Purpose: To evaluate detailed morphologic changes of Terrien marginal degeneration (TMD) using anterior segment optical coherence tomography (AS-OCT).
Methods: Two patients with TMD were examined by 1310-nm wavelength swept source optical coherence tomography, corneal topography, and slit-lamp microscopy.
Results: AS-OCT depicted corneal thinning with intact epithelial layer in the peripheral cornea of both patients. Moreover, AS-OCT images of both patients clearly showed cavity formation surrounded and enclosed by intact epithelial and endothelial layers in the thinned area.
Conclusion: We demonstrate here the existence of cavity formation in the peripheral cornea with TMD. This observation suggests a possibility that corneal thinning in TMD is associated with cavity formation in the corneal stroma. AS-OCT is useful for the observation of detailed morphologic changes of diseased cornea.