نتایج جستجو برای: night blindness

تعداد نتایج: 48292  

2013
Mieke M. C. Bijveld Maria M. van Genderen Frank P. Hoeben Amir A. Katzin Ruth M. A. van Nispen Frans C. C. Riemslag Astrid M. L. Kappers

Congenital Stationary Night Blindness (CSNB) is a retinal disorder caused by a signal transmission defect between photoreceptors and bipolar cells. CSNB can be subdivided in CSNB2 (rod signal transmission reduced) and CSNB1 (rod signal transmission absent). The present study is the first in which night vision problems are assessed in CSNB patients in a systematic way, with the purpose of improv...

2005
Arkady Selenow David Rumpf

OPs in the dark-adapted eye is similar to the scotopic luminosity function. In addition, his results show some of the features of the present study—particularly the large variation in the latency of rod-generated responses as a function of flash intensity and some of the changes in waveform of responses to orange flashes as intensity is reduced. The spectral sensitivity measurements of Wachtmei...

Journal: :Bulletin of the World Health Organization 2001
R Dandona L Dandona R K John C A McCarty G N Rao

OBJECTIVE To assess the level of awareness of eye diseases in the urban population of Hyderabad in southern India. METHODS A total of 2522 subjects of all ages, who were representative of the Hyderabad population, participated in the population-based Andhra Pradesh Eye Disease Study. Of these subjects, 1859 aged > 15 years responded to a structured questionnaire on cataract, glaucoma, night b...

2012
Sherry A. Tanumihardjo Sean Lynch David I. Thurnham

n The assessment of vitamin A status is critical for the planning, implementation, monitoring and evaluation of vitamin A deficiency prevention and treatment programmes. Determination of night blindness is one of the traditional methods of assessing vitamin A deficiency. A variety of subjective and objective methods have been used, however, reported night blindness, the most common method to as...

2012
Douglas Taren

n The assessment of vitamin A status is critical for the planning, implementation, monitoring and evaluation of vitamin A deficiency prevention and treatment programmes. Determination of night blindness is one of the traditional methods of assessing vitamin A deficiency. A variety of subjective and objective methods have been used, however, reported night blindness, the most common method to as...

Journal: :Vision Research 2008
Mineo Kondo Shinji Ueno Chang-Hua Piao Yozo Miyake Hiroko Terasaki

Focal macular cone electroretinograms (ERGs) and multifocal ERGs were recorded to study the macular function in patients with the complete-type of congenital stationary night blindness (cCSNB). The waveforms of the focal macular cone ERGs and the on- and off-responses of the multifocal ERGs in the cCSNB patients were similar to those recorded from monkey retinas treated with L-2 amino-4-phospho...

2005
Pierre Lachapelle John M. Little Robert C. Polomeno

Previous studies have reported that subjects affected with congenital stationary night blindness and myopia demonstrated some photopic (cone) abnormalities in their electroretinogram (ERG). By comparing the photopic ERG elicited with a threshold and a suprathreshold stimulus it was found that, at threshold, no significant differences were noted both in the peak time and in the amplitude of ERGs...

Journal: :Investigative ophthalmology & visual science 2001
M Kondo Y Miyake N Kondo A Tanikawa S Suzuki M Horiguchi H Terasaki

PURPOSE To study the multifocal electroretinogram (mfERG) in patients with the complete type of congenital stationary night blindness (cCSNB), which is thought to be due to a defect in neurotransmission from the photoreceptors to the ON-bipolar cells. METHODS mfERGs were recorded with the VERIS recording system from four patients with cCSNB, none of whom had nystagmus. The stimulus array cons...

2014
Surya S. Nair K. Paul Joseph

Electroretinogram (ERG) is a time-varying potential which arises from different layers of retina. To be specific, all the physiological signals may contain some useful information which is not visible to our naked eye. However this subtle information is difficult to monitor directly. Therefore the ERG signal features which are extracted and analyzed using computers are highly useful for diagnos...

Journal: :EMBO reports 2013
Ankita Singhal Martin K Ostermaier Sergey A Vishnivetskiy Valérie Panneels Kristoff T Homan John J G Tesmer Dmitry Veprintsev Xavier Deupi Vsevolod V Gurevich Gebhard F X Schertler Joerg Standfuss

We present active-state structures of the G protein-coupled receptor (GPCRs) rhodopsin carrying the disease-causing mutation G90D. Mutations of G90 cause either retinitis pigmentosa (RP) or congenital stationary night blindness (CSNB), a milder, non-progressive form of RP. Our analysis shows that the CSNB-causing G90D mutation introduces a salt bridge with K296. The mutant thus interferes with ...

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