There are many different IOL injector systems from multiple different IOL manufacturers. It is the surgeon’s job to know the difference between them and to be competent in their use. I use IOLs from multiple different companies including Alcon, Bausch & Lomb, Johnson & Johnson (formerly AMO/Abbott), and others, each of which has its own injector system and cartridges.
Pre-loaded IOL injectors are starting to become more common and you’ll see me using them in about half of my videos (look for the blue plastic plunger pushing the IOL into the eye). This is likely going to be more common in the future and will be the way that we implant most of our IOLs.
For now, we still use IOL cartridges and then manually load the IOL into these devices for each case. This accounts for about half of my current surgical volume. For the Alcon Monarch system, there are three primary cartridges: B, C, and D. There is an A cartridge which is rarely used because it requires such a large incision.
My simple way of remembering the relative tip size is to think that B = big, C = compact, and D = diminutive. The recommended incision sizes are for placing the tip of the cartridge into the incision. If you are using a wound-assist technique where the cartridge tip simply abuts the incision, then a smaller incision can be used.
The D cartridge can be used for most single-piece acrylic IOLs, keeping in mind that it works best for the aspheric IOLs which are thinner. The C cartridge can be used for all singe-piece acrylic IOLs and some three-piece IOLs using a special method. Finally, the B cartridge is recommended for all three-piece IOLs and the special order single-piece IOLs with high dioptric power (+35 to +40).
click below to understand the difference between the B, C, and D Alcon cartridges: