Astigmatism- The Genetic Disorder

By Emily Gartner




What is Genetic Disorder?


There are many different types of genetic disorder which are all caused by abnormalities or mutations in a person's DNA. These abnormalities can range from a little change in the eye to an entire limb being deformed to a severe mental illness. These abnormalities can be a single gene mutated or a group of genes out of place, which can be inherited or totally new to the person's family. Whatever the disorder is, it is both unique in some way to the person and has a treatment, either discovered or waiting to be found.


What is Astigmatism?


Astigmatism is a genetic/inherited disorder that exists in the eye and can cause many issues in a person's vison. An astigmatism can be one of two forms, both abnormalities in the eye's shape. The two forms of astigmatism are:


  1. Corneal Astigmatism which is caused by the cornea of the eye being an irregular shape, making the light refract or bend.
  2. Lenticular Astigmatism is where the lens of the eye is an improper shape, which also makes the light bend.
Astigmatism is an extremely common disorder, which occurs in two-thirds of the population of near-sighted people and in over 80% of Americans. Most often astigmatism is something one is born with, when the eye doesn't form to be perfectly semetric in the womb. In some less common situations, a disease, like diabetes causes an astigmatism, by making the eye's lens or cornea change shape. Eyes are often not quite rounded and most mild cases, of irregular cornea or lens shapes, can be adjusted to, avoiding need for glasses or contacts, but in more severe conditions, astigmatism can require correction.
Humans have always been effected by this particular disorder. It causes near/long sightedness, headaches, lazy eye, blurred vison, excessive squinting, eye strain, and sensitivity to light. Most moderate cases have at least one or two symptoms.
There are a verity of treatments for astigmatism, each depending on the severity of the person's condition. The most used treatment is correction lenses. They help filter the light in a way that the eye can pick it up better, without it becoming blurry or distorted. There are three types of lenses commonly used: rigid contact lenses, which are made of glass and plastic, gas permeable contact lenses, that are made out of polymers, which allow oxygen behind the lens, and soft contact lenses, that are made of water and polymer, that lets the water and oxygen to touch the eye, but not the plastic. Soft lenses are disposable. The other treatment for astigmatism is laser-eye surgery, where a laser is used to cut the cornea of the eye into a more symmetrical shape. The most used forms of this type of surgery include: Photorefractive keratectomy, when the cornea is cut so that it will heal into a better shape, Lasek, where the whole cornea is removed, then reshaped and put back on the eye, and Lasik, in which a cut is made to the cornea and then the cut is lifted and the eye is sculpted underneath, which is the least painful treatment of the three surgeries. While the laser-eye surgery can be a good, perminant correction of astigmatism, it can also have some bad side effects, such as correctional error, epithelial in-growth, ectasia, and keratitis, all of which could cause worsened vision and need for further surgery, however the chances of their occurence in extremely minute.
What is Gene Therapy?
Gene therapy is where a gene is used to prevent/fight a disorder or disease. The gene is either injected or placed in the indivdual at risk and it replace a mutated gene or deactivate it before it continues causing problems. It is useful, yet dangerous method that is very effective in genetic disorders and inherited diseases.
While gene therapy is used on other disorders like it, gene therapy isn't yet used to correct astigmatism. 
Brief description of what astigmatism is and diagram.
What is astigmatism? Link: http://www.medicalnewstoday.com/articles/158810.php
What is a genetic disorder? Link: http://www.geneticalliance.org/diseases
More about astigmatism. Link: http://www.bbc.co.uk/health/physical_health/conditions/astigmatism2.shtml
What is gene therapy? Link: http://ghr.nlm.nih.gov/handbook/therapy/genetherapy
Top image of eyes. Link: http://www.accuvision.co.uk/astigmatism.html
Lower image of eyes. Link:http://www.theeyepractice.com.au/_blog/Optometrist-Sydney/tag/LASIK/
Video explaining astigmatism. Link:http://www.youtube.com/watch?v=QjkGYEbgC9c