purpose: to evaluate densitometry of crystalline lens after cxl procedure in keratoconic patients. methods: in a quasi-experimental study three-dimensional lens densitometry was performed by pentacam scheimpflug camera at base line and 6 months later. subject group contained patients with diagnosed progressive keratoconus who underwent cxl surgery (n = 40). control group contained aged-matched ...

purpose: to evaluate the effectiveness of corneal collagen cross-linking with uv-a and riboflavin (cxl) for treatment of refractory herpes simplex virus necrotizing keratitis. case reports: two patients with a diagnosis of hsv necrotizing stromal keratitis referred to khalili hospital eye emergency room and who were resistant to conventional treatment underwent cxl. response to treatment was ev...

It has long been recognized that the high tensile strength of collagen is due to formation of intermolecular cross-links within the fiber. Following identification of the first of these intermolecular divalent cross-links in 1968 (Bailey and Peach, 1968), several other divalent and multivalent crosslinks have been proposed. Some of these proposed crosslinks have not stood the test of time, subs...

Determining the structure of cartilage collagen fibrils will provide insights into how mutations in collagen genes affect cartilage formation during skeletal morphogenesis and understanding the mechanism of fibril growth. The fibrils are indeterminate in size, heteropolymeric, and highly cross-linked, which make them refractory to analysis by conventional high-resolution structure determination...

To determine the mechanisms of vitreous liquefaction following vitreous hemorrhage, we investigated the effects of the free radicals produced by a bilirubin-sensitized photochemical reaction on collagen and hyaluronic acid (HA). Bovine vitreous collagen and HA were irradiated by visible light in the presence of bilirubin, which is produced from the degradation of hemoglobin, as a photosensitize...

A well-characterized three-chain peptide [(Col1)2 X T9] from human type III collagen was a rich source of Ehrlich chromogen. The corresponding two-chain peptide [(Col1)2] was not, implying that the Ehrlich chromogen is a trifunctional cross-link. (Col1)2 X T9 also contained pyridinoline, which is not an Ehrlich chromogen. The 7S domain of type IV collagen also contained an Ehrlich chromogen.

Cross-linking of corneal collagen (CXL) is a promising approach for the treatment of keratoconus and secondary ectasia. Several long-term and short-term complications of CXL have been studied and documented. The possibility of a secondary infection after the procedure exists because the patient is subjected to epithelial debridement and the application of a soft contact lens. Formation of tempo...

Corneal ectasia, a weakening of corneal integrity, occurs both due to acquired and congenital conditions such as keratoconus. It is a progressing condition that affects both visual acuity, and corneal stability. Various methods exist for correcting this impairment, however none address the inherit pathology, an increase laxity of the corneal stroma. Collagen cross-linking, a new, minimally inva...