Media update

A Safer Alternative to Laser Eye Surgery?
A new type of procedure for correcting short-sightedness could be safer than laser eye surgery, according to a new Cochrane Systematic Review. The study also shows that patients prefer the new procedure, despite there being little difference between the two in terms of improving vision.

Myopia or short-sightedness is a condition where the eye focuses images in front of the retina instead of directly on it. Myopia affects around a quarter of the population in Western countries and is becoming more common. In recent years, the preferred corrective procedure for people wanting to avoid wearing glasses or contact lenses has been excimer laser refractive surgery, but a new alternative is the insertion of phakic intraocular lenses (IOLs). Both procedures work by changing the path of the light entering the eye and bringing images into focus in the right place. Laser surgery does this by removing parts of the cornea, whereas the new procedure uses a synthetic lens inserted in front of the natural lens.

Until now, there has be no systematic review comparing the accuracy and safety of the two procedures and insertion of phakic IOLs has only been practiced in more severely shortsighted
patients. However, the new study suggests the procedure could be more widely used.

“Our findings suggest phakic IOLs are safer than excimer laser surgery for correcting moderate to high levels of short-sightedness,” says lead author Allon Barsam of the Moorfields Eye Hospital NHS Foundation Trust in London, UK. “Although it’s not currently standard clinical practice, it could be worth considering phakic IOL treatment over the more common laser surgery for patients with moderate short-sightedness.”

The researchers reviewed data from three trials comparing the two types of surgery, which together included surgeries performed on 228 eyes in 132 patients. A year after surgery, the percentage of eyes with 20/20 vision without spectacles was the same for both procedures, but patients undergoing phakic IOL treatment had clearer spectacle corrected vision and better contrast sensitivity. Patients also scored the phakic IOL procedure more highly in patient satisfaction questionnaires.

Phakic IOL treatment carries a slightly increased risk of cataract, but further investigation of long term adverse effects is needed, according to the researchers. “There may be more long term risks unique to patients with phakic IOLs that are not apparent after one year of follow-up,” says Barsam.

Full citation: Barsam A, Allan BDS. Excimer laser refractive surgery versus phakic intraocular lenses for the correction of moderate to high myopia. Cochrane Database of Systematic Reviews 2010, Issue 5. Art. No.: CD007679. DOI: 10.1002/14651858.CD007679.pub2. To arrange an interview with Allon Barsam, please contact Jennifer Beal on medicalnews@wiley.com.

Caffeine Reduces Mistakes Made By Shift Workers
Caffeine can help those working shifts or nights to make fewer errors, according to a new study by Cochrane researchers. The findings have implications for health workers and for any industry relying on shift or night work, such as transportation.

More than 15% of workers in industrialised countries are involved in some shift or night time work, which may upset natural circadian rhythms or ‘body clocks’. In so-called shift work disorder (SWD), workers sleep only for short periods and consequently can become very sleepy during working hours. Sleepiness is thought to increase the risk of adverse events such as traffic crashes, occupational injuries and medical errors.

The researchers reviewed data from 13 trials studying the effects of caffeine on performance in shift workers, mostly in simulated working conditions. Caffeine was given in coffee, pills, energy drinks or caffeinated food. In some trials, performance was assessed by tasks such as driving, whereas in others it was assessed by neuropsychological tests. Caffeine appeared to reduce errors compared to placebos or naps, and improve performance in various neuropsychological tests, including those focusing on memory, attention, perception and concept formation and reasoning.

None of the trials measured injuries directly, but improved performance may translate into reduced numbers of injuries caused by sleepiness, according to researchers. “It seems
reasonable to assume that reduced errors are associated with fewer injuries, although we cannot quantify such a reduction,” says lead researcher Katharine Ker of the London School of Tropical Medicine in London, UK.

The average age in most trials was between 20 and 30 years and thus, because the effect of disruption to the circadian rhythm varies with age, there is still a need for more research on how caffeine affects alertness in older workers. The study also finds that there is a need for research to explore the effects of caffeine compared to other measures in order to reduce errors made by shift workers.

Full citation: Ker K, Edwards PJ, Felix LM, Blackhall K, Roberts I. Caffeine for the prevention of injuries and errors in shift workers. Cochrane Database of Systematic Reviews 2010, Issue 5. Art. No.: CD008508. DOI: 10.1002/14651858.CD008508. Katherine Ker is unavailable for interview, but interviews with co-author Dr. Phil Edwards can be arranged via Gemma Howe at the London School of Hygiene & Tropical Medicine Press Office on +44 (0) 207 927 2802 / +44 (0) 7828 617 901 or Gemma.Howe@lshtm.ac.uk.

Schizophrenia: Regular Exercise Guidelines Still Apply
Regular exercise can play an important a role in improving the physical and mental wellbeing of individuals with schizophrenia, according to a review published in The Cochrane Library. Following a systematic review of the most up-to-date research on exercise in schizophrenia, researchers concluded that the current guidelines for exercise should be followed by people with schizophrenia just as they should by the general population.

“Current guidelines for exercise appear to be just as acceptable to individuals with schizophrenia in terms of potential physical and mental health benefit,” says lead researcher Guy Faulkner of the Faculty of Physical Education and Health at the University of Toronto, Canada. “So thirty minutes of moderate physical activity on most or all days of the week is a good goal to aim for. Start slowly and build up.”

Schizophrenia is a serious mental illness affecting four in every 1,000 people. It is already known that exercise can improve mental health, but so far there has been only limited evidence of effects in schizophrenia. The new review focused on three recent small studies that compared the effects of 12-16 week exercise programmes, including components such as jogging, walking and strength training, to standard care or yoga.

The researchers found that exercise programmes improved mental state for measures including anxiety and depression, particularly when compared to standard care. Changes in physical health outcomes were seen but they were not significant overall. However, the researchers suggest this may be due to the short timescale of the trials.

Two previous reviews have found exercise therapy to be beneficial in schizophrenia, but called for more rigorous research. “This new review suggests that such calls are starting to be addressed,” says Faulkner. “But we still need more research that will help us learn how we can get individuals with schizophrenia engaged in exercise programmes in the first place, and how such programmes can be developed and implemented within mental health services. That’s one of the biggest challenges for this type of intervention.”

Full citation: Gorczynski P, Faulkner G. Exercise therapy for schizophrenia. Cochrane Database of Systematic Reviews 2010, Issue 5. Art. No.: CD004412. DOI: 10.1002/14651858.CD004412.pub2
To arrange an interview with an author, please contact Jennifer Beal on medicalnews@wiley.com.

Vaccination Reduces Burden of Childhood Rotavirus Disease
Vaccination of infants with Rotarix or RotaTeq significantly reduces the rate of severe rotavirus diarrhoea, hospitalizations, medical attention due to rotavirus and severe diarrhoea from all causes. The vaccines are not associated with increased numbers of serious adverse events. These are the conclusions of a Cochrane Systematic Review published in the May 2010 issue of The Cochrane Library.

Rotavirus infection is the most common cause of severe diarrhoea in infants and young children, with the peak incidence of disease occurring between six and 24 months of age. Symptoms can range from mild illness, to hospitalization and death. Rotavirus infections cause over half a million deaths per year in children younger than five years, especially in low- and middle-income countries. The virus also results in higher diarrhoea-related death in children less than five years of age than any other single agent, particularly in low- and middle-income countries.

The researchers identified 34 trials that met their inclusion criteria, of which 26 evaluated Rotarix (GSK Biologicals, Belgium) and 8 evaluated RotaTeq (Merck & co., USA).

Together, these trials included 175,944 participants. The study also searched for data on the use of Lanzhou Lamb Rotavirus (LLR) vaccine, which is approved for use only in China, but did not identify any trials that met their inclusion criteria. Rotarix and RotaTeq reduced all cases of rotavirus diarrhoea by 76% and 73% respectively at one year of age, and by 67% and 62% respectively at age two years. Severe rotavirus disease was reduced by 72% and 93% respectively at one year and 67% and 89% respectively at two years.

“Discovering just how effective both of these vaccines are at combating rotavirus disease will inform decision-making and support vaccine introduction,” says Karla Soares-Weiser, who works at Enhance Reviews Ltd, London and leads a world-wide team of academic and medical researchers.

“New trials with head-to-head comparisons of both vaccines are needed, as well as trials comparing LLR vaccine with placebo, data for special groups of children, such as preterm
infants and malnourished children, and careful monitoring of adverse events where vaccines are routinely used,” says Soares-Weiser.

Full citation: Soares-Weiser K, MacLehose H, Ben-Aharon I, Goldberg E, Pitan F, Cunliffe N. Vaccines for preventing rotavirus diarrhoea: vaccines in use. Cochrane Database of Systematic Reviews 2010, Issue 5. Art. No.: CD008521. DOI: 10.1002/14651858.CD008521

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Jennifer Beal | Publicity Manager
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