What is Astigmatism?
Astigmatism is a common refractive error caused by an irregular curvature of the eye, leading to blurred or distorted vision. Light entering the eye does not focus evenly on the retina, causing images to appear out of focus. There are two types of astigmatism: corneal, which involves an irregular shape of the cornea, and lenticular, which involves the lens being misshapen. Corneal astigmatism is the more prevalent form and can occur in combination with other refractive errors like nearsightedness (myopia) or farsightedness (hyperopia).

Astigmatism can be mild and not require treatment, but in more severe cases, it can impact daily activities and may need correction.

Causes of Astigmatism
While the exact cause of astigmatism is not fully understood, heredity plays a significant role. It may be present at birth or develop later in life due to factors such as:

• The length of the eye
• Eye injury
• Eye disease
• Previous eye surgery

In rare cases, astigmatism can develop as a result of a condition called keratoconus. This occurs when the cornea thins and becomes cone-shaped, which can cause severe astigmatism. Keratoconus cannot be corrected with glasses and requires specialized contact lenses or surgery, such as corneal crosslinking, to prevent further damage. In extreme cases, a corneal transplant may be necessary.

Symptoms of Astigmatism
Symptoms vary based on the severity of the condition and can include:

• Headaches
• Squinting
• Distorted or blurry vision
• Poor night vision
• Eye strain
• Difficulty focusing on fine details

In some cases, symptoms of astigmatism may improve or worsen over time. The irregular curvature of the eye may cause vision to be more blurred in one direction than another.

Treatment of Astigmatism
There are various treatments available to correct astigmatism, depending on the severity and the patient’s personal preference. These treatments include both nonsurgical and surgical options.

Nonsurgical Treatments

• Eyeglasses: A common solution to correct astigmatism by compensating for the eye’s irregular shape.
• Contact Lenses: Both hard and soft contact lenses can help correct astigmatism, with the choice depending on the patient’s needs and comfort.

Surgical Treatments
If nonsurgical treatments are not sufficient or if the patient prefers a more permanent solution, several surgical options are available:

• Laser Eye Surgery: SMILE, LASIK, or PRK can reshape the cornea to correct astigmatism.
• Toric Intraocular Lens Implants: Used for patients undergoing cataract surgery, these lenses help correct astigmatism.
• Limbal Relaxing Incisions (LRI): Performed during cataract surgery, these small incisions in the cornea can help reduce astigmatism.