An emerging generation of foldable Toric phakic intraocular lenses could simplify
refractive treatment of patients with moderate to high myopia combined with astigmatism.
The newer foldable designs make it possible to reliably correct both spherical and
cylindrical errors in a single intraocular procedure. For many cases these lenses
provide an attractive alternative to the bioptic approach, which addresses spherical
error with an IOL followed weeks later by a laser correction of astigmatism.
The key advantage of foldable Toric phakic lenses is they can be inserted through
a 3.0 mm incision, Dr Kenia said. This makes the effect of the lens on postsurgical
refraction more predictable because it reduces induced astigmatism. By contrast,
non-foldable lenses, such as the Artisan Toric (Ophtec), require incisions of 5.0
mm or more.
With a 5mm incision, even if you go back to a scleral incision, as I do, you can
never be sure you will not induce astigmatism. This can defeat the purpose of the
Toric lens However, to be truly competitive with the precise corrections possible
with a bioptic staged procedure, implanted Toric lenses also must be very stable,
Dr Kenia said. Their ability to correct astigmatism is highly dependent upon resisting
rotation once placed in the eye. Movement of even a few degrees can significantly
degrade vision.