Miyake–Apple study of the rotational stability of the Acrysof toric intraocular lens after experimental eye trauma

Abstract

Purpose To evaluate the rotational stability of the Acrysof Toric intraocular lens (IOL) after experimental eye trauma. Methods Two human cadaver eyes were prepared in accordance with the Miyake-Apple technique, with closed-system modification. After phacoemulsification, an Acrysof Toric IOL was implanted in the capsular bag. Experimental traumatisation of the globe was achieved by pressing against the eye wall using a cotton tip or a fingertip, whereas the IOL was observed from the posterior view. Digital photographs of the eye before and after the procedures were overlaid to detect and measure rotation of the IOL. Results The IOL rotated 5.801 when the traumatic procedures did not cause important leakage from the incision. When the traumatic procedures caused important leakage from the incision and anterior chamber collapse, the IOL rotated 41.001. Conclusion Ocular trauma can cause rotation of the Acrysof Toric IOL. In the event of an eye trauma with no or insignificant leakage from the incision, the IOL rotates less than when the trauma causes significant leakage from the incision.

Evaluation of Rotation and Visual Outcomes After Implantation of Monofocal and Multifocal Toric Intraocular Lenses

“…Toric IOL rotation after implantation was due to various mechanisms. Factors that may induce toric IOL rotation include postoperative intraocular pressure fluctuations, 18 reduced friction between the haptics and the capsular bags produced by an incomplete ophthalmic viscoelastic device removal, 19 or capsule size, 20 IOL design and materials, 12 and compression of the IOL from capsule shrinkage. 21 The current results indicated that rotation occurs in all of the lenses during the first hour after surgery and remains stable during the first month.…”

Rotational and centration stability of an aspheric intraocular lens with a simulated toric design

“…Hypotony causes destabilisation of the anterior chamber reducing its integrity and, therefore, resulting in a higher risk of rotation. 39 Post-operative ocular trauma can also cause IOL rotation. If the force on the eye is sufficient to cause significant wound leakage then large degrees of IOL rotation can occur.…”

“…If the force on the eye is sufficient to cause significant wound leakage then large degrees of IOL rotation can occur. 39 Positioning holes, present on many plate haptics, can increase stability. Capsular fibrosis and proliferative lens cortical material migrate through the positioning holes creating an effective anchor.…”

Toric Intraocular Lenses in Cataract Surgery

“…Trauma with leakage from the incision site was associated with IOL rotation of approximately 40 degrees. (Pereira, Milverton et al 2009) However, these human cadaver eyes received post-mortem phacoemulsification with toric IOL implantation, indicating that the IOL had not fused with the capsular bag. This would have resulted in an increased IOL rotation and is possibly not an optimal model to examine toric IOL rotation following ocular trauma.…”