on refining this data by looking at long-term outcomes for patients who have had the implant for two or more years to provide further insights into treatment efficacy.

Ophthalmology specialist pharmacist

The role of the specialist pharmacist in ophthalmology is expanding. Although initially Ms Goacher’s role was concerned with oversight of high-cost drugs, it has since grown considerably. The ophthalmology team at the Sussex Eye Hospital was welcoming and supportive and she soon found that ophthalmology offered many opportunities for pharmacy input. “It may not be that obvious on the outset but as soon as you scratch the surface there’s a lot to do in ophthalmology for pharmacy”, she says. For pharmacists looking to specialise in this important field, Ms Goacher highlights the support available through the UK Ophthalmic Pharmacy Group (UK OPG), which provides a network for advice and collaboration.

Why it matters

Millions of Americans lose vision to eye diseases that often go undetected until significant damage has occurred. Early identification of at-risk individuals could enable timely screening and preventive interventions before irreversible vision loss occurs. This study demonstrates that information already collected during routine doctor visits could help identify patients who would benefit from earlier eye exams, potentially preventing blindness in high-risk individuals. The findings offer a practical way to improve eye disease prevention without requiring additional testing or specialized equipment in primary care settings.

What the study did

Researchers analyzed electronic health records from 35,909 adults aged 40 to 79 years who participated in the All of Us Research Program between 2009 and 2015. They calculated each person’s Pooled Cohort Equations (PCE) cardiovascular risk score using standard health information including cholesterol levels, blood pressure, smoking status, and diabetes. Participants were categorized into four risk groups: Low (less than 5%), Borderline (5-7.4%), Intermediate (7.5-19.9%), and High (20% or greater). The research team then tracked who developed eye diseases over the following years, adjusting for factors not included in the cardiovascular score such as race (with extended subgroups not in PCE), body mass index, kidney disease, and education level.

What they found

Higher cardiovascular risk was strongly associated with increased likelihood of developing eye diseases. Adults in the High-risk group were 6.2 times more likely to develop age-related macular degeneration, 5.9 times more likely to develop diabetic retinopathy, 4.5 times more likely to develop hypertensive retinopathy, 3.4 times more likely to develop retinal vein occlusion, and 2.3 times more likely to develop glaucoma compared to those in the Low-risk group. The cardiovascular score performed particularly well at predicting diabetic retinopathy, hypertensive retinopathy, and age-related macular degeneration. These associations remained consistent across different follow-up periods ranging from five to seven years.

What’s next

The findings suggest that primary care physicians could use cardiovascular risk scores to identify patients who would benefit from referral to eye care specialists for comprehensive screening. Further research is needed to determine the optimal timing and frequency of eye exams for different risk groups, and whether earlier detection and interventions based on cardiovascular risk can actually help prevent vision loss. Implementation studies could help integrate this risk stratification approach into routine primary care workflows and electronic health record systems.

From the experts

“We found that a simple score already calculated in millions of doctor visits each year may meaningfully predict who will develop serious eye diseases,” said Dr. Anne L. Coleman, senior author of the study and chair of the Department of Ophthalmology at UCLA Health. “This gives us an opportunity to identify high-risk patients early, when preventive measures might still protect their vision. The beauty of this approach is that it requires no additional testing; the information is already there in the medical record.”

Article: Cardiovascular Risk and Eye Health: A Prospective Cohort Study of the Pooled Cohort Equations and Ocular Disease Incidence. Ophthalmology Dec 29, 2025. DOI: 10.1016/j.ophtha.2025.12.021

About the Research Team

Deyu Sun, PhD (David Geffen School of Medicine, UCLA) Victoria L. Tseng, MD, PhD (David Geffen School of Medicine and Stein and Doheny Eye Institutes, UCLA) Fei Yu, PhD (David Geffen School of Medicine, Stein and Doheny Eye Institutes, and Fielding School of Public Health, UCLA) Anne L. Coleman, MD, PhD (David Geffen School of Medicine, Stein and Doheny Eye Institutes, and Fielding School of Public Health, UCLA)

Funding and Disclosures

This research was supported by an Unrestricted Grant from Research to Prevent Blindness to the UCLA Department of Ophthalmology. Dr. Victoria L. Tseng has received the Research to Prevent Blindness Career Development Award and the American Academy of Ophthalmology Award for IRIS Registry Research. The sponsor or funding organization had no role in the design or conduct of this research. No conflicting relationship exists for any author.

A drug-eluting implant has been shown to reverse cystoid macular oedema and reduce the need for systemic treatment in 80% of uveitis patients according to a real-world study presented by Ann-Marie Goacher (University Hospitals Sussex).

Uveitis is an inflammatory condition that affects the middle part of the eye (the uvea or uveal tract). It is often associated with systemic inflammatory (auto-immune) disease but many cases are idiopathic. Although uveitis is relatively rare it is important because it is a sight-threatening condition. Treatment involves the use of corticosteroids (first line) and immunosuppressant treatment (second line).

Iluvien (Alimera Sciences Ltd), a fluocinolone acetonide intravitreal implant has been developed to provide a continuous microdose of corticosteroid over an extended period.

The present study was undertaken to determine how these implants perform in a real-world setting.

Patient data for a five-year period were reviewed. This involved 45 eyes from 34 patients, 65% of whom were female.

Key findings included:

• The mean time to treatment failure (reactivation of disease) was 15 months.
• At 6 months, 80% of patients had a resolution of cystoid macular oedema.
• 84% of patients on systemic treatment were able to reduce their doses and 15% were able to stop all systemic treatment
• 58% of patients experienced improved vision.
• 14 eyes developed cataracts, a known complication of corticosteroid treatment; all had previously received dexamethasone implants.

The authors concluded that Iluvien offers significant benefits in managing inflammation and improving visual outcomes.

Goacher A-M, Ortiz G, Hughes E, Davidson C. Evaluating the use of Iluvien in uveitis patients in a real-world clinical setting. Poster presentation. Clinical Pharmacy Congress North, November 2025

Photo: Ann-Marie Goacher

The INSIGHT Health Data Research Hub for Eye Health and Oculomics is benefiting from investment funding of £3.7 million awarded by UKRI Medical Research Council (MRC) and the National Institute for Health and Care Research (NIHR).

INSIGHT will expand from Moorfields Eye Hospital and create a blueprint for linking NHS sites across the country, supporting research, improving patient care, and fostering innovation in eye health.

As part of a four-year programme of work delivered through Moorfields Eye Hospital’s strategic partnership with the UCL Institute of Ophthalmology, INSIGHT will on-board NHS sites including Sunderland Eye Infirmary, one of the UK’s largest regional centres for ophthalmology, working in collaboration with South Tyneside and Sunderland NHS Foundation Trust and North East North Cumbria Secure Data Environment.

INSIGHT will also broaden national data linkages and integrate genetic data from the NIHR BioResource and UK Biobank to accelerate oculomics research, which uses biomarkers in the eye to detect systemic conditions such as dementia and cardiovascular disease.

Patient and public representatives will play a central role, working with project leads to embed standards for data access and governance, address risks of bias in artificial intelligence, and ensure equitable benefits for underserved communities.

The enhanced INSIGHT research data platform will grow from over 30 million images — currently more ophthalmic data than the top three centres in the US combined — to some 50 million images, consolidating the UK as the global leader in ophthalmology and oculomics research and innovation.

INSIGHT Director Professor Pearse Keane (UCL Institute of Ophthalmology and Moorfields Eye Hospital) said: “This funding allows us to expand INSIGHT from Moorfields Eye Hospital into a truly national resource, with significant benefits for clinical research and public health. Ophthalmology is the busiest NHS speciality, increasingly under pressure as patient need grows. By providing a comprehensive, interoperable research resource for ophthalmic data, we can help to accelerate research discoveries, bring new treatments to patients faster, and ultimately reduce the burden of sight-threatening disease in the UK and globally.”

Moorfields Eye Hospital CEO Peter Ridley commented: “The potential of NHS data to improve patient outcomes and tackle health inequalities is immense. We are proud that the INSIGHT Hub has led the way in harnessing routinely collected NHS eye imaging data for medical research, demonstrating how patient data can be optimised for research in a safe and secure way, involving patients and members of the public in decision-making. With this grant funding, we anticipate entering an exciting new phase in the Hub’s development, supporting the UK’s ambitions as a global leader in healthcare technology.”

The award is one of five announced by UKRI MRC and the NIHR to enhance biomedical and health-related data and digital platform resources in the UK, following a UKRI call published last year.

Cyclodextrin-based chlorhexidine eye drops represent a promising approach to formulating stable and effective treatments for Acanthamoeba keratitis, according to researchers from the University of Picardy Jules Verne.

Acanthamoeba keratitis is a rare but serious, sight-threatening corneal infection caused by the acanthamoeba parasite. Chlorhexidine has demonstrated efficacy against acanthamoeba but no eye-drop formulation was available. Moreover, the use of chlorhexidine digluconate (CD), the most soluble form, was limited due to precipitation (of chlorhexidine hydrochloride) in the presence of chloride ions in vivo. In 2024 Akantior® eyedrops (polyhexanide 0.08%) were approved for this indication. Akantior was designated as an orphan medicine. Professor Frédéric Marçon noted that Akantior costs about €8,754 for 30 vials of 0.3 ml. The present study screened a number of cyclodextrins for their ability to form inclusion complexes with CD that would effectively protect the chlorhexidine from precipitation in saline conditions. Two suitable products were found and further investigations showed that they could be formulated as eyedrops and that the antibacterial activity of the chlorhexidine was preserved in vitro.

In vitro conditions may not reflect conditions in the eye and this could influence the efficacy of the formulation. Professor Marçon said that another important consideration was that acanthamoeba parasites tend to encyst in the cornea.

Professor Irene Kraemer said that at the University Hospital of Mainz they prepare polyhexanide eyedrops for this indication in a different strength from the commercial product.

Sebastian Rigaud et al. Formulation of a Cyclodextrin-Based Ophthalmic Drug Solution of Chlorhexidine for the treatment of Acanthamoeba Keratitis. Short communication. GERPAC Congress 2025

Photo: Frédéric Marçon. Photo – courtesy of GERPAC

GLP-1 drugs such as semaglutide are widely used to treat type 2 diabetes and obesity.  They do this by mimicking the action of GLP-1, a hormone that helps the body make more insulin when needed, slows down digestion, curbs appetite and increases feelings of fullness.

Many tissues around the body have GLP-1 receptors (proteins that respond to the hormone) and recent research has suggested the drugs also have anti-inflammatory and antioxidant effects.

For example, some studies have indicated they reduce the risk of diabetic retinopathy, the leading cause of blindness among working-age adults. More than 90% of people with type 1 diabetes and 50-60% of those with type 2 diabetes develop this condition, in which high blood sugar levels damage blood vessels in the light-sensitive tissue at the back of the eye.

“Diabetic retinopathy represents a major public health challenge,” says Ioanna Anastasiou, of the National and Kapodistrian University of Athens, Athens, Greece, who led the research. “Globally, it is projected that over 191 million people will be affected by it by 2030, with around 56 million experiencing vision-threatening stages of the disease.

“These statistics underscore the critical need for effective screening, early detection, and, crucially, more effective treatments.”

It is thought that much of the damage to the retina is done by free radicals, molecules that can damage cells and are produced in higher numbers when blood sugar is high. The theory is that GLP-1 drugs protect the retina by increasing levels of antioxidants, compounds that neutralise free radicals.

However, other studies have suggested that GLP-1 drugs increase the risk of diabetic retinopathy or exacerbate it in those who already have it.

To provide some clarity, Dr Anastasiou and colleagues carried out a detailed study of the effect of GLP-1 drugs on retinal cells in diabetes-like conditions.

For the lab-based study, human retinal endothelial cells were treated with a range of different concentrations of semaglutide.  The cells were kept in media with high glucose levels and oxidative stress (in which there are more free radicals than antioxidants) for 24 hours.

They were then put through a series of tests.  The results showed that the cells that were treated with semaglutide were up to twice as likely to still be alive than cells that were untreated.  They also had larger stores of energy.

Three markers of oxidative stress in diabetic retinopathy were markedly lower in the treated cells: levels of apoptosis (a form of cell death) decreased from approximately 50% in untreated cells to about 10% in semaglutide-treated cells; the production of mitochondrial superoxide (a free radical) decreased from about 90% to about 10%; and the accumulation of harmful compounds called advanced glycation end-products also fell substantially.

Further analysis showed that genes involved in the production of antioxidants were upregulated, or more active, in the treated cells, compared with the untreated cells.  This result – and the enhanced survival – indicate that semaglutide was repairing damage to the cells, says Dr Anastasiou.

Looked at as a whole, the results indicate that GLP-1 receptor agonists enhance retinal cells’ defences against damage in diabetes-like conditions.

Dr Anastasiou explains: “In experiments in the lab, GLP-1-receptor agonists exerted powerful antioxidant effects which protected retinal cells against the type of damage that can occur in diabetes.

“Our study did not find that these drugs harmed the retinal cells in any way – instead, it suggests that GLP1-receptor agonists protect against diabetic retinopathy, particularly in the early stages.

“Excitingly, these drugs may be able to repair damage that has already been done and so improve sight.

“Clinical trials are now needed to confirm these protective effects in patients and explore whether GLP-1 receptor agonists can slow, or even halt, the progression of this vision-robbing condition.”

Dry eye disease is a common condition which affects one-third of the adult population and one-in-five children, in which the eyes either do not make enough tears, or produce only poor-quality tears. It causes the eyes to become uncomfortable, with gritty- or itchy-feeling eyes, watery eyes and short-term blurred vision. It is more common in older adults and can be exacerbated by factors including dry air caused by air conditioning, dust, windy conditions, screen use and incomplete blinks, where the eye does not fully close.

Professor Wolffsohn is head of Aston University’s School of Optometry and a specialist in dry eye disease. While it has long been known that blinking exercises can ease the symptoms of dry eye disease, the optimum technique, number of repetitions and necessary repeats per day are unclear. Professor Wolffsohn set out to determine the best exercises.

His team found that the best technique for a dry eye blinking exercise is a close-squeeze-blink cycle, repeated 15 times, three times per day. Participants found that while they were doing their exercises symptom severity and frequency decreased, and the number of incomplete blinks decreased. Within two weeks of stopping the exercises, their symptoms returned to normal levels, showing the efficacy of the exercises.

To carry out the work, Professor Wolffsohn’s team ran two studies. For the first, they recruited 98 participants, who were assessed for dry eye symptoms before and after the two weeks of blinking exercises. Participants were randomly allocated different blinking exercises to determine the most effective. A second study with 28 people measured the efficacy of the blinking exercise.

Once the optimum blinking routine had been developed, Professor Wolffsohn worked withAlec Kingsnorth, an engineer and former Aston undergraduate and PhD student, and Mark Nattriss, business manager of his spin-out company, Wolffsohn Research Ltd, to develop the app, MyDryEye, which is freely available on Android and iOS operating systems. The app allows users to monitor their dry eye symptoms, assess their risk factors, add treatment reminders and monitor their compliance, complete the science-based blink exercises and find a specialist near them.

Professor Wolffsohn says that the blinking exercises should be carried out as part of a treatment programme which could also include the use of lipid-based artificial tears, omega-3 supplements and warm compresses.

Professor Wolffsohn said:

“This research confirmed that blink exercises can be a way of overcoming the bad habit of only partially closing our eyes during a blink, that we develop when using digital devices. The research demonstrated that the most effective way to do the exercises is three times a day, 15 repeats of close, squeeze shut and reopen – just three minutes in total out of your busy lifestyle. To make it easier, we have made our MyDryEye app freely available on iOS and Android so you can choose when you want to be reminded to do the exercises and for this to map your progress and how it affects your symptoms.”

Read the full paper, ‘Optimisation of Blinking Exercises for Dry Eye Disease’, in Contact Lens and Anterior Eye at https://doi.org/10.1016/j.clae.2025.102453.

In a recent breakthrough, researchers led by Professor Takeo Miyake from the Graduate School of Information Production and Systems, Waseda University, Japan, have developed stable MXene-coated contact lenses with remarkable optical and EMR shielding properties. Their novel fabrication method ensures optimum adhesion and prevents oxidation of the MXene coating, overcoming previous limitations. The study was a collaborative effort between Waseda University, Kyoto University, and Yamaguchi University Hospital, bringing together expertise in nanofabrication, 2D materials, and ophthalmology to ensure eye safety. The findings were published in the journal Small Science on June 04, 2025. This research was coauthored by Dr. Lunjie Hu from the Graduate School of Information Production and Systems, Waseda University; Associate Professor Jun Hirotani from Kyoto University; Professor Kazuhiro Kimura from Yamaguchi University Hospital; Assistant Professor Atsushige Ashimori from Yamaguchi University Hospital; and Assistant Professor Saman Azhari from the Graduate School of Information Production and Systems, Waseda University.

“Smart contact lenses with built-in electronic components are getting a lot of attention as the next big thing in wearable devices. For the first time, though, this means we’ll be placing wireless circuit lenses directly on our corneas, exposing them to electromagnetic waves around the clock. Inspired by breakthroughs in 2D materials and device fabrication technologies, we came up with highly functional protective contact lenses,” says lead author Prof. Miyake.

To fabricate these highly functional contact lenses, the research team started by preparing dispersions of MXene, which were vacuum filtered with mixed cellulose ester (MCE) membranes to produce MXene-based films. The films were then coated onto commercial soft contact lenses through a wet transfer approach using acetone. The prepared lenses were then analyzed extensively for physical properties, conductivity, and safety. “We chose a wet-transfer method for the effortless attachment of MXene nanosheets to the unconventionally shaped surface of soft contact lenses, which ensures scalability,” adds Prof. Miyake.

The fabricated contact lenses showed remarkable results with >80% visible light transmission, high conductivity, dehydration protection, and high biocompatibility with >90% cell viability. The deposited layers of MXene showed variable thickness based on the concentrations of the dispersions, and the adhesive properties of the dissolved MCE membrane ensured optimum attachment of MXene. Additionally, the MCE layer also protected the MXene from oxidizing.

Prof. Miyake discusses the significance of their method, saying, “Our research can have a multifaceted impact. First, the stable and effortless coating of MXene nanosheets via wet transfer broadens the possibilities for commercial applications. Secondly, our method is simple yet effective in preventing MXene oxidation, turning a commonly overlooked challenge—MXene oxidation—into a resolved obstacle.”

To assess electromagnetic shielding, the MXene-coated lenses were tested on porcine eyes exposed to microwave heating and thermal imaging. The lenses exhibited a rapid temperature rise, indicating strong EMR absorption and dissipation, which prevented direct heating of the eyes. When exposed to high-frequency microwaves, MXene effectively absorbed electromagnetic energy and released it as thermal radiation, thereby protecting the porcine eyes from direct heating.

Furthermore, the researchers confirmed a robust electromagnetic shielding efficiency of up to 93%, representing the highest reported specific shielding effectiveness for biocompatible materials at the same thickness level, offering substantial protection against high-frequency radiation. The lenses demonstrated strong protection against high-frequency EMR, ensuring optimal eye health.

With high electromagnetic protection and reliable properties, this breakthrough in smart contact lenses represents a significant advancement toward safer wearable technologies. By leveraging the unique properties of MXene nanosheets, the lenses provide effective protection against high-frequency radiation while maintaining comfort and usability. Beyond eye health, this breakthrough paves the way for the integration of advanced nanomaterials in smart wearables, medical implants, and bioelectronics, addressing both safety and functionality.

***

Reference
Authors: Takeo Miyake¹, Lunjie Hu¹, Jun Hirotani², Kazuhiro Kimura³, Atsushige Ashimori³, Saman Azhari¹
DOI: 10.1002/smsc.202400628
Affiliations: ¹Graduate School of Information Production and Systems, Waseda University, Japan
                         ²Kyoto University, Japan
³Yamaguchi University Hospital, Japan

Why syringe type matters for intravitreal injections

At the GERPAC congress 2024 (held in October 2024) Dr Chennell described a study that evaluated of two types of syringes for bevacizumab solutions for intravitreal administration.  The thinking behind the study was that bevacizumab, a monoclonal antibody, could be altered or destabilised by contact with silicone oil in the syringe.

How the syringe lubricant interacts with the drug inside it

Dr Chennell’s study compared the stability of bevacizumab injection in two different types of syringe – conventional polypropylene syringes, lubricated with silicone oil and syringes that had (non-extractable) cross-linked silicone on the internal surface of the barrel of the syringes. The results showed that fewer bevacizumab particles were formed and the drug appeared to retain its initial physical characteristics in the cross-linked silicone syringes compared with the polypropylene syringes.

Why ready-to-administer syringes improve clinical care

The provision of ready-to-administer bevacizumab in syringes reduces the risks of altering or destabilising the monoclonal antibody during the preparation process and saves time in the administration process.

Unfortunately, cross-linked silicone syringes of the type used in the study are not yet available to hospital pharmacists in France in suitable packs and Dr Chennell is trying to find alternative syringe manufacturers who might be able to provide suitable products.

About Philip Chennell

Philip Chennell is a pharmacist, at the University Hospital of Clermont-Ferrand. He is currently in charge of the Quality Control and Development Laboratory of the hospital’s pharmacy. He is also Assistant Professor at the University Clermont Auvergne and a member of the Materials for Health Research Team, focusing on medical devices and content/container Interactions.

Read and watch the full series on our website or on YouTube.

There are a number of advantages of providing bevacizumab as a ready-to-administer injection, preloaded into a syringe. First, even a brief contact with silicone oil (in polypropylene syringes) combined with the mechanical stresses of manipulating the syringe or, for example, flicking the syringe to remove air bubbles can be enough to trigger changes in the bevacizumab. Second, the clinical care process is smoothed. “By preparing these syringes directly in a pharmaceutical compounding unit it allows us to provide …… ready-to-administer syringes for the ophthalmologist or the end-user which means that they save time – they don’t have to perform the manipulation themselves. What they need to do is to just take the syringe, adjust the needle, [and] inject”, explains Dr Chennell.

Unfortunately, cross-linked silicon syringes are not yet available to hospital pharmacists in France in suitable packs. The packs that are available are designed for industrial use and are too large for use in hospital pharmacy compounding units.   “We can’t really purchase a big bag containing 1,200 syringes and expect to be able to do something with them when we see that in our clinical setting, we only use a couple of dozen every week. Okay, after a year it does add up but we don’t need 1,200 in one big go – and how would we store them? How would we keep them sterile?”, he says.

Since giving the presentation at the GERPAC congress Dr Chennell has been contacted by several colleagues in France who are also interested in this topic. He is also trying to find alternative syringe manufacturers who might be able to provide suitable products.

About Philip Chennell

Philip Chennell is a pharmacist, at the University Hospital of Clermont-Ferrand. He is currently in charge of the Quality Control and Development Laboratory of the hospital’s pharmacy. He is also Assistant Professor at the University Clermont Auvergne and a member of the Materials for Health Research Team, focusing on medical devices and content/container Interactions.

Read and watch the full series on our website or on YouTube.

Dr Chennell’s study set out to compare the stability of bevacizumab injection in two different types of syringes. One type was the conventional polypropylene syringe type, lubricated with silicone oil. The other had (non-extractable) cross-linked silicone on the internal surface of the barrel of the syringe. “Our main hypothesis was that these cross-linked silicone syringes would induce less aggregation, ….. of the antibody so that therefore it wouldn’t impact its stability compared to normal silicone-oil-lubricated syringes”, explains Dr Chennell. Syringes (1 ml) containing 0.2 ml of bevacizumab, 25mg/ml were prepared and stored at 5°C and 32°C for three months. The contents were investigated at three days, one month and three months. In addition to visual examination of the contents, aggregation index measurements, size exclusion chromatography, subvisible particulate counting and dynamic light scattering analysis were also carried out. “These assays allowed us to …..  gain insight into …. the number of particles [and] their size but also how the antibody behaved – did it fragment or did it aggregate into high-molecular-weight species which hadn’t, for example, quite yet formed particles”, he says.

The main finding was that physical stability seemed to be superior with the cross-linked silicone syringes compared to the classical, normal, silicone-oil-lubricated syringes. Fewer bevacizumab particles were formed and the drug appeared to retain its initial physical characteristics.  These differences were likely to be linked to the presence of the silicone oil in the polypropylene syringes, he says. “I think the main conclusion …… from a pharmaceutical point of view, is that it shows, yet again, that choosing the right primary container for monoclonal antibodies, or in fact any medication, really remains [paramount] if you want to maximize patient therapeutic safety”, he adds.

About Philip Chennell

Philip Chennell is a pharmacist, at the University Hospital of Clermont-Ferrand. He is currently in charge of the Quality Control and Development Laboratory of the hospital’s pharmacy. He is also Assistant Professor at the University Clermont Auvergne and a member of the Materials for Health Research Team, focusing on medical devices and content/container Interactions.

Read and watch the full series on our website or on YouTube.