First population-based study to show that environmental factors may outweigh genetics in myopia development; researchers suggest students should spend time outdoors
SAN FRANCISCO — German researchers have found strong evidence that attaining a higher level of education and spending more years in school are two factors associated with a greater prevalence and severity of nearsightedness, or myopia. Published online this month in Ophthalmology, the journal of the American Academy of Ophthalmology, the research is the first population-based study to demonstrate that environmental factors may outweigh genetics in the development of myopia.
While common, nearsightedness has become even more prevalent around the world in recent years and presents a growing global health and economic concern. Severe nearsightedness is a major cause of visual impairment and is associated with greater risk of retinal detachment, myopic macular degeneration, premature cataracts and glaucoma. In the United States, nearsightedness now affects roughly 42 percent of the population. Developed Asian countries report increasing myopia rates of up to 80 percent, the rapid growth rate of which suggests that environmental factors play a significant role. Environmental factors that have been linked to myopia include near work such as reading or using a computer, outdoor activity, living in urban versus rural areas and education.
To further analyze the association between myopia development and education, researchers at the University Medical Center in Mainz, Germany examined nearsightedness in 4,685 Germans ages 35 to 74, excluding anyone with cataracts or who had undergone refractive surgery. Results of their work, known as the Gutenberg Health Study, show that myopia appeared to become more prevalent as education level increased:
- 24 percent with no high school education or other training were nearsighted.
- 35 percent of high school graduates and vocational school graduates were nearsighted.
- 53 percent of university graduates were nearsighted.
In addition to education levels completed, the researchers also found that people who spent more years in school proved to be more myopic, with nearsightedness worsening for each year of school. Furthermore, the researchers looked at the effect of 45 genetic markers, but found it a much weaker factor in the degree of nearsightedness compared to education level.
The antidote to the rise in myopia could be as simple as going outside more often. In the last several years, studies of children and young adults in Denmark and Asia show that more time outdoors and exposure to daylight is associated with less nearsightedness.
"Since students appear to be at a higher risk of nearsightedness, it makes sense to encourage them to spend more time outdoors as a precaution," said Alireza Mirshahi, M.D., lead author of the study.
For more information on myopia, visit the American Academy of Ophthalmology's public education website EyeSmart.
Other notable studies published in the June 2014 print issue of Ophthalmology include:
Visual Acuity after Cataract Surgery in Patients with Age-Related Macular Degeneration. Age-Related Eye Disease Study 2, Report No. 5
After cataract surgery in persons with age-related macular degeneration AMD of varying degrees of severity, improved best-corrected visual acuity was demonstrated after surgery when compared with preoperative visual acuity across all severities of AMD.
The Impact of Anti–Vascular Endothelial Growth Factor Treatment on Quality of Life in Neovascular Age-Related Macular Degeneration
In neovascular age-related macular degeneration, vascular endothelial growth factor inhibitors improve quality of life when vision improves and maintain quality of life when vision is maintained, irrespective of whether the worse or better eye is treated.
About the American Academy of Ophthalmology
The American Academy of Ophthalmology, headquartered in San Francisco, is the world's largest association of eye physicians and surgeons — Eye M.D.s — with more than 32,000 members worldwide. Eye health care is provided by the three "O's" – ophthalmologists, optometrists, and opticians. It is the ophthalmologist, or Eye M.D., who has the education and training to treat it all: eye diseases, infections and injuries, and perform eye surgery. For more information, visit www.aao.org. The Academy's EyeSmart® program educates the public about the importance of eye health and empowers them to preserve healthy vision. EyeSmart provides the most trusted and medically accurate information about eye diseases, conditions and injuries. OjosSanos™ is the Spanish-language version of the program. Visit EyeSmart or OjosSanos to learn more.
Ophthalmology, the official journal of the American Academy of Ophthalmology, publishes original, peer-reviewed, clinically-applicable research. Topics include the results of clinical trials, new diagnostic and surgical techniques, treatment methods, technology assessments, translational science reviews and editorials. For more information, visit www.aaojournal.org.
 Increased Prevalence of Myopia in the United States Between 1971-1972 and 1999-2004. Arch Ophthalmol 2009;12712:1632-1639
 The Association between Time Spent Outdoors and Myopia in Children and Adolescents, Ophthalmology 2012: 11910: 2141-2151
 Evidence Mounts That Outdoor Recess Time Can Reduce the Risk of Nearsightedness in Children, AAO.org