TORIC IOLs in Philadelphia – Dr. James S. Lewis
Cataract surgery with a TORIC implant can reduce or eliminate your residual astigmatism and make you less dependent on glasses for driving, watching TV, or reading. Astigmatism usually arises from a mild pre-existing variation in the curvature of the cornea. Nearly 50% of patients benefit from this choice of IOL.
STAAR TORIC
Surgical video showing the insertion of the STAAR Toric.
Unique features of this lens are presented.
The cornea and the crystalline lens focus parallel light from a distant clock onto an image projected to the retinal surface. That image is sent to the brain and, if it is perfectly focused across all 12 numbers, we say there is no astigmatism. If the 3 and 9 o’clock are perfectly focused but the 12 and 6 are not, we describe this as astigmatism in the optical system. Simply put, light is bending optimally in one axis (3 to 9) but suboptimally in another axis (12 to 6). That can happen when the cornea is shaped more like a football than a basketball.
Patients with pre-existing astigmatism need glasses or contact lenses to see clearly. These same patients can reduce their dependence on appliances if they have cataract surgery and choose a TORIC intraocular lens.
Astigmatism is actually a more complicated subject involving regularity across all meridians (axes) as well as curvatures measurements for the anterior and posterior surface of the cornea. Choosing the best TORIC implant involves estimates of the effective lens position (ELP), calculation of the ideal IOL orientation, and an offset for surgically induced astigmatism. Nevertheless, TORIC implants are remarkably effect in reducing postoperative astigmatism and improving visual clarity without glasses.
Rarely patients with pre-existing astigmatism do not require TORIC lenses. In these cases the lens (which is now a cataract), is the major cause of the astigmatism. Once it is removed, the astigmatism is essentially gone. Similarly, in some cases, the cataract has astigmatism that counterbalances the underlying corneal astigmatism. Removing the cataract unmasks the latent astigmatism. These patients will be advised of their need for a TORIC implant prior to cataract surgery.
TORIC lenses were approved by the FDA in 1998. The manufacturer, Staar Surgical, provided them without additional cost and our practice used them in nearly half of all cataract surgeries. Second generation TORIC lenses were released in 2006, and while vastly superior to the original design, they require an out-of-pocket payment by the patient because health insurance providers consider TORIC lenses a premium service.
Toric Lenses: Are They for Me?
For those who do not choose a TORIC IOL, glasses and contact lenses still work. Also, patients can have LASIK or a related corneal procedure following cataract surgery to reduce or eliminate astigmatism. Most patients select a TORIC IOL for the rapid rehabilitation and the simplicity of this elegant technique.
