Category: Ophthalmology

Categories : Ophthalmology PaediatricsTags :

No Cure for Myopia Progression in Sight as Eyedrops Trial Flops

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Photo by CDC on Unsplash

A US study shows that use of low-dose atropine eyedrops, commonly used in a higher dose to treat lazy eye, was no better than a placebo at slowing myopia progression and elongation of the eye among children treated for two years.

The first randomised controlled trial of its kind aimed at identifying an effective way to manage myopia was published last week in JAMA Ophthalmology. It was conducted by the Pediatric Eye Disease Investigator Group at at Vanderbilt University Medical Center (VUMC) and 11 other hospitals and practices across the United States and funded by the National Eye Institute (NEI).

“We found, interestingly, and honestly shockingly, that there was no difference in the use of 0.01% atropine and placebo in treating these children who ranged in age from 5 to 12,” said associate professor Lori Ann Kehler, OD, and the Vanderbilt site principal investigator for the study.

The onset of myopia usually occurs between the ages of 7 and 16 when developing eyes can start growing too long axially (from front to back). Instead of focusing images on the retina, images of distant objects are focused at a point in front of the retina which causes people to have poor distance vision while their near vision remains unchanged.

The condition results in the need for eyeglasses to improve distance vision, and it can also result in medical complications and serious uncorrectable vision loss later in life, like retinal detachments or myopic macular degeneration.

The study contradicts earlier studies from East Asia that showed the small dose of atropine is effective in slowing progression of myopia.

In 2017 the Academy of Ophthalmology endorsed the findings from East Asia saying that although the FDA had not approved atropine for this use, there was sufficient evidence for prescribing the low dose for myopia. Ophthalmologists across the country, including at VUMC, began to offer the prescription to young patients with myopia.

“That was a really exciting finding at the time because we had had no treatment options for many years,” Kehler said. The prescription of atropine for treating myopia is not covered by most insurance plans.

“The incidence of myopia is increasing worldwide,” Kehler said. “By 2030 it’s predicted that 39 million people in the US will have myopia. By 2050 that number is expected to increase to more than 44 million people in the US and to 50% of the global population. Once it’s detected in children, it tends to get worse every year,” she said. “Investigators all over the world have tried strategies to intervene, to either stop or slow the worsening of myopia.”

Kehler said it is not known why the incidence of myopia is increasing. “There are several theories. Some believe it’s the increase in the use of screens and screen time, but myopia was increasing even before screens were part of children’s lives. Others think it has to do with industrialisation. We were an agricultural society. We were outside more. We weren’t reading. We weren’t looking up close all day. Really, the prevailing thought is whether we’re at a screen or looking at a math book or reading most of the day, we think the lack of sunlight and sustained near effort is what’s causing the increase of myopia.”

Kehler said the percentage of children with myopia using the atropine drop at VUMC is low and estimates fewer than 5% of children with myopia are using the drops nationally.

Going forward, eye specialists should have a frank discussion with parents of children with myopia about the conflicting data between the Asian studies and the new U.S. study.

“The absence of a treatment benefit in our US-based study, compared to East Asian studies, may reflect racial differences in atropine response. The study enrolled fewer Asian children, whose myopia progresses more quickly, and included Black children, whose myopia progresses less quickly compared with other races,” noted the study’s lead co-author, Michael X. Repka, MD, professor of Ophthalmology at Johns Hopkins University, in a news release from the NEI.

“All the studies have shown the drops are safe, so we aren’t putting children at risk if we continue to prescribe the 0.01%,” Kehler said. “But we are telling them there is a difference in these studies and it might have to do with your genetics; it might be that it’s more effective in children from Asia than in the U.S. population,” she said.

Further study is needed, Kehler said. The next step is likely to study a higher dose of atropine to see if children in the U.S. experience a benefit.

The LAMP study out of Hong Kong found that 0.05% might be more effective.

Kehler said other groups are studying the use of red-light therapy to slow the progression of myopia, and there are also new eyeglass lenses that have been developed to slow the progression of myopia, but they are not yet available in the U.S.

“It’s much harder to get drops in very young children,” Kehler said. “But if we had a spectacle option, that would open the door to treating our younger patients.”

Myopia usually stabilises in about half of children around 16 years of age and among an increasingly larger percentage as they get older. By their early 20s, about 10% of individuals with myopia will continue to grow more nearsighted, and by age 24 that percentage is 4%.

Source: Vanderbilt University Medical Center

Categories : Immune System OphthalmologyTags :

Contrary to Prior Belief, T Cells Even Protect the Cornea

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Photo by Stormseeker on Unsplash

Researchers have discovered that the immune cells guarding the healthy human cornea from pathogens and inflammation are T cells, and dendritic cells, as previously thought. The discovery, published in PNAS, redefines current understanding of the immune cell landscape in the cornea of a healthy human eye. It builds on the team’s previous research in Cell Reports that showed that T cells protect the eye against virus infection in mice.

The collaborative research team jointly developed a new imaging technique as part of their investigation.

Research leader Professor Scott Mueller, from the Department of Microbiology and Immunology at the Doherty Institute explained that our knowledge of the various immune cell types in the human cornea is important for establishing the eye’s protective mechanisms against pathogens and disease.

“By combining our newly developed imaging technique with other advanced analytical approaches, we were able to discover that a significant number of cells at the surface of the healthy cornea are actually T cells,” said Professor Mueller.

“Until now, these cells were mistakenly classified as dendritic cells based on static imaging. This completely changes the current dogma in the field that only dendritic cells are present in the healthy cornea.”

The study’s first author, University of Melbourne’s Associate Professor Laura Downie said that being able to dynamically capture the cells’ normal behaviour, and in response to inflammation, provides unique understanding into the immune response in the eye.

“Using our non-invasive imaging approach, which we term Functional In Vivo Confocal Microscopy (Fun-IVCM), we have been able to see that these T cells move around quickly and interact with other cells and nerves in the outermost layer of the cornea. We also captured different cell dynamics in response to contact lens wear and in allergic eye disease, and quantified how these behaviours are modulated by drug treatments,” said Associate Professor Downie.

“These findings reshape our understanding of the distinct immune cell subsets in the human cornea, and how they respond to different stimuli. Using Fun-IVCM, we can achieve rapid, real-time insight into the cellular immune responses in living humans, in this accessible peripheral sensory tissue.”

Senior author Dr Holly Chinnery, also of the University of Melbourne, added that the new research will have major implications for the medical and immunology fields, including for patients and practitioners.

“Because this new technique involves non-invasive, time-lapse imaging of the human cornea, Fun-IVCM could be used in clinics directly to assess immune responses and ocular health. It could even be used for general immune system health,” said Dr Chinnery.

“Changes in T cells and behaviour could be used as a clinical biomarker of disease and assist with treatments.”

Source: The Peter Doherty Institute for Infection and Immunity

Categories : Ophthalmology PaediatricsTags :

Atropine Eyedrops Fail to Slow Myopia Progression in US Children

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Photo by Jeffrey Riley on Unsplash

Use of low-dose atropine eyedrops (concentration 0.01%) was no better than placebo at slowing myopia progression and elongation of the eye among children treated for two years, according to a randomised controlled trial conducted in the US. The trial aimed to identify an effective way to manage this leading and increasingly common cause of refractive error, which can cause serious uncorrectable vision loss later in life. Results from the trial, published in JAMA Ophthalmology, contradict those from recent trials in East Asia.

The study was conducted by the Pediatric Eye Disease Investigator Group (PEDIG) and funded by the National Eye Institute (NEI).

“The overall mixed results on low-dose atropine show us we need more research. Would a different dose be more effective in a US population? Would combining atropine with other strategies have a synergistic effect? Could we develop other approaches to treatment or prevention based on a better understanding of what causes myopia progression?” said Michael F. Chiang, MD, director of the NEI, which is part of the National Institutes of Health.

Identifying an optimal approach for preventing high (advanced) myopia is urgently needed given the escalating prevalence of myopia overall and the risk of it progressing to high myopia. By 2030, it’s predicted that 39 million people in the U.S. will have myopia. By 2050, that number is expected to grow to 44 million in the U.S. and to 50% of the global population.

Much stronger concentrations of atropine eyedrops (0.5-1.0%) have long been used by pediatric eye doctors to slow myopia progression. While effective, such doses cause light sensitivity and blurry near vision while on the nightly eyedrops. Thus, there is interest in clinical studies assessing lower concentrations that have been shown to have fewer side effects.

“The absence of a treatment benefit in our US-based study, compared with East Asian studies, may reflect racial differences in atropine response. The study enrolled fewer Asian children, whose myopia progresses more quickly, and included Black children, whose myopia progresses less quickly compared with other races,” noted the study’s lead co-author, Michael X. Repka, M.D., professor of ophthalmology, Johns Hopkins University.

For the study, 187 children ages 5 to 12 years with low-to-moderate bilateral myopia were randomly assigned to use nightly atropine (0.01%) (125 children) or placebo (62 children) eyedrops for two years. Study participants, their parents, and the eye care providers were masked to the group assignments.

After the treatment period, and 6 months after treatment stopped, there were no significant differences between the groups in terms of changes in degree of myopia compared with baseline. Nor were there significant differences in axial length within the two groups when compared with baseline measurements.

“It’s possible that a different concentration of atropine is needed for US children to experience a benefit,” noted the study’s other lead co-author, Katherine K. Weise, OD, professor, University of Alabama at Birmingham. “Clinical researchers could evaluate new pharmaceuticals and special wavelengths of light in combination with optical strategies, like special glasses or contact lenses, to see what works in reducing the progression of myopia.”

Among children, myopia will stabilise in about half of children around age 16 years, and among an increasingly larger percentage as they get older. By their early twenties, about 10% of individuals with myopia will continue to grow more nearsighted, and by age 24 years that percentage is 4%.

“Vision scientists may help us figure out what’s different about the myopic eye, even among different races and ethnicities, to help create new treatment strategies,” she said. It will take a real convergence of eye research to solve the environmental, genetic, and structural mystery of myopia.”

Source: NIH/National Eye Institute

Categories : Neurodegenerative Diseases OphthalmologyTags :

Thinning of the Retina is an Early Marker of MS

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Retina and nerve cells. Credit: NIH

For the first time, a study has shown that diagnosis of multiple sclerosis (MS) can be significantly improved by additionally measuring the thickness of retinal layers in the eye in a currently existing procedure. Use of the procedure helps to detect the condition at an earlier stage and predict its progression more accurately, which can help to improve patient outcomes. The findings have been published in the journal Neurology.

As part of their investigation, the research team headed by Gabriel Bsteh and Thomas Berger collaborated with ophthalmology colleagues examine 267 MS patients over five years. Their research built on study results published in 2022, which showed that MS relapse-related damage to the retina reflects the degree of damage caused to the patient’s brain. The previous study also demonstrated that a 5µm reduction in the thickness of the retinal layer following optic neuritis indicated a doubling of the risk of permanent disability after the next relapse. Thanks to the latest research with the large cohort of MS patients, the research team has confirmed that the thickness of the retinal layer can be used as a precise biomarker to assist early diagnosis.

Diagnostic procedure already available

The researchers used a procedure known as optical coherence tomography (OCT) to measure the thickness of the retinal layer. An imaging method that uses infrared light, OCT allows for the generation of high-resolution, three-dimensional images of extremely thin layers of tissue measuring just a few µm. OCT is also a tool for diagnosing and evaluating the progression of eye diseases such as glaucoma. “So we already have this procedure at our disposal,” commented Gabriel Bsteh, first author of the study. He added: “If we use optical coherence tomography alongside the current criteria to diagnose MS, we obtain significantly more accurate results at a much earlier stage. This means we can initiate treatment measures sooner, which considerably improves the long-term prognosis for patients.”

The retina: a window to the brain

Multiple sclerosis is an autoimmune, chronic inflammatory disease that causes inflammation and loss of nerve cells throughout the nervous system. For the most part, patients are unable to feel the consequences of this damage to begin with, so the condition often goes undiagnosed until a late stage, meaning that valuable time is lost during which effective treatment could have been administered. Given that early detection and prognosis of the disease’s progression play a decisive role in MS cases, medical researchers have been trying to find improved detection methods for some time now to help avert serious consequences such as impaired mobility and blindness as far as possible. “We have identified a new biomarker for MS diagnosis, namely the retinal layer thickness, which can be likened to a window to the brain,” said Gabriel Bsteh, summing up the study’s key finding. In the next phases of research, the focus will turn to the importance of retinal layer thickness in measuring responses to MS treatment.

Source: Medical University of Vienna

Categories : Ophthalmology Paediatrics

Atropine Eyedrops Shown to Slow Progression of Myopia in Children

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Photo by Anna Shvets on Pexels

The first drug therapy to slow the progression of nearsightedness in children is a step closer after the results of a successful clinical trial.

The results of the CHAMP (Childhood Atropine for Myopia Progression) trial were published in JAMA Ophthalmology. The three-year study found that a daily drop in each eye of a low dose of atropine, a drug used to dilate pupils, was better than a placebo at limiting eyeglass prescription changes and inhibiting elongation of the eye in nearsighted children aged six to 10.

About one in three adults worldwide is nearsighted, and the global prevalence of myopia is predicted to increase to 50% by 2050. Though one federally approved contact lens can slow progression of nearsightedness, no pharmaceutical products are approved in the US or Europe to treat myopia.

That elongation of the eyeball leads to myopia which starts in young children and progresses into the teen years before levelling off in most people. In addition to requiring life-long vision correction, nearsightedness increases the risk for retinal detachment, macular degeneration, cataracts and glaucoma later in life – and most corrective lenses don’t do anything to stop myopia progression.

“The idea of keeping eyeballs smaller isn’t just so people’s glasses are thinner – it would also be so that in their 70s they don’t suffer visual impairment,” said lead study author Karla Zadnik, professor and dean of the College of Optometry at The Ohio State University.

“This is exciting work for the myopia research community, which I’ve been part of for 35 years. We’ve talked about treatment and control for decades,” she said. “And it’s exciting to think that there could be options in the future for millions of children we know are going to be myopic.”

Animal studies years ago hinted at atropine’s ability to slow the growth of the eye, but the full-strength drug’s interference with near vision and concerns about pupil dilation hindered early considerations of its potential as a human therapy for myopia. More recent research has suggested a low dose of atropine might be the ticket.

This new double-masked, randomised phase 3 trial assessed the safety and effectiveness of two low-dose solutions, with atropine concentrations of either .01% or .02%, versus placebo. Treatment for each of the 489 children ages six to 10 assessed for the drug’s effectiveness consisted of one daily drop per eye at bedtime, which minimised the disruption of any blurring effects atropine might have on vision.

Researchers were a bit surprised to find that the most significant improvements at all time points compared to placebo resulted from the solution containing .01% of atropine. Though the .02% atropine formulation was also better at slowing progression of myopia than placebo, the results were less consistent.

“The .01% story is clearer and more obvious in terms of significantly slowing both the growth of the eye as well as then resulting in a lower glasses prescription,” Zadnik said.

Including a measure of the eye’s growth was a key component of the study because “the field is actually moving toward axial elongation being as important as, or more important than, the glasses prescription in terms of the most meaningful outcome,” she said. “If we’re trying to slow eye growth to prevent bad outcomes for people in their 80s, measuring the eye growth directly is really important.”

The drugs’ safety was assessed in a larger sample of 573 participants that also included children as young as 3 and up to age 16. Both low-dose formulations were safe and well tolerated. The most common side effects were sensitivity to light, allergic conjunctivitis, eye irritation, dilated pupils and blurred vision, although reports of these side effects were few.

The CHAMP trial was the first study of low-dose atropine to include placebo controls for three years and to involve a large, diverse population recruited from 26 clinical sites in North America and five countries in Europe. In a second section of the trial, researchers are evaluating how the eyes respond when the treatment is over.

Source: Ohio State University