Lack of Sun Exposure Linked with Short-Sightedness

Lack of Sun Exposure Linked with Short-Sightedness

A study of 1,400 young adults in Western Australia has shown that lack of exposure to sunlight is associated with short-sightedness (myopia). Researchers used a new camera system – developed in Sydney – to take ultraviolet photographs to assess sun damage to the surface of the eye. The photographs indicated that more exposure to sunlight meant more sun damage to the surface of the eye. However, it was these people who were less likely to be short-sighted.

"What we found was that people without very much sun exposure had the highest rates of myopia, and people with lots of sun exposure had the lowest rates of myopia. People with the least sun exposure had double the chance of myopia than people with the most sun exposure," said Dr Charlotte McKnight, Clinical Lecturer with the Lions Eyes Institute at the University of Western Australia. "These ultraviolet photographs provide an objective, more accurate method of assessing a person's exposure to sunlight, than questionnaires used in previous studies."

"Myopia affects over a billion people worldwide, and is becoming increasingly more frequent. In some areas of South-East Asia as many as 80% of people have myopia. The cost of treating myopia (with glasses, contact lenses or laser) is high, and doesn't fix the underlying structural problem with the eye. Severe myopia can result in retinal detachment and blindness," said Dr McKnight.

"Although there are many theories, we don't really understand the complex genetic and environmental factors that cause a person to become myopic, or understand why there has been such an increase in rates of myopia around the world. We also don't have any reliable way to prevent myopia, or reduce the progression to severe myopia."

Dr McKnight will present the research findings during the Annual Scientific Congress of The Royal Australian and New Zealand College of Ophthalmologists – being held in Melbourne this week from 24-28 November.

"The design of the study is not able to prove that low levels of outdoor activity cause myopia; it could equally be true that having myopia makes you less likely to spend time outdoors. Excessive amounts of outdoor activity and sun exposure does have risks (such as skin cancer and eye diseases including pterygium), so we do not want to recommend increasing outdoor time unless we are sure that the benefits outweigh the risks."

"The message is that there's a balance of sun exposure that's beneficial for eye health. Moderation is the key," said Dr McKnight. "To work out if increasing outdoor activity can prevent myopia, interventional studies need to be done. Some of these studies are currently underway around the world."

Other research presented at RANZCO's Congress:

Current approaches to save children's eyes with retinoblastoma (eye cancer), may be failing the whole child

Prof Gallie a Canadian ophthalmologist who focuses her work on Retinoblastoma (RB) (a rare, cancerous tumor of the retina which generally affects children under the age of six) will present to eye specialists the ethical issues and importance of treating the whole child – not just the eye.

When retinoblastoma first shows, cure by removal of the eye is widely available and affordable with cure rate >98%. Despite huge resources, new, widely advocated approaches to save eyes with retinoblastoma, may instead be failing the whole child. Systemic chemotherapy to make subsequent surgery safer may result in the opposite.

The Internet brings to parents facing retinoblastoma everywhere the concept that their duty is to save the eye, blinding them to the potential of the whole child, even without seeing eyes.

ENDS

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