Jeewon Mok

Correlations between tear cytokines, chemokines, and soluble receptors and clinical severity of dry eye disease.

PURPOSE To determine cytokine and chemokine concentrations in the tears of patients with dry eye disease (DED) and analyze the possible relationships with the clinical severity of DED. METHODS Patients were examined using the Ocular Surface Disease Index, corneal and conjunctival staining, tear breakup time, and impression cytology. They were divided into four groups according to the Dry Eye Workshop severity classification. Tears were collected from 133 patients with DED and 70 healthy controls. Concentrations of cytokines, chemokines, and soluble receptors in collected tear samples were analyzed using current technology with a Human Cytokine/Chemokine kit, a Human Cytokine/Chemokine Panel, and a Human Soluble Cytokine Receptor Panel. RESULTS The levels of cytokines interleukin (IL)-1β (P < 0.05), IL-6 (P < 0.001), IL-16 (P < 0.001), IL-33 (P < 0.05), G-CSF (P < 0.001), and transforming growth factor (TGF)-α (P < 0.05) were significantly higher in patients with DED, whereas those of cytokines IL-4 (P < 0.001), IL-12 (p40) (P < 0.001), IL-17A (P < 0.05), and interferon-γ (P < 0.001) were significantly lower. The levels of Fractalkine (chemokine [C-X3-C motif] ligand 1; CX3CL1), MCP-1 (chemokine [C-C motif] ligand 2; CCL2), MIP-1δ (chemokine [C-C motif] ligand 15; CCL15), and ENA-78 (chemokine [C-X-C motif] ligand 5; CXCL5) (P < 0.001, respectively) and soluble receptors, sIL-1RI (P < 0.05), soluble glycoprotein (sgp) 130 (P < 0.05), sIL-6R (P < 0.001), soluble epidermal growth factor receptor (P < 0.05), and soluble tumor necrosis factor receptor 2 (P < 0.001), were higher in patients with DED. There were significant correlations between these molecules and the clinical severity of DED. CONCLUSIONS Fifteen molecules were elevated in the tears of patients with DED; four molecules were decreased. Although the levels of sIL-6R, sIL-6R, and sgp130 may be potential indicators of the homeostatic process, an increase in the levels of IL-6 and IL-1 β are the earliest observable changes in patients with DED. Further study on the biomarkers in the pathogenesis of DED and treatment target modalities would be needed.

VSX1 gene variants are associated with keratoconus in unrelated Korean patients.

AbstractKeratoconus is a bilateral ectatic disorder characterized by the central thinning of corneal tissue leading to visual impairment. To investigate the possibility of visual system homeobox 1 (VSXI) as a candidate susceptibility gene for Korean patients with keratoconus, we performed a mutation screening of the VSXI gene in 249 unrelated patients with keratoconus and 208 control subjects without the ocular disorder. We found two heterozygous novel missense mutations in exon 2: N151S and G160V. The G160V mutation was identified in 13 keratoconus patients (5.3%), and the N151S mutation was found in only one keratoconus patient (0.4%). We also detected three synonymous polymorphisms and four intragenic polymorphisms. The IVS1-11*a allele was associated with a significantly increased risk of keratoconus in Korean patients [3.6 vs. 0.5%, p = 0.001, odds ratio (OR) = 7.76, 95% confidence interval (CI) 1.989-30.241). Other polymorphisms did not show an association with keratoconus risk. Our data is the first reported VSX1 mutation screening in Korean keratoconus patients. We detected two novel missense mutations and one intragenic polymorphism in the VSX1 gene, which show a strong statistical association with unrelated keratoconus patients. Consequently, our study suggests that VSX1 gene variants seem to be significant genetic variants for keratoconus predisposition in unrelated Korean patients.

New susceptibility locus for high myopia is linked to the uromodulin-like 1 (UMODL1) gene region on chromosome 21q22.3

Purpose To ascertain and define the position of a potential disease susceptibility gene around D21S0083i prioritized during our previous whole genome case-control association analysis with 27158 microsatellite markers, in Japanese high-myopia patients.Methods 520 high myopic patients and 520 healthy controls were genotyped using 39 SNPs distributed around D21S0083i on chromosome 21q22.3.Results Only 1 SNP (rs2839471) of 39 SNPs was significant after correction for multiple testing (allele T: P=0.00027, Pc=0.01, OR=1.684). The SNP (rs2839471) did not reside in haplotype blocks constructed by the pair-wise linkage disequilibrium between the SNPs.Conclusions The SNP (rs2839471) is suggested to be located in the frequent recombinant region within UMODL1. Together this region might play a critical role for susceptibility to high myopia, and warrants further confirming studies and investigations as to the mechanisms by which UMODL1 may contribute to myopia.

Tear Osmolarity and Ocular Surface Parameters as Diagnostic Markers of Ocular Graft-Versus-Host Disease.

PURPOSE To evaluate the diagnostic value of tear osmolarity and several ocular surface parameters in screening for ocular surface alterations in ocular graft-vs-host disease (GVHD) patients. DESIGN Case-control study. METHODS Sixty-three patients with ocular GVHD and 74 healthy participants were screened for ocular surface changes using the Ocular Surface Disease Index (OSDI), tear osmolarity, Schirmer test, tear break-up time (TBUT), and fluorescein corneal staining. The severity of ocular GVHD was diagnosed according to the National Institutes of Health (NIH) grading system. The diagnostic sensitivity and specificity and cutoff values were determined for each ocular parameter using a receiver operating characteristic (ROC) curve and area under the curve (AUC) analysis. Significance was defined at P < .05. RESULTS The tear osmolarity, corneal staining score, and OSDI score gradually increased as the severity of ocular GVHD increased, and Schirmer value gradually decreased as the GVHD grade increased in severity. The Schirmer test showed greatest diagnostic sensitivity and specificity for ocular GVHD (92.1% sensitivity, 85.7% specificity, cutoff = 9 mm), followed by the TBUT (87.3% sensitivity, 75.0% specificity, cutoff = 6 s), tear osmolarity (98.4% sensitivity, 60.7% specificity, cutoff = 311 mOsm/L), corneal staining score (66.7% sensitivity, 82.1% specificity, cutoff = 2), and OSDI score (77.8% sensitivity, 66.1% specificity, cutoff = 20.8). CONCLUSIONS Multiple diagnostic modalities should be used to detect ocular surface changes in GVHD patients. The severity of ocular GVHD can be effectively monitored using tear osmolarity; however, additional studies are required.

Absence of an association between lumican promoter variants and high myopia in the Korean population.

Purpose: To determine the association of single nucleotide polymorphisms (SNPs) in the promoter region of the lumican (LUM) gene with high myopic Korean patients. Methods: Genomic DNA samples were obtained from 128 unrelated Korean patients with high myopia who had refractive errors ≤ −9.25 and axial lengths ≥ 26.5 mm in both eyes, and 235 control subjects. We investigated two promoter SNPs of the LUM gene. Results: For the rs3759222, the C/C genotype was less prevalent in the high myopia group compared to the control group (46.1% vs. 53.2%); however, there was no statistical significance (p = 0.068, OR = 0.754, 95% CI: 0.491–1.159). The “C” allele frequency in the high myopia group (68.0%) was slightly lower than the control group (72.6%), but this difference was not statistically significant (p = 0.061, OR = 0.810, 95% CI:0.582–1.126). For the rs3759223, the genotype frequencies of T/T, T/C, and C/C were 67.2%, 26.6%, and 6.2%, respectively, in the high myopia group and 64.7%, 30.6%, and 4.7 %, respectively, in the control group. The allele frequency of T was 80.5% in the high myopia group and 80.0% in the control group (p = 0.077, OR = 1.03, 95% CI: 0.703–1.508). There were no significant differences in the distribution of genotype and allele frequencies for the two promoter SNPs tested. Conclusions: The current study did not support an association between the promoter SNPs of the LUM gene with high myopia in the Korean population.

Heterozygous Avellino corneal dystrophy 9 years after photorefractive keratectomy: natural or laser-induced accelerated course?

Purpose: To report a photorefractive keratectomy (PRK)-treated patient who first developed stromal opacities with a typical granular pattern 9 years after surgery, which was confirmed as heterozygous Avellino dystrophy by DNA analysis. Methods: A 37-year-old woman, who had undergone PRK 17 years ago, has been followed for glaucoma and corneal dystrophy. She had preoperative clear corneas in both eyes. Results: Nine years after PRK, at the age of 29 years, 2-3 small, white, anterior stromal corneal opacities were first detected in both eyes. Seventeen years postoperatively, multiple anterior stromal corneal deposits with a dot, crumb, or snowflake appearance were noted to the same degree in both eyes. The intervening cornea was relatively clear. Her DNA was heterozygous for the R124H mutation. Conclusions: Slowly developing, mild corneal deposits occurred after PRK in this patient with heterozygote Avellino corneal dystrophy. Various clinical manifestations can occur after excimer laser refractive surgery in patients with Avellino corneal dystrophy.

The Blockade of IL6 Counterparts the Osmolar Stress-Induced Apoptosis in Human Conjunctival Epithelial Cells

To determine the effect of hyperosmolarity on cell survival/apoptosis of conjunctival epithelial cells and evaluate the possible role of IL6, Wong-Kilbourne derivative of Chang conjunctival cell line (WKD) was used in this study. Confluent cells were incubated under different osmolarity (290 mOsm and 500 mOsm) with or without neutralizing IL6 antibody (50 ng/mL). The expression of IL6 level was measured in the supernatant of each conditioned medium. Cell viability/apoptosis assay was performed using Annexin V/Propidium Iodide (PI) and Cell Counting Kit-8 (CCK-8). Western blot was conducted to measure the abundance of apoptotic markers and IL6 related downstream signaling pathway. The concentration of IL6 showed time-dependent increase in cells treated with 500 mOsm. Although apoptosis of WKD cell is increased in treated 500 mOsm for 24 h, apoptosis reduced in WKD cell treated 500 mOsm with anti-IL6 for 24 h. Anti-IL6 inhibited the activation of JAK-STAT signaling pathway, which was induced by hyperosmolarity. Hyperosmolar condition induced apoptosis in conjunctival epithelial cells, along with increase of IL6 production. IL6 neutralizing antibody inhibited apoptosis and JAK-STAT signaling in hyperosmolar condition. These findings suggested that IL6 may be involved in apoptotic change and in hyperosmolarity.