Applicator for RF thermokeratoplasty: feasibility study using theoretical modeling and ex vivo experiments

Area of Science:

• Ophthalmology
• Biomedical Engineering
• Medical Devices

Background:

• Radiofrequency (RF) thermokeratoplasty is a procedure to modify corneal curvature using thermal lesions.
• Existing methods for creating these lesions may lack uniformity and predictability.
• A need exists for improved devices to enhance the safety and efficacy of thermokeratoplasty.

Purpose of the Study:

• To design and evaluate a novel RF applicator for creating uniform, predictable, and safe thermal lesions on the cornea.
• To assess the performance of the applicator through experimental studies and theoretical modeling.

Main Methods:

• Development of an integrated RF applicator combining a microkeratome suction ring and a circular electrode.
• Ex vivo experimental study using porcine eyes to create thermal lesions.
• Creation of a theoretical model to simulate the heating process and lesion formation.
• Comparison of experimental and theoretical results using electrical impedance evolution and lesion dimensions.

Main Results:

• The applicator successfully created circular thermal lesions with a mean depth of 34.2 ± 11.0% of corneal thickness at 50 V.
• At 30 V for 30 seconds, the mean lesion depth was 36.8 ± 8.1%.
• The theoretical model demonstrated good agreement with experimental findings regarding impedance changes and lesion dimensions.

Conclusions:

• The novel RF applicator is capable of producing uniform circular thermal lesions.
• The device shows potential as a safe and effective tool for radiofrequency thermokeratoplasty.
• The validated theoretical model can aid in further optimization of the thermokeratoplasty procedure.