ABSTRACT
Ethambutol is a common cause of drug-related optic neuropathy. Prediction of the onset of ethambutol-induced optic neuropathy and consequent drug withdrawal may be an effective method to stop visual loss. Previous studies have shown that structural injury to the optic nerve occurred earlier than the damage to visual function. Therefore, we decided to detect structural biomarkers marking visual field loss in early stage ethambutol-induced optic neuropathy. The thickness of peripapillary retinal nerve fiber layer, macular thickness and visual sensitivity loss would be observed in 11 ethambutol-induced optic neuropathy patients (22 eyes) using optical coherence tomography. Twenty-four healthy age- and sex-matched participants (48 eyes) were used as controls. Results demonstrated that the temporal peripapillary retinal nerve fiber layer thickness and average macular thickness were thinner in patients with ethambutol-induced optic neuropathy compared with healthy controls. The average macular thickness was strongly positively correlated with central visual sensitivity loss (r (2) =0.878, P=0.000). These findings suggest that optical coherence tomography can be used to efficiently screen patients. Macular thickness loss could be a potential factor for predicting the onset of ethambutol-induced optic neuropathy.
ABSTRACT
OBJECTIVE: The purpose of the study is to produce a reconstructed cornea including epithelia and stroma by tissue engineering. The reconstructed tissue may provide a physiologic model for the investigations of interaction between corneal epithelial cells and keratocytes. METHODS: Epithelial cells and keratocytes were isolated from rabbit corneas and cultured on plastic substrates in vitro. The co-culture model was established using a special transwell in which two different cells were separated but were able to interact each other. Histological and immunohistological studies were performed to identify the cell types. Intercellular communication of both the cultured epithelial cells in pure and in co-culture with the keratocytes was studied by laser confocal scanning microscopy. RESULTS: Population doubling time (PDT) was 3.45, 3.30, 2.11 and 2.32 d in pure corneal epithelial cells, co-culture epithelial cells, pure keratocytes and co-culture keratocytes respectively. The epithelial cells in co-culture grew quicker than those in pure (P < 0.01) and the stromal cells in co-culture grew slower than those in pure (P < 0.01). Intercellular communication of the cultured epithelial cells in co-culture were more than that in pure (U = 2.691, P < 0.05). CONCLUSIONS: The co-culture model of epithelial cell and keratocyte is feasible. Under the co-culture system the responses of cell proliferation and intercellular communication are different between epithelial cells and keratocytes.
Subject(s)
Cell Communication , Epithelium, Corneal/cytology , Stromal Cells/cytology , Tissue Engineering , Animals , Cells, Cultured , Coculture Techniques , Cornea , RabbitsABSTRACT
OBJECTIVE: To develop a new photochemical method of experimental retinal vein occlusion and investigate the morphologic and histologic changes in the retina. METHODS: After intravenous injection of rose Bengal, the vessels next to the disc of miniature pigs in the experiment group (n = 15) were exposed to an endo-illuminator for 15 minutes. As a control group, the vessels next to the disc of each pig were exposed to the endo-illuminator without rose Bengal injection. After complete vascular occlusion, the eyes were observed at following times: one hour, and 1, 3, 7, 14, 21, and 28 days. After the 28th day, the eyes were enucleated and prepared for light and electron microscope examination. RESULTS: Histopathologic features were consistent with changes of retinal vein occlusion and formation of retinal vein thrombi was reliable. CONCLUSIONS: Photodynamic method combined with endo-illuminator was a simple, reliable and definitive experimental technique to produce retinal vein occlusion.
