Chapter 11: Refractive Surprise post toric IOL surgery

Refractive Surprise, refractive cylinder post cataract surgery, toric IOLs, correcting astigmatism, What is your approach to rotating a misaligned toric IOL? A month postoperatively is a good time because tissue is able to fully heal by then. The rotation is a relatively straight forward procedure - using visco elastic to separate the leaves of the anterior and posterior capsule, and going in through the How do you measure the axis of the toric implant post-operatively? I use a narrow slit lamp beam with the patients pupil fully dilated so that I can visualise the toric markings on the IOL. It is important to line the beam up with both sets of toric markings. Once in theatre I use the Callisto or Verion guiding systems for accuracy of rotation. Is there a minimum amount of misalignment you consider before rotating the toric IOL? I haven’t rotated any implants that are less than 10° of axis because the patients are not really aware of it. The Assort toric IOL surprise calculator tells me how much reduction in refractive cylinder can be gained by rotating the already implanted IOL. Dr Daniel Tognetto published a paper in the JCRS in 2018 that showed that when you are 30° off you have not lost all of the effect you have only lost half the effect. You don’t lose all the affect until you are 45° off, so misalignment is a lot more forgiving than most are stating. How is a toric IOL analysis different to an incisional or LASIK analysis? So when you do astigmatic analyses always make the point that you want to have the same device before and after measuring the astigmatism. – regardless of Whether it is a topographer, an aberrometer or manifest refraction. The toric IOL analysis is the exception because pre-operatively the manifest refraction in a cataract patient is not very useful because it is imprecise, so you have to use corneal values. Post-operatively you are being judged by the manifest refractive cylinder that is left over so you do what we call a hybrid analysis, and this is what you find in the refractive surprise calculator we have at Assort.com which is also free to use. Hybrid analysis involves comparing vectorially the post-operative refractive cylinder to the pre-operative corneal astigmatism after the effect of the phaco incision.