Astigmatism

Astigmatism is a common optical problem that affects vision. It occurs when the surface of the cornea has an uneven curvature. If the cornea is more oval shaped, like a football, the light rays will come in at two different angles. This causes blurred or distorted vision, glare and ocular fatigue because light rays are not focused at one spot to provide clear vision. This common condition is called "corneal astigmatism." Mild degrees of astigmatism are well tolerated and require no therapy, while greater degrees can be treated with a variety of methods

Astigmatism Management
The most common way to treat astigmatism is through the use of eyeglasses. Optical correction can also be achieved with contact lenses. A toric soft contact lens adds extra power in one specific direction to compensate for the astigmatism. These lenses are customized and it may take several visits to get the exact direction and amount of astigmatism needed for a particular patient.

Astigmatism can also be treated surgically through the use of an excimer laser. During the procedure, the irregularity of the cornea is smoothed out, changing the shape of the cornea from oval to round. Other methods include the use of limbal relaxing incisions or "LRI’s" which treat low-to-moderate degrees of astigmatism. Small incisions are made at the outer edge of the cornea where it is the steepest, allowing it to become rounded while it heals. These incisions can be combined with other types of surgery, including cataract surgery to lessen a person’s dependence on glasses.

One of the newest methods to treat astigmatism for cataract patients is replacing the human lens with an intraocular lens designed to treat this condition. Traditionally, during cataract surgery, the human lens is replaced with a monofocal intraocular lens which does not correct astigmatism.

The new AcrySof® Toric intraocular lens implant is similar to a soft toric contact lens in that a certain degree of power is placed in the lens at a precise location to compensate for the corneal astigmatism. The unique design of the AcrySof® Toric IOL makes it possible to reduce or eliminate corneal astigmatism and significantly improve uncorrected distance vision. Part of our exam includes specific measurements so that this lens can be custom made and used to treat the astigmatism at the time of surgery.

If you would like further information about what method may work best for you, please ask your surgeon.