Astigmatism

Description

Astigmatism (uh - STIG-muh-tiz-um) is a common and generally treatable imperfection in the curvature of the eye that causes blurred distance and near vision.

Astigmatism occurs when the front surface of the eye (cornea) or the lens inside the eye do not match the curves. Instead of having one curve like a round ball, the surface is egg shaped. This causes blurred vision at all distances.

Astigmatism is often present at birth and may occur in combination with nearsightedness or farsightedness. Often not pronounced enough to require corrective action. When it is, the treatment options are corrective lenses or surgery.

Symptoms

The signs and symptoms of astigmatism may include:

  • Blurred or distorted vision
  • The tiredness of the view or discomfort
  • Headaches
  • Difficulty with night vision
  • Squinting your eyes

When to see a doctor

See a doctor if your eye symptoms impair the enjoyment of the activities or interfere with your ability to perform everyday tasks. An ophthalmologist can determine if you have astigmatism and, if so, to what degree. He or she can inform you of your options for correcting your vision.

Children and adolescents

Children may not realize that your vision is blurred, so that should be screened for eye diseases and vision evaluated by a pediatrician, ophthalmologist, optometrist or other trained filter in the following ages and intervals.

  • During the newborn period
  • In well-child visits until they reach school age
  • During the years of school, every 1 to 2 years in the welfare of the child visits, the doctor in the eyes, or through the school or public screenings

Causes

The eye has two structures with curved surfaces that bend (refract) the light on the retina, which makes the images:

  • The cornea, the front surface of the eye, along with the tear film
  • The goal, a clear structure inside the eye that changes shape to help the eye to focus on nearby objects

In a perfection in the form of an eye, each of these elements has a round curvature, like the surface of a smooth ball. A cornea or the lens with the curvature of the curves (refracts) all of the lights the same way to make a well-focused image directly on the retina at the back of the eye.

A refractive error

If the cornea or the crystalline lens is in the form of an egg with two do not match the curves, the light rays do not bend the same, which means that two different images of the way. These two images overlap or combine and result in blurred vision. Astigmatism is a type of refractive error.

Astigmatism occurs when the cornea or lens is curved more pronounced in one direction than in another. You have corneal astigmatism is when the cornea does not match the curves. You have astigmatism lenticular, if the lens does not match the curves.

Any type of astigmatism can cause blurred vision. Blurred vision may occur more in one direction: horizontally, vertically, or diagonally.

Astigmatism can be present from birth, or can develop after an eye injury, illness, or surgery. Astigmatism is not caused or aggravated by the reading in low-light conditions, sitting too close to the television or squint your eyes.

Other refractive errors

Astigmatism can occur in combination with other refractive errors, including:

  • Myopia (nearsightedness). This occurs when the cornea is curved too much or the eye is longer than usual. Instead of being focused precisely on the retina, the light focuses in front of the retina, making distant objects appear blurry.
  • Farsightedness (hyperopia). This occurs when the cornea is curved too little, or the eye is shorter than usual. The effect is the opposite of myopia. When the eye is in a relaxed state, light never comes with a focus on the back of the eye, making close objects appear blurred.

Risk factors

Risk factors for astigmatism are:

  • Genetics. Astigmatism can be hereditary, which means it is passed down from parents.
  • Injury to the eyes.
  • Keratoconus. Astigmatism risk is higher in people who have keratoconus, an eye disease in which the cornea thins and bulges outward.
  • Surgery of the eyes. Astigmatism can occur after eye surgery.

Astigmatism

Diagnosis

Astigmatism is diagnosed with an eye exam. A complete examination of the eyes involves both a series of tests to check the health of the eyes and of the refraction, which determines the way the eyes bend the light. Your eye doctor may use various instruments, aim bright lights directly at your eyes and request that you look through several lenses. Your doctor will use these tests that examine different aspects of their eyes and vision, and to determine the prescription needed to provide a clear vision with eyeglasses or contact lenses.

Treatment

The goal of treatment of astigmatism is to improve the vision, the clarity and visual comfort. Treatments are corrective lenses or refractive surgery.

Corrective lenses

Wearing corrective lenses treats astigmatism by counteracting uneven curvature of the cornea or the crystalline lens.

Types of corrective lenses, including:

  • The glasses. Sunglasses are made with lenses that help to compensate for the uneven shape of the eye. The lenses cause light to bend in the eye properly. The glasses can also correct other refractive errors, like nearsightedness or farsightedness.
  • The contact lenses.Like eyeglasses, contact lenses can correct most of astigmatism. They are available in a variety of types and styles. Wearing contact lenses for long periods of time increases the risk of infection in the eye. Ask your eye doctor about the pros and cons of and risks of contact lenses and what might be best for you.

The contact lenses. Like eyeglasses, contact lenses can correct most of astigmatism. They are available in a variety of types and styles.

Wearing contact lenses for long periods of time increases the risk of infection in the eye.

Ask your eye doctor about the pros and cons and risks of contact lenses and what might be best for you.

Refractive surgery

The refractive surgery improves vision and reduces the need for glasses or contact lenses. An eye surgeon uses a laser beam to reshape the curves of the cornea, which corrects the refractive error. Before the surgery, doctors evaluate and determine if you are a candidate for refractive surgery.

Types of refractive surgery for astigmatism are:

  • Laser-assisted in situ keratomileusis (LASIK). With this procedure, an eye surgeon makes a thin, hinged flap in the cornea. He or she uses an excimer laser to sculpt the shape of the cornea, and then put the flap.
  • Laser-assisted subepithelial keratectomy (LASEK). Instead of creating a flap in the cornea, the surgeon loosens the cornea thin protective cover (epithelium) with a special alcohol. He or she uses an excimer laser to change the curvature of the cornea, and then places the loose epithelium.
  • Photorefractive keratectomy (PRK). This procedure is similar to LASEK, except the surgeon removes the epithelium. It's going to grow in a natural way, according to the cornea a new shape. You may need to use a bandage contact lens a couple of days after theurgery.
  • Epi-LASIK. This is a variation of LASEK. The surgeon uses a special machining blunt the leaf in place of alcohol to separate a very thin sheet of epithelium. He or she then uses an excimer laser to reshape the cornea and repositions the epithelium.
  • Small-incision lenticule extraction (SMILE). This new type of refractive surgery reshapes the cornea using a laser to make a lens in the form of bits of tissue (lenticule) below the corneal surface. The lenticule is then removed through a very small incision. By now, the SMILE procedure is only approved for the treatment of mild myopia.

Other types of refractive surgeries including the removal of the transparent lens contact lenses and implantable. There is a better method for refractive surgery, and you should make a decision only after a comprehensive evaluation and thorough discussion with your surgeon.

Some of the possible complications that may occur after refractive surgery are:

  • Undercorrection or overcorrection of your initial problem
  • Visual side effects, such as a halo or starburst that appear around lights
  • Dry eye
  • Infection
  • Scarring of the cornea
  • Rarely, loss of vision

Discuss the possible risks and benefits of these procedures with your eye doctor.

Preparing for your appointment

You can find three types of eof the lists that seek help for various diseases of the eyes:

  • The ophthalmologist. An ophthalmologist is an eye specialist with a doctor of medicine (M. D.) or a doctor of osteopathy (D. O.) degree, which provides a complete eye care. This care includes the full realization of the eyes evaluations, prescribing corrective lenses, diagnosing and treating common and complex disorders of the eyes, and the realization of surgery of the eye when it is necessary.
  • Optometrist. An optometrist is a doctor of optometry (O. D.) degree. Optometrists are trained to provide your eyes health exams, prescribing corrective lenses, and to diagnose and treat some diseases of the eyes.
  • Optician. An ophthalmologist is a specialist who helps people in the form of eyeglasses following prescriptions from ophthalmologists and optometrists. Some states require opticalians of a license. Opticians are not trained to diagnose or treat eye diseases.

No matter which type of specialist that you choose, here's some information to help you prepare for your appointment.

What you can do

  • List of the symptoms that you are experiencing, Isee none of that may seem unrelated to the reason for which you scheduled the appointment.
  • The list of personal information, including any major stresses or recent life changes.
  • Make a list of all medications, vitamins or supplements that you are taking, inclincluding doses.
  • List of questions to ask your doctor.

Prepare a list of questions that help you get the most out of your visit. For astigmatism, some basic questions to ask include:

  • What is likely causing my symptoms?
  • Other that the most likely cause, what are ottheir possible causes for the symptoms?
  • What kinds of tests do I need?
  • Is my condition likely temporary or chronic?
  • What is the best course of action?
  • What are the alternatives to the primary approach you're suggesting?
  • I have other health conditions. How can I best manage them together?
  • Are there any restrictions that I need to follow?
  • Should I see a corneal specialist?
  • Does my insurance company to pay for surgical procedures?
  • Do you have any brochures or other printed material that I can take home with me? What sites do you recommend?

What to expect from your doctor

Your doctor may ask:

  • When did you first begin experiencing symptoms?
  • The symptoms been continuous or occasional?
  • How severe are the symptoms?
  • What, if anything, seems to improver the symptoms?
  • What, if anything, appears to worsen your symptoms?
Symptoms and treatment of Astigmatism