Corneal Biomechanical Properties Characterization Using Air-jet Indentation Based Optical Coherence Tomography System (AIOCT)

¹ Department of Biomedical Engineering, The Hong Kong Polytechnic University, Hong Kong 999077, China
² Department of Laser Medicine, Chinese PLA General Hospital, Beijing 100853, China
³ Eye Hospital, China Academy of Chinese Medical Sciences, Beijing 100040, China
⁴ School of Mathematics and Physics, Anhui Jianzhu University, Hefei 230601, China
⁵ Beijing Tongren Eye Center, Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing Tongren Hospital, Capital Medical University, ophthalmology Beijing, Beijing, 100730, China

Abstract

We proposed a novel method together with system to quantify the corneal biomechanics. The objectives of this study are to develop a method to measure the corneal biomechanical properties in vivo and to evaluate the performance of AIOCT system. A novel AIOCT system was established and a mathematical model was built on the basis of the current air-jet indentation method. Experiments were performed to evaluate the mechanical properties of eleven custom-made silicone corneal mimicking phantoms by the AIOCT system under different intraocular pressures (IOP). The results were then compared with those measured by the standard mechanical tensile test and indentation test. The phantom’s moduli were ranged from 0.08 to 1.03 MPa according to the tensile and indentation test. The elastic moduli of corneal silicone phantoms (E_airjet) were measured using the AIOCT system with the proposed mathematical model at four IOPs (0.6, 15.3, 29.8, and 44.7 mmHg). The E_airjet were agreed well with the corresponding moduli (E_tensile) measured by the tensile test (E_airjet = 1.188 E_tensile, R² = 0.925). The preliminary results showed that this technique was capable of measuring corneal biomechanical properties in vivo and it may provide a clinical potential non-invasive and non-contact means to the diagnosis of keratoconus suspects in the future.