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]

Glaucoma, the silent thief...

When it comes to whether or not you will develop exfoliation syndrome (ES) -- an eye condition that is a leading cause of secondary open-angle glaucoma and increased risk of cataract as well as cataract surgery complications -- age, gender and where you live does matter.

"Although many studies from around the world have reported on the burden of the disease, some aspects of the basic descriptive epidemiologic features, which may help shed light on the cause, are inconsistent," said Louis Pasquale, M.D., study co-author and director of Massachusetts eye and Ear's glaucoma Center of Excellence. "In this study we found that women are more vulnerable to this disease then men, that ES is not a disease of Norwegian descent, and that where you live does matter when it comes to developing the disease."

Researchers from the Mass. eye and Ear, Harvard Medical School, Boston, Mass., Department of Medicine, Channing Laboratory, Brigham and Women's Hospital, Boston, Mass., Department of Ophthalmology and Visual Sciences, and University of Michigan, Ann Arbor, Mich., set out to find out how demographic and geographic risk factors are associated with ES. Their study, the "Demographic and Geographic Features of Exfoliation glaucoma in two United States-Based Prospective Cohorts" is published in the January 2012 issue of Ophthalmology.

Researchers used data from 78,955 women in the Nurses' Health Study (NHS) and 41,191 men in the Health Professionals Follow-up Study (HPFS) residing throughout the continental United States who were prospectively followed for 20 years or more and who provided lifetime residence information to examine the descriptive epidemiologic features of ES or exfoliation glaucoma suspect (EGS).

This study confirmed established associations with age and family history and exfoliation glaucoma or exfoliation glaucoma suspect (EG/EGS), as well as provided new data on associations with gender, eye color and ancestry. "Importantly, those with a lifetime residential history of living in the middle tier and south tier of the United States was associated with 47% and 75% reduced risks, respectively, compared with living in the northern tier, and across the life span, residence at age 15 was the most strongly associated with risk, followed by current residence," the authors wrote.

The study showed an increased risk in females, but it was unclear as if gender-specific differences in the eye, such as axial length differences or environmental factors related to lifestyle, account for why women are more at risk for this disease.

Other findings include:

• A positive family history of glaucoma was associated with a more than doubling of risk.


• Neither Scandinavian decent nor Southern European ancestry was associated with risk when compared with the larger reference group of mainly other white persons in the study, which indicates that there may be strong environmental factors that may increase risk among populations in Scandinavian countries. Overall the study lacked adequate power to determine whether incidence rates differed by minority groups.


• Iris ( eye) color did not seem to be a risk factor.

"This large prospective cohort study demonstrates that there is a positive association between latitude and ES risk that is robust and not related to demographic features or other systemic covariates," Dr. Pasquale explained. "Another manuscript we published recently suggests that lower ambient temperature interacts with increased solar exposure to increase the risk of ES. This new work demonstrates a relation between increasing latitude and a condition with a strong predisposition to glaucoma. More work is needed to determine how environmental factors conspire to contribute to ES."

According to the National eye Institute, ES is the major known cause of open-angle glaucoma, and is one of the leading causes of blindness. With the rapid aging of the U.S. population, the number of individuals affected by the disease will increase to more than three million by 2020.

ScienceDaily (Jan. 1, 2012) —

http://www.sciencedaily.com/releases/2012/01/120101143342.htm

The above story is reprinted from materials provided byMassachusetts Eye and Ear Infirmary.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

OVEREXPOSURE TO UV RAYS CAN LEAD TO EYE DISEASES
Prime vacation season for the beach is here and most of us are only thinking about protecting our skin. We should also be concerned about protecting our eyes because overexposure to UV rays can lead to eye diseases like cataracts and macular degeneration.

The following tips from the American Optometric Association may help prevent eye and vision damage from overexposure to UV radiation

1. Wear protective eyewear any time the eyes are exposed to UV rays, even on cloudy days and during the winter.

2. Sunglasses or protective contact lenses should block 99 to 100 percent of UV-A and UV-B radiation and screen out 75 to 90 percent of visible light.

3. Consider gray-colored lenses to reduce light intensity without altering the color of objects and provide the most natural color vision. Brown or amber-colored lenses increase contrast as well as reduce light intensity.

4. Don’t forget protection for young children and teenagers, who typically spend more time in the sun than adults and are at a greater risk for damage.

So remember, the next time you go to buy that pair of sunglasses, don’t forget to make sure they are healthy and protective for your eyes also.