tretinoin and Glaucoma

Normal anterior segment embryogenesis is summarized followed by a review of syndromes of spontaneous and inherited conditions of abnormal development in humans and animals. The study of teratogen-induced malformations in animal models has provided valuable information about critical periods during gestation for the initiation of anterior segment dysgenesis. Although the major developmental events leading to iridocorneal angle formation occur during the third trimester, it appears that embryonic insult much earlier in human gestation (during the first three to five weeks post fertilization) can induce an abnormal sequence of events leading to anterior segment dysgenesis.

Topics: Abnormalities, Drug-Induced; Animals; Anterior Eye Segment; Cataract; Disease Models, Animal; Ethanol; Female; Glaucoma; Humans; Mice; Mice, Inbred C57BL; Microscopy, Electron, Scanning; Ochratoxins; Pregnancy; Syndrome; Teratogens; Trabecular Meshwork; Tretinoin

To determine the associations between corneal biomechanical parameters as measured by the Reichert Ocular Response Analyser (ORA) and disc morphology and retinal nerve fibre layer thickness (RNFL) measured by the Heidelberg Retinal Tomograph (HRT) II in Singaporean children.. This is a cross-sectional study conducted on a subset of children enrolled in the Singapore Cohort Study of the Risk Factors of Myopia (SCORM). Corneal hysteresis (CH), corneal resistance factor (CRF) and central corneal thickness (CCT) were measured with the ORA. Optic disc morphology and RNFL thickness were assessed by the HRT II. Cycloplegic refraction and ultrasound A-scans were also performed, and disc tilt was assayed from stereo photographs.. 102 subjects (mean age 12.01 (SD 0.57) years; range 11-14 years) were included in the study. The mean CH was 12.00 (1.40) mm Hg, the mean CRF was 11.99 (1.65) mm Hg, and the mean CCT was 581.12 (33.53) mum. Eyes with tilted discs had significantly longer axial lengths and more myopic refraction than eyes without tilted discs. There were no significant correlations between CH, CRF or CCT and the HRT II parameters, after the application of the Bonferroni correction. When stratified for disc tilt, however, the global disc area was significantly correlated with CCT (r = -0.49, p = 0.001).. Corneal biomechanical properties as measured with the ORA do not vary with optic disc parameters or RNFL. Central corneal thickness is correlated with disc area in Singaporean schoolchildren with tilted discs. This relationship may influence glaucoma risk in myopic subjects.

Topics: Adolescent; Biomechanical Phenomena; Child; Cornea; Corneal Diseases; Cross-Sectional Studies; Diagnostic Techniques, Ophthalmological; Female; Glaucoma; Humans; Intraocular Pressure; Male; Myopia; Nerve Fibers; Optic Disk; Refractive Errors; Singapore; Tretinoin

To study preliminarily in vitro induced differentiation of embryonic stem cells into neurons for further investigation of an alternative for the treatment of glaumatous neuropathy.. Supernatant of cultured Buffalo rat liver cells (buffalorat liver cell-conditioned medium, BRL-CM) was used for culturing embryonic stem cells (ES-D3 cell line). Morphological features of undifferentiated ES cells were studied by HE staining and electron microscopy. Based on the methods used by Bain et al, we modified the methods and used retinoic acid (RA) as an inducer to differentiate ES-D3 cells and cytosine arabinoside (Ara-C) as inhibitor of proliferative cells. The growth of the cells was observed under phase contrast microscope.. ES-D3 cells cultured by BRL-CM grew in aggregates and remained undifferentiated. Electromicroscopy showed large nucleus and a large amount of mitochondria in undifferentiated ES cells and many processes on the surfaces. In the first day after the adding of retinoic acid, some neuron-like cells with one, two or more processes were present. In the second day after adding RA and the first day after the plus of 10 microns Ara-C, a large amount of neuron-like cells appeared, with the formation of neuron-like networks.. Combined use of RA and Ara-C can induce ES cells to differentiate into neuron-like cells. Our present preliminary study might provide insights into an alternative for the treatment of glaucomatous neuropathy by the transplantation of embryonic stem cells.

Topics: Animals; Cell Differentiation; Cell Division; Cells, Cultured; Coculture Techniques; Cytarabine; Embryo, Mammalian; Glaucoma; Hepatocytes; Humans; Neurons; Rats; Retinal Ganglion Cells; Stem Cell Transplantation; Stem Cells; Tretinoin