PURPOSE: Alginate mixers available in the market do not have the automatic proportioning unit. In this study, an automatic proportioning unit for the alginate mixer and controller software were designed and produced for a new automatic proportioning unit. With this device, it was ensured that proportioning operation could arrange weight-based alginate impression materials. MATERIALS AND METHODS: The variation of coefficient in the tested groups was compared with the manual proportioning. Compression tension and tear tests were conducted to determine the mechanical properties of alginate impression materials. The experimental data were statistically analyzed using one way ANOVA and Tukey test at the 0.05 level of significance. RESULTS: No statistically significant differences in modulus of elastisity (P>0.3), tensional/compresional strength (P>0.3), resilience (P>0.2), strain in failure (P>0.4), and tear energy (P>0.7) of alginate impression materials were seen. However, a decrease in the standard deviation of tested groups was observed when the customized machine was used. To verify the efficiency of the system, powder and powder/water mixing were weighed and significant decrease was observed. CONCLUSION: It was possible to obtain more mechanically stable alginate impression materials by using the custom-made proportioning unit.
Tears

No abstract available.
Tears*

This study is to evaluate thickness of lipid layer, NIBUT (non-invasive tear film break-up time), BUT and Schirmer value according to tearscopic pattern of lipid layer.The subjects are seventy-one eyes from seventy-one people without ocular diseases.The pattern of lipid layer is observed by Tearscope(r) (Keeler, U.K.)and the thickness of lipid layer is measured by interference generated from slit lamp microscope.The thickness of lipid layer, NIBUT and BUT are respectively measured three times and averaged.In the case of the pattern of lipid layer, eighteen eyes have the close meshwork type, twenty-nine eyes have the wave type, fifteen eyes have the amorphous type and nine eyes have the color fringe type.The average value of the thickness of lipid layer, NIBUT, BUT and Schirmer test were respectively 29.3 nm, 25.9 seconds, 12.0 seconds, 18.6 mm for close meshwork;47.2 nm, 33.6 seconds, 12.5 seconds, 16.9 mm for wave;66.2 nm, 39.7 seconds, 14.9 seconds, 18.7 mm for amorphous;and 74.4 nm, 30.9 seconds, 13.9 seconds, 18.9 mm for color fringe.The thickness of lipid layer was different significantly among the patterns.NIBUT showed significant difference between close meshwork and wave, and between close meshwork and amorphous.The Cronbach alpha, reproducibility of the test, is 0.84 in the thickness of lipid layer, 0.64 in NIBUT, 0.76 in BUT and 0.94 in Schirmer test.The reproducibility of the pattern of lipid layer observed by Tearscope(r) is 95.8%.
Tears*

PURPOSE: To evaluate the repeatability and reproducibility of inferior tear meniscus measurements using two different spectral domain-optical coherence tomography (OCT), and to compare the inter-device agreements between these devices. METHODS: Two examiners evaluated the tear meniscus depth (TMD) and tear meniscus height (TMH) of 20 eyes in 20 normal subjects using Cirrus OCT and Spectralis OCT with the examiners calculating the TMD and TMH. We analyzed intra-examiner repeatability, inter-examiner reproducibility, and inter-device agreement. RESULTS: The average TMD measurements using the Cirrus OCT and Spectralis OCT devices were 151.25 ± 41.53 µm and 139.10 ± 40.56 µm by examiner 1, respectively, and 152.03 ± 42.77 µm and 138.35 ± 39.70 µm by examiner 2, respectively. The TMHs were 291.90 ± 100.19 µm and 245.43 ± 66.44 µm by examiner 1, respectively, and 288.25 ± 98.72 µm and 244.23 ± 60.69 µm by examiner 2, respectively. The TMDs and TMHs measured using these OCT devices were not statistically significant for intra-examiner and inter-examiner measurements (all, p > 0.05). These devices showed high repeatability (intraclass correlation coefficient ≥ 0.991) for intra-examiner TMD and TMH measurements and the inter-examiner coefficient of variation ranged from 2.04% to 4.32%. The 95% limits of agreement between the two devices were −66.13 to 91.95 µm for TMD and −127.18 to 217.68 µm for TMH. CONCLUSIONS: Both OCT devices are useful for conducting inferior tear meniscus measurements. The inter-device agreement was poor, and the devices were not interchangeable.
Tears

No abstract available.
Tears

PURPOSE: To identify the effects of artificial tear instillation on tear film changes using wavefront aberrations. METHODS: Artifical tear was instilled every 2 hours for 14 days into 20 normal eyes and 20 dry eyes. The changes in tear film using wavefront aberrations were analyzed 1 minute after the final instillation of artifical tear. RESULTS: In dry eyes, total wavefront aberration and total high order wavefront aberration decreased significantly (p<0.05). In normal eyes, total wavefront aberration and high order wavefront aberration did not decrease. CONCLUSIONS: Stabilization of the tear film after instillation of artificial tear may be responsible for the decrease of wavefront abberation in dry-eye patients.
Humans ; Tears*

The complaint of tearing may be due to 1) partial or complete obstruction of the excretory mechanism, 2) increased lacrimal secretion, or 3) decreased basic lacrimal secretion. So the physician should ascertain whether an excess of tears or obstruction of excretory mechanism is present. The most widely used tests for this purpose are the Schirmer test, Jones test and fluorescein dye disappearance test. The Jones test consist of Jones I test and Jones II test, which determine the functional and anatomical integrity of the lacrimal excretory system. In this study, Schirmer test, Jones test and fluorescein dye disappearance test were performed on 400 normal and 100 abnormal eyes to determine the secretion and excretion of tears.
Fluorescein ; Tears*

The tear production of 192 eyes was evaluated by shirmer I and 171 eyes were evaluated by shirmer II among 106 patients (male: 30). The results showed that the average value of total tear production in elderly was 8.7±6.6mm and average value of basic tear production was 6.1±4.3 mm. There was no difference of tear production was reduced with increased ages
Tears ; Aged

PURPOSE: In this study we evaluated the changes in tear film after primary pterygium operation in patients with pterygium. METHODS: We investigated 43 eyes of 42 subjects who showed successful results 3 months after pterygium operation performed by one surgeon. The changes in tear film thickness, tear break-up time (BUT), Schirmer I test, and ocular surface disease index (OSDI) were evaluated. All values were compared before and after surgery. RESULTS: The mean age was 58.0 +/- 11.1 years (34-81 years). Preoperative tear film thickness, tear BUT, and Schirmer I test in eyes which underwent pterygium operation were 21.53 +/- 5.93 microm, 4.84 +/- 2.21 seconds, and 11.67 +/- 6.75 mm, respectively. Three months after the operation, the respective values were 24.23 +/- 4.19 microm (p < 0.05), 5.81 +/- 1.89 seconds (p < 0.05), and 13.02 +/- 7.54 mm (p = 0.094). Tear film thickness and BUT score increased significantly after pterygium operation. There was no statistically significant difference in Schirmer I test, before and 3 months after pterygium operation. The subjective parameter (OSDI) improved 3 months after pterygium operation (p = 0.015). CONCLUSIONS: Pterygium operation can partially restore the tear film function into a normal state by improving tear film thickness and tear BUT after pterygium operation.
Humans ; Pterygium* ; Tears*

Several symptoms of dry eye in the patients who underwent cataract surgery are related to the stability of precorneal tear film layer. We studied the change of the lipid layer pattern in tear film after cataract surgery. Ninety-eight eyes of 87 patients were evaluated for the lipid layer patterns before operation and at two months after operation. Thirty-two eyes(32.7%) among 98 eyes had the change of the pattern of lipid layer. The change was more marked in the eyes of color fringe pattern preoperatively than others(p=0.000). The rate of change was not significantly different between the superior limbal incision group and temporal clear corneal incision group, and between the groups according to the number of sutures(p>0.05). The eyes which had had the dry eye symptoms developed more change of the lipid layer pattern(p=0.006). After cataract surgery, the change of the lipid layer pattern got more marked especially in the eyes which had had color fringe pattern before surgery. In the eyes which had had the dry eye symptoms, however, no difference was shown by the incisional site and by the number of sutures.
Cataract* ; Humans ; Sutures ; Tears*