Non-invasive detection of nanoscale structural changes in cornea associated with cross-linking treatment

TL;DR

This paper introduces a non-invasive, nanoscale-sensitive optical coherence tomography method to detect corneal structural changes during cross-linking treatment, offering potential for real-time clinical monitoring.

Contribution

It demonstrates the application of nsOCT for in vivo detection of nanoscale corneal changes during cross-linking, without additional hardware.

Findings

Nanoscale structural changes can be detected non-invasively.

Corneal spatial period increases after riboflavin instillation.

Significant decrease in spatial period occurs after UVA irradiation.

Abstract

Corneal cross-linking (CXL) using UVA irradiation with a riboflavin photosensitizer has grown from an interesting concept to a practical clinical treatment for corneal ectatic diseases globally, such as keratoconus. To characterize the corneal structural changes, existing methods such as X-ray microscopy, transmission electron microscopy (TEM), histology and optical coherence tomography have been used. However, these methods have various drawbacks such as invasive detection, the impossibility for in vivo measurement, or limited resolution and sensitivity to structural alterations. Here, we report the application of over-sampling nano-sensitive optical coherence tomography (nsOCT) method for probing the corneal structural alterations. The results indicate that the spatial period increases slightly after 30 minutes riboflavin instillation but decreases significantly after 30 min UVA irradiation following the Dresden protocol. The proposed non-invasive method can be implemented using existing OCT system, without any additional components, for detecting nanoscale changes with the potential to assist diagnostic assessment during CXL treatment, and possibly to be a real-time monitoring tool in clinics.