PURPOSE: The purpose of this study was to derive and compare the inherent color (hue angle, chroma), translucency (TP(SCI)), surface gloss (ΔE* SCE-SCI), and surface roughness (Ra) amongst selected shades and brands of three hybrid CAD/CAM blocks [GC Cerasmart (CS); Lava Ultimate (LU); Vita Enamic (VE)]. MATERIALS AND METHODS: The specimens (N = 225) were prepared into square-shaped (12 × 12 mm2) with different thicknesses and shades. The measurements of color, translucency, and surface gloss were performed by a reflection spectrophotometer. The surface roughness and surface topography were assessed by white light interferometry. RESULTS: Results revealed that hue and chroma values were influenced by the material type, material shade, and material thickness (P < .001). The order of hue angle amongst the materials was LU > CS > VE, whereas the order of chroma was VE > CS > LU. TP(SCI) results demonstrated a significant difference in terms of material types and material thicknesses (P ≤ .001). TP(SCI) values of the tested materials were ordered as LU > CS > VE. ΔE* SCE-SCI and Ra results were significantly varied amongst the materials (P < .001) and amongst the shades (P < .05). The order of ΔE* SCE-SCI amongst the materials were as follows LU > VE ≥ CS, whereas the order of Ra was CS ≥ VE > LU. CONCLUSION: Nano-ceramic and polymer-infiltrated-feldspathic ceramic-network CAD/CAM materials exhibited different optical, inherent color and surface parameters.
Interferometry

PURPOSE: To compare and evaluate device efficacy using white-to-white (WTW) diameter measurements by IOLMaster(R), Lenstar(R), Orbscan II(R), and a manual method with anterior segment photographs in normal eyes. METHODS: Three sets of WTW diameter measurements were obtained from 62 normal eyes of 31 patients, using the Orbscan II(R), Lenstar(R), IOLMaster(R), and a manual method with anterior segment photographs. Repeatability of each device was evaluated by coefficient of variation. ANOVA and Pearson's correlation were used to compare the differences among the devices. Bland Altman plot was performed to assess measurement agreement among the devices. RESULTS: The mean WTW distance was 11.79 +/- 0.46 mm with Orbscan II(R), 12.05 +/- 0.38 mm with Lenstar(R), 12.15 +/- 0.36 mm with IOLMaster(R), and 12.30 +/- 0.40 mm with a manual method. There were significant differences in the results among the methods (ANOVA, p < 0.05). There were significant correlations between the devices except Orbscan II(R) (Pearson's correlation, r > 0.8, p < 0.05). The coefficient of variation of Orbscan II(R) was larger than those of Lenstar(R) and IOLMaster(R). CONCLUSIONS: The WTW measurement using Orbscan II(R) has low correlations with other devices and lower repeatability. Our findings suggest that partial coherence interferometry should be considered as a new standard.
Biometry ; Eye ; Humans ; Interferometry

PURPOSE: IOLMaster(R), a non-contact device using partial coherence interferometry, serves as a new optical method for axial length determination. The accuracy of this device was analyzed by comparing the measurements from IOLMaster(R) and A-scan. METHODS: We measured the axial lengths in 150 eyes of 80 patients with IOLMaster(R) and A-scan. Then, we examined the difference of measurements between the IOLMaster(R) and A-scan according to the patients' age, refractive error, type of cataract, and existence of cataract. RESULTS: Axial length could not be measured with IOLMaster(R) in 12 eyes, which all had severe cataract. The measurements from IOLMaster(R) in both, the cataract group and the normal group, resulted 0.02mm longer than those from A-scan, but did not differ significantly (p>0.1). Also, there was no statistical difference of measurements between IOLMaster(R) and A-scan according to the patients' age, refractive error, and types of cataract (p>0.05). CONCLUSIONS: Axial length measurement with IOLMaster(R) shows no significant difference from A-scan measurement. Therefore, IOLMaster(R) can be a new clinical method of axial length measurement except for cases of a severe cataract.
Cataract ; Humans ; Interferometry ; Refractive Errors

PURPOSE: To compare axial length, anterior chamber depth, and keratometric measurements of an optical low-coherence reflectometry device with those of other ocular biometry devices and evaluate the accuracy of predicting postoperative refraction. METHODS: A total of 32 eyes in 32 patients who received cataract surgery were included in the present study. The axial length, anterior chamber depth, and keratometry were measured by optical low-coherence reflectometry (Lenstar LS900(R)), partial coherence interferometry (IOL master(R)), and ultrasound. The SRK/T formula was used to calculate IOL power, and predictive error that subtracts predictive refraction from postoperative refraction was compared among ocular biometry devices. RESULTS: Axial length, anterior chamber depth, and keratometry had a strong correlation and demonstrated no statistically significant differences between Lenstar LS900(R) and other devices. The Bland-Altman plots showed a high degree of agreement between Lenstar LS900(R) and other devices. The mean absolute prediction errors in Lenstar LS900(R) and IOL master(R) were not significantly different. CONCLUSIONS: The ocular biometric measurements and prediction of postoperative refraction using Lenstar LS900(R) were as accurate as IOL master(R) and ultrasound.
Anterior Chamber ; Biometry ; Cataract ; Eye ; Humans ; Interferometry

PURPOSE: To evaluate differences between partial coherence laser interferometry (IOL-Master, Zeiss) and A-scan measurement of axial length and anterior chamber depth in silicone oil-filled eyes according to viscosity. METHODS: Using IOL-Master and A-scan, axial length and anterior chamber depth in silicone oil-filled eyes (n=54) and normal eyes (control, n=54) were measured and analyzed. In silicone oil-filled eyes, calculated axial lengths by A-scan using conversion factors, axial length multiplied by 0.71, and vitreous cavity multiplied by 0.64 (classic method) were compared with those calculated by IOL-Master. Anterior chamber depths were also analyzed., and axial lengths and anterior chamber depths were compared according to the viscosities of silicone oil for measurement by A-scan. RESULTS: Axial length and anterior chamber depth using IOL-Master were shorter than those using A-scan by 9.45+/-1.81 mm (p<0.05) and 0.11+/-1.29 mm, respectively. In normal eyes, axial length and anterior chamber depth using IOL-Master and A-scan were not significantly different. In silicone oil-filled eyes, axial length using IOL-Master and conversion factor was also not significantly different. At the highest silicone oil viscosity the difference in measured axial length was greatest (p<0.05) while the difference in anterior chamber depths was smallest. CONCLUSIONS: In silicone oil-filled eyes, axial length by IOL-Master was more accurate than that by A-scan, regardless of silicone oil viscosity. Thus, IOL-Master is more useful than A-scan when measuring axial length in silicone oil-filled eyes.
Anterior Chamber ; Eye ; Interferometry ; Silicone Oils ; Viscosity

PURPOSE: To evaluate device efficacy using the corneal curvature value. METHODS: Prospectively, 35 patients (70 eyes) were enrolled in the present study. Three sets of corneal curvature values were obtained using the autorefractor (RK-F1(R)), manual keratometer (OM-2(R)), partial coherence interferometry keratometer (IOL Master(R)), wavefront analyzer (KR-1W(R)), and videokeratography (Orbscan II(R)). Repeatability of each device was evaluated by coefficient of variation, standard deviation, and intraclass correlation coefficient. RM-ANOVA on ranks was used to compare the differences in corneal curvatures among the devices. The Bland-Altman plot was performed to assess measurement agreement among the devices. RESULTS: The coefficient of variation values from each device ranged from 2.92% (IOL master(R)) to 3.06% (Orbscan II(R)), and the values of intraclass correlation coefficient ranged from 0.965 (KR-1W(R)) to 0.997 (IOL master(R)). Compared with the manual keratometer, there was a maximum corneal curvature difference of 1.23 D in KR-1W(R), while the other devices had differences less than 0.82 D. CONCLUSIONS: When assessing corneal curvature, the repeatability values were similar among the 5 devices, although a difference greater than 1 D was observed when comparing the KR-1W(R) to the manual keratometer.
Corneal Topography ; Humans ; Interferometry ; Prospective Studies

PURPOSE: To evaluate the accuracy and the influencing factors of partial coherence interferometry in intraocular lens (IOL) power calculation for cataract surgery. METHODS: In 86 eyes of 69 patients who had undergone cataract surgery, we measured axial length using both IOLMaster and contact type ultrasonography, calculated the target refraction with SRK II formula and compared the result with the measured value after operation. We also evaluated the factors influencing the accuracy of the power calculation such as age, sex, type of cataract, severity of nucleosclerosis, corneal power, and preoperative refraction. RESULTS: In IOLMaster and contact type ultrasonography, the mean axial lengths were 23.70 +/- 1.27 mm and 23.55 +/- 1.28 mm (p<0.01), and the mean absolute errors (MAE) of refraction were 0.53 +/- 0.26D and 0.66 +/- 0.39D (p<0.01) respectively. The eyes of longer axial length showed larger MAE than those of shorter axial length (p=0.02). CONCLUSIONS: Partial coherence interferometry was more accurate than contact type ultrasonography in IOL power calculation. The factor associated with the accuracy of partial coherence interferometry was the axial length.
Cataract ; Humans ; Interferometry* ; Lenses, Intraocular* ; Ultrasonography

PURPOSE: To compare the axial lengths, anterior chamber depths, and keratometric measurements and to predict postoperative refractions of Dual Scheimpflug analyzer Galilei G6(R) and intra ocular lens (IOL) Master(R). METHODS: A total of 50 eyes in 50 patients who received cataract surgery were included in the present study. The axial length, anterior chamber depth, and keratometry were measured using 2 types of partial coherence interferometries (Galilei G6(R) and IOL Master(R)). The SRK/T formula was used to calculate IOL power and the predictive error which subtracts predictive refraction from postoperative refraction was compared between the ocular biometry devices. RESULTS: Axial lengths were 23.36 +/- 0.80 mm and 23.36 +/- 0.90 mm measured by Galilei G6(R) and IOL Master(R), respectively. Axial length measured by Galilei G6(R) was not statistically significant compared with IOL Master(R) (p = 0.321). The anterior chamber depth and keratometry were 3.22 +/- 0.35 mm and 44.29 +/- 1.40 D measured by Galilei G6(R) and 3.11 +/- 0.46 mm and 44.39 +/- 1.41 D measured by IOL Master(R), respectively. The differences of anterior chamber depth and keratometry between the 2 devices were statistically significant (p < 0.001 and p = 0.028, respectively). The mean absolute prediction errors were 0.45 +/- 0.37 D and 0.49 +/- 0.39 D in Galilei G6(R) and IOL Master(R), respectively and was not statistically significantly different (p = 0.423). CONCLUSIONS: The ocular biometric measurements and prediction of postoperative refraction using Galilei G6(R) were as accurate as with IOL Master(R).
Anterior Chamber ; Biometry* ; Cataract* ; Humans ; Interferometry

PURPOSE: To investigate the accuracy of intraocular lens power calculations using simulated keratometry (simK) of dual Scheimpflug analyzer and 5 types of formulas in cataract patients. METHODS: The keratometry (K), axial length (AXL) and anterior chamber depth (ACD) were measured using ultrasound biometry (USB) combined with auto-keratometry (Auto-K), parital coherence interferometry (PCI; IOL master®) and dual Scheimpflug analyzer (DSA; Galilei®) in 39 eyes of 39 patients. Predicted refraction was calculated using Auto-K, mean K of PCI, and simK and total corneal power (TCP) of DSA in the Sanders-Retzlaff-Kraff (SRK-T) formula. The SRK-II, SRK-T, Holladay II, Haigis, and Hoffer-Q formula were used to calculate predicted refraction with the simK of DSA and AXL of USB. Manifest refraction, mean numerical error (MNE) and mean absolute error were evaluated 1, 3 and 6 months after cataract surgery. RESULTS: TCP of DSA was lower compared with other keratometric values (p < 0.05). The MNE was not different among Auto-K, mean K and simK. The MNE using TCP was larger compared with Auto-K, mean K and simK at 1 month after surgery (p < 0.05). There was a difference in MNE between simK and TCP of DSA at 6 months after surgery (p < 0.05). The MNE of SRK-T formula was the smallest in the intraocular lens (IOL) power calculation using the simK of DSA. CONCLUSIONS: We suggest using IOL power calculations with simK of DSA and SRK-T formula rather than TCP of DSA in cataract patients with normal corneas.
Anterior Chamber ; Biometry ; Cataract ; Cornea ; Humans ; Interferometry ; Lenses, Intraocular* ; Ultrasonography

PURPOSE: To investigate the accuracy of biometry and intraocular lens (IOL) power calculation using partial coherence interferometry (IOL Master(R)) in highly myopic patients with axial lengths of 26 mm or greater. METHODS: Patients with axial lengths equal to or greater than 26 mm who had undergone cataract surgery were enrolled. IOL power was calculated using IOL Master and/or applanation ultrasonography with the SRK/T formula. Twenty-seven eyes using both IOL Master and applanation ultrasonography were included in a paired group, and forty-eight eyes using the IOL Master only and twenty-five eyes using applanation ultrasonography only were included in unpaired groups. The differences between the predicted refraction and the actual refraction were compared and analyzed. RESULTS: In the paired study, the axial lengths in patients using IOL Master (29.14+/-2.32 mm) were significantly longer than those of patients using applanation ultrasonography (28.57+/-2.23 mm) (p<0.05). The mean absolute error (MAE) of the IOL Master and applanation ultrasonography groups were 0.62+/-0.58D and 0.87+/-0.49D, respectively (p>0.05). In the unpaired study, the MAEs of the IOL Master and applanation ultrasonography groups were 0.61+/-0.61D and 0.65+/-0.63D, respectively. CONCLUSIONS: In eyes with axial lengths of 26.0 mm or greater, the accuracy of IOL power calculation with IOL Master using the SRK/T formula was comparable to that with applanation ultrasonography.
Biometry ; Cataract ; Eye ; Humans ; Interferometry ; Lenses, Intraocular ; Myopia