July 23, 2014
Vision Impairment And Nearsightedness More Pronounced In Those With Higher Levels Of Education
April Flowers for redOrbit.com - Your Universe Online
A new study from the Mainz University Medical Center demonstrates that education and behavior play as large a role in the development of myopia, or nearsightedness, as genetic factors do. The findings, published in Ophthalmology, reveal that people become more nearsighted with each year of schooling completed. The vision impairment becomes more pronounced the higher the level of education achieved.
The research team conducted the first population-based cohort study of nearsightedness, which is a condition caused by the eyeball being too long in relation to the refractive power of the cornea and the lens. The cornea is unable to properly focus on objects in the distance. The human eyeball continues to grow until a person reaches adulthood. Because of this, the nearsightedness can also continue to progress well into a person's 30s. Previous studies have shown that myopia is affected by both genetic predisposition as well as environmental stimuli.
Professor Norbert Pfeiffer and PD Dr. Alireza Mirshahi, both of the Department of Ophthalmology, found compelling evidence that higher education and spending more years in school are both factors associated with an increased prevalence and severity of the condition. The data was obtained from the population-based Gutenberg Heath Study (GHS). GHS is an interdisciplinary study at the University Medical Center led by the Department of Medicine. The study looked at the general health in the city of Mainz and the surrounding region — especially in the areas of cancer, eye diseases, immune system diseases, cardiovascular and vascular health, as well as metabolic and mental diseases. In excess of 15,000 subjects participated in the study between 2007 and 2012. The data gathered from the eye disease component of this study suggests that environmental factors weigh more heavily than genetic ones in the development of myopia.
Because of the increased incidence of nearsightedness, it has become a fairly recent global health and economic concern. Severe myopia is closely linked with an increased risk of complications of the eye, including retinal detachment, macular degeneration, premature cataracts, and glaucoma. Myopia rates in developing Asian countries are seeing increases of up to 80 percent. Environmental factors such as reading, computer usage, and higher education might play a pivotal role in the rapid escalation of this condition.
The research team examined nearsightedness in over 4,500 people between the ages of 35 to 74 in Germany who had not had cataracts or undergone any sort of refractive surgery. Their results indicate that higher levels of education correlate with higher rates of myopia. Of those examined, 24 percent had no high school education or other training. However, 35 percent of those who had graduated from high school or vocational school suffered from myopia, and 53 percent of university graduates were nearsighted.
The researchers also collected information on how long each person spent in school, finding that the longer one was in school, the more likely they were to be nearsighted. In fact, the condition worsened for each year of study undertaken. To compare the results to genetic factors, the team examined the effects of 45 genetic markers. They found, however, that these markers had a much lower effect on the severity of nearsightedness than educational level.
Being nearsighted cannot be "cured." It can be corrected with visual aids or refractive surgery. So far, efforts to slow the progression of nearsightedness with drugs, special glasses or contact lenses have been unsuccessful.
The researchers site a recent study which examined children and young adults in Denmark and Asia. This study revealed that the risk of developing myopia could be decreased by spending more time outdoors and increasing exposure to sunlight. The study suggested 15 hours of outdoor activity a week, with no more than 30 hours a week of close-up work that would fatigue the eyes. "Since students appear to be at a higher risk for nearsightedness, it makes sense to encourage them to spend more time outdoors as a precaution," said PD Dr. Alireza Mirshahi.