Like toric soft contact lenses for astigmatism, toric IOLs have different powers in different meridians of the lens to correct the asymmetric power of the eye that is characteristic of astigmatism.
Cataract surgery with a toric lens implant (IOL) is essentially the same as cataract surgery with a conventional IOL, but with a couple of important 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 astigmatism successfully. Toric IOLs have special markers on the peripheral parts of the lens that enables 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 common cataract surgery complications, but a misaligned toric IOL can cause blurred vision that cannot easily be corrected with eyeglasses or contact lenses. Brands of toric IOLs include AcrySof IQ Toric IOL (Alcon) and Tecnis Toric Aspheric IOL (Abbott Medical Optics).
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.