What is a Toric IOL and how does it work?

Toric lens implants are a unique type of monofocal lens implant that are used to correct and/or reduce high amounts of astigmatism. Asymmetric steepening of the cornea or natural lens causes light to be focused unevenly, which is the main optical problem in astigmatism. To individuals with uncorrected astigmatism, images may look blurry or shadowed (even after the cataract is removed). Astigmatism can accompany any form of refractive error and is very common. If a cataract patient has astigmatism and has aspirations to be glasses free (most commonly at farsightedness) after surgery the Toric lens implant is a good option. Toric lens implants are NOT a correction option for presbyopia. The ACRYSOF® Toric lens implant is a popular choice for this type of lens. Toric IOLs have different powers in different meridians of the lens to correct the asymmetric power of the eye that is characteristic of astigmatism. With the newer, modern cataract surgery and technology higher amounts of astigmatism are able to be reduced inside the eye, which is always better than correcting on the surface or in front of the eye (i.e contact lenses or glasses). The goal with the Toric intraocular lens is to only need over the counter readers or a very thin pair of prescription glasses to fine tune residual refractive error. To achieve this goal – find a surgeon who is only doing the new, modern cataract surgery.

 

Drawing of a toric intraocular lens or IOL.
Alcon’s AcrySof Toric IOL has three dots on each
side of the lens to enable the cataract surgeon to align
the IOL in the eye for precise astigmatism correction. 

 

Cataract surgery with a toric lens implant (IOL) is essentially the same as cataract surgery with a conventional IOL, however with a couple of important and critical differences.

  • Prior to surgery, measurements are taken to enable cataract surgeons to choose the most beneficial toric IOL power and the required orientation of the implant in the eye to correct the astigmatism successfully.
  • Toric IOLs have special markers on the peripheral parts of the lens that enable the surgeon to see the orientation of the astigmatism correction in the lens. Once the toric IOL is implanted in the eye, the surgeon then rotates the lens so the astigmatism correction is properly aligned for best results.

Use of a toric IOL during cataract surgery does not increase the risk of cataract surgery complications, but a misaligned toric IOL can cause blurred vision that cannot easily be corrected with eyeglasses or contact lenses. This is why it is important to only have high powered Toric intraocular lenses implanted by a modern cataract surgeon.

Brands of toric IOLs include AcrySof IQ Toric IOL (Alcon), enVist Toric (Bausch and Lomb) and Tecnis Toric Aspheric IOL (Abbott Medical Optics).

Excellent Toric IOL Outcomes

Research has shown that toric lenses produce excellent visual results after cataract surgery and can correct astigmatism more effectively than limbal relaxing incisions.

One study found that 94 percent of astigmatic eyes treated with toric lens implants had 0.50 D or less astigmatism and 98 percent had 0.75 D or less residual astigmatism after surgery, enabling people to see acceptably well without glasses or contact lenses.

And studies evaluating patient satisfaction after cataract surgery have found the majority of patients receiving toric IOLs are highly satisfied with their vision after surgery. One study found 92 percent of patients report no difficulty with driving at night without eyeglasses six months after surgery, and 97 percent of patients receiving toric lens implants would choose the same IOL to be implanted again.