High Myopia and Preventive Therapy
What is Myopia?
Myopia (also known as nearsightedness) occurs when the eye grows too long from front to back. Instead of focusing images on the retina (the light-sensitive tissue at the back of the eye), the lens of the eye focuses the image in front of the retina. People with myopia have good near vision but poor distance vision.
Myopia can also occur when the cornea is too curved for the length of the eyeball or the lens is too thick.
What is High Myopia?
Conventionally, an eye is considered to have high myopia if it requires -6.0 diopters or more of lens correction. High Myopia increases the risk of retinal detachment, cataract and glaucoma. Each of these conditions can cause vision loss.
What are the potential complications of High Myopia?
Rarely, a condition called Pathological Myopia can occur in eyes with High Myopia when there is an extremely high amount of nearsightedness that causes a major alteration of the shape or structures (retina, choroid, vitreous, sclera and optic nerve) of the eye. Potential complications of Pathological Myopia may include:
- Retinal detachment
- Macular degeneration
- Macular oedema
- Abnormal blood vessel growth in the choroid
How is myopia corrected?
Myopia can usually be corrected with prescription glasses or contact lenses, which refocus light onto the retina. Contact lenses may be advantageous for activities where prescription glasses are not practical (such as sport activities), and they are more suitable for patient with high myopia. However, it is important to follow the proper care and wearing instructions provided by your eye care professional as poor contact lens hygiene can lead to serious eye infection.
Refractive Surgery or Laser Vision Correction is the surgical treatment option for myopia. It can be considered as an option when the patient’s refractive error is stable (usually after the age of 20). The most common types of refractive surgery are Laser-Assisted in Situ Keratomileusis (LASIK) and Photorefractive Keratectomy (PRK). Both techniques aim to change the shape of the cornea in an attempt to focus light the retina. A relatively new refractive procedure called Small Incision Lenticule Extraction (SMILE) has been developed in recent years, which can be used to correct myopia. The details of all these procedures are discussed in Laser Vision Correction section.
Furthermore, there are other alternative surgical treatments available for correcting myopia including Implantable Contact Lens (ICL) and Refractive Lens Exchange. Both procedures are very effective, especially in patients with high myopia, who are not suitable for Laser Vision Correction. However, there are other risks associated with these procedures and therefore it is best to discuss the best treatment options with your ophthalmologist.
Is it possible to slow down the progression of myopia?
Recent clinical trials have shown that a Low Concentration Atropine Eye Drops can slow myopic progression in children. This treatment is not invasive and has very few side effects compared to higher doses of atropine (for examples, light sensitivity or blurred near vision). In addition, a rebound effect was not observed after stopping atropine treatment. This treatment requires daily use of eye drops and does require a compounding pharmacy at this time to formulate the appropriate dosage. It is always important to discuss the risks and benefits of the treatment options with your ophthalmologist.