OBJECTIVES: The aim of this study was to evaluate the optical characteristics such as color and translucency changes before and after light curing, to quantify the CQ and to measure refractive indices of body and opaque shade of resin composites materials. MATERIALS AND METHODS: Resin composites used in this study were A2 body and A2 opaque shade of Esthet-X, Filtek supreme, Gradia Direct, Clearfil Majesty and Beautifil?? Color and translucency changes before and after light curing were evaluated by colorimeter, the CQ was quantified by GC-MS and refractive index changes were measured by spectroscopic ellipsometer. RESULTS: Translucency parameter (TP) was significantly increased after curing. The CQ content of body shades are higher than that of opaque shades in all resin composites. Refractive index increased after polymerization in all materials and significant difference in Deltarefractive index was found between body and opaque shade (significance level 0.05). CONCLUSIONS: For an accurate shade match, direct shade matching of resin composite should be performed by using the cured material.
Composite Resins ; Light ; Polymerization ; Polymers ; Refractometry

PURPOSE: To examine the relationship between the refractive astigmatism by automated refractometry and the corneal astigmatism by a dual Scheimpflug analyzer in pseudophakic eyes. METHODS: Prospectively, 75 patients (100 eyes) were enrolled in the present study. Refractive astigmatism was obtained by automated refraction. Corneal astigmatism was obtained using automated keratometry (ARK-530A®) and dual Scheimpflug scanning analysis (Galilei G4®). All refractive values were converted to the power vector components J0 and J45 for comparison and regression analysis of refractive versus corneal astigmatism. Bland-Altman plots were created to estimate the agreement between measurements. RESULTS: The average astigmatism from each measurement was -1.11 ± 1.44 D (refractive astigmatism from automated refraction), -0.77 ± 1.06 D (corneal astigmatism from automated keratometry), -0.93 ± 1.02 D (simulated K from Galilei G4®), and -1.11 ± 1.48 D (total corneal power from Galilei G4®). Refractive J0 and keratometric J0 were significantly correlated (r = 0.557, p ≤ 0.001), as well as the corresponding J45 values (r = 0.655, p = 0.025). Refractive astigmatism and total corneal power components were also significantly correlated (J0: r = 0.618, p ≤ 0.001; J45: r = 0.608, p = 0.04). In the Bland-Altman plots, keratometric J0 and total corneal power J0 showed the best agreement. CONCLUSIONS: The accuracy of measurements for corneal refraction and astigmatism in pseudophakic eyes is higher using the dual Scheimpflug analyzer, especially for total corneal power. This value of astigmatism can take into account the refractive astigmatism of pseudophakic eyes and can be used in evaluating postoperative corneal astigmatism.
Astigmatism ; Humans ; Prospective Studies ; Pseudophakia ; Refractometry*

The purpose of this study was to detect the relationship between the diopters and corneal curvature. The objects were 752 eyes of 376 people (male 116, female 260) who visited to the department of Ophthalmology, Kyung Hee university hospital during 15 months from Aug. 1, 1985. to Nov. 10, 1986. The range of their refractory power was from 0.00 to -9.00 diopter by retinoscopy. The following results were obtained; 1. The consistent difference in the mean values of horizontal curvaturs and those of vertical curvatures by each diopter were proved to be significant(p<0.005). 2. The difference in the horizontal curvatures between each diopters of the -1.25 ~ -2.00 diopter were stastically significant(p<0.005). 3. The differences in the vertical curvatures in the constant refractive index were not stastically significant. 4. Dividing the each diopter by 3 groups and examining the difference of significancies by each other, the differences in the horizontal curvature and vertical curvatures were statically significant(p<0.005).
Female ; Humans ; Korea* ; Ophthalmology ; Refractive Errors* ; Refractometry ; Retinoscopy

PURPOSE: To compare the accuracy of different power-calculation formulas in predicting the postoperative refraction of three-piece and one-piece intraocular lenses (IOL). METHODS: We retrospectively reviewed the medical records of 74 eyes (62 patients) that had undergone cataract surgery involving implantation of one of two IOLs―the SENSAR® AAB00 1-Piece Acrylic IOL (44 eyes), or the Hoya® VA60BB 3-Piece Acrylic IOL (30 eyes)―between October 2014 and March 2015. Axial length was measured using an optical low-coherence refractometry (Lenstar®), and biometry was then calculated by the pre-installed Lenstar program, which used the SRK/II, Sanders-Retzlaff-Kraff/Theoretical (SRK/T), and Hoffer Q formulas. Mean absolute error (MAE) and mean numeric error (MNE) were measured 1 day, 1 week, 1 month, and 2 months after surgery. RESULTS: Using the SRK/T and Hoffer Q formulas, the one-piece IOL group differed significantly from the three-piece IOL group in terms of the MNE obtained 1 month and 2 months after surgery. Across all formulas and time points, there were no significant differences between the groups in terms of MAE. CONCLUSIONS: There was no significant difference between the different power-calculation formulas. Starting 1 month after surgery, the three-piece IOL group showed myopic postoperative refraction compared to the predictive spherical equivalent using the SRK/T and Hoffer Q formulas.
Biometry ; Cataract ; Lenses, Intraocular* ; Medical Records ; Refractometry ; Retrospective Studies

PURPOSE: To compare high-order aberrations in the pseudophakia with different types of intraocular lenses (IOLs), as well as with normal phakic eyes. METHODS: This single-center prospective study comprised 80 cataract patients who underwent cataract surgery and 20 phakic eyes. Twenty eyes received an AF-1(R) VA-60BB; 20 eyes, a Corneal(R) ACR6D SE; 20 eyes, a Sensar(R) AR40e; and 20 eyes, a ClariFlex(R). One month after cataract surgery, the eye aberration was measured using a Hartmann-Shack type aberrometer. The same test was performed for 20 normal phakic eyes. The individual Zernike polynomials, the root mean square (RMS) values of the third and fourth order aberration, and the total RMS among the groups were compared. RESULTS: The individual Zernike coefficient (Z3(-1), Z3(3), Z4(-4), Z4(0), Z4(4)) showed a significant difference in the IOL-implanted groups compared with the normal phakic eyes. There were statistically significant differences in the RMS values of the third and fourth order aberration, and total among each group. CONCLUSIONS: There was a statistically significant increase in aberration in patients with high refractive index IOL and a statistically significant decrease in patients with silicone IOL, compared to the normal phakic eyes.
Cataract ; Humans ; Lenses, Intraocular* ; Prospective Studies ; Pseudophakia* ; Refractometry ; Silicones

This paper outlines kinds of index of eyes' optical effect and some different testing methods of intraocular lenses' optical quality.
Humans ; Lens Implantation, Intraocular ; Lenses, Intraocular ; Refractometry ; methods ; Sensitivity and Specificity ; Vision Tests ; methods

PURPOSE: In this study, three bioceramic materials, [IPS Empress CAD (Ivoclar), IPS e.max CAD (Ivoclar), and Lava Ultimate CAD (3M ESPE)] were treated with three commercial mouthrinses [Listerine, Tantum Verde, and Klorhex]; and changes in colour reflectance and surface roughness values were then quantitatively assessed. MATERIALS AND METHODS: One hundred and twenty ceramic samples, with dimensions of 2 × 12 × 14 mm, were prepared and divided into nine sample groups, except three control samples. The samples were immersed in the mouthrinse solutions for 120 hrs, and changes in colour reflectance and surface roughness values were measured by UV light spectrophotometry (Vita Easyshade; VITA Zahnfabrik) and by profilometer device (MitutoyoSurftest SJ-301), respectively. The change of surface roughness was inspected by Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM). RESULTS: There was a positive correlation between the ΔE and increase in the surface roughness. Two of the ceramic materials, IPS Empress and Lava Ultimate, were affected significantly by the treatment of the mouthrinse solutions (P<.05). The most affecting solution was Tantum Verde and the most affected material was Lava Ultimate. As expected, the most resistant material to ΔE and chemical corrosion was IPS e max CAD among the materials used. CONCLUSION: This work implied that mouthrinse with lower alcohol content had less deteriorating effect on colour and on the surface morphology of the bioceramic materials.
Benzydamine ; Ceramics ; Corrosion ; Microscopy, Atomic Force ; Microscopy, Electron, Scanning ; Refractometry ; Spectrophotometry ; Ultraviolet Rays

OBJECTIVES: This study examined the influence of the resin thickness on the polymerization of silorane- and methacrylate-based composites. MATERIALS AND METHODS: One silorane-based (Filtek P90, 3M ESPE) and two methacrylate-based (Filtek Z250 and Z350, 3M ESPE) composite resins were used. The number of photons were detected using a photodiode detector at the different thicknesses (thickness, 1, 2 and 3 mm) specimens. The microhardness of the top and bottom surfaces was measured (n = 15) using a Vickers hardness with 200 gf load and 15 sec dwell time conditions. The degree of conversion (DC) of the specimens was determined using Fourier transform infrared spectroscopy (FTIR). Scratched powder of each top and bottom surface of the specimen dissolved in ethanol for transmission FTIR spectroscopy. The refractive index was measured using a Abbe-type refractometer. To measure the polymerization shrinkage, a linometer was used. The results were analyzed using two-way ANOVA and Tukey's test at p < 0.05 level. RESULTS: The silorane-based resin composite showed the lowest filler content and light attenuation among the specimens. P90 showed the highest values in the DC and the lowest microhardness at all depth. In the polymerization shrinkage, P90 showed a significantly lower shrinkage than the rest two resin products (p < 0.05). P90 showed a significantly lower refractive index than the remaining two resin products (p < 0.05). CONCLUSIONS: DC, microhardness, polymerization rate and refractive index linearly decreased as specimen thickness linearly increased. P90 showed much less polymerization shrinkage compared to other specimens. P90, even though achieved the highest DC, showed the lowest microhardness and refractive index.
Composite Resins ; Ethanol ; Hardness ; Photons ; Polymerization* ; Polymers* ; Refractometry ; Spectroscopy, Fourier Transform Infrared ; Spectrum Analysis

An instrument for subjective measurement of tonic accommodation has been established based on the Badal system and Scheiner principle. The results of tonic accommodation between subjective measurement and objective measurement have no significant difference. Its establishment is important for the measurement of accommodation parameter in the myopia research center.
Accommodation, Ocular ; physiology ; Diagnostic Techniques, Ophthalmological ; instrumentation ; Humans ; Optometry ; instrumentation ; methods ; Refractometry ; instrumentation ; methods ; Visual Acuity

BACKGROUND: Baricity of the local anesthetics is a major determinant of the distribution of local anesthetics in CSF. The purpose of this study was to assess the value of refractometry in measuring the specific gravity of CSF, local anesthetics and adding solutions, and then comparing these to the density of CSF and local anesthetics. METHODS: CSF samples were obtained from 30 patients during spinal anesthesia. 0.5% hyperbaric tetracaines were diluted with CSF to create a 1:1 to 1:10 density and specific gravity measurements were made at room temperature, using a refractometer. 2% lidocaine was diluted with distilled water, normal saline, 5% and 10% dextrose water to create 2%, 1%, 0.67%, 0.5% and 0% mixtures measured respectively. RESULTS: Specific gravity of CSF was 1.0066 +/- 0.0006 and SG of 0.5% tetracaine was 1.0285 +/- 0.0028. The effect of specific gravity on the concentrations of tetracaine was determined by linear regression with r = 0.9803, y = 1.0060 + 0.0440 X x. Dilutions of 2% lidocaine with adding solutions were distilled water, y = 1.0008 + 0.0078 X x ; normal saline, y = 1.0056 + 0.0053 X x ; 5% dextrose, y = 1.0208 - 0.0022 X x ; and 10% dextrose, y = 1.0436 - 0.0135 X x. CONCLUSIONS: The relationship between concentration and specific gravity of local anesthetics is linear. We conclude that refractometry is a reliable method to predict density of local anesthetics.
Anesthesia, Spinal ; Anesthetics, Local* ; Glucose ; Humans ; Lidocaine ; Linear Models ; Refractometry* ; Specific Gravity ; Tetracaine ; Water