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Rim T.H.T.,Yonsei University | Kim E.K.,Yonsei University | Kim E.K.,Cornea Dystrophy Research Institute | Kim T.-I.,Yonsei University
Cornea | Year: 2013

Purpose: To assess the sociodemographic and health-related risk factors associated with pterygium and its subtypes in Korea. Methods: From 2008 to 2010, a total of 14,920 randomly selected national representative participants of the Korean National Health and Nutrition Examination Survey underwent additional ophthalmologic examinations by the Korean Ophthalmologic Society. The risk factors for pterygium in general or according to subtype (atrophic, intermediate, and fleshy) were identified using multivariate logistic regression analysis. Results: The prevalence of pterygium was 6.7% (95% confidence interval, 5.9-7.5) in subjects aged 30 years or older. Older age, male sex, lower educational level, rural habitation, nonsmoking, and sun exposure were independent risk factors for pterygium. Among subjects with pterygium, older age, male sex, lower educational level, and nonsmoking were independent risk factors for all types of pterygium. Sun exposure for >5 h/d was the independent risk factor for the severe pterygium subtype. Conclusions: Socioeconomic disparities in pterygium development exist. Proper ocular examination and education to avoid excessive sun exposure would be helpful in reducing disease risk.© 2013 by Lippincott Williams & Wilkins. Source

Lee H.,Yonsei University | Kim E.K.,Yonsei University | Kim E.K.,Cornea Dystrophy Research Institute | Kang S.W.,Ewha Womans University | And 3 more authors.
Free Radical Biology and Medicine | Year: 2013

Changes in the ocular surface induced by ozone have received limited research attention. Here, we investigate the effects of ozone exposure on the integrity of the ocular surface, the production of inflammatory cytokines in tears, and changes in mucin-secreting cells in a mouse model. In addition, ozone-induced nuclear factor-κB (NF-κB)-mediated inflammatory processes were evaluated in cultured human conjunctival epithelial cells. In vivo, ozone induced the breakdown of corneal epithelial integrity, decreased the number of mucin-secreting cells, and induced the production of inflammatory cytokines, without altering tear volume. In vitro, ozone exposure led to increases in NF-κB nuclear translocation, κB-dependent transcriptional activity, NF-κB inhibitor a (IκBα) proteolysis, and expression of phosphorylated IκBα (p-IκBα), but did not cause cytotoxicity or cellular apoptosis. In addition, ozone induced the expression of inflammatory cytokines, Toll-like receptors, and C-C chemokine receptors, but decreased the expression of mucins. Furthermore, inhibition of NF-κB with pyrrolidine dithiocarbamate before exposure of cultured human conjunctival epithelial cells to ozone prevented changes in IκBα and p-IκBα levels in association with a decrease in the levels of inflammatory cytokines. Therefore, we conclude that ozone exposure interferes with ocular surface integrity and induces inflammation involving NF-κB-mediated processes at the level (and/or upstream) of IκBα. Understanding the role of ozone in the initiation of inflammatory processes on the animal ocular surface and in cultured human conjunctival epithelial cells can help elucidate the pathogenesis of ocular surface damage and suggest protective strategies for preserving a healthy ocular surface against ozone exposure. Copyright © 2013 Published by Elsevier Inc. All rights reserved. Source

Lee H.,Yonsei University | Kim E.K.,Yonsei University | Kim E.K.,Cornea Dystrophy Research Institute | Kim H.S.,Yonsei University | Kim T.-I.,Yonsei University
Journal of Cataract and Refractive Surgery | Year: 2014

Purpose: To use Fourier-domain optical coherence tomography (OCT) to evaluate the wound characteristics of clear corneal incisions (CCIs) created with a metal or diamond blade in cataract surgery.Design: Prospective comparative observational study.Methods: Patients who had cataract surgery were randomized into 2 groups based on whether a metal blade (Group 1, 37 eyes) or diamond blade (Group 2, 33 eyes) was used to create a 2.8 mm temporal CCI. One day, 1 week, and 1 month postoperatively, structural characteristics of the CCI were analyzed using RTVue-100 Fourier-domain OCT. Parameters included incision angle, corneal thickness, epithelial or endothelial gaps, and Descemet membrane detachment. Visual acuity, surgically induced astigmatism (SIA), and ocular aberrations were evaluated.Results: There was a significant difference in corneal thickness at the 1.0 mm temporal side from midpoint. The mean uncorrected distance visual acuity in Group 2 (33 eyes) improved significantly over time. In both groups, corneal thickness at the midpoint, 1.0 mm temporal side, and 1.0 mm nasal side from the midpoint of the incision significantly decreased over time. At all timepoints, temporal and nasal thickness in Group 2 was significantly greater than in Group 1 (37 eyes), with the exception of temporal thickness at 1 month. In both groups, wound healing was reliable over time. There were no significant between-group differences in SIA or changes in aberrations.Conclusions: Corneal thickness at the incision site showed a significant difference between the 2 groups. Both groups achieved structural stabilization.Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned. © 2014 ASCRS and ESCRS. Setting: Department of Ophthalmology, Institute of Vision Research, Yonsei University College of Medicine, Seoul, South Korea. Source

Choi S.-I.,Cornea Dystrophy Research Institute | Choi S.-I.,Yonsei University | Dadakhujaev S.,Cornea Dystrophy Research Institute | Dadakhujaev S.,Yonsei University | And 7 more authors.
Journal of Pineal Research | Year: 2011

Considering that oxidative stress plays a role in corneal fibroblast degeneration during granular corneal dystrophy type 2 (GCD2) and melatonin is an effective antioxidant, we examined the ability of melatonin to protect against oxidative stress-induced cell death of primary cultured normal and GCD2-homozygous corneal fibroblasts. Melatonin treatment protected primary cultured normal and GCD2 corneal fibroblasts from paraquat (PQ)-induced oxidative stress and caused increased expression levels of Cu/Zn-superoxide dismutase (SOD1) and glutathione reductase (GR) in both types of cells. Interestingly, catalase expression increased in normal corneal fibroblasts, but decreased in GCD2 corneal fibroblasts after melatonin treatment. Melatonin also reduced the levels of intracellular reactive oxygen species and H 2O 2 in both cell types. In addition, the selective melatonin receptor antagonist luzindole blocked melatonin-induced expression of SOD1 and GR. The expression levels of melatonin receptors 1A (MT1) and 1B (MT2) were significantly higher in GCD2 corneal fibroblasts than in normal cells. These results suggest that increased expression of melatonin receptors may be involved in the defense mechanisms against oxidative stress in GCD2 corneal fibroblasts, and melatonin may have potential therapeutic implications for GCD2 treatment. © 2011 John Wiley & Sons A/S. Source

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