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*

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

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 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

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: 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

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

PURPOSE: The study was conducted to determine if there is a corneal astigmatic changes after upper eyelid surgery by using corneal topography and if these changes are the reason why some patients note a decrease in visual acuity. METHODS: Twenty four eyes of 12 patients with dermatochalasis who had undergone upper eyelid blepharoplasty, and 24 eyes of 12 patients who had undergone aesthetic double fold formation were included. We performed corneal topography during the postoperative 3 months and also evaluated the corneal refractive index change on thirteen points of the central cornea, which were located in the center of the corneal apex and apart from it by 1.5, 2.5, 3.5 mm along each axis corresponding to the 0 degrees, 90 degrees, 180 degrees, 270 degrees respectively. RESULTS: Corneal topography demonstrated increase in with-the-rule astigmatism by 38, 33, and 12% for dermatochalasis patients at 1week, 1month, and 3months after surgery, and by 25%, 17%, and 13% for double fold patients. However the increase in with-the-rule astigmatism seemed to be temporary, showing gradual regression. The refractive index change of thirteen points of central cornea was not significant except a few eyes with astigmatic changes greater than 1D until 1 month after surgery. There was alsoincreased astigmatism after surgery in vector-corrected analysis. CONCLUSIONS: There was a tendency of increase in with-the-rule astigmatism and those changes were temporary and regressed gradually. No patient showed significant refractive index change on the 13 points of central cornea but some showed changes greater than 1 D in the early postoperative period, causing visually significant astigmatic changes temporarily.
Astigmatism ; Axis, Cervical Vertebra ; Blepharoplasty ; Cornea ; Corneal Topography* ; Eyelids* ; Humans ; Postoperative Period ; Refractometry ; Visual Acuity

PURPOSE: This study was designed to evaluate the postoperative changes of astigmatism and corneal refractive power after surgical correction of epiblepharon using computerized topography. METHODS: The surgical data were investigated retrospectively before surgery and 1 month, 3 month after surgery in 23 patients who had undergone surgery for epiblepharon. We evaluated 8 points of the corneal refractive index, the corneal center and nasal, temporal, inferior 1.0 and 2.0 mm and superior 1.0 mm respectively. And the incidences and types of astigmatism were evaluated before and after surgery. RESULTS: After surgery, we observed corneal flattening at all points according to corneal topography, but corneal refractive changes were statistically insignificant except for inferior 1.0mm point (P< 0.05). Mean astigmatism was decreased after surgery and statistically significant 3 month after surgery (P< 0.05). Mean corneal refractive change on vetical meridian was prominent compared to horizontal meridia and statistically significant 3 month after surgery (P< 0.05). CONCLUSIONS: In epiblepharon, children corneal topographic changes were observed due to reduction of corneal irritation and pressure by cilia and lower eyelid after surgery. Astigmatic changes were progressed 3 month after surgery and with-the-rule astigmatism was observed mainly before and after surgery. But corneal refractive changes were prominent on vertical meridian, and therefore there was a tendency toward improvement of with-the-rule astigmatism.
Astigmatism ; Child* ; Cilia ; Corneal Topography ; Eyelids ; Humans ; Incidence ; Refractometry ; Retrospective Studies

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