Manual Marking Versus Guidance System for Centration of Toric IOLs
Narrative Responses:
Purpose
To determine whether an ocular guidance system would achieve greater accuracy then manual marking for the positioning of toric IOL's.
Methods
44 consecutive patients were randomized to have the toric IOL in one of their eyes positioned using a manual corneal marking system with the other eye having the IOL positioned using a microscope mounted guidance system. Preoperatively all patients underwent corneal topography and scanning with the ocular guidance system in the upright position. Intraoperatively a corneal marker was used to identify the axis for the IOL positioning in the manual group and the microscope mounted component of the guidance system used for the guidance group. 6 weeks postoperatively a cycloplegic refraction and wavefront/topography with visual axis identification were carried out.
Results
In 24/44 eyes in the manual group the toric IOL was more than 5 degrees off the intended axis versus 8/44 in the guidance group P<0.03. There was less residual refractive astigmatism (0.37 vs. 0.8) in the guidance group vs. the manual group. 4/44 eyes in the manual group required an IOL axis repositioning or additional LRI versus 1/44 in the guidance group.
Conclusion
An ocular guidance system appears to improve the accuracy of placement of toric IOL's compared to a manual marking method. Larger studies would be required to verify the outcomes.