Pectin Nanoporous Structures Prepared via Salt-Induced Phase Separation and Ambient Azeotropic Evaporation Processes.

Polysaccharide nanoporous structures are suitable for various applications, ranging from biomedical scaffolds to adsorption materials, owing to their biocompatibility and large surface areas. Pectin, in particular, can create 3D nanoporous structures in aqueous solutions by binding with calcium cations and creating nanopores by phase separation; this process involves forming hydrogen bonds between alcohols and pectin chains in water and alcohol mixtures and the resulting penetration of alcohols into calcium-bound pectin gels. However, owing to the dehydration and condensation of polysaccharide chains during drying, it has proven to be challenging to maintain the 3D nanoporous structure without using a freeze-drying process or supercritical fluid. Herein, we report a facile method for creating polysaccharide-based xerogels, involving the co-evaporation of water with a nonsolvent (e.g., a low-molecular-weight hydrophobic alcohol such as isopropyl or n-propyl alcohol) at ambient conditions. Experiments and coarse-grained molecular dynamics simulations confirmed that salt-induced phase separation and hydrogen bonding between hydrophobic alcohols and pectin chains were the dominant processes in mixtures of pectin, water, and hydrophobic alcohols. Furthermore, the azeotropic evaporation of water and alcohol mixed in approximately 1:1 molar ratios was maintained during the natural drying process under ambient conditions, preventing the hydration and aggregation of the hydrophilic pectin chains. These results introduce a simple and convenient process to produce 3D polysaccharide xerogels under ambient conditions.

Scleral Lens Applications Focused on Korean Patients with Various Corneal Disorders.

PURPOSE: We aimed to report on the clinical outcomes of scleral lens applications in Korean patients with various corneal disorders. METHODS: This retrospective review was conducted for 62 eyes of 47 patients who had been fitted with scleral lenses for various corneal disorders. The patients were referred for inadequate spectacle-corrected visual acuity and rigid gas permeable (RGP) or soft contact lens intolerance. Uncorrected visual acuity, habitually corrected visual acuity, best lens-corrected visual acuity, topographic indices, keratometry indices, and lens parameters were evaluated. RESULTS: Twenty-six eyes of 19 patients with keratoconus were enrolled. Other conditions included corneal scar (13 eyes of 12 patients), phlyctenules (three eyes), laceration (four eyes), chemical burn (one eye), keratitis (one eye), Peters' anomaly (one eye), fibrous dysplasia (one eye), ocular graft-versus-host disease (two eyes of one patient), irregular astigmatism (18 eyes of 12 patients), and corneal transplant status (five eyes of four patients). The mean topographic values of the eyes include flat keratometric value (43.0 ± 6.1 diopters [D]), steep keratometric value (48.0 ± 7.4 D), and astigmatism (4.9 ± 3.6 D). Of the eyes fitted with scleral lenses, best lens-corrected visual acuity (0.10 ± 0.22 logarithm of the minimum angle of resolution [logMAR]) was significantly better than the habitually corrected visual acuity (0.59 ± 0.62 logMAR, p < 0.001). CONCLUSIONS: Scleral contact lenses are a good alternative for patients with corneal abnormalities and those who are intolerable to RGP contact lenses, resulting in both successful visual outcomes and patient satisfaction, especially concerning keratoconus, corneal scar, and corneal transplant status.

Equilibrium shift, poisoning prevention, and selectivity enhancement in catalysis via dehydration of polymeric membranes.

Generation of water as a byproduct in chemical reactions is often detrimental because it lowers the yield of the target product. Although several water removal methods, using absorbents, inorganic membranes, and additional dehydration reactions, have been proposed, there is an increasing demand for a stable and simple system that can selectively remove water over a wide range of reaction temperatures. Herein we report a thermally rearranged polybenzoxazole hollow fiber membrane with good water permselectivity and stability at reaction temperatures of up to 400 °C. Common reaction engineering challenges, such as those due to equilibrium limits, catalyst deactivation, and water-based side reactions, have been addressed using this membrane in a reactor.

Consecutive Ink Writing of Conducting Polymer and Graphene Composite Electrodes for Foldable Electronics-Related Applications.

For foldable electronic devices of the future, most components should have very good flexibility and reliability to maintain electrical properties even under repeated deformation. In this study, two types of inks for conducting polymer and graphene were simultaneously printed on flexible plastic substrates via the newly developed consecutive ink writing (CIW) process for the formation of composite electrodes of foldable electronic devices. To consecutively print conducting polymer ink and graphene ink, a conventional three-dimensional (3D) printer was modified by installing two needles in the printer head, and the two inks were printed through the nozzle in the same route with a time interval. By adjusting several printing conditions (ink concentration, printing parameters, printing time intervals between the two inks, etc.), various structures of composite electrodes, such as layered or fused 2D or 3D structures were developed on the glass substrate. Furthermore, by changing the printing order of the two inks and 3D printer bed temperature, the composite electrodes with a higher printing resolution were successfully printed on the flexible polyimide substrate. The printed composite electrodes via CIW process exhibit the lowest surface electrical resistance of 0.9 kΩ and high flexibility, and stable resistance values were maintained after 1000 cycles of the folding test. Consequently, the CIW process developed in this study applies to the production of the electrical parts and components for various flexible devices, such as foldable and wearable electronics.

Physicochemical and biological properties of four calcium silicate-based endodontic cements.

Background/purpose: Several brands of calcium silicate-based cements (CSBCs) are currently marketed. Here we compared physicochemical and biological properties of new products Ortho MTA (BioMTA), Retro MTA (BioMTA), and EZ-Seal (Ezekiel) to widely used ProRoot MTA (Dentsply Tulsa). Materials and methods: CSBCs were analyzed by X-ray diffractometry and examined by scanning electron microscopy. Elemental composition was determined by energy dispersive spectroscopy. Particle size was measured by particle size analyzer. Human stem cells from apical papilla (SCAPs) were incubated with eluates from CSBCs. Survival of SCAP cells was evaluated with MTT assay. The Alizarin red S stain was used to identify calcified nodules formed in SCAP cultures. The effects of CSBC eluates on SCAP proliferation and migration were examined using an in-vitro scratch "wound-healing" assay. Results: All CSBC specimens showed similar X-ray diffraction patterns. The average particle size of EZ-Seal was smaller than ProRoot MTA, Ortho MTA, and Retro MTA (P < 0.001). The least cytotoxicity of eluates was found for EZ-Seal. In the Alizarin red S staining test, calcified nodules were observed in cultures with ProRoot MTA, Ortho MTA, and Retro MTA, however, no calcified nodules were observed in cultures with EZ-Seal. SCAP proliferation and migration capacity in presence of EZ-Seal was higher than with ProRoot MTA, Ortho MTA, and Retro MTA (P < 0.001). Conclusion: EZ-Seal has a smaller average particle size and a better cytocompatibility than all other examined CSBCs.

Relationship Between Tamsulosin Use and Surgical Complications of Cataract Surgery in Elderly Patients: Population-Based Cohort Study.

Purpose: Although several previous studies have investigated the relationship between tamsulosin use and surgical complications of cataract surgery, no population-based cohort study has been conducted for the Asian population. We aimed to investigate the relationship between tamsulosin use and surgical complications of cataract surgery in the Korean elderly population. Methods: This nationwide population-based retrospective cohort study included elderly patients (≥60 years) who had undergone cataract surgery in the period from 2003 to 2015. Baseline characteristics were age, sex, income, residence, and systemic, and ocular comorbidities (glaucoma, myopia, eye trauma, diabetes mellitus with ophthalmic manifestations, severe cataract, age-related macular degeneration). The exposure of interest was tamsulosin use within 1 year before cataract surgery. Logistic regression model was used to evaluate the relationship of tamsulosin use with surgical complications of cataract surgery. Results: The rate of surgical complications of cataract surgery was 0.88% (375/42,539) in the non-tamsulosin group and 0.83% (71/8,510) in the tamsulosin group. The groups showed no significant difference in the risk of surgical complications of cataract surgery in the unadjusted model [odds ratio (OR) = 0.946; 95% confidence interval (CI):0.733-1.220; P = 0.669]. Additionally, tamsulosin use was not significantly associated with surgical complications of cataract surgery in the fully adjusted model accounting for age, income, residence, and systemic and ocular comorbidities (OR = 0.997; 95% CI: 0.749-1.325; P = 0.981). Conclusions: The rate or risk of surgical complications of cataract surgery does not change with tamsulosin use. We suggest that better surgical techniques and surgeons' cognizance of the patient's tamsulosin use could improve surgical outcomes, without increasing surgical complications.

Correlation between air pollution and prevalence of conjunctivitis in South Korea using analysis of public big data.

This study investigated how changes in weather factors affect the prevalence of conjunctivitis using public big data in South Korea. A total of 1,428 public big data entries from January 2013 to December 2019 were collected. Disease data and basic climate/air pollutant concentration records were collected from nationally provided big data. Meteorological factors affecting eye diseases were identified using multiple linear regression and machine learning analysis methods such as extreme gradient boosting (XGBoost), decision tree, and random forest. The prediction model with the best performance was XGBoost (1.180), followed by multiple regression (1.195), random forest (1.206), and decision tree (1.544) when using root mean square error (RMSE) values. With the XGBoost model, province was the most important variable (0.352), followed by month (0.289) and carbon monoxide exposure (0.133). Other air pollutants including sulfur dioxide, PM10, nitrogen dioxides, and ozone showed low associations with conjunctivitis. We identified factors associated with conjunctivitis using traditional multiple regression analysis and machine learning techniques. Regional factors were important for the prevalence of conjunctivitis as well as the atmosphere and air quality factors.

Selective CO2 adsorption and bathochromic shift in a phosphocholine-based lipid and conjugated polymer assembly.

We assemble a film of a phosphocholine-based lipid and a crystalline conjugated polymer using hydrophobic interactions between the alkyl tails of the lipid and alkyl side chains of the polymer, and demonstrated its selective gas adsorption properties and the polymer's improved light absorption properties. We show that a strong attractive interaction between the polar lipid heads and CO2 was responsible for 6 times more CO2 being adsorbed onto the assembly than N2, and that with repeated CO2 adsorption and vacuuming procedures, the assembly structures of the lipid-polymer assembly were irreversibly changed, as demonstrated by in situ grazing-incidence X-ray diffraction during the gas adsorption and desorption. Despite the disruption of the lipid structure caused by adsorbed polar gas molecules on polar head groups, gas adsorption could promote orderly alkyl chain packing by inducing compressive strain, resulting in enhanced electron delocalization of conjugated backbones and bathochromic light absorption. The findings suggest that merging the structures of the crystalline functional polymer and lipid bilayer is a viable option for solar energy-converting systems that use conjugated polymers as a light harvester and the polar heads as CO2-capturing sites.

Effect of intense pulsed light using acne filter on eyelid margin telangiectasia in moderate-to-severe meibomian gland dysfunction.

Evaluate the improvement in clinical signs and symptoms in patients with moderate-to-severe meibomian gland dysfunction (MGD) treated with intense pulsed light (IPL) using an acne filter. A retrospective chart review of 70 eyes of 35 patients with moderate-to-severe MGD treated with IPL using the acne filter was performed. IPL treatment was administered using the acne filter four times at 2- to 3-week intervals to upper and lower eyelids. We evaluated tear break-up time (TBUT), matrix metalloproteinase (MMP)-9, Sjögren's International Clinical Collaborative Alliance (SICCA) staining score, and Oxford staining grade. We performed Schirmer's test I without topical anesthesia, slit-lamp microscopic examination of lid margin and meibomian gland, and patient's symptom score assessment and evaluated the incidence of adverse effects in the ocular and periocular areas at baseline and 30 days after the final treatment. Significant improvements (P < 0.001) were observed in TBUT, SICCA staining score, Oxford staining grade, quality of meibum, consistency of meibum, lid margin telangiectasia, MGD grade, and patient's symptom scores after acne filter IPL treatment. Furthermore, the positivity (100 to 71.43%, P = 0.002) and level (2.43 ± 0.98 to 1.14 ± 0.78, P < 0.001) of MMP-9 significantly decreased after treatment. However, there was no significant improvement in Schirmer's test I (P = 0.224). No systemic or regional adverse effects were observed in any patient. IPL treatment using the acne filter is an effective and safe therapeutic modality for treating moderate-to-severe MGD, especially for lid margin telangiectasia and MMP-9.

Ultrathin Water-Cast Polymer Membranes for Hydrogen Purification.

Among various H2 purification technologies, the use of membrane technology has been considered an ecofriendly approach for addressing the increasing hydrogen demand. Although many H2-selective membrane materials have been reported, processing them into hollow fibers or thin-film composites (TFCs) via traditional methods either affects the performance of the materials or renders their further processing into applicable membrane forms infeasible. Herein, we propose a water-casting method for fabricating TFC membranes for hydrogen purification with high permselectivity. The film integrity and thickness were manipulated by controlling the spreadability of the casting solution, and the resultant water-cast TFC membrane that comprised an ∼30 nm selective layer demonstrated high H2 permeance and H2/CH4 selectivity of approximately 190 GPU and 100, respectively, under optimized conditions. We performed a mixed-gas permeation test using a simulated off-gas of steam-methane reforming from natural gas in a single-stage system and obtained hydrogen gas of >99 mol % purity. This indicates not only the suitability of the water-cast membranes for satisfying the demand for pure hydrogen as a fuel and chemical reagent but also the great potential of the water-casting method for high-performance membranes in various industrial and environmental applications.

Clinical outcomes of a monofocal intraocular lens with enhanced intermediate function compared with an extended depth-of-focus intraocular lens.

PURPOSE: To compare clinical outcomes of a new monofocal intraocular lens (IOL) with enhanced intermediate function and an extended depth-of-focus (EDoF) IOL. SETTING: Asan Medical Center, Seoul, Korea. DESIGN: Nonrandomized prospective comparative case series. METHODS: Patients presenting for cataract surgery and meeting all inclusion and exclusion criteria were implanted with a new monofocal IOL with enhanced intermediate function (Tecnis Eyhance ICB00) or an EDoF IOL (Tecnis Symfony ZXR00) bilaterally. Uncorrected (UDVA), uncorrected intermediate (UIVA), uncorrected near (UNVA), and corrected distance visual acuity (CDVA), defocus curves, and contrast sensitivity were compared after 3 months. Patients were administered questionnaires regarding visual symptoms, spectacle independence, overall satisfaction, and lens recommendations. RESULTS: 24 patients (48 eyes) were enrolled in the Eyhance group and 20 patients (40 eyes) in the Symfony group. Monocular and binocular UDVA, UIVA, and CDVA were similar in the 2 groups. Monocular UNVA and spectacle independence for near distance were better in the Symfony group, whereas binocular UNVA did not differ significantly in the 2 groups. Contrast sensitivity, glare and halo, satisfaction, and recommendation rates were similar in the 2 groups. Although some dissatisfaction and severe glare and halo were reported in the Symfony group, none of these was reported in the Eyhance group. CONCLUSIONS: Bilateral implantation of the Eyhance ICB00 IOL provided comparable clinical performances as bilateral implantation of the Symfony ZXR00 IOL. Binocular UNVA was similar, although spectacle independence was higher in the Symfony group, but this was at the expense of more glare and halos.

Effect of preoperative eyedrops on cytokine concentrations in aqueous humor of patients undergoing femtosecond laser-assisted cataract surgery.

PURPOSE: To compare the anti-inflammatory activity of preoperatively applied eyedrops, as determined by cytokine concentrations in aqueous humor collected during surgery in patients undergoing femtosecond laser-assisted cataract surgery. METHODS: A total of 120 patients undergoing femtosecond laser-assisted cataract surgery were randomly assigned to four groups of 30 patients each. Groups were administered 0.1% fluorometholone eyedrops, 0.45% ketorolac tromethamine eyedrops, both 0.1% fluorometholone and 0.45% ketorolac tromethamine eyedrops, or no eyedrops. Eyedrops were instilled 1 h, 20 min, and just before surgery. After anterior capsulotomy and nuclear fragmentation using a femtosecond laser, 0.1 cc aqueous humor was obtained using a needle and syringe. Cytokine and prostaglandin E2 (PGE2) concentrations were quantitatively determined. RESULTS: The 120 patients included 59 men and 61 women, of mean age 65.02 years. The mean interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) concentrations after treatment did not differ significantly in the four groups. The average interleukin-8 (IL-8) concentrations were significantly lower in the fluorometholone (4.80 pg/mL), ketorolac tromethamine (4.84 pg/mL), and fluorometholone + ketorolac tromethamine (4.68 pg/mL) groups than in the control group (6.83 pg/mL). Furthermore, the average PGE2 concentrations were significantly lower in the ketorolac tromethamine (270.04 pg/mL) and fluorometholone + ketorolac tromethamine (239.00 pg/mL) groups, but not in the fluorometholone (393.16 pg/mL) group, than in the control group (472.36 pg/mL). CONCLUSION: Preoperative fluorometholone instillation reduced IL-8, and ketorolac tromethamine instillation reduced IL-8 and PGE2, in aqueous humor of patients undergoing femtosecond laser surgery, with the combination of both eyedrops being more effective than either alone. TRIAL REGISTRATION: KCT0005717.

Rearranged Copolyurea Networks for Selective Carbon Dioxide Adsorption at Room Temperature.

Copolyurea networks (co-UNs) were synthesized via crosslinking polymerization of a mixture of tetrakis(4-aminophenyl)methane (TAPM) and melamine with hexamethylene diisocyanate (HDI) using the organic sol-gel polymerization method. The subsequent thermal treatment of between 200 and 400 °C induced the sintering of the powdery polyurea networks to form porous frameworks via urea bond rearrangement and the removal of volatile hexamethylene moieties. Incorporating melamine into the networks resulted in a higher nitrogen content and micropore ratio, whereas the overall porosity decreased with the melamine composition. The rearranged network composed of the tetraamine/melamine units in an 80:20 ratio showed the highest carbon dioxide adsorption quantity at room temperature. The results show that optimizing the chemical structure and porosity of polyurea-based networks can lead to carbon dioxide adsorbents working at elevated temperatures.

Clinical Outcomes after Mix-and-Match Implantation of Extended Depth of Focus and Diffractive Multifocal Intraocular Lenses.

PURPOSE: To evaluate the clinical outcomes after bilateral mix-and-match cataract surgery using extended depth of focus (EDOF) and diffractive multifocal (DMF) intraocular lenses (IOLs). Setting. Asan Medical Center, Seoul, South Korea. DESIGN: Prospective clinical study. METHODS: Thirty-seven patients underwent TECNIS Symfony EDOF IOL (ZXR00) implantation in the dominant eye, and TECNIS +3.25 DMF IOL (ZLB00) implantation in the nondominant eye. Patients were followed up for 3 months; uncorrected and corrected distance visual acuity (UDVA and CDVA), uncorrected intermediate and near visual acuity (UIVA and UNVA), contrast sensitivity, defocus curves, stereopsis, and patient satisfaction were assessed. RESULTS: At 3 months, the mean logarithm of the minimum angle of resolution (logMAR) of UDVA was 0.07 ± 0.09 in EDOF IOL eyes, 0.12 ± 0.11 in DMF IOL eyes, and 0.02 ± 0.05 in both eyes. UIVA was 0.11 ± 0.11 in EDOF IOL eyes, 0.16 ± 0.12 in DMF IOL eyes, and 0.04 ± 0.07 in both eyes. UNVA was 0.25 ± 0.15 in EDOF IOL eyes, 0.22 ± 0.16 in DMF IOL eyes, and 0.13 ± 0.13 in both eyes. Thirty patients (81.1%) were more than satisfied with near vision, and 8 patients (21.6%) complained of severe glare and halo. Spectacle independence for near vision was achieved in 34 patients (91.9%), and 31 patients (83.8%) had better than a 50-second arc of stereopsis. CONCLUSION: Mix-and-match cataract surgery with EDOF and DMF IOL implantation provided good visual outcomes for all distances. Additionally, excellent patient satisfaction was achieved with a high level of spectacle independence and acceptable photic phenomena.

Effects of lid debris debridement combined with meibomian gland expression on the ocular surface MMP-9 levels and clinical outcomes in moderate and severe meibomian gland dysfunction.

BACKGROUND: To evaluate the effects of lid debris debridement and meibomian gland expression (MGX) on extracellular matrix metalloproteinase-9 (MMP-9) levels and clinical outcomes of moderate and severe MGD. METHODS: In this retrospective case series study, a total 48 eyes of 24 patients with moderate and severe MGD underwent one session of lid debris debridement using the BlephEx combined with MGX. We evaluated the tear film break-up time (TBUT), corneal and conjunctival fluorescein staining scores, Schirmer 1 test, biomicroscopic examination of lid margins and meibomian gland (MG), ocular surface disease index (OSDI) questionnaire score, and extracellular MMP-9 levels using a point-of-care MMP-9 immunoassay device before and 4 weeks after lid debris debridement and MGX. Linear mixed model and generalized estimating equations model were used to evaluate possible differences. RESULTS: There were significant improvements in the TBUT (P = 0.002), SICCA and Oxford staining scores (all P < 0.001), lid margin telangiectasia (P < 0.001 for upper and lower eyelids), lid thickness (P < 0.001 for upper and lower eyelids), MG orifice plugging (P < 0.001 for upper and lower eyelids), meibum color (P = 0.026 for upper eyelid, P < 0.001 for lower eyelid), meibum consistency (P < 0.001 for upper and lower eyelids), meibum grade (P < 0.001), MGD stage (P < 0.001), and OSDI score (P = 0.002). MMP-9 immunoassay positivity rate significantly decreased from 83.3 to 50.0% 4 weeks after treatment (P = 0.014). CONCLUSIONS: In patients with moderate to severe MGD, lid debris debridement using the BlephEx combined with MGX improved clinical findings, subjective symptoms, meibomian gland function, along with ocular surface MMP-9 level. We hereby suggest lid debris debridement using BlephEx combined with MGX as an effective clinical strategy for treatment of moderate to severe MGD.

Novel Findings about Myopia in Patients with Oculodermal Melanocytosis (Nevus of Ota).

Purpose: To test the hypothesis that ocular pigment in patients with oculodermal melanocytosis decreases myopia severity.Methods: Refractive and biometric parameters were measured and compared between pigmented eyes and non-pigmented contralateral eyes in oculodermal melanocytosis patients that underwent surgical ocular pigmentation removal. To assess pigmentation, the pigmentation score was measured in each quadrant of the sclera and added together for a cumulative score. For subgroup analyses, patients were categorized into three groups according to the severity of myopia in the non-pigmented eye.Results: Fifty-five patients (110 eyes) were included. Spherical power and spherical equivalent were significantly less myopic in pigmented eyes relative to contralateral non-pigmented eyes. The spherical powers of non-pigmented eyes were positively correlated with the difference in spherical power between contralateral eyes (r = 0.697, p < .001). The pigmentation scores of pigmented eyes were positively correlated with the ratio of myopia inhibition (r = 0.373, p = .005). In subgroup analyses, pigmented eyes exhibited significantly less myopic spherical powers and spherical equivalents than non-pigmented contralateral eyes in the moderate and high myopia groups. Pigmented eyes exhibited significantly shorter axial length than non-pigmented contralateral eyes in the high myopia group only.Conclusions: In patients with oculodermal melanocytosis, pigmented eyes exhibited less severe myopia relative to non-pigmented contralateral eyes. This suggested that ocular pigmentation inhibited myopic changes, potentially by blocking UV transmission. This study will be helpful in elucidating the mechanisms of myopic progression.

Evaluation of Astigmatic Correction Using Vector Analysis after Combined Femtosecond Laser-Assisted Phacoemulsification and Intrastromal Arcuate Keratotomy.

The aim of this study was to evaluate astigmatic correction in patients with mild to moderate astigmatism after combined femtosecond laser-assisted cataract surgery (FLACS) and intrastromal arcuate keratotomy (ISAK), using vector analysis. This retrospective study included patients with corneal astigmatism of 0.5-3.0 diopters (D) who underwent FLACS and ISAK. Vector analyses of astigmatism were performed using the Alpins method, considering three vectors: target-induced astigmatism (TIA), surgically induced astigmatism (SIA), and difference vector (DV). Magnitude of error (ME), angle of error (AE), correction index (CI), and coefficient of adjustment (CA) were calculated. Subgroup analysis according to the axis of astigmatism, patient age, and white to white (WTW) diameter was conducted. In total, for the 79 eyes of 79 patients, the TIA was 1.21 ± 0.52 D, the SIA was 0.76 ± 0.53 D, and the DV was 0.86 ± 0.50 D. The ME (difference between SIA and TIA) was -0.46 ± 0.45 D, and the CI (ratio of SIA and TIA) was 0.62 ± 0.34; both these parameters demonstrated slight undercorrection. The CA (inverse of the CI) was 2.48 ± 2.61. The AE was 4.02° ± 28.7°, and the absolute AE was 21.7° ± 19.0°. In the univariate regression analyses to identify factors that affected the CI, there was a negative correlation between age and the CI (P=0.022). In conclusion, vector analysis after the combined FLACS and ISAK revealed slight undercorrection, regardless of the astigmatism meridian. The precision of the nomogram should be improved through long-term vector analysis for the results of arcuate keratotomy and through further research on the relationship between patient demographics and CI. Overall, this study has shown that FLACS and ISAK could reduce postoperative corneal astigmatism effectively and safely.

Changes in the expression of matrix metalloproteinase-9 after intense pulsed light therapy combined with meibomian gland expression in moderate and severe meibomian gland dysfunction.

PURPOSE: To evaluate the combined effect of intense pulsed light (IPL) therapy and meibomian gland expression on extracellular matrix metalloproteinase-9 (MMP-9) levels and clinical outcomes of moderate and severe meibomian gland dysfunction (MGD) treatment. METHODS: This retrospective study was conducted on 45 eyes of 23 patients with moderate and severe MGD. Each eye underwent three IPL sessions and meibomian gland expression at 2-week intervals. In this study the evaluated parameters included tear film break-up time (TBUT), corneal and conjunctival fluorescein staining scores, biomicroscopic examination of lid margins and meibomian glands, ocular surface disease index (OSDI) questionnaire score, and extracellular MMP-9 levels using the immunoassay device before and two weeks after the last treatment session. Linear mixed model and generalized estimating equations model were used to evaluate possible differences. RESULTS: There were significant improvements in TBUT (P < 0.001), SICCA ocular staining score (P = 0.008), Oxford staining score (P = 0.023), lid margin irregularity (P < 0.001 for upper and lower eyelids), lid thickness (P < 0.001 for upper and lower eyelids), meibomian gland plugging (P = 0.010 and P = 0.012 for upper and lower eyelids), meibum color (P = 0.044 and P < 0.001 for upper and lower eyelids), meibum consistency (P < 0.001 for upper and lower eyelids), MGD grade (P < 0.001), and OSDI questionnaire score (P < 0.001). Incidence of positive results for MMP-9 immunoassay significantly decreased from 84.0% to 56.0% (P = 0.031) after treatment. CONCLUSION: In patients with moderate to severe MGD, three sessions of IPL combined with meibomian gland expression improved objective findings, subjective symptoms, meibomian gland function, and MMP-9 immunoassay results. The results support the combination of IPL and meibomian gland expression for treating moderate to severe MGD.

Bending resistance and cyclic fatigue resistance of WaveOne Gold, Reciproc Blue, and HyFlex EDM instruments.

BACKGROUND/PURPOSE: Several single-file systems manufactured using different heat treatment and operated by different kinematics have been released. This study compared the bending resistance and cyclic fatigue resistance of three NiTi files, and examined their phase-transformation behavior. MATERIALS AND METHODS: WaveOne Gold Primary (WOG), Reciproc Blue R25 (RPB), and HyFlex EDM OneFile (HDM) were tested (N = 40/instrument). A vertical load was applied to a point 3 mm from the tip, and the stress was measured until a displacement of 3 mm. Tests were conducted at either room temperature (RT: 22 °C) or body temperature (BT: 37 °C) (n = 10). Cyclic fatigue resistance tests were performed in an artificial canal, which had a curvature angle of 40° and a 5-mm radius. Tests were conducted at either RT or BT (n = 10). Instruments were operated according to the manufacturers' instructions. Test results were analyzed using the Kruskal-Wallis and the Mann-Whitney tests. Additional three instruments of each brand were subjected to differential scanning calorimetry (DSC). RESULTS: At RT the bending resistance of three files were not significantly different. However, at BT the bending resistance of RPB was highest, followed by WOG, and HDM (P < 0.05). At RT, RPB demonstrated the longest fracture time, followed by HDM, and WOG (P < 0.05). At BT, HDM had the longest fracture time, followed by RPB, and WOG (P < 0.05). The WOG, RPB consisted of austenite in a considerable proportion, whereas HDM was mainly martensite state at BT. CONCLUSION: HDM presented superior flexibility and cyclic fatigue resistance at BT.

Evaluation of posterior vitreous detachment using ultrasonography and optical coherence tomography.

PURPOSE: To compare the diagnostic ability of ultrasonography (US) and optical coherence tomography (OCT) in evaluating posterior vitreous detachment (PVD) status. METHODS: In total, 124 eyes in 63 patients were prospectively enrolled. Posterior vitreous detachment (PVD) status was evaluated by two examiners independently using US and OCT (transverse scan with/without peripapillary scan). By combining all examination results from both examiners, a final agreement on the PVD status was made. Inter-observer agreement and inter-examination agreement on PVD detection were evaluated. RESULTS: The inter-observer agreement on PVD grading based on US was substantial (kappa = 0.628). The inter-observer agreement on PVD grading based on OCT was almost perfect (transverse and peripapillary scan, kappa = 0.893; transverse scan only, kappa = 0.923). The PVD grading based on transverse and peripapillary OCT perfectly matched the final PVD grading (kappa = 1.00). The PVD grading made based on US and transverse scan only showed almost perfect agreement with the final PVD grading (US, kappa = 0.834; transverse scan only, kappa = 0.906). CONCLUSION: Both US and OCT could accurately evaluate PVD. The interpretation of the US images was more subjective, leading to lower inter-examiner agreement than that of the OCT. By adding peripapillary OCT scan images, the diagnostic ability of OCT was improved.