Search results for "ophthalmology"
showing 10 items of 1738 documents
Corneal confocal scanning laser microscopy in patients with dry eye disease treated with topical cyclosporine
2017
Purpose To investigate the effect of cyclosporine on corneal ultrastructure and on major signs and symptoms of patients with dry eye disease.Patients and methods In this prospective cohort study, patients with dry eye disease were treated with a drop of cyclosporine 0.05% twice daily. Clinical evaluation was carried out at baseline and at months 1, 3, and 6. All patients completed the Ocular Surface Disease Index (OSDI) questionnaire, and tear film break-up time (BUT), fluorescein and lissamine green staining, and Schirmer test were carried out. In vivo confocal microscopy was also performed and epithelial cellular density, keratocyte activation, and subbasal plexus morphology were assessed…
Phenotypical features of two patients diagnosed with PHARC syndrome and carriers of a new homozygous mutation in the ABHD12 gene.
2018
Abstract PHARC (Polyneuropathy, Hearing loss, Ataxia, Retinitis pigmentosa and Cataracts) (MIM# 612674 ) is an autosomal recessive neurodegenerative disease caused by mutations in the ABHD12 gene. We evaluated two Spanish siblings affected with pes cavus, sensorimotor neuropathy, hearing loss, retinitis pigmentosa and juvenile cataracts in whom the genetic test of ABHD12 revealed a novel homozygous frameshift mutation, c.211_223del (p.Arg71Tyrfs*26). The earliest clinical manifestation in these patients was a demyelinating neuropathy manifested with a Charcot-Marie-Tooth phenotype over three decades. Progressive hearing loss, cataracts and retinitis pigmentosa appeared after the age of 30. …
Dynamic accommodation without feedback does not respond to isolated blur cues
2016
Highlights • A new methodology is used to study a potential cue for dynamic accommodation. • We show that human accommodation is not driven correctly by defocus alone. • Accommodation is most efficient using changes in stimulus vergence with feedback.
Changes in Accommodation and Ocular Aberration With Simultaneous Vision Multifocal Contact Lenses
2012
Objective: The aim of this study was to evaluate ocular aberration changes through different simultaneous vision multifocal contact lenses (CLs). Methods: Eighteen young-adult subjects with a mean age of 29.8 +/- 2.11 years took part. Changes in accommodative response, spherical aberration (C-4(0)), horizontal coma (C-3(1)), vertical coma (C-3(-1)), and root mean square (RMS) of higher-order aberrations (HOAs, third to sixth orders) were evaluated. Measurements were obtained with a distance-single vision CL and 2 aspheric multifocal CLs of simultaneous focus center-near design (PureVision Low Add and PureVision High Add) for 2 accommodative stimuli (-2.50 and -4.00 D). All measurements were…
Accommodative Functions with Multifocal Contact Lenses: A Pilot Study
2011
PURPOSE: To evaluate accommodative response and facility in presbyopic patients fitted with several types of simultaneous-image multifocal contact lenses (CLs). METHODS: Six presbyopic patients, unadapted wearers of simultaneous-image bifocals, were fitted with the Focus Progressives and the low- and high-addition Pure Vision simultaneous vision multifocal CLs. Each individual wore each of the three types of lenses in successive random order. Accommodative response, accommodative facility, visual acuity, and contrast sensitivity at distance and near were evaluated in all cases. A control group of eight non-presbyopic patients was also studied. RESULTS: The mean age was 28.6 +/- 2.72 and 51.…
The effect of longitudinal chromatic aberration on the lag of accommodation and depth of field.
2016
Purpose Longitudinal chromatic aberration is present in all states of accommodation and may play a role in the accommodation response and the emmetropisation process. We study the change of the depth of field (DOFi) with the state of accommodation, taking into account the longitudinal chromatic aberration. Methods Subjective DOFi was defined as the range of defocus beyond which the blur of the target (one line of optotypes of 0.1 logMAR shown on a black-and-white microdisplay, seen through different colour filters) was perceived as objectionable. The subject's eye was paralysed and different, previously-measured accommodative states (corresponding to the accommodative demands of 0D, 2D and …
Influence of contrast polarity on the accommodative response☆
2018
espanolObjetivo Evaluar los cambios de la respuesta acomodativa del ojo al leer un texto en diferentes condiciones de polaridad de contraste: letras negras sobre fondo blanco (condicion BoW) y letras blancas sobre fondo negro (condicion WoB). Metodos En este estudio experimental participaron dieciocho sujetos de edades comprendidas entre 21 y 41 anos. Se obtuvo objetivamente la respuesta acomodativa (AR) del ojo al leer un texto con polaridad de contraste BoW o WoB con un sistema de optica adaptativa que corregia todas las aberraciones salvo las propias del sujeto. Se estudiaron dos tamanos de letra diferentes (condiciones de agudeza visual), mostrados en una micropantalla. Se midio la AR d…
Measuring and modeling real-time responses to music: the dynamics of tonality induction.
2003
We examined a variety of real-time responses evoked by a single piece of music, the organ Duetto BWV 805 by J S Bach. The primary data came from a concurrent probe-tone method in which the probe-tone is sounded continuously with the music. Listeners judged how well the probe tone fit with the music at each point in time. The process was repeated for all probe tones of the chromatic scale. A self-organizing map (SOM) [Kohonen 1997 Self-organizing Maps (Berlin: Springer)] was used to represent the developing and changing sense of key reflected in these judgments. The SOM was trained on the probe-tone profiles for 24 major and minor keys (Krumhansl and Kessler 1982 Psychological Review89 334–…
Metastatic Anterior Chamber Non-Hodgkin Lymphoma in a Patient With Acquired Immunodeficiency Syndrome
1997
Purpose To alert ophthalmologists to the possibility of metastatic anterior chamber intraocular non-Hodgkin lymphoma in patients with acquired immunodeficiency syndrome (AIDS). Methods We examined a 19-year-old man with AIDS who had an anterior uveitis with pseudohypopyon and a history of 2 months of malaise. A specimen of the lesion was obtained with a 25-gauge needle for pathologic examination. RESULTS: Systemic exploration showed hepatomegaly. Abdominal computed tomography showed multiple lesions in the liver and spleen. Fine-needle aspiration disclosed a high-grade non-Hodgkin lymphoma. The result of a fine-needle aspiration obtained from a lesion in the anterior chamber was consistent …
Gentamicin, norfloxacin and lysozyme concentration in human tears: in vivo and in vitro study
1992
Hen's egg lysozyme (HEL) activity was measured in vitro with gentamicin and norfloxacin by a turbidimetric technique. Gentamicin at the concentration of 10(-3) M inhibited HEL activity by 39%, while 10(-3) M norfloxacin did not affect HEL activity. However, an in vivo study in healthy persons did not show any significant statistical difference in tear lysozyme activity when 0.3% gentamicin or 0.3% norfloxacin were topically applied.