Clinical Significance of Tear Film Osmolarity for Non-Sjögren Dry Eye Diagnosis

PURPOSE: To evaluate the diagnostic value of tear film osmolarity for non-Sjogren dry eye syndrome through measuring the correlation between tear osmolarity and several conventional dry eye parameters. METHODS: In this observational cross-sectional study, 274 patients (274 eyes) with non-Sjogren dry eye syndrome were examined using tear film osmolarity and the following conventional dry eye parameters: Schirmer's test, tear film break-up time, ocular surface disease index (OSDI), and corneal staining score. The correlations between tear film osmolarity and each conventional dry eye parameter were assessed using Spearman's correlation coefficients. RESULTS: The mean tear film osmolarity of the study population was 296.34 ± 21.08 mOsm/L. The tear film osmolarity was significantly negatively correlated with the Schirmer's test value (r = -0.431, p < 0.001) and tear break-up time (r = -0.131, p = 0.031), while it was significantly positively correlated with the OSDI scores (r = 0.191, p = 0.001) and corneal staining scores (r = 0.150, p = 0.013). CONCLUSIONS: Tear film instability was significantly correlated with other conventional dry eye parameters. However, additional studies are required to determine its feasibility as a stand-alone diagnostic tool.

Two Cases of Pre-descemet Corneal Dystrophy Associated with X-linked Ichthyosis: A Case Report by Genetic Analysis

PURPOSE: To report the first case of steroid sulfatase (STS) gene deletion, confirmed by multiplex ligation-dependent probe amplification (MLPA) analysis in identical twins with pre-Descemet corneal dystrophy associated with X-linked ichthyosis. CASE SUMMARY: 19-year old identical twin brothers with itching senses and hereditary thick scaly skin of the extremity and trunk visited our dermatologic clinic. Upon visiting, an ophthalmologic consultation with anterior segment examination showed diffuse punctate corneal opacities in the pre-Descemet layer. On MLPA analysis of the identical twin brothers, a definitive diagnosis of X-linked ichthyosis was made by identifying STS gene deletion. CONCLUSIONS: Identification of the deletion and mutation of the involved gene using gene analysis can provide insight to diagnosis and clinical characteristics of X-linked ichthyosis.