Could vitamin D help cure eye infections and prevent blindness?
This research was completed on 31 October 2009
Published on 6 October 2007
Infection of the cornea - the clear window of the eye - is a leading cause of blindness. Worldwide, around 16 million people have lost part, or all of their vision to corneal infections.(1) In the Western World, contact lens wearers are amongst those at highest risk. Researchers think that vitamin D might have the potential to help prevent devastating, infection-related loss of sight. They are working hard to find out more.
What's the problem and who does it affect?
Losing the precious gift of sight
Infection of the cornea, the transparent window at the front of the eye, is painful and frightening. It's a leading cause of preventable vision loss, causing eyesight problems that range from reduced quality of vision to complete blindness. Ordinarily, the eye first becomes painful, red and sticky. Over one third of sufferers must be admitted to hospital,(2) where admission and treatment are often prolonged. Typically patients' develop ulcers or abscesses, and occasionally perforations of the cornea that may require a corneal transplant or even removal of the eye. Even people who recover from their infection reasonably well can find their stereoscopic vision - ability to see in three dimensions which involves the use of both eyes together - is compromised. This makes everyday tasks that involve judging distance, such as picking things up, driving, crossing roads and playing sport, much more difficult. Projects like this one, funded by Action Medical Research, are desperately needed, as the Project Leader, Miss Saaeha Rauz, explains: 'Corneal infections are incredibly common, yet much eyesight-related research is very poorly funded in comparison with research into life-threatening diseases. But patients will tell you that the most precious gift is eyesight.'
What is the project trying to achieve?
Battling bacteria: the role of vitamin D
Most of the corneal infections in the UK are caused by bacteria.(3) Researchers are trying to find out more about how the eye fights these bacterial infections. We already know that some of our immune cells have receptors, called Toll-like receptors (TLR), which recognise molecules on the surface of bacteria. When these receptors detect the presence of bacteria, they send out signals that trigger the immune system's attack against the bacteria. In immune cells, this attack is known to be enhanced by the activation of vitamin D. The research team believes that vitamin D may play a similar role in the cornea. They suspect that a complex interaction between two signalling pathways - involving Toll-like receptors and Vitamin D - helps to coordinate the cornea's immune response to bacterial invasion. They are investigating the presence of, function of, and communication between these pathways in the human cornea, and how they affect the eye's response to infection.
What are the researchers' credentials?
|Project Leader||Miss S Rauz MBBS PhD FRCOphth|
|Location||Academic Unit of Ophthalmology, Birmingham and Midland Eye Centre, City Hospital, Birmingham and the Institute of Biomedical Research, Division of Medical Sciences, University of Birmingham in conjunction with the Department of Biological Sciences, University of Warwick|
|Grant awarded||6 July 2007|
|Start date||1 November 2007|
|End date||31 October 2009|
We do not provide medical advice. If you would like more information about a condition or would like to talk to someone about your health, contact NHS Choices or speak to your GP. Please see our useful links page for some links to health information, organisations we are working with and other useful organisations. We hope you will find these useful. We are not responsible for the content of any of these sites.
The three investigators working on this project form a formidable team. The Project Leader, Miss Saaeha Rauz is both a Clinical Senior Lecturer (an academic) and a Consultant Ophthalmologist (specialist eye doctor and surgeon). Miss Rauz is part of an internationally renowned Ophthalmology research group based at the University of Birmingham, which focuses on studying the inflammatory processes that take place within the eye. Her clinical interests lie in complex, immune-related corneal diseases. Miss Rauz is working with Dr Rosemary Bland and Dr Elizabeth Walker. Dr Bland has vast experience of vitamin D signalling and directs one of the largest vitamin D groups in the UK. Dr Walker has over 15 years' experience in the field of steroid biology and has several ongoing collaborative projects with Miss Rauz. This three-way collaboration, uniting researchers with diverse interests and strengths, provides an excellent basis for the project. All three researchers can count on top-class support and facilities at their respective institutions. Miss Rauz, for example, is based at Birmingham and Midland Eye Centre - the UK's second largest eye unit - where there is good access to clinical material and patients, who are highly supportive of the Academic Unit of Ophthalmology's research efforts. Both Dr Walker and Dr Bland have laboratories in new Research Institutes which contain modern laboratories.
Who stands to benefit from this research and how?
The researchers hope to boost our understanding of how the cornea deals with bacterial infection and provide important information about whether vitamin D helps coordinate the immune response. If the researcher's hypotheses about vitamin D are true, then the race would be on to find out whether applying a formulation of vitamin D to the eye has the potential to help treat corneal infections, reduce the number and duration of hospital admissions, and save people's sight. Researchers envisage that vitamin D could be used alongside antibiotic treatment. It's possible that everyone who develops a corneal infection may benefit in the future. Factors that put people at risk of corneal infection include injuries to the eye, the cold sore virus, and conditions that make the surface of the eye numb (the patient cannot feel anything go in the eye) or exposed (the eyelids fail to close over and protect the eye). In the UK, one third of cases are associated with wearing contact lenses.(4) As most of our 3.3 million contact lens wearers are young,(5) a new treatment that can protect the precious gift of sight could help people live full and productive lives for many years to come.
1. WHO. Magnitude and causes of visual impairment. World Health Organization. 2004; Fact Sheet No 282. 2. Gao A, Murray PI, Rauz S. A Clinical And Microbiological Review Of 303 Consecutive Cases Of Suspected Microbial Keratitis In The United Kingdom. Investigative Ophthalmology & Visual Science 2006;47: E-Abstract 3562. 3. Rauz S, Dart JKG. Ulcerative Keratitis - Approach to Diagnosis and Therapy [Review]. Contemporary Ophthalmology 2003;2:1-10. 4. Morgan PB, Efron N, Hill EA, Raynor MK, Whiting MA, Tullo AB. Incidence of keratitis of varying severity among contact lens wearers. British Journal Ophthalmology 2005;89:430-436. 5. Association of Contact Lens Manufacturers Annual Report 2004.