Does Specialty Soft Contact Lens Wear Decrease the Onset and Progression of Myopia in Optometry School Interns?

BACKGROUND AND SIGNIFICANCE Myopia is a common refractive error that has increased among young adults and has become more prevalent in the growing population across the globe (Fan, et al 2004). This has been more common in Eastern Asian countries with prevalence of myopia as high as 96.5% among 19 year old soldiers in South Korea. (Shimuzu, et al 2003) In the United States between the 1990's to the 2000's there was a sudden increase of >15% myopia progression (Vitale et al 2009). There has been a correlation between education and myopia progression in urban areas calling into question the amount of close up work and being indoors as opposed to being outside working as in the rural populations (Resnikoff, et al 2004). Children between the ages of 7 to 11 years that were forced to spend 80 minutes per day outside showed a significantly better outcome in regards to onset as well as progression of myopia. Those that were spending 80 minutes per day outside had an average onset of 8.4% and progression of 0.25 diopters whereas the children that were not forced to spend time outside had onset and progression at a rate of 17.7% and 0.38 diopters respectively. (Wu, et al 2013) Myopia progression has become a cause for concern due to the complications that arise from the elongation of the eye. Some of the complications include retinal detachment, choroidal thinning, glaucoma and myopic macular degeneration. In a study of the causes of visual impairment in an adult Chinese population, it was found that myopic macular degeneration was the leading cause of bilateral visual impairment in adults between the ages of 45 and 59 years old and the second highest major cause of bilateral blindness. (Tang Y, et al 2015) Pathological myopia is one of the leading causes of blindness that can be prevented (Kang et. al. 2017).

Recent studies have promising conclusions that soft multifocal contact lenses are a viable option for slowing myopia progression. Many studies have been conducted on the topic of myopic control with soft multifocal contact lenses in young patients. Very little data exists on myopia control methods used in young adults. It is often thought that myopic progression will progress even through to young adults which could potentially necessitate a need for control. If the use of Dual-Focus soft contact lenses in young adults controls myopia, this could become a viable, cost effective method to increase productivity around the world. This is an important factor to consider as the direct and indirect cost of loss of productivity due to uncorrected refractive error is 202 billion dollars. (WHO bulletin 2004). Reducing the negative side effects of myopia and possible reduced vision loss in this specific population can open doors to future research in other populations.

A common treatment for myopia progression is Orthokeratology, in which patients wear a rigid gas permeable contact lens overnight in the hope of reshaping their corneas. A major concern however, with this treatment is the increased risk of infection that comes with wearing a lens overnight. It is also not approved for use on patients with a refractive error of >6.00D of myopia, and is not effective in older adult patients (Cooper et al 2017). Another pitfall of Orthokeratology is that once treatment is stopped, the refractive error of the patient returns to normal. This treatment regimen is easily restricted due to the high cost to the patient. This in turn calls for a type of treatment that can be used during the day, is cost effective, and can be easily disposed of to decrease the risk of infection. If the daily multifocal soft contact lenses are used correctly, any risk of infection or major drawback is greatly reduced. Another method of treatment involves the use of Atropine, which has proven to be successful in controlling the advancement of myopia. This however has side effects including blurry vision, increased sensitivity to light, possible flushing, tachycardia, bradycardia and other undesirable side effects. As the dose of Atropine rises, the reported side effects also increase. (Huy et. al. 2017).

LOCATION, FACULTY AND EQUIPMENT TO BE USED

• University of Incarnate Word Rosenberg School of Optometry Eye and Vision Care Clinic
• IOL Master 500 by Zeiss
• Topography
• Pentacam