When I first performed a sutured IOL about 25 years ago, it was suturing a CZ70BD IOL to the sclera using 9-0 or 10-0 polypropylene. That model IOL is a single-piece design made of PMMA (non-foldable) with built-in eyelets on the haptics which made suturing easier. Today, we have moved on to different techniques such as suturing with 8-0 gore-tex with newer IOLs with eyelets, doing the Yamane technique with certain three-piece IOLs, or using flange techniques (Canabrava, McCabe, etc). This video shows a surgeon using a technique to tie a knot around the haptic of a single-piece acrylic IOL using 5-0 (or perhaps 6-0) polypropylene (Prolene) and then using the flange technique on the other end of the suture for intra-scleral fixation. This technique can be very good but we must be careful to avoid damaging the IOL haptics and also to sufficiently bury the flange within the sclera. If you can see the flange sitting right under the conjunctiva, then it may very well erode through, causing more issues.