Threatening Proportions of Myopia

“World has become myopic,” is a colloquial trite. But believe it or not, the situation is really alarming. A recently published article in Nature reported that East Asian countries are afflicted by threatening proportions of myopia or short-sightedness, the inability to see objects at longer distances. In China up to 90% of the teenagers are myopic and figures even disturbing for Seoul where it is 96.5%. While immediate course corrections like glasses, contact lenses and surgery can offer relief but a worst case of short sight can increase risk of cataract, retinal detachment, glaucoma and even blindness.

Myopic condition is the fall of out of the slightly elongated eyeball which causes the lens to focus light away from the object leading to formation of image in front of retina instead of direct image formation on the retina. This condition occurs most commonly in school going kids and adolescents. It is reported that nearly one-fifth of the college going kids in East Asia have an extreme form of myopia and half of them are at the risk of developing irreversible vision loss.  The burgeoning threat of myopia has propelled scientists across the world to address this issue.

Myopia was believed to be the domain of book-worms who were considered to be more prone to this defect. Famous German astronomer Johannes Kepler attributed his short-sightedness to book work. For long even ophthalmologists too believed in the same dogma. By 1960 scientists believed that it is genetically transferred as it is common in genetically identical twins than non-identical twins. Genome analysis showed that 100 regions are responsible for myopia. Increasing cases of myopia among school children in East Asian countries has been linked to enhanced educational performance where in students spend long hours before books. Researchers too have drawn an association between academic performance and the number of hours of study. On average while a Chinese teenager spends 15 hours a week on homework against 5 hrs in UK and 6 hrs in USA. Moreover with teenagers becoming addicted to televisions and hooked onto smart phones eternally, the incidence has peaked.

Documented research reports began to throw light on the deleterious effects of sustained close work capable of affecting the growth of eye ball. Scientists at the Ohio State University, College of Optometry Columbus showed that bright light is protective to eye. The research hypothesis showed that bright light stimulates release of dopamine neurotransmitter in the retina blocking the elongation of eye. Diurnal cycle of eye is strongly controlled by bright light wherein retinal dopamine turns on the cone-based vision during the day and rod-based vision at night in response to the dim light. For people working in the dim light or indoors this cycle is messed up resulting in elongation of the retina.

Research conducted by the Australian National University estimated that children need to spend a minimum of three hours of day under the light intensity of 10,000 lux to be guarded against myopia (an over-cast day provides 10,000 lux against 500 lux of class room). Consequently three hours of outdoor activity has become a norm in Australia. Now schools in China and Taiwan are making way for 3 hrs of outdoor time in the school schedule.  Preliminary findings in those schools are promising. Schools which have relatively inflexible routine are contemplating to conduct classes in rooms fitted with glass to compensate for the outdoor time. An unpublished research also indicated that as the amount of time spent increased the incidence began to lessen. Thus, three hours of outdoor time not only improves the physical well being of the children but protects them against myopia.

In the meanwhile researchers are working on special glasses and contact lenses that can alter the eye growth by focusing light from distant objects at different angles rather than just at the centre as the regular glasses do. To curtail myopic progression regular use of eye drops with a neurotransmitter-blocking drug atropine at night is also recommended. A hand book of Ophthalmic Science and practice authored by Henry Edward Juler in 1904 mentioned that myopic is stationary; change of air- or possibly a sea voyage was prescribed. It ‘as been more than hundred years it took a swarm of brilliant brains with years of dedicated research and sophisticated inventory to confirm the intuitive thinking of yesteryears. 

 

 

 @ Copyrights reserved.