Conjunctivitis: Do antibiotics help?

In more than half of all people who have conjunctivitis, the infection goes away without treatment within a week. Antibiotic eye drops or ointment can speed up recovery. Adverse effects are very rare.

Conjunctivitis makes people’s eyes red and inflamed. It often affects both eyes because the infection can easily spread from one eye to the other. Your eyes get watery and produce a yellowish-white discharge that makes your eyelids stick together. They may become very sore too. Conjunctivitis is contagious but often gets better within a week, even without any treatment. So it is often enough to simply wait.

Conjunctivitis is usually caused by bacteria or viruses.  Because conjunctivitis usually goes away so quickly, though, it is generally not worth doing tests to find out if it is a bacterial or viral infection. Doctors often prescribe antibiotics just in case, in the form of eye drops or ointments. Antibiotics only work against bacteria, though, and not against viruses, so they are not always effective.

Some people use non-antibiotic eye drops. The use of cold or warm compresses is common too. But there is not enough research on these approaches to be able to say whether they have a benefit, no effect, or are possibly even harmful. Sometimes conjunctivitis is linked to an allergy. Then it is treated with allergy medicines like antihistamines.

Research on antibiotics in the treatment of conjunctivitis

Two groups of researchers from the Cochrane Collaboration (an international network of researchers) and from various universities in England, the Netherlands and Australia analyzed the results of trials on the treatment of conjunctivitis with antibiotics. They wanted to find out whether antibiotics help in the treatment of ordinary conjunctivitis, as well as which possible disadvantages they have.

The researchers only analyzed the results of studies that compared at least two groups of people. One group of people used antibiotic eye drops or ointments. The other group used non-antibiotic eye drops or ointments, or did not have any treatment at first. The researchers were only interested in studies in which the participants were randomly assigned to one of the treatment groups. This kind of study, called a randomized controlled trial, delivers the most reliable results. Read our information "Evidence-based medicine" to find out more about how good-quality trials are carried out.

The researchers found 12 trials, involving a total of about 4,000 people with conjunctivitis. Both children and adults participated in the trials.

Antibiotics can speed up recovery

Overall, the analysis of the trial results showed that conjunctivitis goes away somewhat faster if antibiotics are used. This is what was found for people who went to see their family doctor because they had conjunctivitis:

• The infection cleared up within one week in 71 out of 100 people who did not use antibiotics.
• The infection cleared up within that same amount of time in 80 out of 100 people who used antibiotics.

In other words, antibiotics were found to speed up recovery in 9 out of 100 people.

In studies that were carried out in a specialist practice, it took a little longer for the infection to clear up – both in the people who used antibiotics and in those who did not use antibiotics. One possible explanation for this is that people who go to see a specialist doctor probably have more severe cases of conjunctivitis. But the antibiotics had a similar beneficial effect to that found in the family doctor trials.

None of the trials reported that antibiotics had adverse effects. The trials did not look into whether antibiotics helped lower the risk of the infection spreading.

Recognizing signs of complications and avoiding the spread of infection

As already mentioned, conjunctivitis usually goes away without treatment. But some symptoms could be signs of more serious problems. These symptoms include worsening vision, increased sensitivity to light, the feeling that you have something in your eye, and a severe headache together with nausea. It is important to see a doctor if you have any of these symptoms.

In people who wear contact lenses, the infection can spread to the cornea (the clear surface of the eye itself). Inflammation of the cornea, also known as keratitis, is not common though: it is estimated that conjunctivitis leads to keratitis in about 3 out of every 10,000 contact lens wearers. In the trials that the researchers included in their analysis, none of the participants developed keratitis.

If conjunctivitis is caused by viruses it can be highly contagious and hard to get rid of. But there are several things that can be done to try to stop viral infections from spreading. Because the virus is easily spread through finger contact, it is important to avoid touching your eyes with your hands, and to wash your hands if you do accidentally touch your eyes. It is also a good idea to have your own towels and washcloths, and not to share them with other people. Another important way to protect others from infection is by not shaking hands with them and not touching their face.

Original Article found at http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0005040/

Published by the Institute for Quality and Efficiency in Health Care (IQWiG)Next planned update:
October 2015. You can find out more about how our health information is updated in our text "Informed Health Online: How our information is produced".

References

• IQWiG health information is based on research in the international literature. We identify the most scientifically reliable knowledge currently available, particularly what are known as “systematic reviews”. These summarize and analyze the results of scientific research on the benefits and harms of treatments and other health care interventions. This helps medical professionals and people who are affected by the medical condition to weigh up the pros and cons. You can read more about systematic reviews and why these can provide the most trustworthy evidence about the state of knowledge in our information "Evidence-based medicine". We also have our health information reviewed to ensure medical and scientific accuracy.
• Jefferis J, Perera R, Everitt H, van Weert H, Rietveld R, Glasziou P et al. Acute infective conjunctivitis in primary care: who needs antibiotics? An individual patient data meta-analysis. Br J Gen Pract 2011; 61(590): e542-548. [Full text]
• Sheikh A, Hurwitz B, van Schayck CP, McLean S, Nurmatov U. Antibiotics versus placebo for acute bacterial conjunctivitis. Cochrane Database Syst Rev 2012; (9): CD001211. [Summary]

Who is likely to develop Dry Eye?

Who is likely to develop Dry Eye?

Elderly people frequently experience dryness of the eyes, but Dry Eye can occur at any age. Nearly five million Americans 50 years of age and older are estimated to have Dry Eye. Of these, more than three million are women and more than one and a half million are men. Tens of millions more have less severe symptoms. Dry Eye is more common after menopause. Women who experience menopause prematurely are more likely to have eye surface damage from Dry Eye.

Treatment

How is Dry Eye treated?

Depending on the causes of Dry Eye, your doctor may use various approaches to relieve the symptoms.

Dry Eye can be managed as an ongoing condition. The first priority is to determine if a disease is the underlying cause of the Dry Eye (such as Sjögren's syndrome or lacrimal and meibomian gland dysfunction). If it is, then the underlying disease needs to be treated.

Cyclosporine, an anti-inflammatory medication, is the only prescription drug available to treat Dry Eye. It decreases corneal damage, increases basic tear production, and reduces symptoms of Dry Eye. It may take three to six months of twice-a-day dosages for the medication to work. In some cases of severe Dry Eye, short term use of corticosteroid eye drops that decrease inflammation is required.

If Dry Eye results from taking a medication, your doctor may recommend switching to a medication that does not cause the Dry Eye side effect.

If contact lens wear is the problem, your eye care practitioner may recommend another type of lens or reducing the number of hours you wear your lenses. In the case of severe Dry Eye, your eye care professional may advise you not to wear contact lenses at all.

Another option is to plug the drainage holes, small circular openings at the inner corners of the eyelids where tears drain from the eye into the nose. Lacrimal plugs, also called punctal plugs, can be inserted painlessly by an eye care professional. The patient usually does not feel them. These plugs are made of silicone or collagen, are reversible, and are a temporary measure. In severe cases, permanent plugs may be considered.

In some cases, a simple surgery, called punctal cautery, is recommended to permanently close the drainage holes. The procedure helps keep the limited volume of tears on the eye for a longer period of time.

In some patients with Dry Eye, supplements or dietary sources (such as tuna fish) of omega-3 fatty acids (especially DHA and EPA) may decrease symptoms of irritation. The use and dosage of nutritional supplements and vitamins should be discussed with your primary medical doctor.

What can I do to help myself?

• Use artificial tears, gels, gel inserts, and ointments - available over the counter - as the first line of therapy. They offer temporary relief and provide an important replacement of naturally produced tears in patients with aqueous tear deficiency. Avoid artificial tears with preservatives if you need to apply them more than four times a day or preparations with chemicals that cause blood vessels to constrict.
• Wearing glasses or sunglasses that fit close to the face (wrap around shades) or that have side shields can help slow tear evaporation from the eye surfaces. Indoors, an air cleaner to filter dust and other particles helps prevent Dry Eyes. A humidifier also may help by adding moisture to the air.
• Avoid dry conditions and allow your eyes to rest when performing activities that require you to use your eyes for long periods of time. Instill lubricating eye drops while performing these tasks.

Article republished from: http://www.nei.nih.gov/health/dryeye/dryeye.asp

New Eye Imaging Techniques Are On the Horizon

ScienceDaily (May 7, 2012) - The same technology used by astronomers to obtain clear views of distant stars is now being used by optometrists to perform incredibly detailed examinations of the living Eye.

An update on new developments in ocular imaging techniques -- and how they may affect clinical vision care in the not-too-distant future -- is presented in an article titled "Adaptive Optics Scanning Laser Ophthalmoscope-based Microperimetry" published in a special May issue of Optometry and Vision Science, official journal of the American Academy of Optometry.

Cutting-edge techniques now allow researchers to visualize the fine structure of the Eye in a way that was "not conceivable 20 years ago," according to a guest editorial by Scott Read OD PhD FAAO (Candidate) and colleagues. "As these advanced imaging methods continue to develop, the potential for imaging ocular structures down to the cellular level in everyday clinical practice has become a reality -- and the potential to improve patient care is truly stunning," Dr Read and coauthors add.

New Techniques Provide Cellular-Level Images of the Living Eye The special issue presents 30 reports on the latest, most advanced techniques for imaging and measurement of various Eye structures: the retina and optic nerve, lens and ciliary body, and the anterior Eye. Written by leading researchers and clinicians, the contributions provide a fascinating look at these remarkable new technologies, with a glimpse of their likely extensions into clinical practice.

As just one example, William S. Tuten, OD, MS, and colleagues of the University of California, Berkeley, report on the development and use of an "adaptive optics scanning laser ophthalmoscope." Adaptive optics refers to the use of advanced techniques to correct for optical aberrations through any transparent media. Originally developed for use in telescopes to correct for the distorting effects of the atmosphere, adaptive optics is now being applied to evaluating the structure and function of the human eye.

Dr. Tuten and colleagues have applied adaptive optics to perimetry -- also known as visual field testing -- on the microscopic scale. Perimetry is an important part of evaluation for patients with vision disorders including macular degeneration, retinitis pigmentosa, and diabetic retinopathy. Perimetry measures vision in all parts of the visual field, including the peripheral vision.

Promising Applications to Improve Clinical Vision Care The new paper describes (and illustrates) the use of adaptive optics-guided microperimtery to assess visual fields at an unprecedented level of detail. The technique can not only show limitations in visual fields, but can trace the defect to individual retinal photoreceptor cells. High-speed tracking is used to correct for normal eye movement, or "jitter," that is practically undetectable using conventional imaging techniques.

In addition, by using microscopic blood vessels as anatomical landmarks, the adaptive optics technique permits repeated studies to be repeated over time at a high level of precision. This offers unique opportunities for studying how treatments work on the cellular level, as well as following the effects of treatment over time in individual patients.

"This technique opens new horizons for clinician-scientists, and later clinicians, to better understand, and plot out, the relationships between vision and the retinal photoreceptors at a microscopic level," comments Anthony Adams, OD, PhD, Editor-in-Chief of Optometry and Vision Science. "It enables a new understanding of vision loss in patients with retinal disorders where there are discrete photoreceptor losses -- for example, macular degeneration."

Adaptive optics-guided microperimetery and other advanced imaging technologies described in the special issue have the potential to revolutionize the management of eye diseases, Dr. Read and colleagues believe. They conclude, "With ongoing improvements in imaging speed and resolution, and with the application of innovative methods to improve the clinical usefulness of ocular imaging techniques, the future of ocular imaging is bright!"

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http://www.sciencedaily.com/releases/2012/05/120507132017.htm

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Vitamin D Could Help Combat the Effects of Aging in Eyes

ScienceDaily (Jan. 17, 2012) — Researchers funded by the Biotechnology and Biological Sciences Research Council (BBSRC) have found that vitamin D reduces the effects of aging in mouse Eyes and improves the vision of older mice significantly. The researchers hope that this might mean that vitamin D supplements could provide a simple and effective way to combat age-related eye diseases, such as macular degeneration (AMD), in people.

The research was carried out by a team from the Institute of Ophthalmology at University College London and is published in the current issue of the journal Neurobiology of Ageing.

Professor Glen Jeffery, who led the work, explains "In the back of the Eyes of mammals, like mice and humans, is a layer of tissue called the retina. Cells in the retina detect light as it comes into the Eyes and then send messages to the brain, which is how we see. This is a demanding job, and the retina actually requires proportionally more energy than any other tissue in the body, so it has to have a good supply of blood. However, with aging the high energy demand produces debris and there is progressive inflammation even in normal animals. In humans this can result in a decline of up to 30% in the numbers of light receptive cells in the eye by the time we are 70 and so lead to poorer vision."

The researchers found that when old mice were given vitamin D for just six weeks, inflammation was reduced, the debris partially removed, and tests showed that their vision was improved.

The researchers identified two changes taking place in the Eyes of the mice that they think accounted for this improvement. Firstly, the number of potentially damaging cells, called macrophages, were reduced considerably in the Eyes of the mice given vitamin D. Macrophages are an important component of our immune systems where they work to fight off infections. However in combating threats to the aged body they can sometimes bring about damage and inflammation. Giving mice vitamin D not only led to reduced numbers of macrophages in the eye, but also triggered the remaining macrophages to change to a different configuration. Rather than damaging the eye the researchers think that in their new configuration macrophages actively worked to reduce inflammation and clear up debris.

The second change the researchers saw in the eyes of mice given vitamin D was a reduction in deposits of a toxic molecule called amyloid beta that accumulates with age. Inflammation and the accumulation of amyloid beta are known to contribute, in humans, to an increased risk of age-related macular degeneration (AMD), the largest cause of blindness in people over 50 in the developed world. The researchers think that, based on their findings in mice, giving vitamin D supplements to people who are at risk of AMD might be a simple way of helping to prevent the disease.

Professor Jeffery said "When we gave older mice the vitamin D we found that deposits of amyloid beta were reduced in their eyes and the mice showed an associated improvement of vision. People might have heard of amyloid beta as being linked to Alzheimer's disease and new evidence suggests that vitamin D could have a role in reducing its build up in the brain. So, when we saw this effect in the eyes as well, we immediately wondered where else these deposits might be being reduced."

Professor Jeffery and his team then went on to study some of the blood vessels of their mice. They found that the mice that had been given the vitamin D supplement also had significantly less amyloid beta built up in their blood vessels, including in the aorta.

Professor Jeffery continues "Finding that amyloid deposits were reduced in the blood vessels of mice that had been given vitamin D supplements suggests that vitamin D could be useful in helping to prevent a range of age-related health problems, from deteriorating vision to heart disease."

Professor Jeffery thinks that this link between vitamin D and a range of age-related diseases might be linked to our evolutionary history. For much of human history our ancestors lived in Africa, probably without clothes, and so were exposed to strong sunlight all year round. This would have triggered vitamin D production in the skin. Humans have only moved to less sunny parts of the world and adopted clothing relatively recently and so might not be well adapted to reduced exposure to the sun. Secondly, life expectancy in the developed world has increased greatly over the past few centuries, so reduced exposure to vitamin D is now coupled with exceptionally long lifespan.

Professor Jeffery said "Researchers need to run full clinical trials in humans before we can say confidently that older people should start taking vitamin D supplements, but there is growing evidence that many of us in the Western world are deficient in vitamin D and this could be having significant health implications."

Professor Douglas Kell, BBSRC Chief Executive said "Many people are living to an unprecedented old age in the developed world. All too often though, a long life does not mean a healthy one and the lives of many older people are blighted by ill health as parts of their bodies start to malfunction.

"If we are to have any hope of ensuring that more people can enjoy a healthy, productive retirement then we must learn more about the changes that take place as animals age. This research shows how close study of one part of the body can lead scientists to discover new knowledge that is more widely applicable. By studying the fundamental biology of one organ scientists can begin to draw links between a number of diseases in the hope of developing preventive strategies."

http://www.sciencedaily.com/releases/2012/01/120117145234.htm

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The Pupils Are the Windows to the Mind

The eyes are the window into the soul -- or at least the mind, according to a new paper published in Perspectives on Psychological Science, a journal of the Association for Psychological Science. Measuring the diameter of the Pupil, the part of the eye that changes size to let in more light, can show what a person is paying attention to. Pupillometry, as it's called, has been used in social psychology, clinical psychology, humans, animals, children, infants -- and it should be used even more, the authors say.

The Pupil is best known for changing size in reaction to light. In a dark room, your Pupils open wide to let in more light; as soon as you step outside into the sunlight, the Pupils shrink to pinpricks. This keeps the retina at the back of the eye from being overwhelmed by bright light. Something similar happens in response to psychological stimuli, says Bruno Laeng of the University of Oslo, who cowrote the paper with Sylvain Sirois of Université du Québec à Trois-Rivières and Gustaf Gredebäck of Uppsala University in Sweden. When someone sees something they want to pay closer attention to, the Pupil enlarges. It's not clear why this happens, Laeng says. "One idea is that, by essentially enlarging the field of the visual input, it's beneficial to visual exploration," he says.

However it works, psychological scientists can use the fact that people's Pupils widen when they see something they're interested in.

Laeng has used Pupil size to study people who had damage to the hippocampus, which usually causes very severe amnesia. Normally, if you show one of these patients a series of pictures, then take a short break, then show them another series of pictures, they don't know which ones they've seen before and which ones are new. But Laeng measured patients' Pupils while they did this test and found that the patients did actually respond differently to the pictures they had seen before. "In a way, this is good news, because it shows that some of the brains of these patients, unknown to themselves, is actually capable of making the distinction," he says.

Pupil measurement might also be useful for studying babies. Tiny infants can't tell you what they're paying attention to. "Developmental psychologists have used all kinds of methods to get this information without using language," Laeng says. Seeing what babies are interested in can give clues to what they're able to recognize -- different shapes or sounds, for example. A researcher might show a child two images side by side and see which one they look at for longer. Measuring the size of a baby's Pupils could do the same without needing a comparison.

The technology already exists for measuring Pupils -- many modern psychology studies use eye-tracking technology, for example, to see what a subject is looking at, and Laeng and his coauthors hope to convince other psychological scientists to use this method.

http://www.sciencedaily.com/releases/2012/01/120127162800.htm

The above story is reprinted from materials provided by Association for Psychological Science.

Do your eyes hold the secret of life?

In the future, patients in need of perfectly matched neural stem cells may not need to look any further than their own eye.

Researchers reporting in the January issue of Cell Stem Cell, a Cell Press publication, have identified adult stem cells of the central nervous system in a single layer of cells at the back of the eye.

That cell layer, known as the retinal pigment epithelium (RPE), underlies and supports photoreceptors in the light-sensitive retina. Without it, photoreceptors and vision are lost. The new study shows that the RPE also harbors self-renewing stem cells that can wake up to produce actively growing cultures when placed under the right conditions. They can also be coaxed into forming other cell types.

"You can get these cells from a 99-year-old," said Sally Temple of the Neural Stem Cell Institute in Rensselaer, New York. "These cells are laid down in the embryo and can remain dormant for 100 years. Yet you can pull them out and put them in culture and they begin dividing. It is kind of mind boggling."

Temple's group got the RPE-derived stem cells they describe from the eye of donors in the hours immediately after their deaths. But the cells can also be isolated from the fluid that surrounds the retina at the back of the eye, which means they are accessible in living people as well.

"You can literally go in and poke a needle in the eye and get these cells from the subretinal space," she says. "It sounds awful, but retinal surgeons do it every day." By comparison, access to most other neural stem cell populations would require major surgery.

Temple said they were curious about the proliferative potential of the RPE given that the tissue is known to be capable of regenerating entire retinas in salamanders. But that plasticity in adulthood had seemed to be lost in mice and chicks. Still, "given the evolutionary evidence, we thought it was worth revisiting," she said.

They placed RPE tissue taken from 22-year-old to 99-year-old cadavers into many culture conditions to see what they could make the cells do. They found one set of conditions that got the cells dividing. Not all of the RPE cells have this regenerative potential, but perhaps 10 percent of them do.

Further work showed that the cells are multipotent, which means that they can form different cell types, though the researchers admit there is more to do to fully explore the cells' differentiation capacity.

There are other implications as well. For example, these cells may explain diseases in which other tissue types show up in the eye. Their presence also suggests that there might be some way to stimulate controlled repair of the eye in the millions of people who suffer from age-related macular degeneration.

"I think it might be possible," Temple said.

http://www.sciencedaily.com/releases/2012/01/120105131637.htm

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