Accurate alignment of toric intraocular lenses (IOLs) is essential for optimal visual outcomes in patients with astigmatism undergoing cataract surgery. Even small deviations from the intended axis affect refractive results; each degree of misalignment is associated with an approximate 3% increase in residual astigmatism.1
Traditional approaches rely on manual marking to identify the intended axis of implantation. These techniques are susceptible to variability introduced by operator-dependent factors, ocular cycloration, fixation instability and patient movement, all of which may contribute to postoperative toric IOL misalignment. Advances in ocular imaging and surgical guidance have enabled the adoption of digital systems that integrate preoperative biometry with intraoperative visualization. These platforms can provide real-time overlays, using anatomical landmarks to guide axis alignment with greater precision. This medical backgrounder reviews selected clinical studies and a meta-analysis comparing digital and manual marking methods for toric IOL alignment. Across studies, digital marking systems demonstrate improved alignment accuracy and reduced residual postoperative astigmatism relative to manual techniques. However, the magnitude of these differences varies, and in some cases may not translate into clinically meaningful improvements in visual outcomes.