Piggyback IOL power calculator
Calculate the power of a supplementary (piggyback) intraocular lens placed in the ciliary sulcus to correct a residual refractive error after cataract surgery.
When a piggyback lens is used
A piggyback IOL is an option when a pseudophakic eye has a significant residual refractive error and IOL exchange is undesirable — for example in an eye with a fibrosed capsule or prior refractive surgery.
Why the power is not the same as the spectacle error
A sulcus-fixated supplementary lens sits anterior to the primary IOL, so the required power differs from the spectacle refraction at the corneal plane. The conversion factor differs for hyperopic and myopic residual errors.
Frequently asked questions
What is a piggyback IOL?
A piggyback IOL is a second, supplementary intraocular lens implanted in the ciliary sulcus in front of an existing IOL to correct residual refractive error, rather than exchanging the original lens.
See also sulcus IOL placement.