Most people with cataracts want not just to have clear vision after cataract surgery, but liberty from eyeglasses also. One thing that can prevent that from occurring is residual astigmatism after surgery.
Astigmatism is very common prior to and after cataract surgery. Practically one in three people who are prospects for cataract surgery in the United States have at least 1.0 diopter (D) of astigmatism, which suffices to cause significantly blurred vision without glasses or contact lenses.
One study of refractive errors found that 29 percent of the U.S. population has between 1.0 and 2.0 D of astigmatism, 6.5 percent has between 2.0 and 3.0 D, and 2.2 percent has at least 3.0 D. These findings suggest almost 4 out of 10 Americans have a significant amount of astigmatism.
Intraocular Lenses for Astigmatism
In the past, intraocular lenses (IOLs) used in cataract surgery could not correct astigmatism. Some astigmatism could be remedied if the cataract surgeon decided to make incisions in the cornea during cataract surgery– a procedure called limbal relaxing incisions (LRI). Regrettably, the LRI procedure can fix just restricted quantities of astigmatism, and often outcomes are unpredictable.
Thankfully, special intraocular lenses (called toric IOLs) have been established to more naturally appropriate astigmatism during cataract surgery.
How Toric IOLs Work
Like toric soft contact lenses for astigmatism, toric IOLs have various powers in different meridians of the lens to remedy the asymmetric power of the eye that is characteristic of astigmatism.
Cataract surgery with a toric lens implant (IOL) is basically the like cataract surgery with a traditional IOL, however with a few crucial distinctions.
Prior to surgery, measurements are taken to make it possible for cataract surgeons to select the most advantageous toric IOL power and the necessary orientation of the implant in the eye to correct the astigmatism effectively.
Toric IOLs have special markers on the peripheral parts of the lens that make it possible for the surgeon to see the orientation of the astigmatism correction in the lens. When the toric IOL is implanted in the eye, the surgeon then rotates the lens so the astigmatism correction is effectively lined up for best results.
Use of a toric IOL during cataract surgery does not increase the risk of typical cataract surgery complications, however a misaligned toric IOL can cause blurred vision that can not easily be fixed with glasses or contact lenses.
Brand names of toric IOLs consist of AcrySof IQ Toric IOL (Alcon) and Tecnis Toric Aspheric IOL (Abbott Medical Optics).
Excellent Toric IOL Outcomes
Research has revealed that toric lenses produce exceptional visual outcomes after cataract surgery and can fix astigmatism better than limbal relaxing incisions.
One study discovered 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, making it possible for people to see acceptably well without glasses or contact lenses.
And studies assessing patient fulfillment after cataract surgery have discovered the majority of patients receiving toric IOLs are highly satisfied with their vision after surgery. One research study discovered 92 percent of patients report no trouble with having at night without spectacles 6 months after surgery, and 97 percent of patients receiving toric lens implants would choose the same IOL to be implanted once again.
Cost Of Toric IOLs
One reason that more people aren’t going with toric lens implants to lower astigmatism after cataract surgery is the added cost of toric IOLs.
Though cataract surgery typically is completely covered by Medicare and all other medical insurance coverage strategies, the included costs related to premium lens implants such as toric IOLs are an out-of-pocket cost that is the patient’s obligation.
If you select a toric IOL to correct your astigmatism with cataract surgery, you can anticipate to pay approximately $1,310 per eye, according to a 2015 study of U.S. eye surgeons by a leading industry expert. By contrast, an LRI procedure to remedy astigmatism will cost you approximately $584 per eye. Another choice – arc-shaped cuts with a femtosecond laser (a modern, automated LRI-like astigmatism correction procedure) – has an average price of $1,136 per eye.
Another aspect of why the use of toric IOLs is not as prevalent as it might be is that appropriately implanting a toric IOL is more challenging for cataract surgeons than using a standard (round) IOL that’s not developed for astigmatism correction surgery.
To correct astigmatism successfully, a toric IOL needs to be placed precisely within the eye, with the astigmatism correction lined up perfectly with the astigmatism present in the eye. Likewise, the toric IOL must be safely positioned so it does not rotate after it is implanted. Even little errors in the positioning of a toric IOL may significantly affect visual skill after surgery– more so than they would with a spherical IOL.
Ask Your Cataract Surgeon
If you have astigmatism and need cataract surgery, ask your eye doctor to refer you to a cataract surgeon who welcomes the most recent surgical technology, including toric IOLs.
During your assessment prior to surgery, your surgeon will discuss with you the best choices for your specific requirements so you can be less based on eyeglasses after your cataracts are removed.