Photorefractive keratectomy to correct astigmatism with myopia or hyperopia

Area of Science:

• Ophthalmology
• Laser Surgery
• Refractive Error Correction

Background:

• Excimer laser photorefractive keratectomy (PRK) is used for refractive error correction and corneal pathology.
• Radial symmetric ablations are effective for myopia, but astigmatism correction requires advanced techniques.

Purpose of the Study:

• To develop and evaluate a toric ablation technique for correcting astigmatism using excimer laser PRK.
• To assess the safety and efficacy of this novel approach for various types of astigmatism.

Main Methods:

• A new rotatable mask was designed for the MEL 60 Aesculap-Meditec excimer laser.
• Toric ablation was performed by varying ablation depth in specific meridians.
• Seventy-three eyes with different types of astigmatism were treated.

Main Results:

• The procedure successfully reduced both spherical and cylindrical refractive errors.
• Mean preoperative cylindrical refraction was reduced across all astigmatism categories.
• No specific complications were mentioned, suggesting a favorable safety profile.

Conclusions:

• Toric ablation excimer laser PRK is a safe and effective method for correcting various forms of astigmatism.
• This technique allows for simultaneous correction of spherical and cylindrical refractive errors.
• The novel mask design enables precise, meridian-specific corneal reshaping.