Astigmatism

The Zaffater Eye Center offers the AcrySof Toric lens implant, a design proven to correct astigmatism. This lens is used in patients with astigmatism who wish to have their distance vision corrected during cataract surgery.

AcrySof Toric Lens Implant

The AcrySof Toric lens is designed to reduce corneal astigmatism and improve uncorrected functional distance vision. The AcrySof Toric lens offers these advantages over traditional lens implants:

• Correction of corneal astigmatism
• Enhanced clarity and quality of uncorrected distance vision+
• Filtered blue light protection
• Rich, vibrant color perception

Corneal Astigmatism

The AcrySof Toric lens is ideal for patients who wish to be corrected for distance vision and are comfortable wearing reading glasses. Because this lens does not offer the ability to accommodate or adjust one's vision to varying distances, glasses would be required for near and intermediate tasks.

Whether myopic or hyperopic, most eyes have corneal astigmatism to some degree. Corneal astigmatism means that the front part of your eye, the clear window you look through, is not perfectly round. Instead of being spherical like a basketball, an astigmatic cornea is slightly flattened, more oval in shape like a football, with one side steeper than the other (as illustrated above).

Because the astigmatic cornea is curved more (steeper) in one direction than the other, light entering the eye is refracted differently as it passes through these different areas. This causes light to come into focus at several different points on the back of the eye, rather than ideally coming into focus at just one point. Depending on the direction and the amount of astigmatism, vision through an astigmatic cornea will be affected in various ways. The illustration (below) gives a broad example of the visual effects, depending on the overall direction of the curve.

Limbal Relaxing Incisions For The Correction of Astigmatism

Astigmatism can also be corrected using limal relaxation incisions. This procedure involves making tiny incisions in the cornea to "relax" or flatten the steeper meridian, thereby causing the corneal curvature to become more rounded, reducing astigmatism.

These long, thin incisions are placed at the very edge of the cornea (known as the corneal limbus) on the steepest meridian, and differ in number and length according to the amount of astigmatism. Relaxing incisions generally do not eliminate corneal astigmatism completely, but rather reduce it to an acceptable level. Because the cornea is living tissue, there may be "over-response" or "under-response" to these incisions. Seldom is corneal astigmatism completely resolved; however, a significant reduction in your astigmatism produces a more satisfactory uncorrected visual result.

Some patients with extreme amounts of astigmatism may still require the addition of limbal relaxing incisions to correct astigmatism after cataract surgery with the AcrySof toric lens. For these patients implanting the Toric lens means that less corneal surgery in the form of a limbal relaxing incision is needed to achieve the same amount of correction.

UV Blue Light Protection

In addition to its refractive role, the natural lens inside your eye is also responsible for filtering high-energy blue light commonly found within the sun's rays and some artificial light. As part of the aging process, your natural lens gradually turns yellow and it is thought that this change in color may help to protect the aging retina by filtering more of the these harmful wavelengths.

When your natural lens is removed during cataract surgery, the eye loses the ability to filter blue light because most available lens implants are clear and filter UV light only. Some researchers believe that overexposure to blue light may be harmful to the retina and may contribute to macular degeneration and loss of vision. The AcrySof Toric lens implant is unique in its ability to filter blue light, having a patented yellow tint that filters both UV and blue light.

The light yellow color of the AcrySof Toric lens is very similar to that of your natural lens and is necessary to filter blue light, yet the Toric lens does not.

Advantages of the AcrySof Toric Lens Implant

• The AcrySof Toric intraocular lens is designed to correct nearsightedness or farsightedness with associated corneal astigmatism.
• The AcrySof Toric intraocular lens is designed to have the lens capsule “shrink wrap” around it. This helps the lens stay stable and centered within the eye.
• The patented yellow color of the AcrySof Toric intraocular lens implant is biocompatible and bonded to the structure of the acrylic material.
• The yellow color of the AcrySof Toric intraocular lens implant, approximates the natural discoloration (i.e., natural yellowing) of a healthy adult crystalline lens, without a negative impact on color perception.
• The AcrySof Toric intraocular lens implant is compatible with secondary cataract treatment (i.e., Nd:YAG laser treatment), if required.

For more information or to make an appointment call Willis Knighton Zaffater Eye Center:.