An independent evaluation of second generation suction microkeratomes

Area of Science:

• Ophthalmology
• Biomedical Engineering
• Surgical Technology

Background:

• Advancements in microkeratome technology for lamellar refractive surgery are ongoing.
• Three distinct microkeratome systems underwent independent evaluation: Automatic Corneal Shaper, Draeger Lamellar Keratome, and Microprecision test model.

Purpose of the Study:

• To concurrently and independently evaluate the performance of three microkeratome systems.
• To assess the uniformity, accuracy, centering, and smoothness of corneal resections produced by these systems.

Main Methods:

• Keratectomies (primary superficial stromal, secondary intrastromal, primary deep stromal) were performed on human cadaver eyes.
• Resected discs and corneal beds were analyzed for surface characteristics.
• Scanning electron microscopy was utilized for detailed examination of corneal beds and cutting blades.

Main Results:

• All systems produced irregular corneal surfaces with chatter lines; the Draeger rotating machine showed the least roughness.
• Average section diameters were consistently undersized by 10% across all systems.
• Thickness accuracy varied, with Steinway showing better primary keratectomy thickness but over 20 microns variability; secondary thickness accuracy differed between systems, and the Draeger blade exhibited the smoothest edge.

Conclusions:

• Substantial improvements are necessary for all three microkeratome systems to achieve accurate, reproducible, and smooth corneal resections.
• Development of more reliable methods for measuring resected corneal thickness is crucial for advancing refractive surgery techniques.