Study on Factors Affecting Toric Intraocular Lens Rotation Using Intraoperative OCT-Factors Influencing IOL...

Area of Science:

• Ophthalmology
• Biomedical Engineering

Background:

• Cataract surgery frequently unmasks pre-existing corneal astigmatism.
• Toric intraocular lenses (T-IOLs) correct astigmatism, but postoperative rotation can impair efficacy.
• Intraoperative optical coherence tomography (iOCT) enables precise monitoring of T-IOL placement.

Purpose of the Study:

• To investigate factors influencing T-IOL rotation, specifically deployment characteristics and posterior capsule (PC) proximity.
• To evaluate the impact of surgical techniques, such as tacking duration, temperature, and intraocular pressure (IOP) management, on T-IOL stability.
• To assess the utility of iOCT in managing T-IOL positioning during cataract surgery.

Main Methods:

• Six T-IOL models were tested in simulated and porcine eye models.
• Deployment times were measured under varying tacking durations (5s, 30s, 60s) and temperatures (23°C, 28°C, 32°C).
• iOCT was used to assess T-IOL proximity to the PC and the effect of temporary IOP reduction in porcine eyes.

Main Results:

• Shorter tacking durations and higher temperatures accelerated T-IOL deployment.
• The iSert Micro Toric Aspheric 1-Piece IOL (355T3) exhibited the slowest expansion, while Avansee™ Preload 1-Piece Toric (YP-T3) was the fastest.
• Temporary IOP reduction significantly enhanced T-IOL adhesion to the PC, reducing rotation from 14.0° to near 0°.

Conclusions:

• Optimizing T-IOL deployment parameters and employing temporary IOP reduction are key strategies to minimize postoperative rotation.
• Enhanced T-IOL adhesion to the PC is critical for stability.
• iOCT is an invaluable tool for intraoperative monitoring of T-IOL positioning, crucial for preventing rotation and ensuring effective astigmatism correction.