Exploring Corneal Biomechanics with Line-Field Optical Coherence Tomography
Authors: Kazaili, A., Lawman, S., Geraghty, B., Eliasy, A., Zheng, Y., Shen, Y., Akhtar, R.
Journal: Scientific Reports
Publication Date: April 2019
A typical LF-OCT image for a cornea at a pressure of 15 mmHg during the first loading phase (Time = 0 hour). The epithelium layer is clearly visible in the image and can be identified by the thin arc below the anterior surface of the cornea. The average thickness of this cornea was 986.9 µm.
Summary:
Understanding the biomechanical properties of the cornea is essential for various clinical applications, such as measuring intraocular pressure, treating keratoconus, and performing corneal refractive surgery. In our study, we used a novel technique called Line-Field Optical Coherence Tomography (LF-OCT) to accurately measure the mechanical properties of porcine corneas under different intraocular pressures.
Our custom-built LF-OCT device allowed us to observe how corneal thickness, elastic properties, and hysteresis changed as we varied the pressure. We also explored how hydration affected these properties. We discovered that the elastic modulus increased linearly with intraocular pressure, and corneal thickness decreased by 14% when the pressure increased from 0 to 60 mmHg. Additionally, we found that prolonged hydration in phosphate-buffered saline significantly increased the elastic modulus and corneal hysteresis.
The major advantage of our approach is that LF-OCT enables real-time monitoring of corneal geometrical changes during loading and unloading cycles. This high-resolution monitoring allows for better assessment of corneal biomechanics, which can help improve clinical practice and our understanding of ocular diseases.
Our research has important implications for the diagnosis and treatment of various ocular conditions, such as keratoconus and glaucoma. Furthermore, our findings on the impact of corneal hydration on biomechanical properties could help enhance the accuracy of existing models and improve clinical practice.
In conclusion, our study demonstrates that LF-OCT is a powerful tool for accurately measuring the elastic properties of the cornea under physiological pressures. Our method has the potential to help build better numerical and mechanical models for understanding corneal biomechanics, as well as improve the accuracy of diagnosis and treatment for many ocular diseases.