Amblyopic stereo vision is efficient but noisy.

People with amblyopia demonstrate a reduced ability to judge depth using stereopsis. Our understanding of this deficit is limited, as standard clinical stereo tests may not be suited to give a quantitative account of the residual stereo ability in amblyopia. In this study we used a stereo test designed specifically for that purpose. Participants identified the location of a disparity-defined odd-one-out target within a random-dot display. We tested 29 amblyopic (3 strabismic, 17 anisometropic, 9 mixed) participants and 17 control participants. We obtained stereoacuity thresholds from 59% of our amblyopic participants. There was a factor of two difference between the median stereoacuity of our amblyopic (103 arcsec) and control (56 arcsec) groups. We used the equivalent noise method to evaluate the role of equivalent internal noise and processing efficiency in amblyopic stereopsis. Using the linear amplifier model (LAM), we determined the threshold difference was due to a greater equivalent internal noise in the amblyopic group (238 vs 135 arcsec), with no significant difference in processing efficiency. A multiple linear regression determined 56% of the stereoacuity variance within the amblyopic group was predicted by the two LAM parameters, with equivalent internal noise predicting 46% alone. Analysis of control group data aligned with our previous work, finding that trade-offs between equivalent internal noise and efficiency play a greater role. Our results allow a better understanding of what is limiting amblyopic performance in our task. We find this to be a reduced quality of disparity signals in the input to the task-specific processing.

Factors limiting sensitivity to binocular disparity in human vision: Evidence from a noise-masking approach.

Our visual system uses the disparity between the images received by the two eyes to judge three-dimensional distance to surfaces. We can measure this ability by having subjects discriminate the disparity of rendered surfaces. We wanted to know the basis of the individual differences in this ability. We tested 53 adults with normal vision using a relative disparity detection task. Targets were wedge-shaped surfaces formed from random dots. These were presented in either crossed or uncrossed disparity relative to a random dot background. The threshold disparity ranged from 24 arc seconds in the most-able subject to 275 arc seconds in the least-able subject. There was a small advantage for detecting crossed-disparity targets. We used the noise-masking paradigm to partition subject performance into two factors. These were the subject's equivalent internal noise and their processing efficiency. The parameters were estimated by fitting the linear amplifier model. We found both factors contributed to the individual differences in stereoacuity. Within subjects, those showing an advantage for one disparity direction had enhanced efficiency for that direction. Some subjects had a higher equivalent internal noise for one direction that was balanced out by an increased efficiency. Our approach provides a more thorough account of the stereo-ability of our subjects compared with measuring thresholds alone. We present a normative set of results that can be compared with clinical populations.

Association of plasma lactate concentration at admission of severe preeclampsia to maternal complications.

OBJECTIVE: To evaluate in women with severe preeclampsia the association of lactate concentration at admission with maternal complications. METHODS: A prospective cohort was created of women with severe preeclampsia consecutively admitted to an Obstetrical High-Dependency Unit. Plasma lactate concentration was measured at admission and its association to maternal complication was evaluated. RESULTS: A total of 100 women were included, of which 30 (30%) had a maternal complication. The mean lactate plasma concentration in this group was significantly higher than in those uncomplicated cases (2.38 vs 3.1 mmol/L; p < 0.01). A total of 37 (37%) women had lactate concentrations at >3 mmol/L, which was associated to higher incidence of maternal complications (19% vs. 48.6%; p = 0.002; OR 4.03 [95% CI 1.64-9.9]). This association remained independent of other standard severity criteria (OR 3.89; 95%CI 1.22-12.4; p = 0.022). CONCLUSION: Increased plasma lactate concentrations at admission in women with severe preeclampsia are independently associated to maternal complications.

Anestesia en la endodoncia de molares y premolares mandibulares con pulpitis aguda irreversible. Recomendaciones clínicas. Hacia una revisión sistemática / Anesthesia in the endodontic treatment of mandibular molars and premolars with acute irreversible pulpitis. Clinical recommendations. Towards to a systematic approach

Objetivo. El propósito de este trabajo es revisar el estado de la anestesia local odontológica en los pacientes con pulpitis aguda en los dientes posteriores mandibulares, para conocer los métodos más eficaces para lograr su anestesia antes del tratamiento endodóntico. Material y método. Se ha realizado una búsqueda bibliográfica de los ensayos clínicos sobre la eficacia de bloqueos mandibulares en pulpitis agudas de molares y premolares inferiores publicados desde el año 1987 hasta 2015. Resultados. La administración de un cartucho de 1,8 mL de la solución estándar de Lidocaína 2% con Adrenalina 1:100.000 (L- 100) o 1:80.000 (L-80), empleando la técnica de bloqueo mandibular, solo es efectiva en el 30% de los casos. En el caso de administrar dos cartuchos anestésicos, la eficacia aumenta al 45%. Si se administra un cartucho de 1,8 mL de Articaína 4% con adrenalina 1:100.000 (A-100) la eficacia es del 40% y, en el caso de administrar dos cartuchos, la eficacia aumenta hasta un 70%. Si se prescribe un antiinflamatorio no esteroideo (AINE) al paciente una hora antes de la intervención y se administra un cartucho de 1,8 mL de solución estándar L-80 o L-100, el porcentaje de casos con éxito alcanza el 55%. En el caso de prescribir paracetamol una hora antes, la eficacia se reduce al 50%. Si tras haber realizado el bloqueo mandibular con L-80 o L-100 se hace un refuerzo vestibular con otros 1,8 mL de A-100, la eficacia es del 65% y si se realiza un bloqueo mandibular de 1,8 mL de A-100 y refuerzo vestibular con otros 1,8 mL de A-100 la eficacia es del 85%. Conclusiones. Se recomienda la toma de AINES una hora antes de la intervención, efectuar un bloqueo mandibular con 3,6 mL deA-100 y refuerzo por vestibular con 1,8 mL deA-100 (AU)

Aim. The purpose of this paper is to review the state of the dental local anesthesia in patients with acute irreversible pulpitis in mandibular posterior teeth, to find out the most effective methods to achieve anesthesia prior to the endodontic treatment. Materials and methods. A literature review was conducted searching for clinical trials on the efficacy of the mandibular block technique in lower molars and premolars with acute irreversible pulpitis, published from 1987 to 2015. Results. The administration of one cartridge of 1,8 mL standard solution of Lidocaine 2% with Adrenalin 1:100.000 (L-100) or 1:80.000 (L-80) with the mandibular block technique is only effective in 30% of the cases. If administering two cartridges, the effectiveness increases to 45%. One cartridge of 1,8 mL Articaine 4% with Adrenalin 1:100.000 (A-100) is effective in 40% of the cases, increasing to 70% when adding a second cartridge. If prescribing a nonsteroidal anti-inflammatory drug (NSAID) one hour before the treatment and injecting one cartridge of 1,8 mL standard solution L-80 or L-100, the percentage of successfully anesthetized cases reaches 55%. In case of prescribing acetaminophen one hour before treatment, the efficacy is reduced to 50%. If following the mandibular block technique with L-80 or L-100, a buccal reinforcement is made with 1,8 mL A-100, the effectiveness is 65%. If such blockage is made with 1,8 mL of A-100 and the buccal reinforcement with 1,8 mL A-100, the effectiveness is 85%. Conclusion. The recommendations to achieve the highest effectiveness of anesthesia are taking NSAIDs one hour before treatment and performing a mandibular block technique with 3,6 mL of A-100 and buccal reinforcement with 1,8 mL of A- 100 (AU)