Quantum Algorithm for Full Configuration Interaction Calculations without Controlled Time Evolutions.

A quantum phase estimation algorithm allows us to perform full configuration interaction (full-CI) calculations on quantum computers with polynomial costs against the system size under study, but it requires quantum simulation of the time evolution of the wave function conditional on an ancillary qubit, which makes the algorithm implementation on real quantum devices difficult. Here, we discuss an application of the Bayesian phase difference estimation algorithm that is free from controlled time evolution operations to the full-CI calculations.

Bayesian phase difference estimation: a general quantum algorithm for the direct calculation of energy gaps.

Quantum computers can perform full configuration interaction (full-CI) calculations by utilising the quantum phase estimation (QPE) algorithms including Bayesian phase estimation (BPE) and iterative quantum phase estimation (IQPE). In these quantum algorithms, the time evolution of wave functions for atoms and molecules is simulated conditionally with an ancillary qubit as the control, which make implementation to real quantum devices difficult. Also, most of the problems in chemistry discuss energy differences between two electronic states rather than total energies themselves, and thus direct calculations of energy gaps are promising for future applications of quantum computers to real chemistry problems. In the race of finding efficient quantum algorithms to solve quantum chemistry problems, we test a Bayesian phase difference estimation (BPDE) algorithm, which is a general algorithm to calculate the difference of two eigenphases of unitary operators in the several cases of the direct calculations of energy gaps between two electronic states on quantum computers, including vertical ionisation energies, singlet-triplet energy gaps, and vertical excitation energies. In the BPDE algorithm, state preparation is carried out conditionally on the ancillary qubit, and the time evolution of the wave functions in superposition of two electronic states are executed unconditionally. Based on our test, we conclude that BPDE is capable of computing the energy gap with an accuracy similar to BPE without controlled-time evolution simulations and with the smaller number of iterations in Bayesian optimisations.

Predicting Keratoconus Progression and Need for Corneal Crosslinking Using Deep Learning.

We aimed to predict keratoconus progression and the need for corneal crosslinking (CXL) using deep learning (DL). Two hundred and seventy-four corneal tomography images taken by Pentacam HR® (Oculus, Wetzlar, Germany) of 158 keratoconus patients were examined. All patients were examined two times or more, and divided into two groups; the progression group and the non-progression group. An axial map of the frontal corneal plane, a pachymetry map, and a combination of these two maps at the initial examination were assessed according to the patients' age. Training with a convolutional neural network on these learning data objects was conducted. Ninety eyes showed progression and 184 eyes showed no progression. The axial map, the pachymetry map, and their combination combined with patients' age showed mean AUC values of 0.783, 0.784, and 0.814 (95% confidence interval (0.721-0.845) (0.722-0.846), and (0.755-0.872), respectively), with sensitivities of 87.8%, 77.8%, and 77.8% ((79.2-93.7), (67.8-85.9), and (67.8-85.9)) and specificities of 59.8%, 65.8%, and 69.6% ((52.3-66.9), (58.4-72.6), and (62.4-76.1)), respectively. Using the proposed DL neural network model, keratoconus progression can be predicted on corneal tomography maps combined with patients' age.

Baseline factors predicting the need for corneal crosslinking in patients with keratoconus.

INTRODUCTION: The primary purpose of crosslinking is to halt the progression of ectasia. We retrospectively assessed the condition of keratoconus patients who were followed-up at least twice after the initial examination to evaluate keratoconus progression, to identify definitive factors to predict a later need for corneal crosslinking (CXL). METHODS: The medical charts of 158 eyes of 158 keratoconus patients (112 males and 46 females; mean age, 27.8 ± 11.7 years), who were followed up at the Department of Ophthalmology, Keio University School of Medicine at least twice after the initial examination to evaluate keratoconus progression were retrospectively reviewed. Best-spectacle corrected visual acuity, intraocular pressure, steepest corneal axis on the anterior float (Ks), thinnest corneal thickness according to Pentacam® HR, and corneal endothelial cell density were assessed. Gender, age, onset age of keratoconus, history of atopic dermatitis, and Pentacam® indices were also recorded. CXL was performed when the eye showed significant keratoconus progression, an increase in the steepest keratometric value, or an increase in the spherical equivalent or cylinder power of the manifest refraction by more than 1.0 D versus the respective values 2 years prior. Predictor variables and the requirement for CXL were analyzed using logistic regression. RESULTS: Fifty-eight eyes required CXL treatment. The best predictor of the requirement for CXL was patient age, followed by the Pentacam® Rmin (the minimum sagittal curvature evaluated by Pentacam®) value. The incidence of CXL was 86.4% in the < 20 years age group, with an Rmin of ≤ 5.73 mm, whereas 10.8% in the ≥ 27 years age group with an Rmin > 5.73 mm underwent treatment. CONCLUSIONS: An age of < 20 years and an Rmin value of ≤ 5.73 mm predicted keratoconus progression and the requirement for CXL treatment in the near future.

Corneal crosslinking for keratoconus in Japanese populations: one year outcomes and a comparison between conventional and accelerated procedures.

PURPOSE: We retrospectively investigated the efficacy of corneal crosslinking (CXL) on progressive keratoconus in a Japanese population and compared the outcomes of conventional and accelerated CXL. STUDY DESIGN: A retrospective cohort study METHODS: A total of 108 consecutive eyes in 95 patients (75 men; 21.9 ± 6.2 years) with progressive keratoconus were enrolled. The epithelium was ablated in all eyes. After presoaking the corneal stroma in riboflavin, UV-A was irradiated at 3.0 mW/cm2 (conventional CXL) for 30 min on 23 eyes and 18.0 mW/cm2 for 5 min (accelerated CXL) on 85 eyes. Best spectacle-corrected visual acuity (BSCVA), manifest refraction, keratometric value, corneal thickness, corneal endothelial cell density (ECD), intraocular pressure, and complications were evaluated at 1, 3, 6, and 12 months after the procedure. RESULTS: BSCVA, manifest refraction, ECD, and corneal thickness did not change significantly after both procedures. The keratometric value was significantly decreased from the preoperative value at 12 months (p < 0.001). Progression to more than 1.0 D after CXL was observed in 10 eyes (9.3%). The ΔKmax was negatively associated with preoperative Kmax (p < 0.001) and positively associated with preoperative thinnest corneal thickness (p < 0.001). Both treatment modules showed no significant difference in all parameters. CONCLUSION: CXL was as effective in treating keratoconus in Japanese patients as in individuals of other ethnicities. Overall, CXL could be performed using either the conventional or accelerated approach to halt the progression of keratoconus in Japanese populations.

Punctal plugs for treatment of post-LASIK dry eye.

PURPOSE: To evaluate the efficacy of punctal plugs for patients with post-LASIK dry eye. MATERIALS AND METHODS: A prospective study was conducted on 25 eyes of 18 patients who underwent LASIK. All eyes fulfilled the Japanese dry-eye criteria and had not responded to conventional treatment with artificial tears by 1 month postsurgery. They were randomly divided into a plug and a non-plug group. Punctal plugs were inserted into the superior and inferior puncta in the plug group after the 1-month examination. Uncorrected and best corrected visual acuity (UCVA, BCVA), refraction, functional visual acuity (FVA) after 10 s eye opening (FVA 10), surface regularity index (SRI) after 10 s eye opening (SRI 10), corneal sensitivity, Schirmer test, fluorescein staining (FS), tear break-up time (TBUT), and symptoms were compared between the groups 1 and 3 months postsurgery. Changes in these data from 1 to 3 months were also compared between the groups. RESULTS: The values in SRI 10, FS, and TBUT were significantly better in the plug group at 3 months. Changes in the values of UCVA, FVA 10, FS, TBUT, and symptoms between 1 and 3 months improved significantly in the plug group compared with the non-plug group. CONCLUSION: Our results suggest that punctal occlusion for both puncta is effective for patients with post-LASIK dry eye that cannot be controlled by artificial tears alone. Punctal plugs can improve not only the symptoms and tear function, but also the quality of vision, for example FVA.

Thermophilic two-stage dry anaerobic digestion of model garbage with ammonia stripping.

To avoid the inhibition of methane production by ammonia that occurs during the degradation of garbage, anaerobic digestion with prior ammonia production and subsequent stripping was investigated. In the ammonia production phase, the maximum ammonia concentration was approximately 2800 mg N/kg of total wet sludge in the range of 4 days of sludge retention time, indicating that only 43% of total nitrogen in the model garbage was converted to ammonia. The model garbage from which ammonia was produced and stripped was subjected to semi-continuous thermophilic dry anaerobic digestion over 180 days. The gas yield was in the range of 0.68 to 0.75 Nm(3)/kg volatile solid, and it decreased with the decrease of the sludge retention time. The ammonia-nitrogen concentration in the sludge was kept below 3000 mg N/kg total wet sludge. Microbial community structure analysis revealed that the phylum Firmicutes dominated in the ammonia production, but the community structure changed at different sludge retention times. In dry anaerobic digestion, the dominant bacteria shifted from the phylum Thermotogae to Firmicutes. The dominant archaeon was the genus Methanothermobacter, but the ratio of Methanosarcina increased during the process of dry anaerobic digestion.

Topography-guided conductive keratoplasty: treatment for advanced keratoconus.

PURPOSE: To evaluate the use of topography-guided conductive keratoplasty in eyes with keratoconus. DESIGN: Interventional case series. METHODS: We examined 21 eyes in 21 patients with advanced keratoconus. Topography-guided conductive keratoplasty was performed with intraoperative monitoring of corneal astigmatism using a surgical keratometer. Uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), corneal topography, manifest refraction, intraocular pressure (IOP), corneal endothelial cell counts, complications, and eventual outcomes were evaluated. RESULTS: UCVA (logarithm of the minimal angle of resolution [logMAR]), which was 1.65 ± 0.49 preoperatively, improved to 1.04 ± 0.64 at 1 week (P < .001) and 1.12 ± 0.61 at 1 month after surgery (P < .001). BSCVA, which was 1.02 ± 0.56 preoperatively, improved to 0.76 ± 0.65 at 1 week (P = .026) and 0.76 ± 0.60 at 1 month after surgery (P = .003). Manifest refraction, which was -15.13 ± 6.66 diopters (D) before surgery, declined to -9.97 ± 6.71 D at 1 month after surgery (P = .002). Although corneal topography reverted to the preoperative pattern and UCVA and BSCVA also regressed toward preoperative values, 12 of 21 eyes were better able to tolerate and conduct normal daily activities using contact lenses. Five subjects have undergone or are considering corneal transplantation after unsatisfactory postoperative results. No serious perioperative complication was observed. CONCLUSIONS: Topography-guided conductive keratoplasty may be effective in reshaping corneal configuration in eyes with keratoconus, without serious complications, and possibly contributed to avoiding or delaying corneal transplantation.

Visual performance after reduced blinking in eyes with soft contact lenses or after LASIK.

PURPOSE: To evaluate visual performance during concentrated visual work in patients wearing soft contact lenses or after LASIK. METHODS: Thirty-one eyes of 17 patients who had worn soft contact lenses before LASIK were examined by the following tests immediately and 10 seconds after eye opening: 1) functional visual acuity, which is defined as visual acuity measured after prolonged eye opening without blinking; 2) surface regularity index (SRI) and surface asymmetry index (SAI) in corneal topography; and 3) higher order aberration measured with NIDEK OPD-Scan. Results were compared in the same patients before (with soft contact lenses and no eye surgery) and 1 month after LASIK (without soft contact lenses). RESULTS: Functional visual acuity was significantly decreased 10 seconds after eye opening compared with immediately after eye opening, both with soft contact lenses and after LASIK, and decreased to a greater extent with soft contact lenses. The SRI and SAI were significantly increased 10 seconds after eye opening compared with immediately after eye opening, both with soft contact lenses and after LASIK, and increased to a greater extent with soft contact lenses. Higher order aberration was increased 10 seconds after eye opening with soft contact lenses, but not after LASIK. CONCLUSIONS: Our results suggest that prolonged eye opening induces a decreased quality of vision in eyes of soft contact lens wearers and after LASIK. Under conditions in which blinking is restricted due to concentrated visual work, such as visual display terminal work, reading, and driving, visual performance may be more compromised with soft contact lens wear than after LASIK.

Five-year outcome of LASIK for myopia.

PURPOSE: To investigate the efficacy and safety of LASIK over a 5-year postoperative period. DESIGN: Observational case series. PARTICIPANTS: We examined 779 eyes in 402 patients with myopia or myopic astigmatism who underwent LASIK to correct their refractive errors and received regular postoperative assessments for 5 years. METHODS: Postoperative examinations were performed 1 day; 1 week; 1, 3, and 6 months; and 1, 2, 3, 4, and 5 years after LASIK surgery. MAIN OUTCOME MEASURES: We evaluated changes in uncorrected visual acuity (UCVA) (logarithm of the minimum angle of resolution [logMAR]), manifest refraction, best-corrected visual acuity (BCVA) (logMAR), intraocular pressure, corneal thickness, corneal endothelial cell counts, and complications. RESULTS: Preoperative UCVA of 1.27 improved to -0.03 at 1 day after surgery and -0.08 at 1 month and revealed minimal but significant decreases thereafter. Postoperative manifest refraction was also improved by surgery, showing minimal but significant regression after 1 year. Final BCVA loss was seen in 10 eyes of 7 patients; in 7 cases, there were obvious reasons such as the progression of cataracts in 3 eyes, epithelial disintegrity due to dry eye in 2 eyes, irregular astigmatism due to flap striae in 1 eye, and age-related macular dystrophy in 1 eye. Intraocular pressure and corneal thickness decreased by 4.0 mmHg and 76.9 microm, respectively, due to surgery, but remained stable throughout the follow-up period. Corneal endothelial cell counts (2689.0+/-232.9 cells/mm(2) before surgery) showed a statistically significant decrease at 5 years after surgery (2658.0+/-183.1 cells/mm(2); 1.2% loss for 5 years), likely within the range due to physiological age-related loss. No serious, vision-threatening, irreversible complication such as keratectasia or progressive endothelial cell loss was observed. CONCLUSION: LASIK surgery is an effective and safe procedure for correcting myopia/myopic astigmatism as long as inclusion and exclusion criteria are strictly respected. However, minimal regression occurred during the 5-year investigative period.

Detection of cyclotorsional rotation during excimer laser ablation in LASIK.

PURPOSE: Positionally induced cyclotorsion could be an important factor in the correction of astigmatism during refractive surgery. We analyzed the change in cyclotorsional rotation during excimer laser ablation in LASIK surgery using the NIDEK Torsion Error Detector (TED). METHODS: One hundred ten patients (192 eyes) who underwent LASIK for myopic astigmatism, using the NIDEK Advanced Vision Excimer Laser (NAVEX) were measured for cyclotorsion during surgery using the TED system. The manifest refraction of these patients was -6.80+/-2.74 diopters (D) (range: -1.00 to -13.75 D). The iris pattern of the patient's eyes in the supine position was recorded via a CCD camera in the EC5000CXII excimer laser system, and it was compared to the iris pattern acquired during OPD-Scan measurement in the sitting position. RESULTS: During laser ablation, the degree of cyclotorsional rotation detected by TED was 1.33+/-1.88 degrees (range: -6.33 to 2.99 degrees) clockwise and 1.00+/-1.79 degrees (range: -3.70 to 7.34 degrees) counterclockwise. The absolute degree of torsion error detected by the TED system was 2.33+/-1.16 degrees (range: 0 to 6.21 degrees). CONCLUSIONS: The effectiveness of the cylinder treatment can be reduced due to torsion errors. The degree of cyclotorsion constantly changes during laser ablation. Therefore, a monitoring system should be developed for the measurement of torsion error, and this will enable the maximum possible correction of the error during laser ablation.

Pupil decentration and iris tilting detected by Orbscan: anatomic variations among healthy subjects and influence on outcomes of laser refractive surgeries.

PURPOSE: To investigate the anatomic variations of entrance pupil decentration and tilting angle of the iris in healthy subjects and the influence of these factors on the outcome of laser in situ keratomileusis (LASIK). SETTING: Minamiaoyama Eye Clinic, Tokyo, Japan. METHODS: The degree of pupil decentration and tilting angle of the iris in 2280 eyes of 1144 myopic patients without abnormal findings by ophthalmologic examination were assessed using Orbscan. Of these, 901 eyes of 467 patients had LASIK. Multiple analysis of variance (ANOVA) was used to determine risk factors for reduction of postoperative best spectacle-corrected visual acuity (BSCVA) considering patient age, refractive power, tilting angle of the iris, pupil decentration, and corneal power. RESULTS: The mean pupil decentration in all eyes was 0.19 mm +/- 0.11 (SD) (range 0 to 0.9 mm); tilting angle of the iris was 4.06 +/- 1.41 degrees (range 0.19 to 12.69 degrees). By multiple ANOVA, refractive power, pupil decentration, and tilting angle of the iris were significant for the reduction of BSCVA. CONCLUSIONS: Some eyes with pupil decentration or tilting angle of the iris could not be detected under typical ophthalmologic examination but only with topographic examination. Attention should be paid to eyes with large pupil decentration and tilting angle of the iris because these may be risk factors for reduction of postoperative BSCVA during corneal refractive surgeries.

Experience with the Artisan phakic intraocular lens in Asian eyes.

PURPOSE: To investigate the efficacy and safety of implantation of an iris-claw phakic intraocular lens (PIOL), Artisan Myopia, in Asian eyes. SETTING: Minamiaoyama Eye Clinic, Tokyo, Japan. METHODS: Forty-four eyes of 32 Japanese patients and 1 Korean patient with high myopia had Artisan Myopia lens implantation to correct their refractive errors. Lens models, 5/8.5 or 6/8.5 (optic diameter/overall diameter), were chosen as standard lens model. A smaller lens model (5/7.5-Artisan Myopia Small) was implanted in eyes with corneal diameter less than 11.0 mm. Postoperative examinations were performed on 1 day, 1 week, 1 month, 3 months, 6 months, 1 year, and 2 years after surgery. Uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), manifest refraction, corneal endothelial cell counts, intraocular pressure, and complications were evaluated. RESULTS: Artisan Myopia Small lenses were implanted in 4 eyes (9.1%) and 8.5 mm diameter lenses were implanted in 40 eyes. Preoperative UCVA (logMAR) improved from 1.57 to 0.09 at 1 month after surgery and no regression was observed thereafter. Postoperative manifest refraction was -1.02 +/- 0.87 D (-3.25 to -0.00 D), and within 1.0 D in 20 eyes (55.6%), within 2.0 D in 32 eyes (88.9%) at 1 month after surgery, and stable during the follow-up period. The final BCVA decreased 2 lines in 2 eyes (4.5%) due to progression of age-related cataract. No serious complications such as angle closure or progressive endothelial cell loss were observed. CONCLUSION: Implantation of an Artisan iris-claw PIOL implantation may be a safe and effective procedure for Asian eyes.