Quantification of refractive error: comparison of autorefractor and focometer.

PURPOSE: The advantages of a focometer (FOCOMETER) over other methods of refraction for use in developing countries are that it is lightweight, compact, relatively inexpensive, fairly quick, and easy to use with minimal training. This clinical trial compared the repeatability, validity, and ease of use of the focometer with an autorefractor. METHODS: The refractive status of the right eye of 80 participants was determined with an autorefractor (Canon RK3). Three measurements were also taken with the focometer. RESULTS: The spherical equivalent (M) of the focometer was 0.25 D more positive than the autorefractor (p < 0.001) and 84% of measurements were within 0.75 D of the autorefractor. The autorefractor detected astigmatism in 91% (73) of the eyes, whereas the focometer identified only 32% (26). The design of the clock target restricts cylinder axis accuracy to the nearest 15 degrees . There was evidence of a learning effect for the focometer: the second and third measurements were more repeatable in the untrained group. There were no differences between the mean (1.03 +/- 2.28) and third focometer (-1.05 +/- 2.32) measurements (p = 0.34). However, using the third focometer measurement, 94% of participants had visual acuities of at least 6/12(-2). CONCLUSIONS: This study highlighted the focometer's restricted power range, inaccuracy of astigmatism and axis determination, and dependence on subject understanding and compliance. Therefore, in most clinical settings, the focometer would not be adequate for quantifying refractive error, but the focometer spherical equivalent was within acceptable limits of the autorefractor, and the visual acuity with lenses determined by the focometer indicates its potential usefulness in public health settings, especially where only spherical ready-made spectacles are dispensed. There may be more cost-effective ways to determine refractive error in these circumstances. A potentially important enhancement in focometer methodology that improves its ease of use was identified: use only the third measurement for each eye.     

Maternal Position at Midwife‐Attended Birth and Perineal Trauma: Is There an Association?

ABSTRACT: Background: Most women will sustain some degree of trauma to the genital tract after vaginal birth. This study aimed to examine the association between maternal position at birth and perineal outcome in women who had a midwife‐attended, spontaneous vaginal birth and an uncomplicated pregnancy at term. Methods: Data from 3,756 births in a major public tertiary teaching hospital were eligible for analysis. The need for sutures in perineal trauma was evaluated and compared for each major factor studied (maternal age, first vaginal delivery, induction of labor, not occipitoanterior, use of regional anesthesia, deflexed head and newborn birthweight >3,500 g). Birth positions were compared against each other. Subgroup analysis determined whether birth positions mattered more or less in each of the major factors studied. The chi‐square test was used to compare categorical variables. Results: Most women (65.9%) gave birth in the semi‐recumbent position. Of the 1,679 women (44.5%) who required perineal suturing, semi‐recumbent position was associated with the need for perineal sutures, whereas all‐fours was associated with reduced need for sutures; these associations were more marked in first vaginal births and newborn birth weight over 3,500 g. When regional anesthesia was used, semi‐recumbent position was associated with a need for suturing, and lateral position associated with a reduced need for suturing. The four major factors significantly related to perineal trauma included first vaginal birth, use of regional anesthesia, deflexed head, and newborn weight more than 3,500 g. Conclusions: Women should be given the choice to give birth in whatever position they find comfortable. Maternity practitioners have a responsibility to inform women of the likelihood of perineal trauma in the preferred birth position. Ongoing audit of all clinicians attending births is encouraged to further determine effects of maternal birth position and perineal trauma, to investigate women's perception of comfortable positioning at birth, and to measure changes to midwifery practice resulting from this study.     

麦冬类中药组织切片计算机三维重建图鉴

利用计算机技术实现麦冬类中药组织连续切片三维重建与动态显示,为计算机辅助生药学鉴定和教学提供了新的三维图像技术和研究资料。     

Movements of cultured corneal epithelial cells and stromal fibroblasts in electric fields

The effects of an externally applied direct-current electric field on the movement of cultured rabbit corneal epithelial cells and stromal fibroblasts were studied. After a latency of approximately 20 minutes in an electric field, both epithelial cells and stromal fibroblasts became spindle shaped and underwent galvanotropism by aligning their long axes perpendicular to the applied electric field. The electric field stimulus thresholds for galvanotropic movements in epithelial cells and stromal fibroblasts were 4V/cm and 6 V/cm, respectively. After an additional latency of 30 minutes, both cell types manifested galvanotaxic movements: epithelial cells commenced migration in the cathodal (downfield) direction and stromal fibroblasts in the anodal (upfield) direction. For both types of cells, ruffled membranes and lamellipodia were abundant at the leading edges of migrating cells and cell processes underwent retraction at the trailing edges. At field strengths of above 10 V/cm, evidence of cellular damage (manifested by cellular rounding and detachment), attributable to the electric field treatment, was observed after 4 hours. These preliminary results suggest that galvanotaxic responses could be exploited clinically in the enhancement of corneal wound healing.     

Non-tuberculous mycobacterial keratitis: a study of 22 cases.

AIM: To investigate causes and clinical findings of non-tuberculous mycobacterial keratitis, and to study its response to topical antibiotic therapy and surgical extirpative keratectomy. METHOD: A single centre, retrospective review of 22 patients with non-tuberculous mycobacterial keratitis seen in a 3 year period. Laboratory diagnoses were established with Ziehl-Nielsen acid fast staining and Löwenstein-Jensen cultures. RESULTS: In 20 patients (91%), there was an antecedent history of foreign body eye trauma (18 patients) or elective surgery (two patients). There were 19 cases of Mycobacterium chelonei, and three of M fortuitum. Clinical signs included epithelial defects, satellite or ring stromal infiltrates, crystalline keratopathy, and hypopyon. For topical antibiotic therapy, 20 patients received amikacin, while one patient received rifampin and another received ciprofloxacin, each in accordance with the results of the in vitro drug sensitivities. An extirpative keratectomy was performed in 15 cases; four of these cases additionally required a temporary conjunctival flap in order to finally eradicate the infection. At the end of the follow up period (median 18 months; range 3 months to 3 years) all eyes were stable and free of infection, with 19 (86%) having final visual acuities of 20/200 or better. CONCLUSION: Early clinical recognition and prompt laboratory diagnosis, together with aggressive topical antibiotic therapy and early keratectomy, may shorten morbidity and improve the clinical outcome of non-tuberculous mycobacterial keratitis.     

Predicting survival and recurrence in localized melanoma: A multivariate approach

Several clinical and pathologic factors appear to affect melanoma recurrence and survival. While much attention has been directed at identifying prognostic factors, few researchers have developed predictive models for survival and recurrence. Two major clinical questions are of interest in the management of melanoma: 1) what is the patient's chance of surviving for a given period, e.g., 5 or 10 years, after diagnosis of melanoma; and 2) after a patient has been disease free for a period of time, e.g., 5 years, what is his or her chance of melanoma recurrence or death in the following interval, e.g., 5 years or 10 years. In this paper, a generalized multivariate prognostic model to address both of these clinical questions is presented.Tables of the estimated probabilities of melanoma recurrence and death for prognostic subgroups are shown to facilitate prediction of an individual patient's outcome. The model was based on a database of 4,568 patients with localized melanoma, one of the largest melanoma databases in the world with detailed clinical and pathologic information, and long-term follow-up. Tumor thickness at diagnosis was the single most important prognostic factor for all outcomes. Tumor ulceration, Clark's level, lesion location, and sex had an impact on overall survival from diagnosis for some of the subgroups defined by tumor thickness. Tumor thickness at diagnosis was strongly indicative of melanoma recurrence and death even after a disease free interval of 2, 5, or 10 years. Lesion location and ulceration were of prognostic importance after disease free intervals up to 5 years, but their impact on melanoma recurrence and death diminished after longer disease free intervals.Prediction models for melanoma outcome at diagnosis and after a disease free period can provide useful information to clinicians in the management of melanoma patients. Utilization of the model will be valuable in identifying patients at high risk for melanoma recurrence and death.

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Resumen Diversos factores clínicos y patológicos parecen afectar las tasas de recurrencia y mortalidad del melanoma. En tanto que se ha dispensado bastante atención en cuanto a identificar factores de pronóstico, pocos investigadores han desarrollado modelos de predicción de sobrevida y de recurrencia. Dos interrogantes principales son de interés en cuanto al manejo del melanoma: 1) cual es la probabilidad del paciente de sobrevivir un determinado período, por ejemplo 5 o 10 años, después del diagnóstico de melanoma; y 2) después de que el paciente se ha mantenido libre de enfermedad por un período de tiempo, por ejemplo 5 años, cual es su probabilidad de recurrencia del melanoma o de muerte en el siguiente período de tiempo, por ejemplo 5 o 10 años. En este artículo se presenta un modelo generalizado y multivariable de pronóstico para enfrentar estos interrogantes clínicos.Se presentan tablas para estimar las probabilidades de recurrencia y de muerte en divesos subgrupos de pronóstico que facilitan la predicción del destino final de un individuo. El modelo se fundamentó en una base de datos de 4568 pacientes con melanomas localizado, una de las más grandes bases de datos de melanoma existentes en el mundo, con detallada información clínica y patológica y con seguimiento a largo plazo. El espesor del tumor en el momento del diagnóstico apareció como el factor individual de pronóstico de mayor importancia. La ulceración del tumor, el nivel de Clark, la ubicación de la lesión y el sexo exhibieron importancia en cuanto a la sobrevida para algunos de los subgrupos definidos según el espesor del tumor. El espesor del tumor en el momento del diagnóstico fue un factor fuertemente indicativo de recurrencia y de muerte, aún después de un intervalo libre de enfermedad de 2, 5 o 10 años. La ubicación de la lesión y la ulceración aparecieron como de importancia en cuanto el pronóstico después de intervalos libres de enfermedad hasta de 5 años, pero tal importancia disminuyó después de intervalos libres de enfermedad de mayor duración.Los modelos de predicción del resultado final en el melanoma aplicados en el momento del diagnóstico y después de un período libre de enfermedad pueden proveer información útil para el manejo clínico de pacientes con melanomas. La utilización del modelo es de valor en la identificación de pacientes con mayor riesgo de recurrencia y muerte por melanoma.

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Résumé Plusieurs facteurs cliniques et anatomopathologiques semblent déterminer la récidive et la survie des mélanomes. De nombreux auteurs se sont intéressés à l'identidification des facteurs de pronostic, mais peu d'équipes ont essayé d'élaborer un modèle permettant de prédire survie et récidive. Deux problèmes restent à résoudre dans le traitement des mélanomes: 1) quelles sont les chances de survie après le diagnostic de mélanome pour un patient donné, pendant une période donnée, par exemple 5 à 10 ans et 2) quels sont les risques de récidive ou de décès dans les 5 à 10 ans qui suivent une période donnée (par exemple 5 ans) où un patient semblait en rémission. Dans cet article, nous avons créé un modèle d'évaluation pronostique multifactorielle pour tenter de répondre à ces 2 questions.Des tables montrant les probabilités de récidive et de décès par mélanome, calculées à partir de sous groupes différents, peuvent aider à déterminer le pronostic. Ce modèle repose sur une banque de données de 4568 patients atteints de mélanome non disséminé. Il s'agit d'une des plus grandes banques de données au monde contenant des informations cliniques, anatomopathologiques et sur l'évolution à long terme. L'épaisseur de la tumeur au moment du diagnostic était le facteur pronostic le plus important pour déterminer l'évolution. Le caractère ulcéré, le stade de Clark, la localisation de la lésion et le sexe avaient tous une importance pronostique, influant sur la survie globale liée à l'épaisseur de la tumeur. L'importance de l'épaisseur de la tumeur au moment du diagnostic était un facteur de récidive et mortalité même après un intervalle long de 2, 5 ou 10 ans. Le site de la tumeur et son caractère ulcéré étaient également des facteurs associés à un risque de récidive tumorale ou de décès après une rémission de 5 ans. L'influence de ces facteurs diminuait en cas de rémission plus prolongée.Les modèles permettant d'évaluer l'évolution du mélanome malin au moment du diagnostic et apreès un intervalle de rémission sont utiles au cours du traitement du mélanome. Ils doivent permettre d'identifier les patients à risque de récidive et de décès.

     

Locomotor strategies before independent walking: prospective study of 50 mentally retarded children.

To investigate the association between pre-walking locomotor strategies and psychomotor developments in children with mental retardation (MR), 50 children with non-specific MR were included in this study. There were 29 boys and 21 girls, 96% of whom had moderate to severe MR. They were followed from 4-53 months to 25-99 months of age, and their follow-up periods ranged from 10 to 48 months (mean 30 months). According to the pre-walking locomotor strategies, these children were categorized into three groups: the crawling group (n = 34) who used crawling or creeping as their main locomotion pattern before independent walking; the shuffling group (n = 9) who used shuffling prior to independent walking; and the direct-walking group (n = 7) who did not have any other locomotor strategies except rolling. In almost all motor developmental milestones, children in the direct-walking group developed earlier than those in the crawling and shuffling groups. Children in the crawling group had more advanced developments than those in the shuffling group. The difference in the mean ratio developmental quotients of the Bayley Mental Scale among the three groups was not significant. The present study showed that crawling may not be a necessary prerequisite for early ambulation or better cognitive function in MR children.     

THE IMPACT OF PRE-CLERKING CLINICS ON SURGICAL OPERATION CANCELLATIONS: A PROSPECTIVE AUDIT

Pre-clerking of all patients undergoing elective general surgical operations was introduced at our hospital in an attempt to reduce an unacceptably high operation cancellation rate. A prospective audit has been performed on the effect of this policy on the cancellation rate. Before the introduction of pre-clerking there was a marked seasonal variation in the number of patients who failed to attend for surgery, which could be explained by absence on holiday. This seasonal variation disappeared after the start of pre-clerking clinics, but there has been no reduction in the number of cancellations for medical reasons.