Purpose The purpose of this study was to characterize the relation between corneal hydration and stiffening effects of the UVA/riboflavin collagen crosslinking treatment and to investigate how artificially swelling the cornea prior to this treatment procedure affects tensile property improvement. Methods Porcine corneas were collagen crosslinked in vitro at different hydration levels using a ...

Reports of increased corneal thickness and altered endothelial morphology suggest that there is abnormal corneal hydration control in diabetic patients. To study the possible influence of hyperglycemia on corneal hydration control, experiments were done on normal and alloxan-induced diabetic rabbits to assess: (1) stromal dry weight, hydration, and swelling pressure; (2) corneal thickness and c...

Corneal hydration control was tested in 22 patients with Fuchs' dystrophy, and eight subjects of similar age without the disease, by measuring the corneal thickness recovery from swelling induced by hypoxia or following overnight sleep. Measurement precision was enhanced by using a modified optical pachometer and conducting two test procedures which were analyzed by a coupled exponential model....

An estimate of overall corneal hydration control can be obtained by measuring the rate of thickness recovery following induced corneal swelling; it is expressed as the percent recovery per hour (PRPH). This recovery is nearly, but not exactly, exponential, because there appears to be an initial slower recovery phase lasting about 30-40 minutes. This 30-40 minute period of slower recovery corres...

Although the ameliorating effect of glutathione on corneal deturgescence is known, its chemical mechanism is not understood. An endeavor toward the latter was made by perfusing freshly excised rabbit corneas with selected perfusion fluids, measuring corneal thickness, and assaying the endothelial cells for reduced and oxidized glutathione after 2 and 5 hr of perfusion. Ringer's solution, contai...

Ultrastructural changes in in vitro ageing spinach chloroplasts have been studied in detail. Prolonged storage caused swelling of the chloroplasts due to the increase in the thickness and spacing of the thylakoid membranes. The increase in the thickness of the membrane is partly accompanied by the release of lipids. Addition of crystalline bovine serum albumin was found to stabilize the membran...

Influence of convective cooling at the extrudate’s free surfaces on its own swelling behaviour is examined numerically when viscous fluids of a Newtonian type are extruded. In circular die extrusion, increasing the surface heat transfer coefficient h increases extrudate’s thickness swell at low Nahme-Griffith number Na; at high Na, however, this trend tends to be reversed. With annular dies, a ...

Mucoepidermoid carcinoma is a locally invasive tumor of the major and minor salivary glands. A 29-year-old male patient reported complaint slow-growing, painless, non-ulcerated palatal swelling. On clinical evaluation, swelling appeared benign; hence, complete excision lesion was carried out under general anesthesia, with closure by reconstruction partial-thickness flap. Healing uneventful. The...

PURPOSE To evaluate the thinnest corneal thickness changes during and after corneal collagen cross-linking treatment with ultraviolet-A irradiation, using hypo-osmolar riboflavin solution in thin corneas. METHODS Eighteen eyes of 18 patients were included in this study. After epithelium removal, iso-osmolar 0.1% riboflavin solution was instilled to the cornea every 3 minutes for 30 minutes. H...

PURPOSE Studies have shown that stromal acidosis reduces the rate of corneal thickness recovery after induced edema, providing the first human in vivo evidence that corneal pH can influence corneal hydration control. This finding raises the question of the possible effect that pH may have on induced corneal swelling. To explore this question, the corneal swelling response to hypoxia was measure...