When IOLs are implanted in the aphakic patient—either after clear lensectomy for the correction of refractive error or after cataract extraction to restore eyesight—astigmatism in these patients is mainly attributable to the cornea.
The surgeon can ascertains the astigmatic, or steepest, meridian in a number of ways, including manifest refraction or corneal topography.
Some of the risks that FDA have been found so far during a three-year study of the Artisan are: One of the causes of the risks above is that the lens can rotate inside the eye, if the PIOL is too short if the eye was incorrectly measured, or because the sulcus has a slightly oval shape (the height is slightly smaller than the width).
The most common type of IOL is the pseudophakic IOL.
Again, these lenses can rotate inside the eye postoperatively, or be placed incorrectly by the operating surgeon.
Either way, the patient's preexisting astigmatism may not be corrected completely or may even increase.
This is to ensure that eye growth, which disrupts IOL lenses, will not occur post-surgery.
Once implanted, IOL lenses have three major benefits.