Purpose: Terrien disease is a rare form of peripheral corneal degeneration characterized by vascularization, opacification, lipid deposition, and corneal thinning. In this study, a high-frequency ultrasound biomicroscope (UBM) was used to detect the morphologic changes before and after surgery and to determine the stages of this disease.
Methods: Two patients with Terrien disease were examined by UBM, corneal topography, and a keratometer before and after surgery (full-thickness keratectomy).
Results: The absence of the Bowman layer and thinning of the Descemet layer in the ectatic part of the peripheral cornea were detected by using the UBM before surgery. Earlier, these signs could be detected only with optical and electron microscopy from histologic samples; now we can detect the signs of Terrien disease with noninvasive devices such as the UBM.
Conclusions: The UBM is an effective device for following the progression of Terrien disease and determining the timing of these patients' surgeries.