Developments in Contact Lens Imaging: New Applications of Optical Coherence Tomography

Abstract

Optical coherence tomography (OCT) is a high-speed and non-contact optical imaging technology widely used for noninvasive cross-sectional imaging of biological objects. Two main OCT technologies have been developed: time domain and Fourier domain technologies. The latter can be further divided into spectral domain OCT, which uses a broadband light source and a spectrometer as a detector, and swept source OCT, which employs a quickly-rotating laser source. Advances in OCT technology have made it one of the most helpful devices in ophthalmic practice. Fourier OCT has revolutionized imaging of the posterior segment of the eye, as well as of anterior structures and has enhanced the ability to diagnose and manage patients. It provides high-resolution information about the tear film, contact lens (CL), a qualitative and quantitative assessment of the anterior eye that is important in contact lens fitting, and allows possible eye surface changes while wearing contact lenses to be monitored. Potential swept source OCT technology applications include industrial processes of lens design and quality control. In this paper, we describe clinical applications and outline a variety of multifunctional uses of OCT in the field of refractive error correction with contact lenses.

Shape of the anterior surface of the cornea after extended wear of silicone hydrogel soft contact lenses

“…31 Furthermore, both corneal and corneal epithelial thickness were mapped with OCT as this is an accurate, non-invasive and reproducible technique. 5,6,7,9,14,28,32,33 The advantage of the OCT system is that it allowed measurement of epithelial thickness changes in the corneal periphery. The analysis covered a 9-mm-diameter circular region, with data presented in 25 sectors.…”

“…It provides measurements with good to excellent repeatability 31 . Furthermore, both corneal and corneal epithelial thickness were mapped with OCT as this is an accurate, non‐invasive and reproducible technique 5,6,7,9,14,28,32,33 . The advantage of the OCT system is that it allowed measurement of epithelial thickness changes in the corneal periphery.…”

“…While we assessed corneal parameters before applying and immediately after removing the SCLs, we did not follow the subjects for a longer period to verify recovery of the cornea back to the initial state as this has previously been reported 12,26 . Many contact lens‐induced changes in corneal curvature and structure are reversible, but the time to resolve corneal warpage following cessation of SCL wear varies with the lens material, modality and previous duration of SCL wear 16,17,26,27,28,29,30,31 . The time for full corneal topographical recovery after stopping SiH lens wear was up to 2 weeks, with a shorter time for daily wearing 16,26 …”

“…12,26 Many contact lens-induced changes in corneal curvature and structure are reversible, but the time to resolve corneal warpage following cessation of SCL wear varies with the lens material, modality and previous duration of SCL wear. 16,17,26,27,28,29,30,31 The time for full corneal topographical recovery after stopping SiH lens wear was up to 2 weeks, with a shorter time for daily wearing. 16,26 The observations made in this study have clinical significance.…”

“…Moreover, the influence of positive‐ and negative powered SiH lenses on corneal shape has not been investigated. New technologies used in clinical practice have expanded the ability to assess the anterior eye by mapping corneal epithelium thickness 6,14,28 . This feature was recently introduced into commercially available Fourier‐domain optical coherence tomography (OCT).…”