Hg and Se in Muscle and Liver of Blue Shark (Prionace glauca) from the Entrance of the Gulf of California: An Insight to the Potential Risk to Human Health.

The blue shark (Prionace glauca) is the most commonly caught species of Elasmobranchii at the entrance to the Gulf of California. Although fins are the primary target commodity, the entire organism is consumed. This study examined the concentration of Hg and Se in muscle and liver to understand the antagonistic process that occurs between these two elements within the organism. Twenty-two individuals were captured at the Gulf of California inlet between September 2019 and March 2021. Hg was measured by cold vapor atomic absorption, and Se by atomic absorption spectrophotometry in a graphite furnace. All individuals studied showed higher concentrations (µg g-1 wet weight) of Hg (0.69) and Se (2.49) in liver than in muscle (Hg 0.63 and Se 0.08). Although the mean Hg values were below the maximum allowable limits (Hg 1.0 µg g-1 wet weight), the molar ratio (< 1.0) and the negative health benefit value of selenium (HBVSe) in muscle show that additional caution should be taken when consuming this species. We recommend a more thorough study of the antagonistic interaction between Hg and Se to accurately assess the health risk for consumers of blue shark.

Metal(loid)s (As, Cd, Cu, and Zn) in three fish species from a dam after a mine-tailing spill: differential bioaccumulation and potential health risk.

The failure of a tailings dam occurred in January 2013 at the Santa María de Otáez mining region (Mexico) released a spill (~ 300,000 m3) on Los Remedios River, which was transported through the San Lorenzo River, and finally to El Comedero (EC) dam. The concentrations of metal(loid)s in the muscle, liver, gills, and guts of three fish species (Cyprinus carpio, Oreochromis aureus, Micropterus salmoides) collected from EC dam were examined twenty months later to assess the performance of the cleaning operations. The bioaccumulation patterns of the metal(loid)s in the tissues were different in the three fish species. Tilapia had the highest Cd (11.23 ± 8.53 µg g-1) and Cu (871 ± 1261 µg g-1) concentrations in the liver, as well as As concentration (83.6 ± 61.7 µg g-1) in the gut, while the highest Zn concentration (745 ± 356 µg g-1) was measured in the gills of the carp. Such variability can be caused by the variant bioavailability of the metal(loid)s and by the feeding habits of each species; and also by the fact that some metals are essential and better regulated by organisms than other non-essential. Compared to a study of tilapia carried out 90 days after mine spill, a decrease was evident in the liver for As, Cd, Cu, and Zn by 129, 5, 10, and 1.7 times, respectively. This revealed that cleaning operations were more efficient for As. The target hazard quotient and the hazard index were < 1, which indicates there will be no risk of consuming muscle in moderated rations of the three fish species.

Actualización sobre las contraindicaciones en cirugía refractiva láser corneal / Update on contraindications in laser corneal refractive surgery

Los más de 25 años de experiencia con las técnicas de cirugía refractiva (desde que se aprobara por la Food and Drug Administration [FDA] de EE. UU. el uso del láser excímer en el remodelamiento de la córnea en 1995), sumado a los avances tecnológicos en oftalmología (láser de femtosegundo, ablación guida por topografía, sistemas de imagen de segmento anterior) y el mayor entendimiento de los errores refractivos, las aberraciones de alto orden y la biomecánica corneal, hacen que la cirugía refractiva corneal con láser sea un método seguro y eficaz para la corrección de estos defectos. Sin embargo, a día de hoy, siguen existiendo ciertas circunstancias que suponen una contraindicación para su aplicación, además de otras que podrían asociarse a complicaciones, y que deben ser analizadas con detenimiento.Esta revisión repasa las contraindicaciones actuales para la cirugía refractiva corneal con láser recogidas en los Protocolos de Práctica Preferente (PPP) de la Academia Estadounidense de Oftalmología y de la Sociedad Española de Oftalmología. Estos protocolos están basados en la mayor evidencia científica disponible en la actualidad y permiten extraer recomendaciones claras, mejorando el perfil de seguridad de estas técnicas.Las contraindicaciones pueden diferenciarse en relativas o absolutas; entre estas últimas están: la edad inferior a 18 años, la ausencia de estabilidad refractiva y la existencia de ciertas afecciones oculares (entre las que destacan determinadas distrofias corneales, queratocono, ojo seco mal controlado) o sistémicas (procesos autoinmunes activos o diabetes mellitus mal controlada)...(AU)

More than 25 years of experience with refractive surgery techniques (since the FDA [Food and Drug Administration] of the United States approved the use of the excimer laser in the remodeling of the cornea in 1995), added to the technological advances in ophthalmology (femtosecond laser, topography-guided ablation, anterior segment imaging systems) and increased understanding of refractive errors, higher order aberrations, and corneal biomechanics make corneal laser refractive surgery a safe method and effective for the correction of these defects. However, to date, there are still certain circumstances that represent a contraindication for its application, in addition to others that could be associated with complications, and that must be carefully analyzed.This review analyzes the current contraindications for laser corneal refractive surgery listed in the Preferred Practice Protocols (PPPs) of the American Academy of Ophthalmology and the Spanish Ophthalmology Society. These protocols are based on the best scientific evidence currently available and allow clear recommendations to be drawn, improving the safety profile of these techniques.Contraindications can be differentiated into relative or absolute; among the latter are: age less than 18 years, the absence of refractive stability and the existence of certain ocular pathologies (including certain corneal dystrophies, keratoconus, poorly controlled dry eye) or systemic pathologies (active autoimmune processes or poorly controlled diabetes mellitus). Other circumstances such as the use of certain drugs (amiodarone, isotretinoin), extreme values of mean central keratometry and pachymetry, history of previous uveitis or glaucoma, pregnancy and lactation, are considered relative contraindications according to the PPPs. However, there are studies that demonstrate the safety of refractive surgery in some of these cases. (AU)

Laser in situ keratomileusis and surface ablation in pregnancy.

PURPOSE: Although corneal refractive surgery is contraindicated during pregnancy, some patients are unaware that they are pregnant when they undergo surgery. Our objectives were to determine the functional outcomes of corneal refractive surgery during pregnancy and to compare the results with those of nonpregnant women. METHODS: We performed a multicenter, retrospective, interventional case series review of patients who were pregnant and who underwent laser in situ keratomileusis (LASIK) or surface ablation (photorefractive keratectomy, PRK) from September 11, 2002 to December 12, 2020 (group 1, n=82 eyes). Patients were included consecutively. Findings were compared with those of nonpregnant women (group 2, n=164 eyes). Functional (visual and refractive) outcomes are described. Follow-up was at least 550 days (control group, median [IQR], 990 days [715-1496]; study group, 895 days [709-1310]). The setting was Clínica Baviera, Spain, (AIER Eye Hospital Group). RESULTS: A statistically significant difference was found between the groups in terms of efficacy index (EI). No complications of pregnancy or labor were reported. Similarly, a search of medical records revealed no adverse effects in the infants. CONCLUSIONS: To the best of our knowledge, this is the first case series on pregnancy and refractive surgery. We do not recommend performing LASIK or surface ablation on pregnant women. Our objective in the present study was to present relevant scientific data obtained from women who underwent refractive surgery while unaware that they were pregnant.

Update on contraindications in laser corneal refractive surgery.

More than 25 years of experience with refractive surgery techniques (since the FDA [Food and Drug Administration] of the United States approved the use of the excimer laser in the remodeling of the cornea in 1995), added to the technological advances in ophthalmology (femtosecond laser, topography-guided ablation, anterior segment imaging systems) and increased understanding of refractive errors, higher order aberrations, and corneal biomechanics make corneal laser refractive surgery a safe method and effective for the correction of these defects. However, to date, there are still certain circumstances that represent a contraindication for its application, in addition to others that could be associated with complications, and that must be carefully analyzed. This review analyzes the current contraindications for laser corneal refractive surgery listed in the Preferred Practice Protocols (PPPs) of the American Academy of Ophthalmology and the Spanish Ophthalmology Society. These protocols are based on the best scientific evidence currently available and allow clear recommendations to be drawn, improving the safety profile of these techniques. Contraindications can be differentiated into relative or absolute; among the latter are: age less than 18 years, the absence of refractive stability and the existence of certain ocular pathologies (including certain corneal dystrophies, keratoconus, poorly controlled dry eye) or systemic pathologies (active autoimmune processes or poorly controlled diabetes mellitus). Other circumstances such as the use of certain drugs (amiodarone, isotretinoin), extreme values of mean central keratometry and pachymetry, history of previous uveitis or glaucoma, pregnancy and lactation, are considered relative contraindications according to the PPPs. However, there are studies that demonstrate the safety of refractive surgery in some of these cases.

High accumulation of metals and metalloids in the liver of the blue tilapia (Oreochromis aureus) during a massive mortality event induced by a mine tailing spill.

In this study, the concentration of six metal(loid)s was examined in the fish Oreochromis aureus collected from El Comedero dam during a massive mortality event induced by a mine tailing spill. A major spill (~ 300,000 m3) of waste was released into the San Lorenzo River System following a rupture in the tailing dam of a mining plant in NW Mexico; consequently, the discharged material flowed into El Comedero dam. The accumulation of metal(oid)s in the tissues of O. aureus showed higher levels in the liver than in the guts and muscle. Concentrations in the liver were high (As, 1.1-1063; Cd, 8.9-392; Cu, 372-59,129; Hg, 0.46-19.79; Se, 8.7-748; and Zn, 116-820 µg g-1), revealing that these fish were exposed to high concentrations of these elements. The mortality of fish could have resulted from the combined effect of the six analyzed metal(loid)s, as well as other residues present in mine tailings.

Corrección de la presbicia tras cirugía cristaliniana. ¿Dónde nos encontramos en 2020? / Lens-based surgical correction of presbyopia. Where are we in 2020?

INTRODUCCIÓN: La presbicia es la pérdida progresiva e irreversible de la acomodación debido al envejecimiento. Es una de las principales causas de disminución de la calidad de vida en personas a partir de los 45 años derivada de la, muchas veces novedosa, dependencia de las gafas. El afán por corregirla por parte de los oftalmólogos, impulsados por el deseo de millones de personas que la padecen, se ha convertido en uno de los principales motores de desarrollo de la tecnología de las lentes intraoculares (LIO) durante los últimos 20 años. MATERIAL Y MÉTODOS: Esta revisión repasa las distintas alternativas que han permitido ir mejorando el enfoque quirúrgico cristaliniano de la presbicia; desde las lentes monofocales y la técnica de la monovisión, a las lentes acomodativas, pasando por las lentes multifocales refractivas y difractivas y terminando con las más recientes lentes de foco o campo extendido conocidas como EDOF. RESULTADOS: Cada una de estas LIO tiene sus ventajas, limitaciones e inconvenientes; y además, no existe la lente que se adapte a las necesidades de todos los pacientes. CONCLUSIONES: Es necesario conocer la variedad de lentes disponibles, y comprender en profundidad tanto sus propiedades ópticas como el impacto que estas van a tener luego en su rendimiento clínico y en la calidad visual de los pacientes. Esto nos debería ayudar a poder seleccionar la mejor alternativa para cada uno de ellos

INTRODUCTION: Presbyopia is the progressive and irreversible loss of accommodation due to aging. It is one of the main causes of loss of quality of life in people from 45 years of age, due to the, often novel, dependence on spectacles. The eagerness to correct it by ophthalmologists impulsed by the desire of millions of people who suffer from it, has become one of the main drivers for the development of intraocular lens (IOL) technology over the last twenty years. MATERIAL AND METHODS: This review briefly presents the different alternatives that have allowed us to improve the crystalline lens surgical approach of presbyopia; from monofocal lenses and monovision technique, accommodative, refractive, and diffractive multifocal lenses, and finally the most recent extended depth of focus/field lenses known as EDOFs. RESULTS: Each IOL has its advantages, limitations and disadvantages. Furthermore, there is no single lens that suits the needs of all patients. CONCLUSIONS: It is necessary to know the variety of lenses available, and to have an in-depth understanding of their optical properties, as well as the impact that these will have later on their clinical performance and on the visual quality of the patients. This should help us to select the best alternative for each of them

Lens-based surgical correction of presbyopia. Where are we in 2020? / Corrección de la presbicia tras cirugía cristaliniana. ¿Dónde nos encontramos en 2020?

INTRODUCTION: Presbyopia is the progressive and irreversible loss of accommodation due to aging. It is one of the main causes of loss of quality of life in people from 45 years of age, due to the, often novel, dependence on spectacles. The eagerness to correct it by ophthalmologists impulsed by the desire of millions of people who suffer from it, has become one of the main drivers for the development of intraocular lens (IOL) technology over the last twenty years. MATERIAL AND METHODS: This review briefly presents the different alternatives that have allowed us to improve the crystalline lens surgical approach of presbyopia; from monofocal lenses and monovision technique, accommodative, refractive, and diffractive multifocal lenses, and finally the most recent extended depth of focus/field lenses known as EDOFs. RESULTS: Each IOL has its advantages, limitations and disadvantages. Furthermore, there is no single lens that suits the needs of all patients. CONCLUSIONS: It is necessary to know the variety of lenses available, and to have an in-depth understanding of their optical properties, as well as the impact that these will have later on their clinical performance and on the visual quality of the patients. This should help us to select the best alternative for each of them.

Pb2+, Cd2+ and Hg2+ removal by designed functionalized swelling high-charged micas.

The increasing accumulation of toxic heavy metals in the environment has generated the need of efficient removal systems, being the adsorption method the most popular one applied in aqueous solutions. Of particular concern is the case of Pb2+, Cd2+ and Hg2+ due to their high potential hazard. In this paper, we describe the feasibility of a new family of nanomaterials, swelling high charge micas, in the removal of these cations from aqueous solutions. Batch adsorption experiments were carried out in the as-made micas, NaMn, and after functionalization with ethylammonium, EA-Mn, and mercaptoethylammonium, MEA-Mn. The results have demonstrated that all of them are efficient heavy metal adsorbents, being Na-M2 the best adsorbent for Pb2+ and Cd2+, and, MEA-M2 for Hg2+.

Assessment of nutrient contamination in the waters of the El Fuerte River, southern Gulf of California, Mexico.

This study assessed the spatial and temporal nutrient variability in the El Fuerte River basin in northwestern Mexico, considering its effects on the water trophic status as well as the nutrient loading to the Gulf of California. Physicochemical parameters, inorganic species of nitrogen, phosphate, total nitrogen, total phosphorus, and chlorophyll-a (chl-a) were quantified at 16 selected sites along the river in April (dry season) and October (rainy season) 2017. Mean concentrations of nutrients during dry and rainy seasons were 36.3 ± 24.1 and 55.1 ± 74.6 µg L-1 of total ammonia nitrogen, 3.4 ± 3.6 and 4.5 ± 3.5 µg L-1 of NO2--N, 190.8 ± 256.0 and 163.6 ± 261.0 µg L-1 of NO3--N, 42.4 ± 44.2 and 104.9 ± 76.2 µg L-1 of PO43--P, 1.0 ± 1.3 and 691 ± 2242 mg L-1 of TN, 0.06 ± 0.06 and 0.08 ± 0.09 mg L-1 of TP, and 0.9 ± 0.6 and 2.0 ± 0.9 µg L-1 of chl-a with significant differences (p < 0.05) between sites and seasons. When waters are transported downstream, nutrient levels are enriched by 4 to 35 times compared to those upstream due to increased population and agriculture downstream, confirming the hypothesis of the study. The calculated TN and TP fluxes were 1.23 × 104 and 3.57 × 101 ton year-1, respectively. Factor analysis indicated that inorganic nitrogen species and phosphorus are the main factors affecting the river water quality. Despite N excess during the rainy season, the river reached mesotrophic waters due to phosphorus limitation. This suggests the need to establish a water quality monitoring program to understand the vulnerability of the river course to changes in its trophic state.

Development and evaluation of a loop-mediated isothermal amplification (LAMP) diagnostic test for detection of whipworm, Trichuris trichiura, in faecal samples.

Whipworm infection or trichuriasis caused by Trichuris trichiura is of major public health concern in sub-Saharan Africa, particularly among pre-school and school-going children. It is among the neglected tropical diseases targeted for elimination through mass drug administration (MDA). One of the outcomes of MDA is a rapid decline in levels of infection intensity, making it difficult to monitor effectiveness of control measures using the conventional Kato-Katz procedure, which relies on the microscopic detection of parasite ova in faecal samples. In the present study, a loop-mediated isothermal amplification (LAMP) test was developed for the detection of T. trichiura infection in faecal samples. LAMP technology offers greater sensitivity and specificity than the microscopy-based tests. A set of four specific primers targeting the internal transcribed spacer 2 region of the ribosomal DNA were designed using Primer Explorer software. DNA was extracted from faecal samples using the alkaline lysis method (HotSHOT) and the LAMP reaction performed at 63°C for 1 h. The amplicons were visualized by both gel electrophoresis and with the naked eye following staining with SYBR green dye. Sensitivity and specificity tests were determined using the standard Kato-Katz diagnostic procedure as a reference test. The developed LAMP assay reliably detected T. trichiura DNA in faecal samples, with a specificity and sensitivity of 88% and 77%, respectively. No cross-reactivity was observed with several common helminth parasites. The developed LAMP assay is an appropriate diagnostic method for the detection of T. trichiura DNA in human faecal samples due to its simplicity, low cost, high sensitivity and specificity.

Mercury in sediment cores from the southern Gulf of Mexico: Preindustrial levels and temporal enrichment trends.

Spatial and temporal variability of mercury concentrations in sediments was evaluated in 210Pb-dated sediment cores from offshore and intertidal areas in the southern Gulf of Mexico. In offshore cores, mercury concentrations were comparable (11.2-69.2 ng g-1), and intermediate between concentrations in intertidal cores from the eastern (6.0-34.4 ng g-1) and the western (34.9-137.7 ng g-1) inlets of Términos Lagoon. The enrichment factor (EF) indicated minimal contamination (EF < 2) in most offshore cores, whereas in some intertidal cores steadily increasing mercury enrichment and fluxes were observed along the past century. No evidence of oil industry related mercury contamination was found, as the minor but increasing enrichment in intertidal cores is most likely related to land-derived sources such as catchment eroded soils and waste water runoff. Results highlight the importance to control catchment erosion and untreated sewage releases to reduce mercury loadings to the coastal zone.

Trace Elements in Tissues of Whale Sharks (Rhincodon typus) Stranded in the Gulf of California, Mexico.

Concentration of essential (Se, Zn and Cu) and non-essential (As, Cd, Hg and Pb) trace elements were measured in selected tissues of two dead whale sharks (Rhincodon typus) stranded in the Gulf of California (GC) in 2017 and 2018. Concentrations of Cd and Pb in the skeletal muscle of the whale shark from La Paz Bay, GC were higher compared to a previous study on whale shark from China. The shark from La Paz Bay also presented higher concentration of Pb in the epidermis, compared to the same tissue of the other whale shark stranded in Punta Bufeo, GC. The Hg in all analysed tissues was lower than those documented in carnivorous sharks. Molar ratio Se:Hg shows an excess of Se over Hg in all the tissues sampled in both sharks.

Resultados visuales, independencia de gafas e insatisfacción tras implante de una lente intraocular difractiva trifocal / Visual outcomes, spectacle independence and satisfaction after diffractive trifocal intraocular lens implantation

OBJETIVO: Evaluar los resultados visuales, la independencia de gafas y la satisfacción tras el implante de una lente intraocular trifocal. MÉTODOS: Estudio retrospectivo de 5.186 sujetos intervenidos de facoemulsificación con implante de la lente trifocal difractiva FineVision Micro F12 (PhysIOL, Liège, Bélgica). RESULTADOS: La queratometría media preoperatoria fue 43,61±1,55 D y el cilindro queratométrico medio -0,86 ± 0,66 D. A los 3 meses, cambiaron a 43,59±1,56 y −0,71±0,46 D respectivamente. La esfera media pasó de 2,04±2,60 a 0,14±0,38 D y el equivalente esférico medio de 1,64±2,61 a −0,05±0,36 D. Más del 60% alcanzaron una mejor agudeza visual corregida de lejos. La mayoría presentó un defecto residual final (predictibilidad) menor de 1 D (99,1%). El 14,3% precisó un ajuste refractivo, el 2,2% capsulotomía posterior y se recolocó la lente intraocular en 5 casos. Un porcentaje elevado estaba satisfecho en términos de visión e independencia de gafas en todas las distancias. Aunque un 2% refirió un empeoramiento en la visión nocturna, únicamente un 2% estaba poco satisfecho y 20 pacientes insatisfechos. Las causas fueron: visión borrosa (7 casos), necesidad de gafas (10), disfotopsias (7) y sequedad ocular (4). CONCLUSIONES: La implantación de esta lente permite obtener buenos resultados visuales en las 3 distancias así como un alto grado de independencia de gafas y de satisfacción

PURPOSE: To investigate visual outcomes, spectacle independence, and patient satisfaction after trifocal intraocular lens implantation. METHODS: A retrospective study conducted on 5,186 patients who underwent phacoemulsification and were implanted with a diffractive trifocal intraocular lens (FineVision Micro F, PhysIOL SA, Liège, Belgium). RESULTS: The mean pre-operative keratometry was 43.61±1.55 D, and mean keratometric cylinder was -0.86±0.66 D. At 3 months post-operatively, values changed to 43.59±1.56 and -0.71±0.46 D, respectively. Mean sphere varied from 2.04±2.60 to 0.14±0.38 D, and mean spherical equivalent from 1.64±2.61 to -0.05±0.36 D. More than 60% of the patients achieved better corrected distance visual acuity. The majority had a final residual refractive error (predictability) lower than 1 D (99.1%), with 14.3% needing optical adjustment (bioptics). Posterior capsulotomy was performed in 2.2%, and the lens was replaced in 5 patients. A high percentage of patients were satisfied in terms of vision and spectacle independence at all distances. Although 2% referred to worsening of night vision quality, only 2% were not very satisfied and 20 patients were dissatisfied. The causes were: blurred vision (7 cases), spectacle dependence (10), dysphotopsia (7), and dry eye (4). CONCLUSIONS: The implantation of this model provided good visual performance in all distances, as well as high levels of spectacle independence and satisfaction

Visual outcomes, spectacle independence and satisfaction after diffractive trifocal intraocular lens implantation. / Resultados visuales, independencia de gafas e insatisfacción tras implante de una lente intraocular difractiva trifocal.

PURPOSE: To investigate visual outcomes, spectacle independence, and patient satisfaction after trifocal intraocular lens implantation. METHODS: A retrospective study conducted on 5,186 patients who underwent phacoemulsification and were implanted with a diffractive trifocal intraocular lens (FineVision Micro F, PhysIOL SA, Liège, Belgium). RESULTS: The mean pre-operative keratometry was 43.61±1.55 D, and mean keratometric cylinder was -0.86±0.66 D. At 3 months post-operatively, values changed to 43.59±1.56 and -0.71±0.46 D, respectively. Mean sphere varied from 2.04±2.60 to 0.14±0.38 D, and mean spherical equivalent from 1.64±2.61 to -0.05±0.36 D. More than 60% of the patients achieved better corrected distance visual acuity. The majority had a final residual refractive error (predictability) lower than 1 D (99.1%), with 14.3% needing optical adjustment (bioptics). Posterior capsulotomy was performed in 2.2%, and the lens was replaced in 5 patients. A high percentage of patients were satisfied in terms of vision and spectacle independence at all distances. Although 2% referred to worsening of night vision quality, only 2% were not very satisfied and 20 patients were dissatisfied. The causes were: blurred vision (7 cases), spectacle dependence (10), dysphotopsia (7), and dry eye (4). CONCLUSIONS: The implantation of this model provided good visual performance in all distances, as well as high levels of spectacle independence and satisfaction.

Comparación de 5.468 retratamientos tras láser in situ queratomileusis levantando el lentículo o mediante queratectomía fotorrefractiva sobre el lentículo / Comparison of 5468 retreatments after laser in situ keratomileusis by lifting the flap or performing photorefractive keratectomy on the flap

Objetivo: Describir los resultados visuales del retratamiento tras láser in situ queratomileusis (LASIK) levantando el lentículo previamente o realizando queratectomía fotorrefractiva (PRK) sobre él, establecer si el riesgo de crecimiento epitelial de la interfase (CEI) es mayor cuanto más tiempo ha pasado entre el LASIK inicial y el retratamiento por levantamiento y determinar la incidencia de la opacidad corneal (haze) tras PRK. Métodos: Estudio retrospectivo de 4.077 pacientes (5.468 ojos) tratados mediante LASIK y retratamiento para estudiar los resultados visuales e identificar los casos de CEI y haze corneal. Resultados: Se estudiaron 5.196 ojos de 3.876 pacientes retratados de miopía levantando el lentículo y 272 ojos de 201 pacientes retratados mediante PRK en el lentículo. No se encontraron diferencias estadísticamente significativas entre los retratamientos en predictibilidad, eficacia y seguridad. Se encontró un total de 704 casos de CEI tras levantar el lentículo; se necesitó limpieza quirúrgica en 70. La limpieza quirúrgica disminuyó el índice de eficacia al compararlo con el de los pacientes con CEI que no precisaron limpieza (p = 0,01). Las diferencias en términos de seguridad y predictibilidad no fueron estadísticamente significativas. La incidencia de haze corneal tras la ablación de superficie sobre el lentículo previo fue del 14,34%, aunque ninguno de estos casos fue clínicamente relevante. Conclusiones: Los resultados visuales son similares entre los pacientes retratados mediante levantamiento del lentículo o mediante PRK. La incidencia de CEI levantando lentículo fue del 13,55%. La incidencia de CEI aumenta a medida que aumenta el tiempo entre el procedimiento primario y el retratamiento (AU)

Purpose: To assess visual outcomes of retreatment after laser in situ keratomileusis (LASIK) by lifting the flap or performing photorefractive keratectomy (PRK) on the flap, as well as to establish whether there was an increased risk of epithelial ingrowth (EIG) when LASIK and lifting of the flap are separated by a long time interval and to determine the incidence of corneal haze after PRK. Methods: Retrospective study of 4077 patients (5468 eyes) who underwent LASIK and subsequent retreatment were reviewed in order to study their visual results and identify cases of EIG and corneal haze. Results: Enhancements included 5196 eyes from 3876 patients that were retreated by lifting the flap, and 272 eyes from 201 patients that were retreated by PRK on the flap. No statistically significant differences were found between the retreatments in terms of predictability, efficacy, and safety. A total of 704 cases of EIG were found after lifting the flap, for which surgical cleansing was necessary in 70. Surgical cleansing decreased the efficacy index when compared with patients with EIG who did not need cleansing (P = .01). Differences in terms of safety and predictability were not statistically significant. The incidence of corneal haze after ablation of the surface of the previous flap was 14.34%, although none of these cases were clinically relevant. Conclusions: Visual outcomes were similar between patients who were retreated by lifting the flap and those who underwent PRK. The incidence of EIG when the flap was lifted was 13.55%. The incidence of EIG increases with the time elapsed between the primary procedure and retreatment (AU)

Comparison of 5468 retreatments after laser in situ keratomileusis by lifting the flap or performing photorefractive keratectomy on the flap. / Comparación de 5.468 retratamientos tras láser in situ queratomileusis levantando el lentículo o mediante queratectomía fotorrefractiva sobre el lentículo.

PURPOSE: To assess visual outcomes of retreatment after laser in situ keratomileusis (LASIK) by lifting the flap or performing photorefractive keratectomy (PRK) on the flap, as well as to establish whether there was an increased risk of epithelial ingrowth (EIG) when LASIK and lifting of the flap are separated by a long time interval and to determine the incidence of corneal haze after PRK. METHODS: Retrospective study of 4077 patients (5468 eyes) who underwent LASIK and subsequent retreatment were reviewed in order to study their visual results and identify cases of EIG and corneal haze. RESULTS: Enhancements included 5196 eyes from 3876 patients that were retreated by lifting the flap, and 272 eyes from 201 patients that were retreated by PRK on the flap. No statistically significant differences were found between the retreatments in terms of predictability, efficacy, and safety. A total of 704 cases of EIG were found after lifting the flap, for which surgical cleansing was necessary in 70. Surgical cleansing decreased the efficacy index when compared with patients with EIG who did not need cleansing (P=.01). Differences in terms of safety and predictability were not statistically significant. The incidence of corneal haze after ablation of the surface of the previous flap was 14.34%, although none of these cases were clinically relevant. CONCLUSIONS: Visual outcomes were similar between patients who were retreated by lifting the flap and those who underwent PRK. The incidence of EIG when the flap was lifted was 13.55%. The incidence of EIG increases with the time elapsed between the primary procedure and retreatment.

Técnicas quirúrgicas no cristalinianas para la corrección de la presbicia / Non-lens-based surgical techniques for presbyopia correction

Introducción: La presbicia es el error refractivo más prevalente. Con el envejecimiento progresivo de la población, su corrección quirúrgica supone un importante reto tanto para la comunidad oftalmológica como para los millones de pacientes que la padecen y que cada vez demandan más alternativas a su corrección mediante gafas o lentes de contacto. Material y métodos: Esta revisión presenta una discusión sintetizada sobre las teorías fisiopatológicas de la presbicia y una descripción actualizada y analítica de las técnicas quirúrgicas no cristalinianas utilizadas para tratar la presbicia. Resultados: Los procedimientos corneales incluyen varios tipos de implantes corneales y técnicas fotoablativas que generan una córnea multifocal, o una monovisión. Los procedimientos esclerales ejercen una tracción sobre la esclera supralenticular que supuestamente mejoraría la amplitud de acomodación. Conclusiones: Ninguna de ellas permite eliminar completamente la necesidad de gafas para la visión cercana, pero muchas de ellas permiten mejorar la situación refractiva de los pacientes. Son necesarios más estudios, con métodos rigurosos y estandarizados, para evaluar los cambios en la visión cercana de los pacientes, y con un mayor seguimiento postoperatorio para corroborar la utilidad real y práctica de muchas de estas técnicas (AU)

Introduction: Presbyopia is the most prevalent refractive error. With a progressive aging population, its surgical correction is an important challenge for the ophthalmology community, as well as the millions of patients who suffer from it, and who are increasingly demanding alternatives to its correction with glasses or contact lenses. Material and methods: A review is presented with a synthesised discussion on the pathophysiological theories of presbyopia and an updated and analytical description of the non-lens involvement surgical techniques used to treat presbyopia. Results: Corneal procedures include various types of corneal implants and photo-ablative techniques that generate a multifocal cornea, or monovision. Scleral procedures exert a traction on supralenticular sclera that supposedly would improve the amplitude of accommodation. Conclusions: None of the techniques are able to completely eliminate the need for near -vision glasses, but many of them manage to improve the refractive status of the patients. More studies with rigorous and standardised methods and longer follow-up are needed to evaluate the changes in the near vision of the patients, in order to corroborate the real and practical usefulness of many of these techniques (AU)

Monitoring of inland waters for culturing shrimp Litopenaeus vannamei: application of a method based on survival and chemical composition.

This study evaluated the suitability of 21 inland waters (16 well waters and 5 surface waters) from Northwest Mexico via short- (48 h) and medium-term (28 days) tests using postlarvae (PL18) of Litopenaeus vannamei. In the short test, survival was assessed at 48 h after shrimp were placed in groups of 10 postlarvae into 2-L containers of inland water, to which they had been previously acclimated. The second, medium-term test consisted of four replicates with 10 postlarvae, and each group was placed in 15-L containers with the treatment water. Weights (initial and final) and survival were evaluated weekly for 28 days. In those waters for which the short test was positive and the medium-term test was negative and which also had a deficiency of potassium and/or magnesium, a third test was conducted. These last waters were supplemented with salts, and the shrimp survival and weights (initial and final) were recorded for 28 days. The water samples from San Jose, Mochicahui, Sinaloa River, Caimanero inner Lagoon, La Pipima, Campo Santa Fe, Escopama, and Fitmar had >60% survival in the short test. The Caimanero inner Lagoon water had the highest survival (87.5 ± 9.6%) and final mean weight (201.3 ± 86.2 mg). In the third test, it was found that shrimp in the water from La Pipima, Campo Santa Fe, and Fitmar exhibited 100% survival for 2 weeks. Finally, in this work, a decision tree to evaluate the suitability of low-salinity water for shrimp farming was proposed, which can be applied in other regions.

Non-lens-based surgical techniques for presbyopia correction. / Técnicas quirúrgicas no cristalinianas para la corrección de la presbicia.

INTRODUCTION: Presbyopia is the most prevalent refractive error. With a progressive aging population, its surgical correction is an important challenge for the ophthalmology community, as well as the millions of patients who suffer from it, and who are increasingly demanding alternatives to its correction with glasses or contact lenses. MATERIAL AND METHODS: A review is presented with a synthesised discussion on the pathophysiological theories of presbyopia and an updated and analytical description of the non-lens involvement surgical techniques used to treat presbyopia. RESULTS: Corneal procedures include various types of corneal implants and photo-ablative techniques that generate a multifocal cornea, or monovision. Scleral procedures exert a traction on supralenticular sclera that supposedly would improve the amplitude of accommodation. CONCLUSIONS: None of the techniques are able to completely eliminate the need for near -vision glasses, but many of them manage to improve the refractive status of the patients. More studies with rigorous and standardised methods and longer follow-up are needed to evaluate the changes in the near vision of the patients, in order to corroborate the real and practical usefulness of many of these techniques.