Comparing Manual and Verion Image-guided Marking Methods in Toric Intraocular Lens Implantation: A Vector Analysis Study

Abstract

Aim: To compare slit-lamp manual marking and Verion imageguided marking in toric intraocular lens (IOL) implantation using vector analysis. Material and Method: Eyes with manual marking were defined as group 1 and eyes with Verion image-guided marking were defined as group 2. Target-induced and surgically induced astigmatism, the magnitude and angle of error, the success index, toric IOL rotation, and refractive outcomes were compared. Results: A total of 67 eyes were examined, with 37 in group 1 and 30 in group 2. Higher degrees of IOL rotation (≥10°) were predominantly observed in the manual marking group. Group 2 had a lower toric IOL rotation in eyes with against-the-rule astigmatism than in group 1 (P=0.003). In Group 2, error size was negatively correlated with refractive astigmatism (r=−0.37, P=0.04), whereas the angle of error was positively correlated with best-corrected visual acuity (r=0.526, P=0.003). Conclusion: Vectorial analysis shows that digital marking is more effective and yields more predictable outcomes for toric IOL rotation compared to manual marking, particularly in eyes with against-the-rule astigmatism and high astigmatism. This improved predictability is attributed to more accurate axis alignment.

Keywords

• astigmatism
• phacoemulsification
• image-guided marking
• manual marking
• toric intraocular lens
• vector analysis

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