ABSTRACT
Taking visual acuity is an important part of an eye routine examination. This study was conducted to compare visual acuity measured using an Iranian digital tumbling E chart with visual acuity measured using an Italian digital tumbling E chart as a familiar foreign chart. This study was carried out on 200 participants [400 eyes; healthy n=40, glaucoma n=40, retinal disorders n=40, post lasik n=40, corneal n=40] with mean age 44.28 years. Visual acuity of both eyes in half of the subjects [n=100, n=20 from each group] was first measured using the Italian digital chart and then measured using Iranian digital chart. Visual acuity of the rest of subjects [n=100, n=200 from each group] was first measured using the Iranian digital chart and then measured using the Italian digital chart. Measured visual acuities were recorded in logMAR notation. Mean of the Iranian and Italian Tumbling E chart is 0.280 +/- 0.012 and 0.277 +/- 0.012, respectively. Paired t-test used to evaluate the mean difference between two groups [p=0.721] indicated that there was no statistically significant difference between means of the two tests. Spearman correlation coefficient for the results of both tests was 0.942 [p<0.001], which was statistically significant and could be categorized as a strong positive correlation. The two digital Tumbling E charts acted similarly at different levels of acuity in different disorders. However, the Iranian chart requires a more accurate design for optotypes of the lower acuity lines in order to obtain more accurate measurement of visual acuities in healthy subjects
Subject(s)
Humans , Female , Male , EyeABSTRACT
Background: Artificial tears have been among the first line of therapy in management of Dry Eye Syndrome [DES]. This study was conducted to compare a local artificial tear with an imported one in reduction of DES. This comparison would help to evaluate the cost and benefits of each drop in the proper management of DES.
Materials and Methods: In this double-blind randomized clinical trial study, a total 65 students meeting our inclusion criteria for DES entered the study. The OSDI questionnaire, TBUT, corneal and conjunctival staining and Schirmer test, were performed. The patients were divided into two groups by block randomization. Group 1 received first drop and group 2 received second drop. Both groups were instructed to use the drops 4 times a day for 14 days. The same tests were performed by the same examiner who was blind to the treatment type after two weeks. Repeated measured ANOVA was used to analyze the data.
Results: A total of 58 patients completed the study. In both groups, after the intervention, the OSDI scores [P<0.001], TBUT score [P=0.041], corneal [P<0.001] and conjunctival staining scores [P<0.001] showed improvement in compare to those before the intervention. However, the Schirmer test score did not show significantly difference before and after intervention. In comparing two groups the OSDI scores, the TBUT score, the corneal and conjunctival staining scores and the Schirmer scores did not show statistically significant difference.
Conclusion: The two artificial tears equally reduced the symptoms and signs of DES in two weeks.
ABSTRACT
Objective: Selection of an appropriate shade of composite is critical in achieving an esthetic restoration. Different systems are used to assess and describe color parameters. This study aimed to assess the effect of color and thickness of Filtek Supreme [FS] and Premise [P] composite resins on correction of tooth discoloration
Methods: In this in vitro experimental study, 10 anterior teeth with Vita A2 color shade were selected. Composite specimens were fabricated in 0.5 and 0.75 mm thicknesses of FS and P composites. Intact teeth, prepared teeth, prepared teeth with enamel and dentin composite discs on their buccal surfaces, stained teeth and stained teeth with composite discs were photographed using a digital camera under standard conditions and color change [[Delta]E] at different phases was calculated
Results: The L[asteristk], a[asteristk] and b[asteristk] color parameters in prepared and unstained teeth were not significantly different from those of intact teeth. In stained teeth, the L[asteristk] parameter only in prepared and stained teeth with 0.75mm P composite was not significantly different from the L[asteristk] parameter in intact teeth. Significant differences were seen in other stained teeth. The a[asteristk] and b[asteristk] parameters only in prepared and stained teeth with 0.5 mm FS composite were significantly different from those in intact teeth. By increasing the thickness of composite, the color change in comparison with intact teeth decreased in both groups
Conclusion: The results showed that the effect of type of composite, its thickness and their interaction on the color change was significant when using FS and P composites in 0.5 and 0.75mm thicknesses in comparison to intact teeth and the lowest color difference with intact teeth was achieved using 0.75mm thickness of P composite [enamel and dentin]
ABSTRACT
Objective: Evidence shows that the powder/liquid mixing ratio recommended by the manufacturers is often not respected when mixing the glass ionomer [GI] powder and liquid, yielding a GI cement with disproportionate powder/liquid ratio. Considering the confirmed effect of powder/liquid ratio on the GI properties, and more importantly, its fluoride release potential, this study aimed to assess the effect of powder/liquid ratio on fluoride release of GI cements
Methods: Fuji II, Fuji II LC Improved and Fuji IX GI cements were used in this experimental study. Of each material, three groups with powder 20% less than recommended, the exact recommended ratio and powder 20% more than recommended, were prepared. To assess the fluoride release potential, 45 disc-shaped specimens measuring 2×4mm were prepared [5 per each group]. After fabrication, the specimens were immersed in 5 mL of distilled water. The amount of fluoride released into distilled water was measured at days 1 to 7, and also at 13, 14, 15, 28, 29, 30, 58, 59, 60, 88, 89, and 90 days, using Ion Selective Electrode [ISE]. After each time of measurement, distilled water was replaced. Data were analyzed using repeated measures ANOVA. Tukey's post hoc test was used for pairwise comparison of groups and powder/liquid mixing ratio. For pairwise comparison of time points, the Bonferroni adjustment was applied [p<0.05]
Results: Based on the results, although the amount of fluoride released from Fuji IX was higher than Fuji II, this difference was not statistically significant [p=0.589]. The lowest fluoride release was seen in Fuji II LC and this difference was statistically significant [p<0.05]. Change by 20% in the powder/liquid mixing ratio in the three GI cements had no significant effect on fluoride release [p=0.650, p=0.103, p=0.082]
Conclusion: Fluoride release from GI was time-dependent and the amount of released fluoride decreased over time. Fuji II LC resin-modified GI [RMGI] released less fluoride than Fuji II and Fuji IX. Also, 20% change in powder/liquid mixing ratio had no significant effect on fluoride release in different groups
ABSTRACT
Dry eye is the major contributor to computer vision syndrome. The reductions in the blink rate and amplitude have been considered as the possible mechanisms leading to this condition. The purpose of this study is to evaluate the changes in the lower tear meniscus heights and areas in the computer reading task, in dry eye subjects, with and without soft contact lenses. In this quasi-experimental study, 39 subjects [with mean age of 21.2 +/- 2.4 years], with dry eye, were enrolled. The lower tear meniscus height and area [TMH, TMA] of the right eye was captured by Spectral Optical Coherence Tomography before and after 45 minutes of reading task behind desktop 17" Cathode Ray Tube monitors. The same procedure was performed after the insertion of the hydrogel soft contact lenses with 58% water content. The results of TMHs, TMAs were analyzed with a repeated measures analysis of variance [ANOVA] with two within-subject factors.: The mean +/- standard error of TMH and TMA pre and post computer tasks were 283.6+/- 25.4 micro m, 0.029+/-0.005 mm2, 297.6+/-20.7 micro m , 0.036 +/- 0.005 mm2 respectively. After contact lens insertion, the mean TMH and TMA pre and post computer task were 231.6 +/- 10.6 micro m, 0.020+/-0.0019 mm2, 213.0+/-9.0 micro m, 0.018 +/- 0.0011 mm2, respectively. Repeated measures analysis of variance showed that the changes in TMH [P=0.86] and TMA [P=0.37] after computer task, were not statistically significant, while the insertion of the soft contact lens had reduced the TMH and TMA significantly [P<0.001 for both]. After 45 minutes of reading task behind desktop monitors, the tear volume has not changed, with and without high water SCLs. A reduction in tear volume might be expected with longer duration of computer task or at late hours of the day. The creation of a more stable tear film should be considered in the management strategies for shorter duration of work behind desktop monitors