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Congenital nystagmus, involuntary oscillating small eye movements, is commonly thought to originate from aberrant interactions between brainstem nuclei and foveal cortical pathways. Here, we investigated whether nystagmus associated with congenital stationary night blindness (CSNB) results from primary deficits in the retina. We found that CSNB patients as well as an animal model (nob mice), both of which lacked functional nyctalopin protein (NYX, nyx) in ON bipolar cells (BCs) at their synapse with photoreceptors, showed oscillating eye movements at a frequency of 4-7 Hz. nob ON direction-selective ganglion cells (DSGCs), which detect global motion and project to the accessory optic system (AOS), oscillated with the same frequency as their eyes. In the dark, individual ganglion cells (GCs) oscillated asynchronously, but their oscillations became synchronized by light stimulation. Likewise, both patient and nob mice oscillating eye movements were only present in the light when contrast was present. Retinal pharmacological and genetic manipulations that blocked nob GC oscillations also eliminated their oscillating eye movements, and retinal pharmacological manipulations that reduced the oscillation frequency of nob GCs also reduced the oscillation frequency of their eye movements. We conclude that, in nob mice, synchronized oscillations of retinal GCs, most likely the ON-DCGCs, cause nystagmus with properties similar to those associated with CSNB in humans. These results show that the nob mouse is the first animal model for a form of congenital nystagmus, paving the way for development of therapeutic strategies.
This article was published in the following journal.
Name: PLoS biology
To assess the pupil light response (PLR) to chromatic stimulation in patients with different types of X-linked congenital stationary night blindness (CSNB).
Congenital nystagmus is one of the most common neuro-ophthalmological disorders. X chromosome-linked forms are associated with pathogenic variants of the GPR143 and FRMD7 genes.
This study aimed to investigate the prevalence and causes of childhood blindness in a rural area of Bangladesh. We adopted a cross-sectional quantitative study design for this study, which was perform...
This paper presents a classification and definitions for types of nystagmus and other oscillatory eye movements relevant to evaluation of patients with vestibular and neurological disorders, formulate...
The purpose of this study was to test the extent of light damage in different models of night blindness and apply these paradigms in testing the therapeutic efficacy of combination therapy by drugs ac...
To assess the effect of oral administration of the alga Dunaliella bardawil containing approximately 50% all-trans beta-carotene and 50% 9-cis beta-carotene isomers on visual functions pat...
The purpose of this study is to investigate the long-term safety, tolerability and efficacy of neramexane mesylate in the treatment of congenital idiopathic nystagmus (CIN). In addition, a...
The purpose of this study is to investigate the safety and efficacy of neramexane mesylate in the treatment of congenital idiopathic nystagmus (CIN) in comparison to placebo. In addition, ...
This study will examine the safety and effectiveness of a new surgical procedure to correct congenital nystagmus-a disorder of eye muscle-vision-brain coordination characterized by rapid t...
Involuntary oscillations of the eyes (nystagmus) impairs vision so that affected patients, who have neurological disorders such as Multiple Sclerosis (MS) , cannot read or watch TV. Two me...
Failure or imperfection of vision at night or in dim light, with good vision only on bright days. (Dorland, 27th ed)
Institutional night care of patients.
Nystagmus present at birth or caused by lesions sustained in utero or at the time of birth. It is usually pendular, and is associated with ALBINISM and conditions characterized by early loss of central vision. Inheritance patterns may be X-linked, autosomal dominant, or recessive. (Adams et al., Principles of Neurology, 6th ed, p275)
An X chromosome-linked abnormality characterized by atrophy of the choroid and degeneration of the retinal pigment epithelium causing night blindness.
A nutritional condition produced by a deficiency of VITAMIN A in the diet, characterized by NIGHT BLINDNESS and other ocular manifestations such as dryness of the conjunctiva and later of the cornea (XEROPHTHALMIA). Vitamin A deficiency is a very common problem worldwide, particularly in developing countries as a consequence of famine or shortages of vitamin A-rich foods. In the United States it is found among the urban poor, the elderly, alcoholics, and patients with malabsorption. (From Cecil Textbook of Medicine, 19th ed, p1179)
Congenital conditions are those which are present from birth. They include structural deformities or loss of function in organs such as the <!--LGfEGNT2Lhm-->heart, gut or skeletal system. They can be corrected by <!--LGfEGNT2Lhm-->surgery, m...
Within medicine, nutrition (the study of food and the effect of its components on the body) has many different roles. Appropriate nutrition can help prevent certain diseases, or treat others. In critically ill patients, artificial feeding by tubes need t...