ABSTRACT
Stem cells are a group of self-renewal cells with the potential to differentiate into a variety of cell lineages. Embryonic stem cells can differentiate into more than 200 types of cell lineages belonging to endodermal, mesodermal and ectodermal tissues. Corneal epithelial cells derive from epidermal ectoderm during embryonic development. When the ocular surface is severely damaged, corneal epithelium with proliferation potential is essential for its reconstruction. Recent studies are focused on differentiation of bioactive corneal epithelial cells. This review summarizes signaling pathways including Notch, Wnt, bone morphogenetc protein or fibroblast growth factor pathways that are involved in regu?lating the development of embryonic ectoderm and corneal epithelial cells revealed in previous studies.
ABSTRACT
Objective:To investigate the clinical manifestations and distribution characteristics of dry eye patients with ocular discomfort symptoms in Jilin Province, and to analyze the relationship between the risk factors associated with dry eye and its severity. Methods:The secondary or tertiary hospitals in Jilin Province were randomly selected and used as screening bases from July 2014 to August 2015.1 173 people initiative to the hospital for eye examinations after publicity were selected.Questionnaire was used to collect the subjective symptoms of dry eye.The breakup time(BUT) of tear film, corneal fluorescein staining, meibomian gland and tear secretion were examined and the detection rate and risk factors of dry eye of the dry eye patients with different clinical characteristics were analyzed.Results: A total of 1 122 people was actually surveyed, 896 individuals were diagnosed as dry eye, and the prevalence rate was 79.8%. The prevalence rate of the females was higher than of the males(χ2 =4.070,P<0.05).The prevalence of dry eye between different ages was statistically significant(χ2 =61.547,P<0.05).The multivariate Logistic regression analysis results showed that the age ≥40 years (40-49 years,OR =6.313,95% CI: 3.498-11.393;50-59 years,OR =6.919,95% CI: 3.876-12.351;60-69 years,OR =5.175,95% CI: 2.650-10.104;over 70 years,OR =9.508,95% CI: 3.608-25.061), moderate grade of meibomian gland dysfunction(MGD) (OR =2.123,95% CI: 1.186-3.803), and the patients with rheumatoid arthritis (OR =2.186,95% CI: 1.098-4.353) and eye surgery (OR =3.692,95% CI: 1.204-11.323) were the risk factors for dry eye. While the occupation of farmer was a protective factor for dry eye (OR =0.351, 95% CI: 0.135-0.917).Conclusion:Age, occupation, MGD grade, rheumatoid arthritis and eye surgery history affect the occurrence of dry eye to a certain extent. So enough attention and appropriate health guidance should be given to reduce the incidence of dry eye.