They have essentially the same optic and optical properties ie
1. -0.27 microns of spherical aberration
2. High Abbe number and low chromatic aberration
3. Low incidence of glistenings
The biggest difference is that the single piece ZCB00 lens is implanted through a smaller corneal wound ~2.2 to 2.4mm, while the ZA9003 lens needs to go through a larger corneal wound ie about 2.8-3.0mm. Why this range?
For ZCB00, I typically use a 2.2mm phaco incision, but it can be quite hard to use the 'wound assisted' technique and usually extend the wound slightly. In fact extending the wound slightly to about 2.4mm gives a better sealing wound since the corneal wound is not stretched as much.
For the 3 piece ZA9003, I could use either a 2.2 or 2.65mm phaco incision, but regardless, I have to extend the corneal wound out to about 2.8-3.0mm to allow the 3 piece lens to be injected, since it uses a cartridge with a larger tip diameter than the single piece ZCB00. This has probably to do with the risk of damaging/kinking the haptics of the ZA9003 if you try and squeeze it through a smaller cartridge and corneal wound.
So, I usually use the 1 piece ZCB00 lens. But if you ask me what is the difference between a 2.4mm and a 3mm incision, I would say, a 3mm incision gives more induced corneal astigmatism if the surgeon does a superior corneal incision. If a temporal incision is used, the difference is really minimal.
I believe that the ZA9003 is a 3 piece lens. If you fish around the AMO tecnis website, it does show the specific properties of each lens. However, the website, while comprehensive, is not all that clear to the reader at times. For example, the website shows a "one piece monofocal lens " but does not provided the model name. On another page it states the name to be the ZCB00. Probably, like yourself, I would like to know if there is an advantage to having the one piece vs the three piece lens installed. I did learn that some ophthalmologists have a supply of the one piece lens (ZCB00) in stock.
There are so many IOLs and they change their design so frequently. You will need to go to the tecnis website and review the differences yourself.
JCH MD