1. The authors have no financial interest
Rotational Stability of Single-Piece Hydrophobic Acrylic Intraocular Lens During Removal of OVD
Hwan Eok Yeo, MD1,4
Won Ryang Wee, MD2,3
Jin Hak Lee, MD1,3
Joon Young Hyon, MD1,3
1. Department of Ophthalmology, Seoul National University Bundang Hospital, Seongnam, Korea
2. Department of Ophthalmology, Seoul National University Hospital, Seoul, Korea
3. Seoul National University College of Medicine, Seoul, Korea
4. Kim’s Eye Hospital, Seoul, Korea
The authors have no financial interest

2. Purpose
The toric IOL with a single-piece hydrophobic acrylic platform showed satisfactory postoperative torsional stability. However, unintended intraoperative rotation of the IOL may occur during removal of the OVD
To evaluate the rotational stability of a foldable hydrophobic single-piece acrylic IOL during removal of OVD and assess the suitability of IOL platform as a toric lOL

3. Patients and Methods 20 eyes of 20 patients Prospective study
The position of the IOL was determined from digital photograph during surgery
Before and After removal of OVD
Unintended over-rotation of the IOL was measured with image analysis

4. Patients and Methods Surgical Technique
2.75 mm temporal clear corneal incision
Phacoemulsification
OVD
Cohesive : Healon GV®
Dispersive : Viscoat®

5. Image analysis Comparison axis: using 2 critical details on the IOL α
reference axis: using 2 critical details on conjunctiva or cornea
Comparison axis: using 2 critical details on the IOL

6. Results The mean IOL rotation Rotation within 5 degree: 15 %
Range from 0.9 up to 42.7
Rotation within 5 degree: 15 %
Rotation of 5 degree to 15 degree: 25%
Rotation over 15 degree: 60 %
The mean IOL rotation of two OVDs
Cohesive OVD: 22.5±9.3 degree
Dispersive OVD: 11.6±10.28 degree

7. IOL Rotation During Removal of OVD
Clockwise rotation
Counter-clockwise rotation

8. Discussion
Toric IOL implantation is a predictable and precise method to control the preexisting corneal astigmatism during cataract surgery
In the present study, 85 % of IOLs were out of 5 degree of intended axis
The numbers of clockwise rotation were more than those of counterclockwise rotation
Better torsional stability with dispersive OVD

9. Discussion
The differences in the rotational angle during removal of OVD may be explained by several factors
IOL design
Capsular bag size
Character of OVD
Surgical techniques
starting of removal before fully unfolding of IOL, aggressive irrigation and aspiration, anterior chamber collapse after drawing of the I&A device

10. Conclusion
IOL rotation could occur during removal of OVD, amount of which may be visually significant
Verification of the IOL axis after removal of OVD should be warranted to achieve the intended amount of astigmatic correction with the toric IOL of a single-piece hydrophobic acrylic platform

11. References
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