The treatment of astigmatism during cataract surgery

Past Event Date: 


Tsutomu Ohashi, M.D., Ohashi Eye Center/ Host: Steve Heinen

Meeting room: 

Room 204 - Main Conference Room

Event Type: 


Image-guided system (IGS, Verion®) compared with manual marking method for toric intraocular lens implantation.

Purpose: To evaluate the difference between the preoperative marking methods for toric intraocular lens implantations using the Image guided system (IGS, Verion®), compared to using the manual marking method.

Methods: 22 patients (26 eyes) underwent cataract surgery using both manual and IGS. First, a preoperative reference mark was placed with a marking pen at 6 o’clock limbus and at 3 o’clock and 9 o’clock under slitlamp biomicroscopy. The final orientation of steep meridian was confirmed against this marking on the operating table using an intraoperative axial marker. The steep meridian was then determined by IGS on the same eye. We compared the difference between the positions of steep meridian made by the manual method and those made by IGS and also compared the degree of error from the targeted steep meridian position in both cases.

Results: 4 eyes showed identical position with both methods, however, a more than 10-degree difference was found in 5 eyes. There was a significant statistical difference between the two methods. The average difference was 4.6±3.5° (P<0.001). The average error of IGS and manual method from the targeted steep meridian position was 3.3±2.9 and 6.0±4.8, each (P<0.01). 

Conclusion: Although many doctors continue to use the manual method only, our results suggest IGS is more useful for accurate toric lens implantation.

A discussion of some of Tsutomu's previous work, as well as a presentation of current cataract surgery techniques.