Prevalence of Computer Vision Syndrome and Its Risk Factors in a Spanish University Population.

OBJECTIVES: To determine the prevalence of digital eye strain or computer vision syndrome (CVS) and its risk factors in a university population (University of Valladolid, Spain). METHODS: An anonymous cross-sectional online survey was conducted in a university population [staff (lecturers and administrative employees) and students (undergraduate, master's, and PhD)], including two validated questionnaires (Ocular Surface Disease Index [OSDI] and the 17-item Computer-Vision Symptom Scale questionnaire [CVSS17]) and questions about sociodemographic data and visual display terminal use. The prevalence and risk factors for CVS (CVSS17≥29) (multivariate logistic regression model) were calculated. RESULTS: One thousand nine participants responded to the survey (35.2±15.2 years; 64.1% women). The mean OSDI and CVSS17 questionnaire scores were 18.9±15.6 and 31.5±6.4, respectively, and 35.4% of the respondents had dry eye symptoms (OSDI>22). The total prevalence of CVS was 65.4% (95% CI 62.1-68.3). Undergraduate students showed the highest CVS prevalence (72.6%; P <0.01), which was significant. In addition, women, participants younger than 36 years old, contact lens wearers, and subjects with dry eye symptoms reported a statistically higher CVSS17 score ( P ≤0.01). In the multivariate model, significant factors associated with the presence of CVS ( P ≤0.03) were female sex (OR=2.10; 95% CI 1.54-2.88), dry eye symptoms (OSDI>22) (OR=16.98; 95% CI 10.36-27.84), VTD use ≥6 hr daily (OR=1.96; 95% CI 1.09-3.52), and being an undergraduate student (OR=2.23; 95% CI 1.54-3.24). CONCLUSION: A high prevalence (65.4%) of CVS was found among the Spanish university population, with the undergraduate student group having the highest prevalence (72.6%). Female sex, more than 6 hr/day of visual display terminal use, being an undergraduate student, and dry eye symptoms significantly increased the risk of CVS in the university population.

Magnetic anisotropy engineering in onion-structured metal oxide nanoparticles combining dual exchange coupling and proximity effects.

A series of exchange-coupled magnetic nanoparticles combining several magnetic phases in an onion-type structure were synthesized by performing a three-step seed-mediated growth process. Iron and cobalt precursors were alternatively decomposed in high-boiling-temperature solvents (288-310 °C) to successively grow CoO and Fe3-δO4 shells (the latter in three stages) on the surface of Fe3-δO4 seeds. The structure and chemical composition of these nanoparticles were investigated in depth by combining a wide panel of advanced techniques, such as scanning transmission electron microscopy (STEM), electron energy-loss spectroscopy-spectrum imaging (EELS-SI), 57Fe Mössbauer spectrometry, and X-ray circular magnetic dichroism (XMCD) techniques. The size of the nanoparticles increased progressively after each thermal decomposition step, but the crystal structure of core-shell nanoparticles was significantly modified during the growth of the second shell. Indeed, the antiferromagnetic CoO phase was progressively replaced by the CoFe2O4 ferrimagnet due to the concomitant processes of partial solubilization/crystallization and the interfacial cationic diffusion of iron. A much more complex chemical structure than that suggested by a simple size variation of the nanoparticles is thus proposed, namely Fe3-δO4@CoO-CoFe2O4@Fe3-δO4, where an intermediate Co-based layer was shown to progressively become a single, hybrid magnetic phase (attributed to proximity effects) with a reduction in the CoO amount. In turn, the dual exchange-coupling of this hybrid Co-based intermediate layer (with high anisotropy and ordering temperature) with the surrounding ferrite (core and outer shells) stabilized the particle moment well above room temperature. These effects allow for the production of Fe oxide-based magnetic nanoparticles with high effective anisotropy, thus revealing the potential of this strategy to design rare-earth-free permanent nanomagnets at room temperature.

T3-T4 index as a prognostic marker of response to biological treatments in elderly patients with inflammatory bowel disease.

Following the growing trend of trying to individualise treatment in inflammatory bowel disease and in view of the challenge posed by elderly patients requiring biologic treatments, we have conducted a study in our centre to assess the T3/T4 index as a predictor of response to biologic treatments in elderly patients.

Exploring a new generation of bimetallic magnetic ionic liquids with ultra-low viscosity in microextraction that enable direct coupling with high-performance liquid-chromatography.

BACKGROUND: The incorporation of bimetallic magnetic ionic liquids (MILs) in microextraction methods is an emerging trend due to the improved magnetic susceptibility offered by these solvents, which relies on the presence of metallic components in both the cation and the anion. This feature favors easy magnetic separation of these solvents in analytical sample preparation strategies. However, reported liquid-phase microextraction methods based on bimetallic MILs still present an important drawback in that the MILs are highly viscous, making a dispersive solvent during the microextraction procedure necessary, while also requiring a tedious back-extraction step prior to the chromatographic analysis. RESULTS: We propose for the first time a new generation of ultra-low viscosity bimetallic MILs composed of two paramagnetic Mn(II) complexes characterized by their easy usage in dispersive liquid-liquid microextraction (DLLME). The approach does not require dispersive solvent and the MIL-DLLME setup was directly combined with high-performance liquid chromatography (HPLC) and fluorescence detection (FD), without any back-extraction step. The approach was evaluated for the determination of five monohydroxylated polycyclic aromatic hydrocarbons, as carcinogenic biomarkers, in human urine. Optimum conditions of the MIL-DLLME method included the use of a low MIL volume (75 µL), a short extraction time (5 min), and no need of any dispersive solvent neither NaCl. The method presented limits of detection down to 7.50 ng L-1, enrichment factors higher than 17, and provided inter-day relative standard deviation lower than 11%. Analysis of urine samples was successfully performed, with biomarker content found at levels between 0.24 and 7.8 ng mL-1. SIGNIFICANCE: This study represents the first liquid-phase microextraction method using the new generation of low-viscous bimetallic MILs. The proposed MIL-DLLME approach represents 2 important advances with respect to previous methods employing bimetallic MILs: 1) no dispersive solvent is required, and 2) direct injection of the MIL in the HPLC is possible after minor dilution (no back extraction steps are required). Therefore, the microextraction strategy is simple, rapid, and consumes very small amounts of energy.

The Repeatability and Agreement of Ocular Parameters Measured with the MYAH and Myopia Master Devices between Expert and Non-Expert Practitioners.

In myopia control, it is essential to measure the axial length (AL) and corneal parameters, and to monitor whether changes in these parameters have occurred over time. The aim of this study was to analyse the repeatability and agreement between expert and non-expert practitioners in ocular parameters measured by the MYAH and Myopia Master. Three repeated measurements (n = 42) were recorded with the MYAH and Myopia Master by two (an expert and a non-expert) observers in a randomized order. The AL, K1, K2, and white-to-white (WTW) distance were collected. The intraobserver repeatability was excellent in all parameters measured with both devices in both observers. The AL outcome presented the best repeatability with the MYAH and Myopia Master (intraclass correlation coefficient, ICC = 1.0; coefficient of variation, CV ≤ 0.06% for both observers), while the WTW presented poorer results (ICC ≤ 0.991; CV ≤ 0.52%). The Myopia Master provides a significantly (p ≤ 0.01) flatter K1 and K2 as well as a lower WTW (p ≤ 0.01) than the MYAH. No statistically significant difference in AL measurements was found with either device (p ≥ 0.10; ICC = 1.0). None of the parameters showed differences (p ≥ 0.12) between the expert and non-expert observer. The MYAH and Myopia Master provide consistent measurements in a healthy adult population regardless of the previous clinical experience of the observer. AL measurements should be used interchangeably but K1, K2, and WTW should be used interchangeably with caution.

Fully Automated Flow Protocol for C(sp3)-C(sp3) Bond Formation from Tertiary Amides and Alkyl Halides.

Herein, we present a novel C(sp3)-C(sp3) bond-forming protocol via the reductive coupling of abundant tertiary amides with organozinc reagents prepared in situ from their corresponding alkyl halides. Using a multistep fully automated flow protocol, this reaction could be used for both library synthesis and target molecule synthesis on the gram-scale starting from bench-stable reagents. Additionally, excellent chemoselectivity and functional group tolerance make it ideal for late-stage diversification of druglike molecules.

Clinical and laboratory features of rickettsioses in Yucatan, Mexico.

Rickettsia species are obligate intracellular bacteria that can cause mild to severe human disease. Based on phylogeny, clinical symptoms, and antigenic properties, rickettsiae are classified into four groups. Infections by these agents are characterized by clinical symptoms ranging from self-limited to severe and even fatal febrile illnesses, depending on the Rickettsia spp. involved, the patient's predisposition, and timely medical care. The present study aimed to characterize rickettsial diseases in Yucatan according to clinical and laboratory features appearing in medical records corresponding to 427 samples taken between 2015 and 2018. A study was conducted over the period 2015-2018 on 427 samples. Clinical and laboratory features were documented from the patients' medical records. For molecular diagnosis, blood was collected in 3.8 % sodium citrate as anticoagulant, and DNA was extracted. Single-step and nested PCR amplification was performed using genus-specific primers for the rickettsial 17kDa and ompB genes. The amplicons obtained were purified and sequenced. A total of 22.7 % (97/427) positive cases of Rickettsia spp. were identified by PCR from 14.15 % (15/106) of the municipalities in Yucatan. 75.2 % (73/97) of the cases were from the city of Merida during the autumn (September-December). The age groups with the highest frequency of confirmed cases were pediatric (5-14 years) (57.7 %) and adults (25-49 years) (42.2 %). There were six fatal cases in children, one associated with R. typhi and five with R. rickettsii. In non-fatal cases, 32.9 % (32/97) corresponded to the spotted fever group (SFG), and 60.8 % (59/97) to the typhus group (TG). Significant differences in signs, and laboratory data, were observed between the pediatric and adult populations. For the treatment of patients, oral and intravenous doxycycline was used in severe hospitalized cases. Typhus group and spotted fever group Rickettsiae are endemic pathological agents found in urban and rural areas of our region. Molecular identification allows for greater diagnostic accuracy and timely treatment and consequently a better prognosis. It is necessary to implement or reinforce measures focused on the dissemination of knowledge regarding rickettsial diseases and their prevention.

ffectiveness and safety of ustekinumab dose escalation in Crohn’s disease: a multicenter observational study / Efectividad y seguridad del aumento de dosis de ustekinumab en la enfermedad de Crohn: un estudio observacional multicéntrico

Background: ustekinumab has proven effective in Crohn’s disease (CD). However, some patients will partially respond or lose response over time. Data supporting the effectiveness of dose escalation in this scenario is scarce. Aim: to evaluate the effectiveness of ustekinumab dose escalation in CD. Methods: patients with active CD (Harvey-Bradshaw ≥ 5) who had received intravenous (IV) induction and at least a subcutaneous (SC) dose were included in this retrospective observational study. Ustekinumab dose was escalated, either via shortening of the interval to six or four weeks or IV reinduction plus shortening to every four weeks. Results: ninety-one patients were included, and ustekinumab dose was escalated after a median of 35 weeks of treatment. At week 16 after intensification, steroid-free clinical response and remission were observed in 62.6 % and 25.3 % of patients, respectively. Systemic corticosteroids were discontinued in 46.7 % of patients who were on corticosteroids at baseline. Follow-up data beyond week 16 were available for 78 % of patients; at the last visit, 66.2 % and 43.7 % were in steroid-free clinical response and remission, respectively. After a median follow-up of 64 weeks, 81 % of patients were still treated with ustekinumab. Adverse events were reported in 4.3 % of patients; these were all mild and did not lead to hospitalization or discontinuation of treatment. Five patients (5.5 %) underwent surgical resection, with no immediate postsurgical complications. Conclusion: ustekinumab dose escalation was effective in recapturing response in over half of the patients. These findings suggest that dose escalation should be considered in patients who experience loss or partial response to the standard maintenance.(AU)

Comparison of the Ocular Surface Disease Index and the Symptom Assessment in Dry Eye Questionnaires for Dry Eye Symptom Assessment.

BACKGROUND: Patient-reported dry eye symptoms (DESs), assessed using the Ocular Surface Disease Index (OSDI) and the Symptom Assessment iN Dry Eye (SANDE) questionnaires, were compared in a large sample of patients. METHODS: The correlation (Spearman coefficient) and agreement (Bland-Altman analysis) between the OSDI and SANDE questionnaire scores (with and without score normalization) were assessed in 1033 patients and classified according to the OSDI score as non-DES and DES in a cross-sectional analysis. RESULTS: The normalized and non-normalized SANDE results were higher than the OSDI results in all samples (2.83 ± 12.40 (p = 0.063) and 2.85 ± 15.95 (p = 0.016), respectively) and in non-DES (p > 0.063) and DES (p < 0.001) with both OSDI cutoff values. Weak correlations were found (Spearman coefficient <0.53; p < 0.001) in all cases except DES (0.12, p = 0.126). Weak agreement was found with a Bland-Altman analysis of the normalized and non-normalized scores of both questionnaires (mean difference from -7.67 ± 29.17 (DES patients) to -1.33 ± 8.99 (non-DES patients) without score normalization, and from -9.21 ± 26.37 (DES patients) to -0.85 ± 4.01 (non-DES) with data normalization), with a statistically significant linear relationship (R2 > 0.32, p < 0.001). The SANDE questionnaire did not yield the same patient classification as OSDI. The same operative curves (ROC) of the SANDE normalized and non-normalized scores were used to differentiate among patients with DES using OSDI < 12 (0.836 ± 0.015) or OSDI < 22 (0.880 ± 0.015) cutoff values. CONCLUSIONS: Normalized and non-normalized data collected from the SANDE questionnaire showed relevant differences from those of the OSDI, which suggests that the results of the SANDE visual analog scale-based questionnaire provide different patient classifications than the OSDI score.

A dynamical method to objectively assess infantile nystagmus based on eye tracking. A pilot study

Purpose The purpose of this research is to propose a new method for the easy, inexpensive and objective quantification of nystagmus using eye-tracking records collected during a simple reading task that could be implantable in clinical practice to assess patients with nystagmus. Methods This is a prospective, observational pilot study. Eye movements of 4 nystagmus patients and 9 healthy children during a reading task (a paragraph with 82 words) on a 15′’ monitor were collected and compared. Data are time series indicating the gaze position on the screen. Two quantifiers were proposed: IndS (based on the speed of movements) and IndF (based on the variation of the gaze trajectory). Results The indices proposed reflect differences in the behavior of eye movements between the two groups. Nystagmus patients present higher values of IndS - indicating smaller number of slow movements (16% of movements with speeds <0.33 1/s for nystagmus and 85% for the control group, with p = 0.01) - and higher values of IndF - indicating higher gaze fluctuation (p = 0.01). Differences were not related with reading speed as show the mean and standard deviation: the nystagmus group required 115±45 s to complete the task and the control group 151±85 s; p = 0.73. Conclusions The proposed indices provide a new method that allows an objective assessment of nystagmus, with potential use in clinical and research practice to improve the follow-up of patients by monitoring the nystagmus over time or treatment. (AU)

A tool to assess analytical sample preparation procedures: Sample preparation metric of sustainability.

Sample preparation is a key step in most analytical methods, generally regarded as the least green step of the entire procedure. The existing green metrics assess the greenness of sample preparation techniques through the evaluation of the whole analytical procedure: including sampling, sample preparation, and the final detection/quantitation. Such inclusion of the entire method makes assessing the sustainability of a newly developed sample preparation technique quite challenging, as many aspects not solely linked to the sample preparation step are unavoidably considered. Thus, an alternative metric that can explicitly and exclusively evaluate the sample preparation is proposed. The metric is simple; it reports the result with a clock-like diagram, displaying the greenness outcome of main sample preparation parameters and a total score. This new metric can differentiate closely related microextraction approaches in terms of sustainability. The metric is also open-source and can be used by downloading the Excel sheet provided.

Understanding the Raman enhancement of carbon nanohorns labelled with organic dyes.

Carbon nanohorns have been non-covalently functionalized with two different benzothiadiazoloquinoxalines prepared via Stille cross-coupling reactions under solvent-free conditions and microwave irradiation. The close interactions between these organic molecules and the nanostructures resulted in a prominent Raman enhancement, which makes them attractive candidates for multiple applications. A complete experimental physico-chemical characterization has been combined with in silico studies to understand these phenomena. The processability of the hybrids was exploited to prepare homogeneous films on substrates with different natures.

Effectiveness and safety of ustekinumab dose escalation in Crohn's disease: a multicenter observational study.

BACKGROUND: ustekinumab has proven effective in Crohn's disease (CD). However, some patients will partially respond or lose response over time. Data supporting the effectiveness of dose escalation in this scenario is scarce. AIM: to evaluate the effectiveness of ustekinumab dose escalation in CD. METHODS: patients with active CD (Harvey-Bradshaw ≥ 5) who had received intravenous (IV) induction and at least a subcutaneous (SC) dose were included in this retrospective observational study. Ustekinumab dose was escalated, either via shortening of the interval to six or four weeks or IV reinduction plus shortening to every four weeks. RESULTS: ninety-one patients were included, and ustekinumab dose was escalated after a median of 35 weeks of treatment. At week 16 after intensification, steroid-free clinical response and remission were observed in 62.6 % and 25.3 % of patients, respectively. Systemic corticosteroids were discontinued in 46.7 % of patients who were on corticosteroids at baseline. Follow-up data beyond week 16 were available for 78 % of patients; at the last visit, 66.2 % and 43.7 % were in steroid-free clinical response and remission, respectively. After a median follow-up of 64 weeks, 81 % of patients were still treated with ustekinumab. Adverse events were reported in 4.3 % of patients; these were all mild and did not lead to hospitalization or discontinuation of treatment. Five patients (5.5 %) underwent surgical resection, with no immediate postsurgical complications. CONCLUSION: ustekinumab dose escalation was effective in recapturing response in over half of the patients. These findings suggest that dose escalation should be considered in patients who experience loss or partial response to the standard maintenance.

Intrasession repeatability and agreement of a new method to measure the foveal fixation axis.

Purpose: Ophthalmic lens adaptation, particularly with progressive addition lenses, requires accurate measurements of the patient nasopupillary distance (NPD) and interpupillary distance (IPD), which are usually collected using the pupil centre as a reference. However, differences between the pupil centre and visual or foveal axis could induce some subsidiary effects of correcting lenses. This study aimed to assess the intrasession repeatability of a new prototype (Ergofocus®; Lentitech, Barakaldo, Spain) that can measure the foveal fixation axis (FFA) distance and assess the agreement with the NPD measurements collected using a traditional method (frame ruler). Methods: The FFA at far and near distances was measured three consecutive times in 39 healthy volunteers to determine the intrasession repeatability according to the British Standards Institute and International Organization for Standardization. Additionally, the FFA and NPD (standard frame ruler) were measured in 71 healthy volunteers and compared using Bland-Altman analysis. Two blinded experienced practitioners conducted each FFA and NPD measurement. Results: The FFA measurements showed acceptable repeatability at far distances (right eye (RE): Sw = 1.16 ± 0.76 mm and coefficient of variation (CV) = 3.92 ± 2.51%; left eye (LE) Sw = 1.11 ± 0.79 mm and CV = 3.76 ± 2.51%) and at near distances (RE: Sw = 0.97 ± 0.85 mm and CV = 3.52 ± 3.02%; LE: Sw = 1.17 ± 0.96 mm and CV = 4.54 ± 3.72%). Additionally, agreement with the NPD showed large differences at far distances (RE: -2.15 ± 2.34, LoA = -6.73 to 2.43 mm (P < 0.001); LE: -0.61 ± 2.62, LoA = -5.75 to 4.53 mm (P = 0.052)) and near distances (RE: -3.08 ± 2.80, LoA -8.57 to 2.42 mm (P < 0.001); LE: -2.97 ± 3.97, LoA: -10.75 to 4.80 mm (P < 0.001)). Conclusions: FFA measurements showed clinically acceptable repeatability at both far and near distances. Agreement with the NPD measured using a standard frame ruler showed significant differences, suggesting that both measurements are not interchangeable in clinical practice to prescribe and center ophthalmic lenses. Further research is necessary to assess the impact of FFA measurement in ophthalmic lens prescriptions.

A dynamical method to objectively assess infantile nystagmus based on eye tracking. A pilot study.

PURPOSE: The purpose of this research is to propose a new method for the easy, inexpensive and objective quantification of nystagmus using eye-tracking records collected during a simple reading task that could be implantable in clinical practice to assess patients with nystagmus. METHODS: This is a prospective, observational pilot study. Eye movements of 4 nystagmus patients and 9 healthy children during a reading task (a paragraph with 82 words) on a 15'' monitor were collected and compared. Data are time series indicating the gaze position on the screen. Two quantifiers were proposed: IndS (based on the speed of movements) and IndF (based on the variation of the gaze trajectory). RESULTS: The indices proposed reflect differences in the behavior of eye movements between the two groups. Nystagmus patients present higher values of IndS - indicating smaller number of slow movements (16% of movements with speeds <0.33 1/s for nystagmus and 85% for the control group, with p = 0.01) - and higher values of IndF - indicating higher gaze fluctuation (p = 0.01). Differences were not related with reading speed as show the mean and standard deviation: the nystagmus group required 115±45 s to complete the task and the control group 151±85 s; p = 0.73. CONCLUSIONS: The proposed indices provide a new method that allows an objective assessment of nystagmus, with potential use in clinical and research practice to improve the follow-up of patients by monitoring the nystagmus over time or treatment.

Interdevice agreement in the measurement of physiognomy parameters and frame angles to prescribe progressive addition lenses.

CLINICAL RELEVANCE: Ophthalmic lens adaptation requires accurate measurements of physiognomy parameters and frame angles, with a great impact on subject vision, especially when personalised progressive addition lenses are prescribed. BACKGROUND: The aim of this study is to describe interdevice agreement between different methods and traditional methods (frame ruler). METHODS: The agreement of the interpupillary distance, nasopupillary distance and fitting point height measured with four devices (PD-5, OptiCenter, Visioffice and a frame ruler) and of pantoscopic and frame wrap angles measured with three devices (OptiCenter, Visioffice and Essilor standard ruler) was assessed in 21 healthy volunteers, by a Bland-Altman analysis; mean difference and limits of agreement (LoA) were calculated. RESULTS: Frame ruler nasopupillary distance measurements showed limited agreement with PD-5 [-0.38 ± 1.03 (LoA -2.40 to 1.64) and 0.44 ± 1.02 (LoA -1.72 to 2.61)] and Visioffice [0.62 ± 1.24 (LoA -1.81 to 3.05) and -0.16 ± 1.72 (LoA -3.54 to 3.22)] measurements for the right and left eyes, respectively. Poor agreement was found for interpupillary distances (PD-5 [0.21 ± 1.47 (LoA -2.67 to 3.09)], OptiCenter [-0.05 ± 1.16 (LoA -2.32 to 2.22)] and Visioffice [0.46 ± 1.95 (LoA -3.36 to 4.28)]), fitting point height (OptiCenter [-1.27 ± 2.56 (LoA -6.27 to 3.75) and -0.92 ± 2.77 (LoA -6.35 to 4.51)] and Visioffice [-5.88 ± 6.21 (LoA -18.05 to 6.29) and -5.98 ± 6.12 (LoA -17.98 to 6.02)] for the right and left eyes, respectively) and pantoscopic and frame wrap angles (OptiCenter [-4.13 ± 3.75 (LoA -11.48 to 3.22) and -1.09 ± 0.60 (LoA -2.27 to 0.09)] and Visioffice [-6.18 ± 3.53 (LoA -13.10 to 0.74) and -1.93 ± 3.49 (LoA -8.77 to 4.91)], respectively). CONCLUSIONS: These results suggest that measurements of physiognomy and frame angles are not interchangeable between assessed devices and that these differences could induce lens centration errors with a large impact on progressive addition lens prescriptions.

Optometric practices and attitudes in keratoconus patient management in Latin America.

CLINICAL RELEVANCE: To explore optometric practices and attitudes in the management of keratoconus patients in LatinAmerica and how they are influenced by eye-care technology will help to minimise disease progression and their impact on patients' quality of life in Latin America. BACKGROUND: Keratoconus is a progressive, bilateral and asymmetric corneal disorder that requires a multidisciplinary approach, the use of different eye assessment technology, and different management approaches; mainly contact lenses and surgery. METHODS: Self-reported answers to an online survey (adapted to primary eye care) distributed via a newsletter emailed by various professional organisations across 15 Latin American countries were assessed and compared with those previously reported in three European countries. RESULTS: Answers from 977 eye care practitioners (60%) with >10 years of experience (396 in Latin America and 581 in Europe) were assessed. A total of 65.9% of Latin American responders prescribed rigid corneal lenses (RCL), although more than half of the respondents (54.0%) would fit more RCL if they underwent further training in RCL fitting. A majority of Latin American practitioners (74.0%) considered that RCL fitting is more difficult in keratoconus, requiring more diagnostic lenses (4.6 ± 2.7; median 4; range 1-10) than are necessary for healthy eyes. Low availability of corneal topography was reported in Latin America (23%), although practitioners with topographers are more likely to prescribe RCL (92.3%) and detect more new patients with keratoconus per year (83.5%). A minority of respondents referred keratoconus patients to another optometrist (25.8%) or (40.4%) participated in comanagement with ophthalmologists. CONCLUSION: This study provides initial evidence regarding keratoconus management in Latin America and suggests that actions are necessary to improve RCL training, facilitate eye-care technology accessibility and encourage comanagement between eye care practitioners to minimise disease progression and their impact on patients' quality of life in Latin America.

Molecular Detection of Leishmania (Leishmania) mexicana in Sandflies from the State of Yucatan, Mexico.

Background: Leishmaniases are a group of vector-borne zoonotic diseases of public health relevance within the tropical and subtropical regions of the world. The state of Yucatan is a vulnerable and receptive area to localized cutaneous leishmaniasis (LCL) due to its proximity to the high-transmission endemic states of Campeche and Quintana Roo. Autochthonous cases of LCL caused by Leishmania (Leishmania) mexicana have been documented in the state, showing a geographical expansion of the disease. Materials and Methods: Using CO2-supplemented Centers for Disease Control and Prevention light traps and Shannon traps, we captured anthropophilic sandflies in the surroundings of a locality with recent records of autochthonous cases of LCL. Sandflies carrying Leishmania DNA were evidenced using PCR. Results: A total of 140 Phlebotominae (Diptera: Psychodidae) females of four species were captured: Lutzomyia (Tricholateralis) cruciata (Coquillett), Psathyromyia (Psathyromyia) shannoni (Dyar), Lutzomyia (Lutzomyia) longipalpis (Lutz and Neiva), and Dampfomyia (Coromyia) deleoni (Fairchild and Hertig). Molecular results showed that 6.1% (95% confidence interval [CI] = 2.3-12.9%) of Lu. cruciata and 43.8% (95% CI = 19.8-70.1%) of Pa. shannoni showed evidence of carrying L. (L.) mexicana DNA. Conclusion: We provide evidence of anthropophilic sandflies carrying L. mexicana DNA in a municipality with recorded autochthonous cases of LCL caused by this parasite species in the state of Yucatan, suggesting the emergence of new focus of LCL in Mexico.

Magnetic Ionic Liquids in Analytical Microextraction: A Tutorial Review.

Magnetic ionic liquids (MILs) are materials of special interest in analytical chemistry and, particularly, in analytical microextraction. These solvents possess several of the properties derived from their inherent nature of ionic liquids, combined with their magnetism, that permits their manipulation with an external magnetic field. This feature allows for performing typical steps of the microextraction procedure in a simpler manner with the aid of a strong magnet. Although there are several important reviews summarizing the most innovative advances in this field, there is a gap of information, as they do not provide useful details and tips related to the experimental set up of these procedures. This tutorial review fills this gap by providing a guide for the proper handling of MILs, their manipulation with magnets, and their proper hyphenation with the most used analytical techniques. Attention is paid to dispersive liquid-liquid microextraction, stir-bar dispersive liquid microextraction, aqueous biphasic systems, and single-drop microextraction, for being the analytical microextraction techniques mostly employed with MILs. This review also introduces a classification of the MILs employed in analytical microextraction in three classes (denoted as A, B, and C) as a function of the MIL nature (metal-containing anion, metal-containing cation, and radical-containing ion), and discuss about the prospect and future trends regarding new MIL families in microextraction together with new directions expected in these procedures.

Clinical tool to measure fluorescein patterns in orthokeratology.

Background: Orthokeratology (ortho-k) is an overnight clinical contact lens wear technique to correct myopia and to reduce myopia progression wearing reverse-geometry rigid gas-permeable lenses. The lens fitting procedure in clinical practice usually requires subjective assessment of fluorescein pattern (fluorescein "bull's eye" pattern). The aim of this study was to develop a novel tool for fluorescein pattern measurements to reduce subjective practitioner dependency, especially in inexperienced practitioners, in ortho-k practice. Methods: A new MATLAB customized algorithm to measure the horizontal width of the four main zones of ortho-k fluorescein patterns (central bearing, tear reservoir, mid-peripheral bearing and edge lift) was designed. The algorithm was tested on a small image database consisting of 26 ortho-k fluorescein pattern images of 13 volunteers fitted with reverse geometry lenses (Seefree, Conoptica-Hecht Contactlinsen). The agreement between two independent observers and the ImageJ measurements was determined. Results: The new clinical tool provided similar measurements to ImageJ software for the central bearing (4.20 ± 0.74 and 4.27 ± 0.69 mm; P = 0.21), tear reservoir (1.69 ± 0.41 and 1.69 ± 0.45 mm; P = 0.69), mid-peripheral bearing (1.17 ± 0.11 and 1.13 ± 0.10 mm; P < 0.01) and edge lift (0.48 ± 0.06 and 0.48 ± 0.06 mm; P = 0.81) zones. Good agreement between the software (limits of agreement lower than ±0.55 mm) and inter-observer measurements (limits of agreement lower than ±0.66 mm) was found. Conclusions: The proposed clinical tool for semiautomatic fluorescein pattern measurements in ortho-k could help to reduce practitioner dependency in fluorescein pattern assessment with future potential to introduce prediction algorithms or artificial intelligence methods in myopia control management.