Search results for " Error."
showing 10 items of 1034 documents
The effect of spherical aberration on visual performance and refractive state for stimuli and tasks typical of night viewing
2018
Purpose: The aim of this work was to examine the impact of Seidel spherical aberration (SA) on optimum refractive state for detecting and discriminating small bright lights on a dark background. Methods: An adaptive-optics system was used to correct ocular aberrations of cyclopleged eyes and then systematically introduce five levels of Seidel SA for a 7-mm diameter pupil: 0, ± 0.18, and ± 0.36 diopters (D) mm−2. For each level of SA, subjects were required to detect one or resolve two points of light (0.54 arc min diameter) on a dark background. Refractive error was measured by adjusting stimulus vergence to minimize detection and resolution thresholds. Two other novel focusing tasks for si…
Visual Acuity in Simple Myopic Astigmatism: Influence of Cylinder Axis
2006
Purpose. The relationship between astigmatic refractive errors and their associated visual acuity has been studied in recent years in the context of refractive power space. The influence of the axis of astigmatism remains a matter of controversy. Our goal in this study is to provide additional experimental evidence to clarify this subject. The influence of the simulated axis orientation was compared with other factors that affect visual acuity such as the particular design of the test and the differences between eyes. Methods. Simple myopic astigmatism from 0 to 3.00 D, in steps of 0.25 D, and with five different axes between 0° and 90°, were simulated on four healthy eyes of young observer…
Impact of the line of sight on toric phakic intraocular lenses for hyperopia
2003
We present a hyperopic patient with a decentered line of sight in whom the residual refractive error after toric phakic intraocular lens (TP IOL) implantation was improved by displacement and individualized treatment. A 35-year-old woman presented with asthenopic complaints 2 months after bilateral TP IOL implantation and IOL rotation 4 weeks later. Examination revealed the line of sight to be nasally and inferiorly decentered in relation to the center of the pupil. A more nasal reenclavation of the TP IOL decreased the coma, and the uncorrected visual acuity was 20/20. We conclude that line of sight should be measured before TP IOL implantation, especially in hyperopic eyes.
Blue-yellow deficiencies in young moderate smokers.
2021
Purpose To evaluate whether tobacco affects color vision in young moderate smokers. Methods Chromatic mechanisms of 13 moderate smokers (10–20 cigarettes/day and at least 5 years smoking) and 17 non-smokers in the 18–35 age range were assessed with the Farnsworth-Munsell 100-hue (FM100h) test and short wavelength automated perimetry (SWAP). Results FM100h Total Error Scores (TES) were higher for smokers, and although differences were not significant (p = 0.14), a linear model with principal component analysis was able to explain 95% of the variance in TES and red-green partial error scores, though not in blue-yellow partial error scores (p = 0.07), using the number of years as smokers and t…
Isolated Endometriosis on the Rectus Abdominis Muscle in Women without a History of Abdominal Surgery: a Rare and Intriguing Finding
2009
We report 2 rare cases of endometriosis on the rectus abdominal muscle diagnosed incidentally during an operation for inguinal hernia repair in women with no surgical history. Two women sought medical attention for a mass found in the pubic abdominal wall. Only 1 woman reported occasional pain. At physical examination in both women, an ovoid swelling in the right pubic area was felt. One woman experienced pain on palpation, and one reported slight discomfort. Ultrasonography demonstrated a heterogeneous hypoechogenic formation with indistinct edges; diagnosis was difficult. Routine clinical and instrumental (pelvic ultrasonography) gynecologic examination in both patients performed shortly …
Improved accuracy of hysteroembryoscopic biopsies for karyotyping early missed abortions
2003
Abstract Objective To assess the potential of direct embryo and chorion biopsies obtained by hysteroembryoscopy for karyotyping early missed abortions. Design Clinical prospective descriptive study. Setting Instituto Valenciano de Infertilidad, Valencia, Spain. Patient(s) Sixty-eight women (71 gestational sacs) with missed abortions. The gestational age on ultrasound was 6.3 weeks (range, 4–10 weeks). Intervention(s) Transcervical hysteroembryoscopy before curettage. Main outcome measure(s) Comparison between the cytogenetic results from hysteroembryoscopic biospies and those of the curettage material. Result(s) Hysteroembryoscopic biopsies could be taken in 97.2% of the gestational sacs. D…
OCT for Assessing Artificial Tears Effectiveness in Contact Lens Wearers
2011
PURPOSE: To apply a commercially available high-resolution spectral domain optical coherence tomographer (SOCT) to assess the change in tear volume after application of a new artificial tears formulation specifically developed for contact lens (CL) users. METHODS: Twenty OD from young healthy CL wearers (mean age, 24.7 ± 3.5 years) with refractive errors ranging from -0.75 to -2.50 D (mean, -1.56 ± 0.69 D) were examined. All subjects were fitted with Focus Dailies CL (Ciba Vision), and two drops of Blink Contacts (AMO), lubricating formulation specifically developed for CL wearers, were instilled after baseline measures. Tear meniscus volume (TMV) was measured immediately after and 1 min, 1…
Biportal neuroendoscopic microsurgical approaches to the subarachnoid cisterns. A cadaver study.
1996
A preclinical cadaver study was performed to develop the technique of biportal neuroendoscopic dissection in the subarachnoid space of the basal cisterns and to test the feasibility, utility, and safety of this new technique. In 23 fresh post-mortem adult human cadavers and 2 formalin-fixed adult human head specimen a total of 33 biportal endomicrosurgical dissections into and within the basal cisterns were carried out. Following suction of cerebrospinal fluid from the subarachnoid space 0 degree-, 30 degrees-, and 70 degrees-lens-scopes (Aesculap AG, Tuttlingen, Germany) with outer diameters of 4.2 mm and trochars with outer diameters of 5 to 6.5 mm were introduced into the surgical field.…
Pulmonary artery sarcoma with angiosarcoma phenotype mimicking pleomorphic malignant fibrous histiocytoma: a case report
2012
Abstract Primary sarcomas of the major blood vessels can be classified based on location in relationship to the wall or by histologic type. Angiosarcomas are malignant neoplasms that arise from the endothelial lining of the blood vessels; those arising in the intimal compartment of pulmonary artery are rare. We report a case of pulmonary artery angiosarcoma in a 36-year old female with pulmonary masses. The patient had no other primary malignant neoplasm, thus excluding a metastatic lesion. Gross examination revealed a thickened right pulmonary artery and a necrotic and hemorrhagic tumor, filling and occluding the vascular lumen. The mass extended distally, within the pulmonary vasculature …
Prevalence of general binocular dysfunctions in a population of university students.
1997
Although some authors report that the prevalence of general binocular dysfunctions (nonstrabismic) for nonpresbyopes in the clinical population is greater than any condition except refractive error, limited research is available to support this statement. This clinical study determined the presence and clinical implications of these conditions in a population of university students with heavy near visual demands.From a group of second year students who were given a thorough eye examination, 65 students were selected. The criteria for selection were the absence of significant uncorrected refractive error, healthy eyes, and no strabismus or amblyopia.32.3% of the subjects showed general binoc…