Software-based evaluation of toric IOL orientation in a multicenter clinical study

Area of Science:

• Ophthalmology
• Medical Imaging
• Biomedical Engineering

Background:

• Toric intraocular lenses (IOLs) correct astigmatism during cataract surgery.
• Accurate IOL rotational stability is crucial for effective astigmatism correction.
• Evaluating IOL rotation often relies on image analysis, requiring precise methodologies.

Purpose of the Study:

• To assess the rotational stability of a novel one-piece hydrophobic acrylic toric IOL.
• To validate a custom-developed software for analyzing slit-lamp photographs of toric IOLs.

Main Methods:

• A prospective, multicenter study involving 174 eyes implanted with the TECNIS Toric IOL.
• High-resolution slit-lamp photographs from 156 eyes were analyzed at baseline and 1, 3, and 6 months postoperatively.
• Custom software utilizing iris and sclera landmarks was employed for image alignment and rotation analysis.

Main Results:

• Software validation demonstrated high precision (0.02° with protractors, 2.22° with slit-lamp images).
• At 6 months, 94.2% of eyes exhibited 5° or less IOL rotation from baseline.
• Mean absolute axis change from day 1 to 6 months was 2.70° ± 5.51°, indicating good rotational stability.

Conclusions:

• The custom software provides a precise and efficient method for evaluating postoperative toric IOL rotation.
• The TECNIS Toric IOL demonstrates significant rotational stability in the early postoperative period.
• Accurate landmark identification in slit-lamp images is essential for reliable IOL rotation measurements.