Jee Won Mok

Changes in corneal sensation and ocular surface in patients with asymmetrical keratoconus.

Purpose: To describe tear function, ocular surface changes, and corneal sensitivity in patients with asymmetrical keratoconus (KC). Methods: Thirty-one patients with asymmetrical KC (31 KC and 31 subclinical KC eyes) and 30 control subjects (1 eye in each subject) were enrolled in this prospective, case-control study. The patients and control subjects underwent ocular surface examinations including corneal sensitivity measurements, the Schirmer test using topical anesthesia, tear osmolarity test, and conjunctival impression cytology. Results: Mean corneal sensitivity and Schirmer test values were significantly lower in the KC and subclinical KC eyes compared with the control eyes. The conjunctiva of KC and subclinical KC eyes showed significantly higher grades of squamous metaplasia and goblet cell loss compared with the control group. However, no significant difference in tear osmolarity was found among the groups. Conclusions: The corneal sensitivity and ocular surface changes were significant in the subclinical KC and KC eyes compared with the control subjects. Ocular surface disease in KC was characterized by tear deficiency disorder and abnormal impression cytology results. However, no significant difference in tear osmolarity was found among the groups. The decrease in corneal sensitivity and ocular surface change may be associated with the pathogenesis of ocular surface changes in KC and the progression of the disease.

Antiapoptotic Effects of Anthocyanin from the Seed Coat of Black Soybean Against Oxidative Damage of Human Lens Epithelial Cell Induced by H2O2

Abstract Purpose: To describe the protective effect of anthocyanin from black soybean in human lens epithelial cell line (HLE-B3) under H2O2-induced oxidative stress. Methods: Cytotoxicity of anthocyanin and H2O2 were determined by Cell Counting Kit-8 test. Viability of HLE-B3 cells under various H2O2 concentration (0, 50 and 100 μM) with or without pretreatment of anthocyanin (0, 50, 100 and 200 μg/ml) was measured. After quantifying the percentage of the apoptosis by Annexin V assay and APO-BrdU TUNEL assay, we conducted western blot and immunostaining of apoptosis-related molecules; Bcl2, BAD, BAX, p53 and caspase-3. To confirm the effect of anthocyanin on an ex vivo model, its effect on cultures of the lenses of porcine were examined. Results: Anthocyanin reduced cell death of HLE-B3 under H2O2-induced oxidative stress in a dose-dependent manner. In Annexin V analysis, anthocyanin protected HLE-B3 cells from apoptosis. H2O2 increased the expression of BAX, BAD, p53 and caspase-3 in a time-dependent manner, those of which anthocyanin significantly decreased. On the other hand, Bcl2 was increased from anthocyanin-treated lens cells. And in anthocyanin-treated lens organ culture, transparency was maintained. Conclusions: This study showed that anthocyanin protects HLE-B3 cells under oxidative stress from apoptosis, and the mechanism of the effect is related to the intrinsic pathway of apoptosis. Anthocyanin has a potential in prevention of cataract.

Gene–Gene Interactions of CFH and LOC387715/ARMS2 with Korean Exudative Age-related Macular Degeneration Patients

Abstract Purpose: To evaluate the association and interaction of single nucleotide polymorphisms in CFH and LOC387715/ARMS2 with age-related macular degeneration (AMD) in a Korean population. Methods: A total of 114 exudative AMD patients and 240 normal subjects participated in the study. PCR and direct sequencing were used to screen SNPs in the CFH and in the LOC387715/ARMS2. Genotype and haplotype analyses were performed. Two-locus gene–gene interactions were evaluated by the data mining approach multifactor-dimensionality reduction method. Results: The *C/*T genotype frequency of rs1061170 in CFH showed a significant difference (OR = 1.79). Genotype and allele frequencies of rs551397 (*C/*C, OR = 2.84; *C, OR = 1.67) and rs800292 (*G/*G, OR = 2.198; *G, OR = 1.676) in CFH, and rs10490924 (T/*T, OR = 12.45; *T, OR = 4.45) and rs2736911 (*C/*C, OR = 3.21; *C, OR = 2.71) in LOC387715/ARMS2 were significantly higher in patients. In the haplotype analysis, C-T of rs2736911-rs10490924 in LOC387715/ARMS2 (OR = 4.85) and C-G of rs551397-rs800292 in CFH (OR = 2.22) predisposed significantly to AMD. After cross-validation consistency (CVC) and permutation tests, we identified the 1 marker model (rs10490924), which has a prediction accuracy of 73.5%, and the two locus model, rs10490924_ rs800292, with 75.3% balanced accuracy in predicting AMD disease risk. Conclusions: Korean individuals with the LOC387715/ARMS2 rs10490924, and to a lesser extent, CFH rs800292 variants might be at a greater risk for the development of exudative AMD. Furthermore, the risk of exudative AMD may increase significantly if these variants are both present in the two genes.

The Influence of Overnight Orthokeratology on Ocular Surface and Meibomian Glands in Children and Adolescents.

Purpose: The aim of this study was to investigate the influence of overnight orthokeratology (OOK) on ocular surface and meibomian glands in children and adolescents. Methods: Prospective, noncomparative study included the ocular surface disease index (OSDI), tear osmolarity, corneal and conjunctival fluorescein staining, tear film breakup time (TBUT), the Schirmer I test, and meiboscore using noncontact meibography. Immunofluorescence confocal microscopy of interleukin-1&bgr; (IL1&bgr;), interleukin-6 (IL6), epidermal growth factor (EGF), and matrix metalloproteinase (MMP)-9 using impression cytology filter paper was performed. The tests were performed before and at 6, 12, 24, and 36 months after OOK wear. Results: Fifty-eight subjects using OOK were observed. Significant increases in OSDI score (P=0.0009) and corneal and conjunctival staining score (P<0.0001) were observed compared with baseline values at 36 and 24 months, respectively. Ocular surface and meibomian changes were noted in 2 patients (3.5%). One patient exhibited an increase in OSDI score, concurrent with a decrease in TBUT at 36 months and minor loss of the meibomian gland at the distal portion of the lower lid at 24 months. The other patients exhibited the development of papillary hypertrophy and meibomian gland distortion at 24 months. No significant changes were detected in IL1&bgr;, IL6, EGF, or MMP expression after OOK use. Conclusion: Based on the findings, OOK was a relatively safe modality. However, given the potential changes in the meibomian gland and tear film stability, special attention must be paid to children with baseline meibomian gland distortions or a history of allergic conditions.

Prevalence of and risk factors for age-related and anterior polar cataracts in a Korean population.

Objective To investigate the potential risk factors associated with nuclear, cortical, posterior subcapsular, and anterior polar cataracts (APC) in the Korean population. Research Design and Methods This was a population-based, cross-sectional study of 7992 adults (over 40 years of age) from the data of the fourth annual Korea National Health and Nutrition Examination Survey, performed from 2007 to 2009. The presence of lens opacity was examined by slit-lamp biomicroscopy and evaluated according to LOCS II standard photographs. The subtype of cataract present, including nuclear, cortical, posterior subcapsular, and anterior polar cataracts, was noted. Multivariable adjusted logistic regression analysis was conducted to examine the odds ratio (OR) and 95% confidence interval (CI) for association of each specific type of cataract with age, sex, health examination, and medical history. Results The prevalence of nuclear, cortical, and posterior subcapsular cataract increased gradually with increasing age. However, the prevalence of APC peaked in the 50- to 59-year-old subjects. All types of cataract except for APCs were more prevalent in women. Oral steroid use was associated with a lower risk of APC. Conclusions These findings showed the unique characteristics of APC in the Korean population.

Ex vivo Human Corneal Epithelial Cell Expansion from a Xeno-Feeder-Free System

Purpose: The purpose of this study was to establish a simple, xeno-feeder-free method for cultivating human corneal epithelial cells. Methods: Limbal tissue explants from a cadaver were cultured in Iscoves modified Dulbeccos medium and low-calcium Panserin 801 medium in a 1:1 ratio. The outgrowing cells were characterized by flow cytometry, immunohistochemistry and real-time PCR (rtPCR). Limbal epithelial cells were expanded in a xeno-feeder-free, low-calcium medium and airlifted for 2 weeks each. Results: Migration of fibroblast-like stromal cells initially occurred from the limbal explants, and then epithelial cells migrated and grew on the stromal cells as an autofeeder layer. After airlifting, the cultured epithelium consisted of two to three layers. The cultured cells expressed stem cell-associated markers (ABCG2 and ΔNp63), differentiation markers (CK3 and CK12) and extracellular matrix-associated markers (lumican and decorin). rtPCR showed increased expression of markers for epithelial progenitor cells compared to fresh limbal tissue. Side population cells comprised 0.43 ± 0.04% of the cells (n = 5) in the primary culture. Flow cytometry showed that 49.12, 40.44 and 44.55% of the cells from the explants expressed E-cadherin, ΔNp63 and ABCG2, respectively. Conclusion: This explant culture system using stromal cells as an autofeeder layer was useful in expanding human corneal epithelial cells. This system may offer clinical insight for the expansion of limbal progenitor cells for the reconstruction of the ocular surface.

A Family with Axenfeld-Rieger Syndrome: Report of the Clinical and Genetic Findings

Purpose To describe clinical findings in a Korean family with Axenfeld-Rieger syndrome. Methods A retrospective review of clinical data about patients with diagnosed Axenfeld-Rieger syndrome. Five affected members of the family underwent a complete ophthalmologic examination. We screened the forkhead box C1 gene and the pituitary homeobox 2 gene in patients. Peripheral blood leukocytes and buccal mucosal epithelial cells were obtained from seven members of a family with Axenfeld-Rieger syndrome. DNA was extracted and amplified by polymerase chain reaction, followed by direct sequencing. Results The affected members showed iris hypoplasia, iridocorneal adhesions, posterior embryotoxon, and advanced glaucoma in three generation. None had systemic anomalies. Two mutations including c.1362_1364insCGG and c.1142_1144insGGC were identified in forkhead box C1 in four affected family members. Conclusions This study may help to understand clinical findings and prognosis for patients with Axenfeld-Rieger syndrome.

Wakayama symposium: Interface between innate and adaptive immunity in dry eye disease

Although the mechanism of dry eye disease is not clearly understood, it is certain that inflammation and the immune response play a major role in determining the health of the ocular surface in dry eye patients. Accurate ocular surface characterization during the early stages of dry eye disease is critical for successful treatment, because there exists no single standard, objective test to diagnose the early phase of dry eye disease. The treatment target should be direct to prevent the perpetuation of chronic inflammation and immune responses. Numerous studies have categorized dry eye disease as an autoimmune-related inflammatory disease. However, relatively little is known about how innate immune mechanisms act following a local insult, why some patients are particularly vulnerable, and why local inflammation fails to resolve in these patients. Within this review, particular attention will be given to the very early events and corresponding defense mechanism in dry eye disease. The transition from innate to adaptive immunity will also be discussed.

Genetic association of VEGF and PEDF polymorphisms with age-related macular degeneration in Korean

Age-related macular degeneration (AMD) causes progressive impairment of central vision and is the leading cause of vision loss in older individuals. Although the etiology of AMD has not been clearly elucidated, genetic and environmental factors have been implicated. Vascular endothelial growth factor (VEGF) and pigment epithelium-derived factor (PEDF), a major regulator of vascular permeability and angiogenesis, have been suggested to play an important role in the pathogenesis of AMD. This study was performed to determine whether VEGF and PEDF variations are associated with AMD in the Korean population. Four SNPs of both the VEGF gene the PEDF gene were used to screen for genetic variation. This analysis was performed using polymerase chain reaction–restriction fragment length polymorphism, direct sequencing and an allele-specific oligonucleotide analysis. The study investigated four SNPs in VEGF and PEDF in Korean patients with AMD. The frequency of the TT genotype of rs1413711 and the recessive VEGF allele significantly differed between the patient and control groups. The TT genotype of rs1136287 (M72T) in PEDF significantly differed between the patient and control groups. Six haplotypes in the VEGF gene and two haplotypes in the PEDF gene were significantly associated with AMD. In this study, rs1413711 of VEGF, rs1136287 of PEDF and haplotypes were identified as candidate variants associated with AMD in Korean patients.