Astigmatism

1 What is Astigmatism?

Astigmatism is a common eye condition caused by imperfect curvature of the cornea or lens resulting in blurred or distorted vision.

It is a type of refractive error that often occur in association with other conditions like myopia or hyperopia.

Most people are born with some degree of astigmatism. Children with this condition may not realize the issue with vision.

If left untreated, it may affect the child’s performance in school.

It may also lead to

It is usually diagnosed during a routine eye test. Glasses are recommended to correct the defects in vision due to astigmatism.

Pronounced symptoms are treated by surgery. 

2 Symptoms

Common signs and symptoms of astigmatism include

Blurred vision may be in one direction or in both directions.

These symptoms are generic and hence can be caused by other conditions as well.

People with symptoms should schedule and eye exam to detect the cause of the condition. 

3 Causes

Astigmatism is caused by imperfect curvature of cornea or lens.

Both cornea and lens play and important role in focusing the image on to the retina at the back of the eye. Imperfections in the curvature may lead to uneven focusing of image, leading to blurred or distorted vision.

Astigmatism is classified into two types based on imperfection – corneal astigmatism and lenticular astigmatism.

Corneal astigmatism is caused by imperfect curvature of the cornea, while uneven lens surface causes lenticular astigmatism.

Astigmatism may occur in association with other refractive errors like myopia or hyperopia.

Myopia

Refers to the blurred vision of distant objects caused by focusing of light in front of the retina. Myopia results from increased curvature of the cornea.

Hyperopia

Is caused by reduced curvature of the cornea that causes the light to focus behind the retina. It is characterized by blurred vision of nearby objects.

This eye condition may be congenital or acquired after a surgery or injury.

4 Making a Diagnosis

Diagnosis of astigmatism is based on review of symptoms and eye examination.

Visual acuity test measures the vision.

Keratometer is used to measure the amount of light reflected from the cornea, which indicates the curvature of cornea. This procedure, called keratometry, helps to confirm the presence of astigmatism.

Variations in the surface of cornea is also mapped by computerized corneal mapping done with the help of videokeratoscope.

A phoropter is used to measure the focusing of light by placing different lenses in front of the eyes in a visual acuity test. It can also be measured using a retinoscope.

Both methods assess the degree of refractive error due to the abnormality in the curvature. 

5 Treatment

Corrective lenses and surgery are the major treatment options for astigmatism. Corrective lenses compensate the imperfections in curvature of the cornea.

Corrective lenses suggested include

  • Eye glasses made of special lenses that counteract the uneven curvature of the cornea. It is also helpful in correcting other refractive errors like myopia and hyperopia.
  • Contact lenses that are available in different forms like hard, soft, extended wear, disposable, gas permeable, and bifocal contact lenses.

Refractive surgery is a surgical method to correct the shape of eye surface.

Some common refractive surgery methods include

  • Laser-assisted in-situ keratomileusis (LASIK) is a procedure in which a keratome is used to make a hinged cut in the cornea to reshape the cornea. An excimer laser is used to sculpt the shape of the cornea under the flap of the cut.
  • In photorefractive keratectomy (PRK), excimer laser is used to shape the curvature of the cornea after removing the outer protective layer.
  • Laser-assisted subepithelial keratomileusis (LASEK) is a procedure in which the thinner layer of cornea is folded back to reduce the risk of injury.

6 Prevention

Since most cases of astigmatism are caused by congenital conditions, it is hard to prevent the condition.

Protecting the eye from injuries and strain help in reducing the risk of astigmatism.

Following a good diet keeps the eye healthy.

Some eye exercises are also helpful in keeping the eyes strong and perfect. 

7 Alternative and Homeopathic Remedies

Homeopathic remedies that help in treating astigmatic symptoms are

  • gelsemium,
  • lilium tig,
  • physostigma,
  • sepia,
  • tuberculinum,
  • androctonos,
  • anhalonium,
  • ruta,
  • picric acid,
  • heloderma.

Acupuncture and traditional

Chinese medicines are also implied in the treatment of this eye condition.

Herbal remedies used in the treatment of different symptoms include

  • Indian gooseberry,
  • turmeric,
  • bilberry,
  • green tea,
  • cassia seed,
  • gingko biloba,
  • milk thistle,
  • wolfberry. 

8 Lifestyle and Coping

Having a healthy lifestyle and following therapeutic eye exercises help to improve vision and cope with Astigmatism.

Have more of antioxidants in the diet to have healthy eyes.

Start the treatment as soon as possible to have better results. 

9 Risk and Complications

Amblyopia or lazy eye is the most serious complication associated with astigmatism.

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