PURPOSE To evaluate the biomechanics of corneal ring implants by providing a related mathematical theory and biomechanical model for the treatment of myopia and keratoconus. METHODS The spherical dome model considers the inhomogeneity of the tunica of the eye, dimensions of the cornea, lamellar structure of the corneal stroma, and asphericity of the cornea. It is used in this study for calcul...

Ring reactions of the cornea have been given a new nomenclature based upon their mechanism of formation. The term immune corneal ring includes all types and distinguishes ring reactions from the general term, "anaphylactic" keratitis. The systemic immune ring, arising slowly from serum antibody ami cells at the limbus, is distinguished from the local immune ring, which rapidly develops at the "...

PURPOSE To examine epithelial and stromal layers by three-dimensional very high-frequency (VHF) digital ultrasound scanning before and after implantation of Intacs (intracorneal ring segments [ICRS]). METHODS Three-dimensional scanning was performed in five eyes before and 3 months after Intacs insertion. Digital signal processing techniques provided high-resolution B-scan imaging and I-scan ...

INTRODUCTION Corneal thinning disorders caused by keratoconus often lead to protrusion, irregular astigmatism, and even perforation. Keratoconus, like other corneal ectasia, does not have a known cause. Severe cases of keratoconus may require correction or restoration of tectonic integrity of the cornea by surgical means. Intracorneal ring segments are a new modality in the treatment of corneal...