Prior to developing a cataract some patients may suffer from astigmatism. This visual error is caused by varying curvatures of the cornea leading to unequal focusing. The shape of an astigmatic eye is sometimes described as being shaped like a rugby ball rather than a normal eye which would be round like a soccer ball. Therefore, different optical corrections are needed in the two major meridians of the eye.
Astigmatism is noticeable by images appearing blurred, a shadow may also be perceived in certain directions. Points appear as streaks, which is why straight lines appear distorted. Left uncorrected astigmatism may lead to double-vision.
Astigmatism is not considered an illness, but, more than 15% of all patients due for cataract surgery present with astigmatism of more than two diopters.
Generally, toric glasses or special toric contact lenses compensate this visual error. In routine standard cataract surgeries astigmatism is not or only partially corrected, which means the patient will still need spectacles after cataract surgery.
Appropriate astigmatic patients can now benefit from implantation of the Torica® IOL. After correct axial placement in the eye this IOL corrects the prevalent astigmatism and therefore enables improved vision and usually spectacle independence for far vision.
HumanOptics (formerly Dr. Schmidt Intraocularlinsen) is one of the first manufacturers to have developed and produced toric IOLs – in 1997 experiences with the implantation of our toric IOLs were already published. Our long-term experience in this field results in today’s Torica® design – for the benefit of the patients!