The metabolic changes in diabetics result in progressive retinopathy and influence corneal metabolism. Changes in corneal autofluorescence were demonstrated originating from mitochondrial flavoproteins and influenced by the metabolic changes in cornea in diabetics. The corneal autofluorescence was determined to evaluate its correlation with diabetic retinopathy using fluorophotometer in 25 healthy controls, 25 diabetic mellitus(DM) pationts without retinopathy, 25 background diabetic retinopathy(BDR)patients, 25 preproliferative diabetic retinopathy (PPDR) patients, and 25 proliferative diabetic retinopathy(PDR) patients. The mean values(mean +/- standard deviation in ng fluorescein/ml) were 13.9 +/- 1.9, 18.7 +/- 3.1, 19.6 +/- 2.3, 20.2 +/- 4.0, 24.3 +/- 4.2, respectively. The means of coreal autofluorescence values in diabetics were significantly higher than that of the healthy controls(p<0.001). The mean values in DM patients without retinopathy, BDR patients and PPDR patients did not differ significantly(p>0.05), but the mean value in PDR patients was significantly higher than those of the other 4 groups(p<0.001). These results indicate that measurement of corneal autofluorescence can play a supplementary role in diagnosing diabetic retinopathy.
Cornea ; Diabetic Retinopathy* ; Flavoproteins ; Humans ; Metabolism

OBJECTIVEThe aim of this review is to comprehensively and unbiasedly summarize the improvements in the techniques for classical corneal collagen cross-linking (CXL) by covering the reasons for this improvement, measure, and effect to approach the future direction of the CXL.

DATA SOURCESAll articles used in this review were mainly retrieved from the PubMed database.

STUDY SELECTIONOriginal articles and reviews were selected if they were related to the improvement in the technique of classical CXL. Data were mainly extracted from 94 articles, which are listed in the reference section of this review.

RESULTSThis innovative research involves every step such as instrument preparation, epithelial management, riboflavin instillation, and UVA irradiation. These clinical and experimental results seem promising.

CONCLUSIONSCXL treatment is the only recent promising method for preventing the progress of keratoconus. The limitations and potential complications that accompany classical CXL such as corneal thickness limitations, ultraviolet-A (UVA) light injury, and the impact of de-epithelialization encourage people to research new improvements in techniques. While this research needs to be further investigated, we hope our review can help related researchers and patients.

Collagen ; metabolism ; Cornea ; metabolism ; radiation effects ; Humans ; Ultraviolet Rays

The role of nitric oxide (NO) in ocular surface diseases remains unknown. We investigated the conditions leading to increase NO generation in tears and the main sources of ocular surface tissue. We evaluated the possibility of a dual action (cell survival or cell death) depending on the amount of NO. The concentration of nitrite plus nitrate, the stable end-product of NO, was measured in the tears of various ocular surface diseases. We also examined the main source of nitric oxide synthase (NOS) using immunohistochemical staining & Western blot analysis. When cultured human corneal fibroblasts were treated with NO producing donor with or without serum, the viability of cells was studied. We found that sources of NO in ocular surface tissue primarily included corneal epithelium, fibroblasts, endothelium and inflammatory cells. Three forms of NOS (eNOS, bNOS, & iNOS) were expressed in experimentally induced inflammation. Cell death by NO revealed TUNEL positive staining, however in the EM finding, this NO specific cell death was an atypical necrosis showing perinuclear large vacuolization and mitochondrial swelling. In the fibroblasts culture system, the NO donor (SNAP, S-nitroso-N-acetyl-D, L-penicillamine) prevented the death of corneal fibroblasts caused by serum deprivation in a dose dependent manner up to 500 m SNAP, although a higher dose decreased cell viability. This study suggested that NO might act as a double-edged sword in ocular surface disease depending on the degree of inflammatory condition related with NO concentration.
Animal ; Cells, Cultured ; Cornea/metabolism ; Eye Diseases/*physiopathology ; Human ; Nitric Oxide/*metabolism ; Tears/metabolism

OBJECTIVETo study the corneal penetration of PAMAM dendrimers-coated puerarin liposomes in rabbits.

METHODEvaluated PAMAM (G2, G3) dendrimers-coated puerarin liposomes were prepared and the in vitro transcorneal penetration were compared to puerarin drop solution and uncoated liposomes. The effect of different proportion of PAMAM to phospholipids in formulation on corneal penetration and the penetration parameters were investigated.

RESULTThe steady state fluxes and permeability coefficients of puerarin by PAMAM G2 (1.0%) and PAMAM G3 (0.5%) coated puerarin liposomes were greater than that by puerarin drop solution and uncoated liposomess (P < 0.01), meanwhile the PAMAM G2 (1.0%) and PAMAM G3 (0.5%) coated liposomes were better than other ratios of coated liposomes for improvement of corneal penetration (P < 0.01).

CONCLUSIONThe PAMAM coated liposomes is able to enhance the corneal penetration of puerarin and promising as an ocular drug carriers.

Animals ; Cornea ; metabolism ; Dendrimers ; chemistry ; metabolism ; In Vitro Techniques ; Isoflavones ; chemistry ; Liposomes ; chemistry ; metabolism ; Rabbits

No abstract available.
Adult ; Cornea/*metabolism ; Fluorescent Antibody Technique, Indirect ; Humans ; Microscopy, Fluorescence ; Middle Aged ; alpha-Synuclein/*metabolism

To study corneal lymphangiogenesis after corneal transplantation, corneal allogenic transplantation models were established in rats. 8 female Wister rats were used as donors, and 16 Sprague Dawley (SD) rats were used as recipients and 2 SD served as controls. Corneal lymphangiogenesis and hemangiogenesis was examined by electron microscopy 1 and 2 weeks after corneal penetrating transplantation, and the expression of lymphatic vessel endothelial receptor (LYVE-1) was examined 1, 3, 7, 14 days after the transplantation respectively. In addition, 19 allograft failed human corneas were examined by 5'-nase-alkaline phosphatase (5'-NA-ALP) double-enzyme-histochemistry staining to detect corneal lymphangiogenesis and hemangiogenesis. By immunohistochemistry for LYVE-1, it was found that blown lymphatics were localized in the stroma 3 days after the corneal transplantation. With electron microscopy, new lymphatic vessels and blood vessels were found 1 and 2 weeks after the corneal transplantation. By 5'-NA-ALP enzyme-histochemistry, corneal hemangiogenesis was found in all allograft failed human corneas and 5 of 19 (26.3 %) cases had developed corneal lymphangiogenesis. It is concluded that corneal lymphangiogenesis is present after corneal transplantation, which may play an important role in allograft rejection.
Cornea/*blood supply ; Cornea/chemistry ; Cornea/ultrastructure ; Corneal Neovascularization/etiology ; Corneal Neovascularization/metabolism ; Corneal Transplantation/adverse effects ; Corneal Transplantation/*methods ; Immunohistochemistry ; Lymphangiogenesis ; Microscopy, Electron ; Rats, Sprague-Dawley ; Rats, Wistar ; Vesicular Transport Proteins/biosynthesis

OBJECTIVESTo observe the expression of betaig-h3 in normal cornea and keratoconus and to elucidate the role of extracellular matrix in keratoconus.

METHODSIn situ hybridization was used to detect the expression of betaig-h3 in the cornea. The cDNA library was screened with human betaig-h3 cDNA probe to locate betaig-h3 mRNA in cells.

RESULTSExpression of betaig-h3 was found mainly in the stroma of the normal cornea and keratoconus, but decrease depending on the degree of keratopathy. In some serious cases, no expression signal was detected. The strongest expression was seen at the border of the normal region and keratoconus.

CONCLUSIONSbetaig-h3, the structural component of the extracellular matrix, can affect cell adhensiveness in the development of corneal fibrous interstitial organization. During the development of keratoconus, decreasing levels of betaig-h3 cause the diminution of corneal steadiness, which is related to formation of keratoconus.

Cornea ; metabolism ; Extracellular Matrix Proteins ; Humans ; Keratoconus ; metabolism ; Neoplasm Proteins ; genetics ; RNA, Messenger ; analysis ; Transforming Growth Factor beta ; Wound Healing

Normally the cornea has a water content varying between 76-78%, a state of relative dehydration maintained through its own metabolism by the active transport of water and ions across its limiting membrane, the epithelium and endothelium. If the metabolism is grossly disturbed or if the effectivity of the limiting membrane is impaired, the living cornea will swell by the absorption of the fluid. Corneal edema are developed due to trauma, inflammation, glaucoma, degeneration, and neuropathic and metabolic conditions. Essential corneal edema are encountered for which no cause can be found, the condition apparantly occuring without other ocular pathology. A 29 years old Korean lady has been found to have bilateral essential edema of the cornea.
Absorption ; Adult ; Biological Transport, Active ; Cornea ; Corneal Edema* ; Dehydration ; Edema ; Endothelium ; Epithelium ; Glaucoma ; Humans ; Inflammation ; Ions ; Membranes ; Metabolism ; Pathology ; Water

Wilson's disease is a familial disease characterized by coarsely nodular cirrhosis of the liver, sometimes associated with progressive damage to the nervous system, and the appearance of a coloured ring in the cornea. Wilson's disease is an inborn error of copper metabolism in which the synthesis of ceruloplasmin, with which copper forms a table compound in the blood, is diminished and there is an increased absorption of copper from the gastrointestinal tract together with an increased output in the urine. The Kayser-Fleischer ring is originally described by Kayser(1902) and later by Fleischer(1903). The colours of Kayser-Fleischer ring is seen, varing from rub by red to bright green or an 1lltramarine blue. sometimes interspersed with yellow or smoky shade of brown. The ring starts dose to the limbus as a sharp line just where the endothelial pattern begins to be seen distinctly, extends over a breadth of I to 3mm.. and gradually fades away towards the center of the cornea. Harry et al(1970) described that electron microscopy showed the presence of electron dense deposits of varing size lying mainly in Descmet's membrane and confirmed that the deposits were copper. A 14 year old korean boy with Wilson's disease was found to have Kayser-Fleischer ring in the cornea(ou) and greenish brown pigments on the anterior surface of the lens (ou). In about 16 months after the administration of penicillamine(chelating agent), greenish brown pigments on the anterior surface of the lens (ou) were disappeared remaining Kayser Fleischer ring unchanged.
Absorption ; Adolescent ; Ceruloplasmin ; Copper ; Cornea ; Deception ; Fibrosis ; Gastrointestinal Tract ; Hepatolenticular Degeneration* ; Humans ; Liver ; Male ; Membranes ; Metabolism ; Microscopy, Electron ; Nervous System

Bietti's crystalline retinopathy is a rare form of tapetoretinal degeneration characterized by yellow, polygonal, glistening intraretinal crystals in the posterior pole and in the superficial paralimbal cornea, which may be due to a systemic abnormality of lipid metabolism, and has been to have a autosomal recessive pattern.Also lots of the reports described similar cases without any corneal changes. 56 years-old female with complaint of progressive visual decrease had corrected visual acuity of 0.1 in her right eye and 1.0 in her left eye.Yellow intraretinal crystals with retinal pigment epithelial (RPE)dystrophy and choroidal sclerosis were noticed without any corneal changes.During follow-up for thirty months, visual acuity gradually decreased to counting fingers in her right eye and 0.7 in her left eye, and RPE degeneration and choroidal sclerosis worsened with no change in intraretinal crystals.
Choroid ; Cornea ; Crystallins* ; Female ; Fingers ; Follow-Up Studies ; Humans ; Lipid Metabolism ; Middle Aged ; Retinaldehyde ; Retinitis Pigmentosa ; Sclerosis ; Visual Acuity