Biomaterial Database

Disturbances of small-field horizontal and vertical optokinetic nystagmus in amblyopia. 1980

C M Schor, and D M Levi

Horizontal and vertical small-field optokinetic nystagmus (OKN) were examined in persons with strabismic or anisometropic amblyopia. Reduced velocity for the slow phase of OKN driven by temporalward and upward target motion presented monocularly was observed in both the amblyopic and nonamblyopic eyes of some subjects. Several experiments were conducted in search of a sensory disturbance of perceived motion sensitivity which could account for the abnormal OKN. Comparisons between the frequency response for OKN and the contrast sensitivity function for perceived motion revealed that amblyopes with asymmetric OKN had equal sensitivity to nasal and temporal target motion. Contrast thresholds for driving the temporal slow phase of OKN were elevated by over 1 log unit above contrast thresholds for perceived temporal target motion, whereas contrast thresholds for stimulating nasal movement and driving the nasalward slow phase of OKN were equal. Contrast sensitivity to nasal and temporal target motion was symmetrical at the fovea and parafovea of the amblyopic eye. These studies did not reveal a sensory a /mso observed in both eyes of persons with congenital strabismus without amblyopia and in the nondeprived eye in monocular congenital cataract. These observations suggest a relationship between directional asymmetries of OKN and the incomplete development of binocular vision.

UI	MeSH Term	Description	Entries
D009039	Motion Perception	The real or apparent movement of objects through the visual field.	Movement Perception,Perception, Motion,Perception, Movement
D012030	Refractive Errors	Deviations from the average or standard indices of refraction of the eye through its dioptric or refractive apparatus.	Ametropia,Refractive Disorders,Ametropias,Disorder, Refractive,Disorders, Refractive,Error, Refractive,Errors, Refractive,Refractive Disorder,Refractive Error
D005133	Eye Movements	Voluntary or reflex-controlled movements of the eye.	Eye Movement,Movement, Eye,Movements, Eye
D005403	Fixation, Ocular	Positioning and accommodation of eyes that allows the image to be brought into place on the FOVEA CENTRALIS of each eye.	Focusing, Ocular,Ocular Fixation,Eye Gaze,Eye Gazes,Gaze, Eye,Gazes, Eye,Ocular Focusing
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000328	Adult	A person having attained full growth or maturity. Adults are of 19 through 44 years of age. For a person between 19 and 24 years of age, YOUNG ADULT is available.	Adults
D000550	Amblyopia	A nonspecific term referring to impaired vision. Major subcategories include stimulus deprivation-induced amblyopia and toxic amblyopia. Stimulus deprivation-induced amblyopia is a developmental disorder of the visual cortex. A discrepancy between visual information received by the visual cortex from each eye results in abnormal cortical development. STRABISMUS and REFRACTIVE ERRORS may cause this condition. Toxic amblyopia is a disorder of the OPTIC NERVE which is associated with ALCOHOLISM, tobacco SMOKING, and other toxins and as an adverse effect of the use of some medications.	Anisometropic Amblyopia,Lazy Eye,Amblyopia, Developmental,Amblyopia, Stimulus Deprivation-Induced,Amblyopia, Suppression,Stimulus Deprivation-Induced Amblyopia,Amblyopia, Anisometropic,Amblyopia, Stimulus Deprivation Induced,Amblyopias,Amblyopias, Anisometropic,Amblyopias, Developmental,Amblyopias, Stimulus Deprivation-Induced,Amblyopias, Suppression,Anisometropic Amblyopias,Deprivation-Induced Amblyopia, Stimulus,Deprivation-Induced Amblyopias, Stimulus,Developmental Amblyopia,Developmental Amblyopias,Eye, Lazy,Eyes, Lazy,Lazy Eyes,Stimulus Deprivation Induced Amblyopia,Stimulus Deprivation-Induced Amblyopias,Suppression Amblyopia,Suppression Amblyopias
D013285	Strabismus	Misalignment of the visual axes of the eyes. In comitant strabismus the degree of ocular misalignment does not vary with the direction of gaze. In noncomitant strabismus the degree of misalignment varies depending on direction of gaze or which eye is fixating on the target. (Miller, Walsh & Hoyt's Clinical Neuro-Ophthalmology, 4th ed, p641)	Concomitant Strabismus,Dissociated Horizontal Deviation,Dissociated Vertical Deviation,Heterophoria,Heterotropias,Hypertropia,Non-Concomitant Strabismus,Nonconcomitant Strabismus,Phorias,Squint,Strabismus, Comitant,Strabismus, Noncomitant,Convergent Comitant Strabismus,Mechanical Strabismus,Comitant Strabismus,Comitant Strabismus, Convergent,Deviation, Dissociated Horizontal,Dissociated Horizontal Deviations,Dissociated Vertical Deviations,Heterophorias,Heterotropia,Horizontal Deviation, Dissociated,Hypertropias,Non Concomitant Strabismus,Noncomitant Strabismus,Phoria,Strabismus, Concomitant,Strabismus, Convergent Comitant,Strabismus, Mechanical,Strabismus, Non-Concomitant,Strabismus, Nonconcomitant
D014787	Vision Tests	A series of tests used to assess various functions of the eyes.	Test, Vision,Tests, Vision,Vision Test
D014792	Visual Acuity	Clarity or sharpness of OCULAR VISION or the ability of the eye to see fine details. Visual acuity depends on the functions of RETINA, neuronal transmission, and the interpretative ability of the brain. Normal visual acuity is expressed as 20/20 indicating that one can see at 20 feet what should normally be seen at that distance. Visual acuity can also be influenced by brightness, color, and contrast.	Acuities, Visual,Acuity, Visual,Visual Acuities