Efficacy of Strip Meniscometry for Dry Eye Syndrome Diagnosis

PURPOSE: To evaluate the efficacy of strip meniscometry test for dye eye syndrome (DES) by measuring the correlation between strip meniscometry and conventional test measurements. METHODS: All subjects were examined using the Schirmer test, tear breakup time (TBUT) and strip meniscometry using SMTube (Echo Electricity Co., Ltd., Fukushima, Japan). Tear meniscus height (TMH), tear meniscus depth (TMD) and tear meniscus area (TMA) were measured using Fourier-domain optical coherence tomography. The DES group (n = 46 eyes) was compared with the normal group (n = 30 eyes) and correlation was assessed using Spearman's correlation coefficient. RESULTS: Strip meniscometry measurement was significantly correlated with Schirmer score (r = 0.6080, p < 0.01), TBUT (r = 0.5980, p < 0.01), TMH (r = 0.6210, p < 0.01), TMD (r = 0.6080, p < 0.01) and TMA (r = 0.6370, p < 0.01). Strip meniscometry was significantly lower in the DES group (4.58 ± 1.94 mm) than the normal group (7.07 ± 2.61 mm, p < 0.05). CONCLUSIONS: Strip meniscometry was significantly correlated with other conventional test measurements for dry eye syndrome. Strip meniscometry is less time consuming and a less invasive method than the Schirmer test. Strip meniscometry could be an efficient tool to evaluate patients with dry eye syndrome in a clinical setting.

Evaluation of Changes in Tear Film Lipid Layer Thickness Using Ocular Surface Interferometer after Artificial Tear Application

PURPOSE: The changes in tear film lipid layer thickness (LLT) after artificial tears application using LipiView®II interferometer were assessed. METHODS: We performed a prospective study of patients with dry eye disease. All subjects underwent measurement of tear film break-up time, Schirmer test, ocular surface staining, meibomian gland evaluation, and subjective score assessment using the Ocular Surface Disease Index. All subjects were randomly assigned to 1 of 3 groups using table of random numbers (group 1, sodium hyaluronate [HA] 0.1% eye drops without preservatives; group 2, HA 0.3% eye drops without preservatives and group 3, HA 0.1% with benzalkonium chloride 0.003%). LLT was measured before, immediately after and 1 hr, 3 hrs, and 6 hrs after artificial tears application. Additionally, the patients were divided into 2 subgroups depending on the presence of meibomian gland dysfunction (MGD) and further evaluated. RESULTS: Significant change in LLT was observed at 3 hrs after artificial tears instillation. LLT in groups 1 and 2 showed significant changes over time (p < 0.01 and p < 0.01, respectively). However, LLT in group 3 showed no change. LLT was unchanged in patients without MGD. Conversely, in MGD patients, a significant difference in LLT between groups 1 and 2 was observed immediately after and 1 hr and 3 hrs after instillation of artificial tears (p = 0.04, p < 0.01 and p = 0.02, respectively) but not at 6 hrs. However, no significant difference in LLT between groups 1 and 3 was observed in MGD patients. CONCLUSIONS: LLT after instillation of artificial tears measured using LipiView®II interferometer was affected by artificial tear concentration and presence of preservatives. Additionally, the presence of MGD can impact the pattern of LLT changes induced by artificial tear instillation. Therefore, LLT measurements using LipiView®II interferometer require at least a 6-hrs interval after use of eye drops, especially for patients with MGD or using artificial tears with preservatives.

Comparison of Surface Roughness and Bacterial Adhesion between Cosmetic Contact Lenses and Conventional Contact Lenses

PURPOSE: To determine the surface roughness of cosmetic and conventional contact lenses (CLs) and their susceptibility to bacterial adhesion. METHODS: Concave surface roughness of cosmetic and conventional hydrogel (Etafilcon A) CLs was measured by atomic force microscopy (AFM) and scanning electron microscopy (SEM). In particular, the surface of the color tinted area of cosmetic CLs was measured. CLs were immersed into a bacterial solution of Pseudomonas aeruginosa for 1, 12, or 24 hours and culture of P. aeruginosa that had adhered to the CLs was performed. RESULTS: Concave surface roughness of cosmetic CLs significantly increased compared with conventional CLs by AFM (p 0.9, p < 0.05). By SEM, P. aeruginosa had adhered to the color-tinted area more than to the non-color-tinted area of cosmetic CLs. CONCLUSIONS: Surface of cosmetic CLs was significantly rougher and initial adhesion of bacteria was higher to cosmetic CLs than to conventional CLs. In particular, an increased number of bacteria was found to be adhered to the color-tinted area of cosmetic CLs. Initial bacterial adhesion is important because it is the first stage of bacterial attachment process to any surface. After then, the adherent bacteria can progress to form a biofilm. Increased surface roughness of CLs contributes to opportunities for the CL to come into contact with bacteria, and thus, initial bacterial adhesion increases. In this study, it is clear that cosmetic CLs are more vulnerable to bacterial adhesion. To avoid serious complications, such as bacterial keratitis, the manufacturing process for smoothing and treating the surface in order to inhibit bacterial adhesion should be developed in the future.

Comparison of Surface Roughness and Bacterial Adhesion between Cosmetic Contact Lenses and Conventional Contact Lenses

PURPOSE: To determine the surface roughness of cosmetic and conventional contact lenses (CLs) and their susceptibility to bacterial adhesion. METHODS: Concave surface roughness of cosmetic and conventional hydrogel (Etafilcon A) CLs was measured by atomic force microscopy (AFM) and scanning electron microscopy (SEM). In particular, the surface of the color tinted area of cosmetic CLs was measured. CLs were immersed into a bacterial solution of Pseudomonas aeruginosa for 1, 12, or 24 hours and culture of P. aeruginosa that had adhered to the CLs was performed. RESULTS: Concave surface roughness of cosmetic CLs significantly increased compared with conventional CLs by AFM (p 0.9, p < 0.05). By SEM, P. aeruginosa had adhered to the color-tinted area more than to the non-color-tinted area of cosmetic CLs. CONCLUSIONS: Surface of cosmetic CLs was significantly rougher and initial adhesion of bacteria was higher to cosmetic CLs than to conventional CLs. In particular, an increased number of bacteria was found to be adhered to the color-tinted area of cosmetic CLs. Initial bacterial adhesion is important because it is the first stage of bacterial attachment process to any surface. After then, the adherent bacteria can progress to form a biofilm. Increased surface roughness of CLs contributes to opportunities for the CL to come into contact with bacteria, and thus, initial bacterial adhesion increases. In this study, it is clear that cosmetic CLs are more vulnerable to bacterial adhesion. To avoid serious complications, such as bacterial keratitis, the manufacturing process for smoothing and treating the surface in order to inhibit bacterial adhesion should be developed in the future.