Eyeworld

Figure 2. Comparison of formulas Figure 3. Absolute mean errors of previous methods in a cohort study 3 measurements were blinded regarding algorithm predictions. Figure 2 displays data from the study. Predictions based on the three- dimensional OCT morphology-based algorithm demonstrated the highest correlation coefficient with the TLP in comparison with the Olsen and Haigis predictions. Bland-Altman plots also demonstrated tighter 95% limits of agree- ment between the predicted lens position and the TLP. Interestingly, correlations for TLP predictions were also higher for the Haigis and Olsen formulas than previous- ly published results. Conclusion Intraoperative three-dimensional OCT morphology may be superior to current axial-based formulas in predicting post- operative ELP. The correlation coefficients for these formulas in our study using LACS are also higher than published values. Further study of this may enable us to demonstrate the benefit of a more consistent capsulorhexis. In addition, TLP may prove to be use- ful for outcomes analysis utilizing a dif- ferent paradigm. New formulas based on predicted TLP may help improve refrac- tive accuracy. For comparison, instead of a potential 280- to 400-µm lens position prediction error, comparable to approxi- mately 0.4 D of refraction error, objective measurement will likely achieve an error in the order of approximately 50 µm. We are currently studying a ray trace method, as well as a radial basis function model (similar to that recently proposed by Dr. Hill), using this data. However, even with our current, more-basic algo- rithm, we have demonstrated that we can obtain better predictive results than more commonly used methods (Figure 3). We hope this work will ultimately add to the accuracy and consistency of postopera- tive refractive outcomes and continue to improve the lives of our patients.

• Cover