By Nigel Little
Ortho-k opticians are leading the battle to provide an effective non-surgical treatment for shortsightedness - otherwise known as myopia - where distant objects appear blurred. Myopia describes the condition where light from distant objects focuses in front of the retina rather than directly on it and occurs because the eyeball has elongated. The condition can occur during childhood or as an adult and traditionally has been treated by prescribing glasses or daytime contact lenses or surgically via laser treatment. However, the new overnight ortho-k corrective contact lenses - which are only worn while sleeping - address this problem by gently flattening the surface of the cornea during sleep to correct the focusing distance. As a result, the ortho-k lens wearer has perfect daytime vision after removing the lenses each morning and the effect lasts throughout the day until the lenses are reinserted at night.
The importance of ortho-k opticians in being able to treat myopia is demonstrated by recent US research from Susan Vitale of the National Eye Institute which showed that the incidence of shortsightedness had grown dramatically over the past 30 years and now affected over 40% of the population compared with only 25% in the 1970s. Similar rapid growth in myopia prevalence has also been reported in Europe and Asia, with the latter showing rates at up to 80% in China. The assumption has been that some genetic link must be responsible and now a gene, LEPREL1, has been identified within a southern Israeli Beduin tribe in studies conducted led by Prof. Ohad Birk of the Morris Kahn Laboratory of Human Genetics at Ben-Gurion University's National Institute for Biotechnology and the Dayan clinical genetics wing at Soroka University Medical Center in Israel.
However, the rapid growth in myopia prevalence is not due to genetics alone and recent research has highlighted other important environmental factors which play a part. One of the most important of these is exposure to natural outdoor light which is around ten times brighter than when indoors. New studies have shown that children now spend increasingly more time indoors than was the case 30 years ago and this reduced exposure to outdoor light impacts on retinal dopamine levels which is a known inhibitor of eyeball growth. When combined with other current day environmental factors such as significantly increased time spent on near distance screen-based activities like TV, computers and mobile phones, it is believed that this explains why myopia prevalence has grown so rapidly. So the work of ortho-k opticians is equally likely to grow significantly as myopia sufferers consider their treatment options.
Check if you are suitable for overnight ortho-k corrective contact lenses .