Myopia, also known as short-sightedness or nearsightedness, is a type of refractive error that currently affects over 30% of Australians. The prevalence of nearsightedness has been well-documented as being on a steep upward trajectory, with a predicted prevalence of almost 5 billion cases worldwide by the year 2050.
How Does Nearsightedness Work?
The eyeball is a complex organ involving multiple light-transmitting anatomical structures that refract (or focus) light and sensory neuronal structures that detect this light then carry signals to various areas of the brain for interpretation and response. Nearsightedness is a defect in the coordination of the focus of the eyeball – a type of refractive error. To put it simply, the focusing power of the eye is too strong for the length of the eyeball, which results in the focal point of light falling in front of the sensory retina which lines the back of the eye. In most cases, myopia arises from what is known as the axial length of the eye being too long.
Nearsightedness results in unclear vision of distant objects, while closer objects, such as books and smartphones are easier to see. However, depending on the degree of nearsightedness and other factors such as the presence of astigmatism and the person’s age, sometimes even near objects can be blurry. Many people often take their vision for granted, but uncorrected myopia can have a significant impact on an individual’s daily activities – it affects the vision used in driving safely, watching movies or TV, recognising faces from a distance, and even reading aisle signs at the supermarket.
The development and progression of myopia is still undergoing thorough research and investigation, as vision scientists try to understand how we can prevent or slow this condition. At present, we know that there are both genetic and environmental factors to the presence of nearsightedness and various risk factors have already been identified, such as a family history of myopia, Asian ethnicity, reduced time outdoors during childhood, and increased time spent on near work indoors during childhood. In recent years, myopia has also been recognised as a health concern as it is associated with a number of potentially sight-threatening eye diseases, some of which, such as myopic macular degeneration and glaucoma, are a result of the elongated nature of a myopic eyeball.
While the risk of associated eye diseases cannot be ameliorated with optical correction (the eye still has an excessive axial length), we have access to many solutions to improve the quality of vision – and therefore quality of life – in a patient with nearsightedness. Spectacles and contact lenses are readily available even in higher myopic prescriptions, but surgical options have also been gaining in popularity as medical technology advances to improve visual outcomes.
With the refining of refractive surgery techniques, myopic patients now have access to an even greater number of options in myopia treatment, resulting in excellent distance vision without the need for optical correction. The most suitable treatment will depend on the degree of nearsightedness, the unique anatomy of the individual eye, and the presence of presbyopia (the normal age-related decline of the eye’s focusing ability). LASIK (laser in situ keratomileusis), PRK (photorefractive keratectomy), refractive lens exchange, intraocular contact lens, and SMILE® laser eye surgery are all considered options for myopia treatment.
SMILE® Laser Eye Surgery (small incision lenticule extraction)
SMILE® deserves a special mention as this technique has come to the fore in recent years due to its safety profile and ability to provide excellent visual outcomes.
With the use of a femtosecond laser, a precisely sculpted disc of tissue, known as a lenticule, is created within the depths of the corneal layers. This lenticule is then surgically removed via a tiny keyhole incision, resulting in a reshaping of the cornea and redirection of light through the remaining tissue such that images focus to a clear point on the retina. The final outcome is clear vision without the need for glasses or contact lenses.
Unlike LASIK, SMILE® laser eye surgery does not require the creation of a corneal flap, meaning flap-related complications are eliminated. And unlike PRK, the SMILE® method does not require removal of the superficial corneal epithelium, improving postoperative comfort and greatly reducing recovery time. Due to the minimally invasive nature of this technique, SMILE® carries a very low risk of postoperative dry eye. Because of these benefits, SMILE® is a great option for:
- Patients with pre-existing dry eye. As the incidence of dry eye increases with age, older patients may find SMILE® to be the most appealing refractive surgery solution.
- Patients who cannot afford a long recovery time. The cornea contains the highest density of nerves in the human body – disruption of these nerves in the course of surgery can cause discomfort and prolong recovery. Because SMILE® is minimally invasive, there is less interruption to the biomechanical stability of the cornea and healing times are shorter.
- Patients who engage in frequent physical activity or are exposed to dirty, dusty environments. One of the significant advantages of SMILE® is the lack of a corneal flap. Though flap-related complications are uncommon, this flap has the potential to become dislodged during rough physical activity, or for debris to become caught beneath the flap interface, posing a risk for infection or inflammation.
At the present time, SMILE® surgery is best suited for patients with nearsightedness and can be effective up to prescriptions of even -10 dioptres. SMILE® can also be offered to patients with astigmatism but is not yet available for hyperopia (long-sightedness) or presbyopia – other techniques such as LASIK, PRK, or refractive lens exchange are more suitable for these patients.
Regardless of whether you are myopic, astigmatic, hyperopic, or presbyopic, Eye Laser Specialists may have a solution for you. Call us now to book your complimentary assessment.