Corneal Scars and Opacities

This observational study aims to validate the use of THz scanning system in corneal edema and corneal scars, and to investigate the accuracy and performance on the use of THz scanning system in the evaluation of the progression of corneal edema and corneal scars. Participants corneal scars and corneal edema will undergo THz scanning, followed by a series of conventional clinical examinations for detailed characterization of the corneal lesion. The performance of the use of THz system on corneal scars and edema will be evaluated by correlating measurements from the THz scans with those obtained from standard clinical methods. The investigators hypothesize that the THz scanning system has the capacity to evaluate the hydration level on human corneas.