Photorefractive keratectomy: a technique for laser refractive surgery

Area of Science:

• Ophthalmology
• Biomedical Engineering
• Laser Surgery

Background:

• The excimer laser enables novel corneal surgery techniques.
• Photorefractive keratectomy (PRK) involves reshaping the cornea using laser ablation.

Purpose of the Study:

• To describe conditions for photorefractive keratectomy.
• To present equations for refractive corrections via tissue ablation.
• To demonstrate improved beam uniformity for corneal reshaping.

Main Methods:

• Utilized far ultraviolet radiation for direct corneal reshaping.
• Developed equations for calculating tissue ablation based on refractive error.
• Implemented beam integration by rotation to enhance beam uniformity.
• Observed corneal healing in rabbits post-ablation.

Main Results:

• Calculations for achieving refractive corrections were established.
• A method for improving excimer laser beam uniformity was demonstrated.
• Shallow corneal cuts showed more regular healing patterns compared to deep cuts.
• Observed healing irregularities in deep cuts five days post-treatment.

Conclusions:

• Excimer laser photorefractive keratectomy offers a new approach to corneal surgery.
• Precise control over tissue ablation and beam uniformity is crucial for PRK.
• Shallow ablation depths appear to promote more predictable corneal healing.