Toric IOL refractive surprises

April 1, 2014

Consideration of all the available options should be made to correct refractive surprises, emphasized Dr Noel Alpins (NewVision Clinics, Cheltenham, Victoria, Australia) when speaking during the 'Assessment of Astigmatism' session at the 2013 ESCRS Congress.

In his presentation, he discussed two cases to demonstrate how calculation of refractive surprises, using a new application of free internet software, can assist in the decision of which option to take to reduce or eliminate the remaining refractive cylinder. Here, we highlight the outcomes of this presentation.

Case 1

"However, we were surprised as we didn't get the result we expected, which is a disappointment to the patient and to us," Dr Alpins continued. So, using the online calculator again as a problem solver, he noted that by inputting the postoperative sphero-cylindrical refraction it is possible to determine the position of the implant and thus if rotation can minimize the remaining refractive cylinder.

Case 2

In the second case a male patient was implanted with a lens of 24 D sphere and 4 D cylinder (ZCT400, AMO, Santa Ana, California, USA), and his remaining astigmatism was also around 2.5 D. However, in this case, when looking at the position of the lens, the remaining refractive cylinder by rotation would only go down to about 1.75 or 2 D, which was not considered satisfactory.

"Therefore, rotation was not going to work for this patient," confirmed Dr Alpins. "So, what is the next option for him? Well, you think perhaps we should change the implant. So, we looked at the astigmatic vector analysis and found that his magnitude of error was very low indicating that the correct toricity of the IOL was selected, and so this wouldn't help either. Hence, LASIK was the best option for him to correct his unaided vision."