I can still remember the day that I got my first pair of glasses. It isn’t my fondest memory, but quite a common one. I was struggling to see the blackboard at school, so my parents took me back to the optometrist. It was a disappointment to learn that I needed glasses, but not unexpected given that my father, brother and one of my sisters all needed them as well. While I was happy to be able to see clearly again, it was the start of my vision decline over the next decade as my prescription worsened until young adulthood.
Like approximately one third of the rest of North America, I have myopia or nearsightedness – a refractive condition that occurs when light entering the eye is focused in front of the retina rather than directly on it, so that while near objects remain clear, distant objects appear blurred. And my story is unfortunately becoming much more common. The rates of myopia have been increasing at a significant pace, so much so that some are calling it an epidemic. In the United States, the prevalence of myopia among individuals aged 12-54 years old in the early 1970s was reported to be 25%, and in 2004 this had increased to 41.6%. In some parts of East Asia (Taiwan and Singapore) the current prevalence of myopia in teens and young adults has surpassed 80-90%. Myopia is increasing in numerous countries worldwide. In 2010 the worldwide rate of myopia was 28%, and it is expected that by the year 2050 approximately half of the world’s population will be myopic
Do we need to be concerned about myopia? Can’t a person just wear glasses, contact lenses or have laser surgery to treat it? Unfortunately, myopia is more than just the inconvenience of needing vision correction to see clearly. Myopia has been implicated as the sixth leading cause of vision loss. People with myopia have a greater risk of developing several eye conditions including myopic macular degeneration, cataract, glaucoma, retinal holes and tears, and retinal detachments. Many of these can be sight-threatening and cause permanent visual impairment, and the higher the amount of the myopia, the greater the risk. Myopic macular degeneration is now the number one reason for blindness in some Asian countries.
Research has been striving to understand what drives myopia development and determine what we can do to slow its progression. Both genetic and environmental factors have been associated with the onset and progression of myopia. For example, a child who has one myopic parent is 3 times more likely to become nearsighted, and if both parents are myopic then the risk increases 6 times. But the rapidly changing rates of myopia point to environmental habits as being a much larger contributing factor than we once thought. Currently, genetic make up cannot be altered, however the environmental influences can be.
Next month we will discuss more about the environmental factors that may contribute to myopia development and our current myopia management options.