The „Add-On” principle is the procedure of implanting a second intraocular lens in front of another one into one eye.
Conventional, primary IOLs are usually implanted into the capsular bag (4), the place where the natural lens is located before it is removed by cataract surgery. The Add-On lens is implanted into the sulcus ciliaris (3) in addition to the IOL already in the capsular bag. The sulcus ciliaris is the area that stretches across from behind the iris to the capsular bag, the original place of the natural lens.
Add-On IOLs have a special design. So they are a little lager than conventional IOLs, to ensure safe and secure fixation.
After surgery the patient will not feel the implant and it will not be visible to others. Both lenses should remain problem-free in the eye permanently. The first Add-On IOL was successfully implanted back in the year 2000.
With the Diffractiva® Add-On model spectacle independence additionally for near distance is possible. Therefore the advantages of multifocal IOLs are also available for patients who already had a cataract procedure performed before multifocal IOL technology was available. It is surgically a lot easier and less traumatic to add an Add-On lens than to remove and replace a primary pre-existing lens, which is a big advantage of this system.
In contrast to visual corrections by laser (LASIK, etc.) no natural corneal tissue is ablated by correction using Add-On lenses. The eye’s cornea remains untouched apart from a small (and immediately self-sealing) incision of a few millimeters at the corneal rim. As no tissue is ablated the procedure is reversible and the Add-On lens can be removed any time.
The Add-On procedure is suitable at any time after cataract surgery, even if the previous cataract treatment dates back some years.