Screening for previous refractive surgery in eye bank corneas by using optical coherence tomography

Area of Science:

• Ophthalmology
• Biomedical Optics
• Corneal Surgery

Background:

• Accurate identification of previous refractive surgery is crucial for donor cornea assessment.
• Standard methods may not reliably detect subtle surgical alterations in preserved corneas.
• Optical coherence tomography (OCT) offers high-resolution cross-sectional imaging capabilities.

Purpose of the Study:

• To evaluate the utility of optical coherence tomography (OCT) for detecting prior refractive surgery, specifically laser in situ keratomileusis (LASIK), in donor corneas.
• To assess if OCT-derived parameters can differentiate between corneas with and without a history of LASIK.

Main Methods:

• A custom tabletop OCT scanner operating at a 1310-nm wavelength was utilized.
• Donor corneas, both normal and those with a history of LASIK, were scanned in their preservation medium and container.
• Image processing software was developed for automated mapping of corneal surfaces and analysis of stromal reflectivity.

Main Results:

• While flap interfaces were not visible on OCT, significant differences were observed in anterior surface power and anterior/posterior stromal reflectivity ratio between control and post-LASIK corneas.
• The anterior/posterior reflectivity ratio in the central 4-mm diameter was significantly lower in post-LASIK corneas.
• Death-to-scan time was longer for LASIK corneas, suggesting potential impact on tissue properties.

Conclusions:

• OCT can generate detailed thickness, topography, and reflectivity maps of donor corneas without removal from preservation.
• Anterior corneal curvature and the anterior/posterior stromal reflectivity ratio show potential as reliable indicators for detecting previous LASIK surgery.
• OCT imaging provides a non-invasive method to aid in the assessment of donor cornea suitability for transplantation.