Anterior segment optical coherence tomography angiography: Development and application of OCT angiography for corneal vascularisation

Corneal diseases are among the most common causes of blindness in the world. Vascularization of the cornea is a common and potentially vision-threatening problem; the healthy cornea has no vessels and vascularization is the result of every inflammatory process in which the cornea is involved. The current gold standard for imaging vascularization is invasive; it requires injection of an intravenous contrast fluid (indocyanine green, ICG). OCT angiography (OCTA) is a new, non-invasive imaging technique that has been developed to visualize the vessels of the retina. However, the current OCTA systems are not optimized for the cornea. The main goals of my PhD thesis are (1) to establish that OCTA systems designed for the retina (posterior segment of the eye) can also be used to image the cornea (anterior segment of the eye), (2) to to design a method to analyze and quantify OCTA images of the cornea and (3) to compare OCTA with the current gold standard, ICG angiography (ICGA), histology, and confocal microscopy. The research described in this thesis opens the possibility for a new, non-invasive and rapid imaging technique to evaluate the cornea and corneal vessels simultaneously. The results support that this new technique is capable of evaluating corneal vessels in a fast, safe, and reliable manner, with a good correlation with other clinical tools used in our practice, and with a possibility to observe changes over time. The same technique could also be used in a broader range of clinical applications in ophthalmology such as glaucoma.