Exercise as it relates to Disease/The role of physical activity in the progression and development of Myopia

This is an analysis of the journal article "Jacobsen N, Jensen H, Goldschmidt E. Does the level of physical activity in university students influence development and progression of myopia? A 2-year prospective cohort study. Investigative ophthalmology & visual science. 2008 Apr 1;49(4):1322-7".

What is the background to this research?

Myopia is a visual condition that affects an individual’s ability to see objects at distance in focus. Myopia is currently a leading cause of visual disability in the world and is a major cause of avoidable blindness, it is estimated that myopia effects almost two billion people world-wide according to a report by the World Health Organisation in 2015. This article looks to see if physical activity can prevent or slow the progression of myopia. This article looks at myopia amongst Caucasians of European heritage a specific population shown to have lower rates of myopia. This article not only looks at myopia and physical activity, but it allows you to compare rates of myopia with other studies across demographics. A study released in 2013 estimated that the annual cost of myopia in Singapore was $755million USD, in a nation with less than six million people which demonstrates the significant financial burden of a condition that is avoidable.

Where is the research from?

This study was a peer-reviewed journal article conducted at the University of Copenhagen, Denmark over a two-year period from 2005 to 2007 by researchers from the Danish National Eye Clinic and Institute for Myopia Research and it was published in the ARVO Journal 49^th volume, issue 4 .

What kind of research was this?

This was a two-year longitudinal cohort study that examined Danish born medical students to identify a correlation between physical activity and myopia. This study is good for monitoring the development and/or progression of myopia over two years.

What did the research involve?

Researchers recruited 156 participants, all first-year medical students starting at the University of Copenhagen in 2005. The researchers conducted baseline testing establishing that 37% of the cohort were myopic. Both the baseline and follow up examination used the following test procedures:

• Visual Acuity
• Subjective Refraction
• Maddox Wing
• Cycloplegic Autorefraction
• Oral Questionnaire
• Partial Coherence Interferometry
• Slit Lamp Examination
• Cycle Ergometer Test

At the end of the students second year of university a follow up examination was completed using the same protocols. The researchers looked to see if there was a positive correlation between physical activity being a protective mechanism against myopia, if the rate of myopia increased and if the condition progressed in those already suffering from myopia.

What were the basic results?

An association between physical activity and myopia was established suggesting that physical activity can act as a barrier against myopia or slow the progression of myopia amongst university students already with the condition, although a consideration was made that this may be due to time spent outside rather than physical activity which is supported by other literature.

The study also found a correlation between younger students and high risk of developing myopia, this is reflected in studies from Asia that not only is that rate of myopia increasing but the onset is occurring sooner. It was also observed that there was greater refractive change in individuals with myopia than the rest of the cohort.

What conclusions can we take from this research?

The study highlights that participants engage in a large amount of near use activity due to study, whilst being physically active to help correlate physical activity as a barrier against myopia, but the reality is 37% of participants had myopia at the start of the study and the number rose to 43% which is higher than that of the global prevalence. This article does note that rather than physical activity being a barrier, spending time outside is more significant in preventing myopia which is further supported by other research in this field. What we can conclude from this article is that physical activity can act as instrument to encourage individuals to spend more time outdoors, which may not only help prevent myopia, but also improve an individual’s overall health.

This study suggested that for every three hours of study that one hour of physical activity can act as a protective barrier against myopia, put into perspective the average nine to five worker would have to complete almost three hours of physical activity a day, which is about the same as the current weekly physical activity recommendations in Australia. If we are to consider this as a guideline it means that people must work less to spend more time being physically active, make more time to be physically active or find a job where you are outside and physically active. Based on this could we assume that Myopia is more than just a health epidemic and has become social issue. Are we at a point where our endeavours for knowledge, technological progression and “a better life” are having a profound effect on our health?

Practical advice

If you are an individual that spends a lot of time engaging in near use work, take regular breaks and change your focus, use the 20:20 rule. Get a baseline eye examination and know your family history when it comes to eye health.  Be active outdoors, integrate outdoor physical activity into your daily routines such as travel to and from work or join a social sports team.  

Further information/resources

Below are resources for information on myopia, corrective procedures available and daily physical activity guidelines:

• Focus provides information and symptoms of Myopia: https://www.focusclinics.com/blog/myopia-epidemic-across-world/
• Better health Victoria: https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/short-sightedness
• Vision Eye Institute Australia, for information on corrective eye surgery including laser in situ keratomileusis (LASIK) or Small incision lenticule extraction (SMILE): https://visioneyeinstitute.com.au/eyematters/smile/

While not generally supported by mainstream optometry and ophthalmology, some therapies purport to reduce myopia naturally. A behavioral optometrist reported reducing her own myopia by over three diopters:

• Antonia Orfield M.A. O.D. (1994). "Seeing Space: Undergoing Brain Re-Programming to Reduce Myopia" (PDF). Journal of Behavioral Optometry. 5 (5): 123–31.