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It is difficult to assess the pure impact of the type of residual astigmatism (with-the-rule; WTR, against-the-rule; ATR, and oblique astigmatism) on uncorrected distance visual acuity (UDVA) in pseudophakic eyes due to different age distribution of patients between those subgroups. We conducted the current study to investigate the association between astigmatism type and UDVA in eyes after cataract surgery with consideration for various confounding factors such as age. Data were retrospectively collected from 1535 pseudophakic eyes with corrected distance visual acuity (CDVA) of 20/20 or better, and spherical equivalent between − 0.125 D and 0.0 D. They were classified based on the pattern of residual refractive astigmatism into four groups; minimum astigmatism (< 0.5 D), WTR, ATR, and oblique astigmatism groups. The stepwise multivariate regression analysis showed that the magnitude of residual refractive astigmatism (standardized partial regression coefficient β = 0.559, p < 0.001), CDVA (β = 0.381, p < 0.001), minimum astigmatism group (β = − 0.188, p < 0.001), and WTR astigmatism group (β = − 0.058, p < 0.001) were significantly associated with UDVA (r2 = 0.795). Variables excluded from the multivariate regression model include age, preoperative corneal astigmatism, axial length, anterior chamber depth, intraocular lens power, and postoperative spherical equivalent. These results indicate that UDVA is significantly better in eyes with minimum and WTR astigmatism than in those with ATR and oblique astigmatism, after adjustment for confounding parameters. In pseudophakic eyes, oblique and ATR astigmatism exerts a greater impact on UDVA than WTR astigmatism does, even after controlling for age. [ABSTRACT FROM AUTHOR]

A chemoselective demethylation method for various methoxypyridine derivatives has been developed. Treatment of 4-methoxypyridine with L -selectride in THF for 2 h at reflux temperature afforded 4-hydroxypyridine in good yield; no reaction to anisole occurred. The utility of our method was demonstrated by the efficient synthesis of the metabolic substances of the antiulcer agent omeprazole. Chemoselective demethylation at the site of 3,5-dimethyl-4-methoxypyridine in the presence of 4-methoxybenzimidazole was achieved. [ABSTRACT FROM AUTHOR]

Purpose: To determine the effects of astigmatism on contrast sensitivity (CS). Methods: Eighteen normal volunteers (30.5 ± 6.0 [mean ± SD] years) were recruited. After correcting each refractive error by spectacles, against-the-rule (ATR) or with-the-rule (WTR) astigmatism of +1.00, +2.00 and +3.00 D was intentionally produced in both eyes, and then binocular CS was measured. The cylindrical addition of different powers (+1.00–+3.00 D) was compensated with spherical lenses so that the spherical equivalent refraction became zero in each eye. Subsequently, the above cylindrical addition was monocularly induced, and binocular CS was measured again. The relation between CS and astigmatic power, axis, and monocular or binocular astigmatism was investigated. Results: With binocular ATR and WTR astigmatism, increases in astigmatic power significantly correlated with decreases in the area under the log contrast sensitivity function (AULCSF). With monocular astigmatic defocus, astigmatic power addition did not affect AULCSF. With binocular astigmatic defocus of high-power (+2.00 and +3.00 D), ATR astigmatism deteriorated AULCSF more than WTR astigmatism. In a comparison between binocular and monocular astigmatic defocus, CS was significantly worse with binocular astigmatic defocus than with monocular astigmatic defocus at higher spatial frequencies regardless of astigmatic power. Conclusions: Binocular astigmatic defocus deteriorates CS depending on the amount of astigmatic power. ATR astigmatism reduces CS more than WTR astigmatism dose. In addition, binocular astigmatic defocus affects CS more severely than monocular astigmatic defocus especially at high spatial frequencies. [ABSTRACT FROM AUTHOR]

Aromatic polyimide (API) thin films were deposited onto silicon wafers with microscopic-scale trenches (width: 5 μm, depth: 30 μm) using supercritical carbon dioxide at deposition temperatures that ranged from 150 to 230 °C and at a constant deposition time of 90 min. Moreover, the relationship between deposition time and film thickness was also investigated for durations that ranged from 30 to 180 min at a deposition temperature of 200 °C. We used 4,4′-diaminodiphenyl ether and pyromellitic dianhydride of Kapton-type polyimide API monomers. Although the morphologies of the API films deposited on the outside surfaces of the trenches depended on the distance from the supply outlets of the monomers, the API thin films were deposited onto the surfaces of the walls of the trenches with an approximately equal thickness from the outer surface position to the bottom position regardless of the distance from the supply outlets. However, the film thickness on the walls of the trenches depended on the distance from the supply outlets, because the trenches near the supply outlets were likely to be blocked by the masses of APIs during deposition. The film deposited at 230 °C was much smoother than that deposited at either 150 or 200 °C, which could have been caused by the differences in imidization rates and the amounts of PAA entering into the trenches based on the differences in the deposition temperatures although the film thickness showed no significant temperature dependency in the experimental conditions. The film thickness increased with increases in deposition time on the walls of the trenches in positions where no masses of APIs were found on the outer surface. [ABSTRACT FROM AUTHOR]

The deposition of aromatic polyimide (API) thin films was carried out in supercritical carbon dioxide (scCO 2 ) with 20 mol% of N,N-dimethylformamide (DMF) as a cosolvent, and using 4,4′-diaminodiphenyl ether (ODA) and pyromellitic dianhydride (PMDA) as monomers. A new apparatus based on a flow method that consisted of a cold-wall type reactor and two supply lines for each of the API monomers was used. The effect on the morphology of the films was investigated at feeding monomer concentrations and deposition temperatures ranging from 5 × 10 −4 to 5 × 10 −6 on a mole fraction basis and from 423 to 523 K, respectively. The results showed that increasing the monomer concentration and decreasing the deposition temperature increased the thickness of the films, and a smooth surface of the film was obtained at 423 K. Additionally, FT-IR study and thermogravimetric (TG) analysis of the film deposited at monomer mole fractions of 5 × 10 −5 and at a deposition temperature of 473 K were also carried out. The FT-IR spectrum of the deposited film in scCO 2 with DMF represented imide structures although there was a small peak of amide carbonyl stretching that originated from the polyamic acid and DMF. The TG curve indicated the temperature of 5% weight loss was more than 800 K under an air atmosphere after complete imidization. [ABSTRACT FROM AUTHOR]

Purpose: To compare the Acrysof IQ toric intraocular lens (IOL) and the Acrysof IQ aspheric nontoric IOL and evaluate the effect of preoperative corneal astigmatism orientation on results. Setting: Department of Ophthalmology, Faculty of Medicine, University of Tsukuba, Ibaraki, Japan. Design: Comparative case series. Methods: This retrospective chart review comprised patients with cataract and preoperative corneal astigmatism between 1.0 diopter (D) and 2.5 D having toric IOL (toric group) or aspheric nontoric IOL (nontoric group) implantation. Eyes were grouped depending on the preoperative axis of corneal astigmatism; that is, with the rule (WTR), against the rule (ATR), and oblique. Preoperative and postoperative analyses included uncorrected (UDVA) and corrected (CDVA) distance visual acuities and cylindrical power preoperatively and 3 months postoperatively. Results: The postoperative CDVA was not significantly different between the 2 IOLs; however, the postoperative UDVA was significantly better in the toric group than in the nontoric group (P<.0001). The postoperative residual cylindrical power was significantly smaller in the toric group (P<.0001). In eyes with ATR and oblique astigmatism, the mean postoperative UDVA was significantly better in the toric group, whereas there were no differences between the 2 groups in patients with WTR astigmatism. Conclusions: There was significant improvement in postoperative cylinder and UDVA with toric IOLs compared with nontoric IOLs. With a superior corneal incision, the benefits of astigmatism correction with the toric IOL were more significant in patients with ATR and oblique astigmatism than in those with WTR astigmatism. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned. [Copyright &y& Elsevier]

Purpose: The purpose of this study was to determine the incidence of and risk factors for intraocular pressure (IOP) elevation within 24 h following vitrectomy for rhegmatogenous retinal detachment (RD). Methods: We assessed 34 eyes of 34 consecutive patients with RD undergoing vitrectomy and 12 eyes of 12 patients with macular hole as controls. IOP was measured using Tonopen XL before surgery, at the end of surgery, and at 5 h and 1 day postoperatively. IOP at the end of surgery was adjusted to 15.0 ± 2.0 mmHg. Results: IOP elevation was found in five RD eyes at 5 h and in 13 1 day postoperatively. IOP in patients with RD at both 5 h and 1 day postoperatively was significantly higher than that of controls. Circumferential dimension of retinal tears and disease duration were significantly associated with IOP elevation at both 5 h and 1 day postoperatively. Conclusions: IOP elevation in the early postoperative period following vitrectomy for RD is common. The risk factors for IOP elevation include the extent of retinal tears and duration of detachment. Prophylactic treatment may be useful in eyes with higher risks of IOP elevation. [ABSTRACT FROM AUTHOR]

In hard disk drives, it is important to enlarge the control bandwidth in order to shorten the track pitch for larger data capacity. However, it is difficult for the H∞ control method to increase the control bandwidth if the mechanical resonance modes have uncertainty. This is because the robustness of the H∞ control method is assured by the small-gain theorem for additive or multiplicative perturbation and the control bandwidth is limited by the uncertainty. In this study, we propose an H∞ control method for high-bandwidth design by introducing a new uncertainty model with a feedforward and a feedback path in order to reduce the conservatism of robust design. The effectiveness is shown by numerical simulations. © 2010 Wiley Periodicals, Inc. Electr Eng Jpn, 173(4): 54–62, 2010; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.21025 [ABSTRACT FROM AUTHOR]

Purpose: To assess the accuracy of intraocular lens (IOL) power formulas, namely, SRK/T, Haigis, Barrett Universal II, Barrett True-K for keratoconus, Kane formula, and Kane formula for keratoconus, for cataract with keratoconus in Japanese eyes. Setting: Five surgical sites in Japan. Design: A retrospective case series. Methods: Eyes with keratoconus undergoing cataract surgery were included. Postoperative refraction was compared with the prediction by the formulas. Visual acuity, manifest spherical equivalent, prediction error (PE), and mean absolute errors (MAEs) were determined 1 month postoperatively. The PE within 0.50 diopter (D), 1.00 D, and 2.00 D were compared between IOL formulas. Subgroup analysis based on the steepest keratometry (stage 1, ≤ 48 D; stage 2, > 48 D and ≤ 53 D; and stage 3, > 53 D) was performed. The relationship between PE and preoperative biometric data were assessed. Results: Fifty eyes were included. The MAE of the Barrett True-K for keratoconus, Kane keratoconus, and Kane formulas were significantly lower than that of Haigis. A statistically significant difference in the prediction accuracy within ± 0.50 D was found between Kane keratoconus and Haigis. The prediction accuracy of the Barrett True-K for keratoconus, SRK/T, and Kane within ± 1.00 D was statistically significant compared with that of Haigis. In stage 3, the Barrett True-K for keratoconus had a significantly lower MAE than SRK/T and Haigis. Conclusion: Keratoconus-specific formulas were more accurate than existing formulas in Japanese eyes. The Barrett True-K formula for keratoconus had higher prediction accuracy in severe keratoconus. [ABSTRACT FROM AUTHOR]

Purpose: To assess whether the outcomes of toric intraocular lens (IOL) implantation in eyes with oblique astigmatism can be improved by direct measurements of posterior corneal astigmatism using anterior segment optical coherence tomography (AS-OCT) instead of by using anterior corneal measurements alone. Study design: Retrospective case series. Methods: Two toric IOL power calculation methods were compared: anterior corneal astigmatism was used in the keratometry group, whilst total corneal astigmatism determined by ray tracing through the measured anterior and posterior corneal surfaces was used in the AS-OCT group. In a total of 279 eyes of 232 patients, subgroup analysis was conducted for with-the-rule (WTR) (85 eyes in the keratometry group and 34 eyes in the AS-OCT group), against-the-rule (ATR) (73/29 eyes), and oblique (26/32 eyes) astigmatism. Results: In the WTR and ATR astigmatism groups, the uncorrected distance visual acuity (UDVA) was significantly better in the AS-OCT group than in the keratometry group (P = 0.012 and P < 0.001, Mann–Whitney test), and the residual astigmatism was significantly smaller in the AS-OCT group than in the keratometry group (P = 0.037 and P < 0.001). In eyes with oblique astigmatism, the UDVA (P = 0.299) and residual astigmatism (P = 0.373) of the keratometry and AS-OCT groups did not differ. Conclusion: Incorporation of posterior corneal astigmatism measured with AS-OCT can significantly improve the outcomes of toric IOL implantation in eyes with WTR and ATR astigmatism, but not in eyes with oblique astigmatism. [ABSTRACT FROM AUTHOR]

Coimplantation of CTR did not affect refractive and visual outcomes of trifocal IOL implantation. The use of CTR significantly increased IOL decentration probably because CTR eyelets interfered with IOL haptics. Purpose: To assess the influence of capsular tension ring (CTR) on surgical outcomes of trifocal intraocular lens (IOL) implantation in femtosecond laser-assisted cataract surgery. Setting: Sugita Eye Clinic, Tokyo, and University of Tsukuba, Ibaraki, Japan. Design: Prospective, randomized, paired-eye clinical study and laboratory study. Methods: In the clinical study involving 44 eyes of 22 patients with no risk of zonular instability, 1 eye received IOL alone and the contralateral eye received IOL with CTR. Preoperative capsular bag diameter and postoperative IOL tilt/decentration were measured using anterior segment optical coherence tomography. In the laboratory study, IOL and CTR were implanted into an artificial capsular bag of 10 mm in diameter, and IOL centration was evaluated. Results: Throughout the 12-month follow-up period, there was no significant difference in refractive and visual outcomes between groups. The amount of IOL decentration was significantly larger in eyes with CTR than in eyes without CTR at 12 months postoperatively (P =.037). There was a significant negative correlation between capsular bag diameter and the amount of IOL decentration in eyes with CTR (P =.038), but not in eyes without CTR (P =.873). The laboratory study indicated that interference between CTR eyelets and IOL haptics significantly increased IOL decentration (P <.001). Conclusions: The use of CTR did not affect refractive and visual outcomes of trifocal IOL implantation in eyes without the risk of zonular weakness. CTR coimplantation increased IOL decentration possibly due to the interference between CTR eyelets and IOL haptics. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the repeatability of the optical coherence tomography (OCT) retinal shape measurement with and without alignment correction in children and adults. Methods: 62 eyes of the 31 subjects were examined on the OCT with auto-alignment and alignment correction functions. We performed three measurements on each eye, created 2D retinal height maps, and extracted horizontal and vertical profiles for repeatability analysis and Legendre polynomial representation. Repeatability was determined from the average standard deviation. We estimated the refractive errors produced by the observed alignment errors. We also examined the repeatability improvement of the slopes, curvatures, and higher-order coefficients for the subjects using the Student t test. Results: Repeatability was higher in the data with alignment. We observed the average repeatability in the child group with standard deviation (SD) equal 38.20 µm in raw data, and SD = 6.11 µm in the corrected data, in adults SD = 17.04 µm in raw data, and SD = 5.22 µm in the corrected data. The slope repeatability improved in both child [horizontal t (18) = 4.62, p < 0.001 and vertical t (17) = 4.43, p < 0.001] and adult groups [t (18) = 2.73, p = 0.007 and vertical t (26) = 2.14, p = 0.02], while higher-order coefficients were not affected. Conclusions: Alignment correction improved repeatability of the OCT retinal shape measurements, especially for child subjects. Curvature and higher-order distortions were not affected by the alignment error. The refractive errors produced by alignment errors are low, and the model can be used to estimate the peripheral refraction. [ABSTRACT FROM AUTHOR]

Purpose: To investigate factors related to the rotational stability of an acrylic toric intraocular lens (IOL). Setting: Four ophthalmic surgical sites in Japan. Design: Prospective case series. Methods: The study included 120 eyes of 120 patients undergoing phacoemulsification and implantation of a toric IOL (AcrySof IQ, Alcon Laboratories, Inc.). At 1 hour postoperatively, the area of continuous curvilinear capsulorhexis (CCC) was measured, and the state of anterior capsule coverage on the IOL optic (total on or partial on) was recorded. The toric IOL axis orientation was assessed at the end of surgery and at 1 hour, 1 week, 1 month, and 6 months postoperatively. Multiple regression analysis was performed to explore any clinical factors relevant to IOL rotation from the end of surgery to 6 months postoperatively. The explanatory variables included age, anterior chamber depth preoperatively, axial length, type of corneal astigmatism (with-the-rule, against-the-rule, or oblique astigmatism), area of CCC, state of anterior capsule overlap on IOL optic (total coverage vs partial coverage), and surgical sites (surgeons). Results: The multiple regression analysis in 110 eyes of 110 patients indicated that anterior capsule overlap on the IOL optic was the only variable associated with IOL rotation at 6 months postoperatively (P =.0482). The mean absolute rotation at 6 months was 1.96 +/- 1.81 degrees in the total on group and 3.79 +/- 3.12 degrees in the partial on group (P =.0004). Conclusions: Rotational stability of a single-piece, acrylic toric IOL was better in eyes with total anterior capsule coverage than that in those with partial anterior capsule coverage on the IOL optic. [ABSTRACT FROM AUTHOR]

Purpose: To measure ophthalmodynamometric pressure (ODP) during vitrectomy in patients with proliferative diabetic retinopathy (PDR). Design: Prospective, interventional, consecutive case series. Methods: This study included 75 eyes of 75 patients undergoing vitrectomy for PDR. After core vitrectomy, the intraocular pressure was gradually raised using a vented-gas forced-infusion system (VGFI), and the optic nerve head was continuously monitored through a planoconvex contact lens. When the central retinal artery or its branches on the optic nerve head showed pulsations, the pressure was recorded as ODP. Diastolic blood pressure (DBP) and systolic blood pressure (SBP) were measured at the time of ODP measurement. Multiple regression analysis was performed to investigate the relationship between ODP and various explanatory variables: DBP, SBP, age, gender, body mass index, presence of hypertension, serum hemoglobin A1c, serum total cholesterol, fasting plasma glucose, presence of rubeosis iridis, and severity of PDR. Results: ODP was 63.6 ± 11.5 mm Hg (range 15.5-84.4 mm Hg). The ODP significantly correlated with DBP (r = 0.570, P < .0001) and the mean arterial blood pressure (r = 0.522, P < .0001), but not with SBP (r = 0.121, P = .303). Multiple regression analysis revealed that ODP had a significant correlation with DBP (P < .0001), presence of rubeosis iridis (P < .0001), and severity of PDR (P = .046). Conclusions: We measured ODP using VGFI during vitrectomy in patients with PDR. The ODP was significantly associated with DBP. The ODP was lower in patients with rubeosis iridis and severe PDR. [ABSTRACT FROM AUTHOR]