A New Slit Lamp Based Method for Corneal Marking for Toric IOL Implantation and A Comparative Series of 60 Eyes Comparing the Results of the New and Conventional Marking Techniques

Purpose: To compare a new slit lamp based technique using Purkinje images for corneal marking prior to toric IOL implantation with conventional techniques of corneal marking Methods: 30 consecutive eyes were marked using the new technique and another 30 consecutive eyes were marked using conventional (bubble) marker. The results were evaluated photographically using a dedicated planimetry software on pre and post-operative photographs. The astigmatic results and the difference between actual and anticipated residual astigmatism were also compared statistically between the two groups. Results: Accurate bisection of the cornea through the optical centre was more consistently obtained by our technique, which also obviated the need for separate placement axis marking on table. Software based analysis showed significantly more accurate placement of the corneal marks as well as IOL placement. Post-operative outcome at 6 months showed significantly better correlation with anticipated residual astigmatism in the group marked with the new technique. Conclusions: This technique was found to be more accurate and reproducible than currently used techniques. Surgeons found it easier to align the toric IOLs to the marks because of the accurate corneal centrations of the marks.