The visual system of newborn infants is not like that of adults. Both ocular and neural structures essential for vision will undergo anatomical and physiological changes as maturation process. The maturation of all visual systems occurs relatively rapidly in normal children. So, early examination of visual acuity is critical for normal visual funciton achievement. Visual acuity in preverbal children can be assessed using several techniques, such as fixation and following behavior under both monocular and binocular conditions, the optokinetic nystagmus technique, preferential looking, visual evoked potential, and recognition acuity using a vision chart. Most clinicians consider the standard technique of recognition acuity to be the gold standard for visual acuity assessments, 20/20 vision should be achieved by 7 years of age. Significant refractive error, a high degree of hyperopia, myopia, or astigmatism may result in not only blurred vision, but also strabismus and amblyopia. Therefore, early vision screening is very valuable. Subjective and objective refractive techniques are standard for detecting significant refractive errors in children and are available under either non-cycloplegic or cycloplegic conditions. Amblyopia is the most common cause of vision loss in children and young adults, defining as a reduction of best-corrected visual acuity due to the interruption of normal visual development during the so-called sensitive period. If the problem is not identified until the sensitive period is complete, the vision loss is permanent. Visual impairment in childhood affects all aspects of the child's development. Earlier treatment is associated with better outcomes. Of course, patient compliance and parental support are the most important factors contributing to treatment success.
Adult ; Amblyopia ; Astigmatism ; Child ; Evoked Potentials, Visual ; Humans ; Hyperopia ; Infant, Newborn ; Myopia ; Nystagmus, Optokinetic ; Parents ; Patient Compliance ; Refractive Errors ; Strabismus ; Telescopes ; Vision Disorders ; Vision Screening ; Visual Acuity* ; Young Adult

The visual system of newborn infants is not like that of adults. Both ocular and neural structures essential for vision will undergo anatomical and physiological changes as maturation process. The maturation of all visual systems occurs relatively rapidly in normal children. So, early examination of visual acuity is critical for normal visual funciton achievement. Visual acuity in preverbal children can be assessed using several techniques, such as fixation and following behavior under both monocular and binocular conditions, the optokinetic nystagmus technique, preferential looking, visual evoked potential, and recognition acuity using a vision chart. Most clinicians consider the standard technique of recognition acuity to be the gold standard for visual acuity assessments, 20/20 vision should be achieved by 7 years of age. Significant refractive error, a high degree of hyperopia, myopia, or astigmatism may result in not only blurred vision, but also strabismus and amblyopia. Therefore, early vision screening is very valuable. Subjective and objective refractive techniques are standard for detecting significant refractive errors in children and are available under either non-cycloplegic or cycloplegic conditions. Amblyopia is the most common cause of vision loss in children and young adults, defining as a reduction of best-corrected visual acuity due to the interruption of normal visual development during the so-called sensitive period. If the problem is not identified until the sensitive period is complete, the vision loss is permanent. Visual impairment in childhood affects all aspects of the child's development. Earlier treatment is associated with better outcomes. Of course, patient compliance and parental support are the most important factors contributing to treatment success.
Adult ; Amblyopia ; Astigmatism ; Child ; Evoked Potentials, Visual ; Humans ; Hyperopia ; Infant, Newborn ; Myopia ; Nystagmus, Optokinetic ; Parents ; Patient Compliance ; Refractive Errors ; Strabismus ; Telescopes ; Vision Disorders ; Vision Screening ; Visual Acuity* ; Young Adult

BACKGROUND: Saccade test, smooth pursuit test, and optokinetic nystagmus test are clinically useful tests to accurately diagnose vertigo. However, there have only been a few studies regarding a correlation between the anatomical site of the lesion and the abnormality of eyeball movement in patients with vertigo. METHODS: The medical records of 97 patients with vertigo between January 2006 and June 2008 were reviewed retrospectively. We classified many kinds of abnormalities regarding the saccade test, smooth pursuit test and optokinetic nystagmus test into several categories and analyzed the localizing lesion of vertigo. RESULTS: According to the saccade test, both total saccade abnormality (S-total) and slow velocity of saccade (S-type 3) were shown to be significantly higher in the central lesion of vertigo. According to the smooth pursuit test, symmetrical unidirectional smooth pursuit abnormality (SP-type 2) was observed to be significantly higher in the peripheral lesion over vertigo. Moreover, according to the optokinetic nystagmus test, total optokinetic nystagmus abnormalities (OKN-total) were shown to be significantly useful findings in the diagnosis of the central lesion of vertigo. The coexisting abnormalities of all three tests (S+SP+OKN abnormalities) were shown to be significantly higher in the central lesion of vertigo. CONCLUSION: These results suggest that all these tests, saccade test, smooth pursuit test, and optokinetic nystagmus test, are very useful to distinguish between the central lesion and the peripheral lesion of vertigo. However, these tests are not beneficial in localizing the central lesion of vertigo.
Diagnosis ; Humans ; Medical Records ; Nystagmus, Optokinetic* ; Pursuit, Smooth* ; Retrospective Studies ; Saccades* ; Vertigo

BACKGROUND: Saccade test, smooth pursuit test, and optokinetic nystagmus test are clinically useful tests to accurately diagnose vertigo. However, there have only been a few studies regarding a correlation between the anatomical site of the lesion and the abnormality of eyeball movement in patients with vertigo.METHODS: The medical records of 97 patients with vertigo between January 2006 and June 2008 were reviewed retrospectively. We classified many kinds of abnormalities regarding the saccade test, smooth pursuit test and optokinetic nystagmus test into several categories and analyzed the localizing lesion of vertigo.RESULTS: According to the saccade test, both total saccade abnormality (S-total) and slow velocity of saccade (S-type 3) were shown to be significantly higher in the central lesion of vertigo. According to the smooth pursuit test, symmetrical unidirectional smooth pursuit abnormality (SP-type 2) was observed to be significantly higher in the peripheral lesion over vertigo. Moreover, according to the optokinetic nystagmus test, total optokinetic nystagmus abnormalities (OKN-total) were shown to be significantly useful findings in the diagnosis of the central lesion of vertigo. The coexisting abnormalities of all three tests (S+SP+OKN abnormalities) were shown to be significantly higher in the central lesion of vertigo.CONCLUSION: These results suggest that all these tests, saccade test, smooth pursuit test, and optokinetic nystagmus test, are very useful to distinguish between the central lesion and the peripheral lesion of vertigo. However, these tests are not beneficial in localizing the central lesion of vertigo.
Diagnosis ; Humans ; Medical Records ; Nystagmus, Optokinetic ; Pursuit, Smooth ; Retrospective Studies ; Saccades ; Vertigo

BACKGROUND AND OBJECTIVES: Although disequilibrium is common type of dizziness in older people, it is sometimes difficult to identify a specific cause for this problem. The diffuse brain pathology including subcortical ischemia and atrophy can be a cause for patients with disequilibrium of unknown cause. Aim of this study is to identify the eye movements and neuroimaging features in patients with disequilibrium. MATERIALS AND METHODS: We performed a prospective investigation in patients with disequilibrium of unknown cause. We collected information on demographic characteristics and clinical features of disequilibrium. The impact of dizziness on everyday life was assessed by 25-item dizziness handicap inventory (DHI). Vestibular function test (VFT) includes smooth pursuit, saccade, optokinetic nystagmus, and rotatory chair test. Subcortical white matter lesions and brain atrophy were graded from brain magnetic resonance image (MRI). RESULTS: This study included 14 patients (12 female and 2 male), aged between 64 and 84 years, mean age 74.01+/-6.02 years. The score of DHI was 39.4+/-11.8 (20-58). Eye movements were abnormal in 13 patients and normal in only one patient. The degree of subcortical ischemia was mild in 7, moderate in 4, and severe in 3 patients. Ventricular brain ratio was 0.23+/-0.03. However, there was no significant relationship between MRI findings and the degree of oculomotor alterations (result of VFT). CONCLUSION: Patients with disequilibrium of unknown cause are usually elderly women. Alterations in oculomotor movements and diffuse brain pathology including white matter lesions and atrophy were observed in patients with disequilibrium of unknown cause.
Aged ; Atrophy ; Brain ; Brain Diseases ; Brain Ischemia ; Dizziness ; Eye Movements ; Female ; Humans ; Ischemia ; Magnetic Resonance Imaging ; Neuroimaging ; Nystagmus, Optokinetic ; Prospective Studies ; Pursuit, Smooth ; Saccades ; Vestibular Function Tests

PURPOSE: The objective visual acuity test is mandatory in certain cases, such as infants, nonverbal subjects, and subjects who need legal assistance. We designed an objective system for visual acuity test (SOVAT) consisting of three components: stimuli applied via a suppression method, display and evaluation and made a suppression method as stimuli component for SOVAT. Usefulness of the SOVAT was evaluated. METHODS: The visual stimuli were presented on a high-resolution head-mounted display (HMD). An eye movement tracking program and gaze monitoring device allowed us to monitor the patient's fixation status during the test. The suppression method, in addition to a conventional induction method, was developed to use with the SOVAT and its accuracy and confidence level were evaluated. RESULTS: On the basis of clinical data, we present the reference values for the SOVAT as below. For the induction method, objective visual acuity (smallest pixel size), the presumed subjective visual acuity was 3: 0.35-0.6, 7: 0.05-0.25, 12: below 0.05 and for the suppression method it was 1: 0.6-1.0, 1.5: 0.4-0.7, 3: 0.15-0.4, 5: 0.1-0.2. CONCLUSIONS: SOVAT using this suppression method to assess objective visual acuity proved to be more useful than that with a conventional induction method, especially in the range of high visual acuity.
Eye Movements ; Humans ; Infant ; Nystagmus, Optokinetic ; Organothiophosphorus Compounds ; Reference Values ; Track and Field ; Visual Acuity

BACKGROUND AND PURPOSE: Congenital nystagmus (CN) is an ocular oscillation that usually manifests during early infancy. Typical features of CN include bilateral, conjugate, uniplanar, and usually horizontal eye movements, a null position, increased oscillation during fixation, and decreased amplitude during convergence. Our purposes were description and analysis of clinical and oculomotor findings of patients with X-linked familial CN. METHODS: We describe the clinical and oculographic features of five patients from three families with X-linked CN. Three-dimensional video-oculography disclosed various patterns of CN and variable degrees of gaze-holding deficits and visual impairments. RESULTS: The features of CN varied even in patients from the same family. Head tilt, strabismus, reversal of optokinetic nystagmus, and impairments of the vestibulo-ocular reflex, smooth pursuits, and saccades were frequent findings. CONCLUSIONS: The intra- and interfamilial diversities imply that heredity plays a secondary role in determining the clinical phenotypes and waveforms of CN.
Eye Movements ; Head ; Heredity ; Humans ; Nystagmus, Congenital* ; Nystagmus, Optokinetic ; Phenotype ; Pursuit, Smooth ; Reflex, Vestibulo-Ocular ; Saccades ; Strabismus ; Vision Disorders

BACKGROUND AND PURPOSE: Congenital nystagmus (CN) is an ocular oscillation that usually manifests during early infancy. Typical features of CN include bilateral, conjugate, uniplanar, and usually horizontal eye movements, a null position, increased oscillation during fixation, and decreased amplitude during convergence. Our purposes were description and analysis of clinical and oculomotor findings of patients with X-linked familial CN. METHODS: We describe the clinical and oculographic features of five patients from three families with X-linked CN. Three-dimensional video-oculography disclosed various patterns of CN and variable degrees of gaze-holding deficits and visual impairments. RESULTS: The features of CN varied even in patients from the same family. Head tilt, strabismus, reversal of optokinetic nystagmus, and impairments of the vestibulo-ocular reflex, smooth pursuits, and saccades were frequent findings. CONCLUSIONS: The intra- and interfamilial diversities imply that heredity plays a secondary role in determining the clinical phenotypes and waveforms of CN.
Eye Movements ; Head ; Heredity ; Humans ; Nystagmus, Congenital* ; Nystagmus, Optokinetic ; Phenotype ; Pursuit, Smooth ; Reflex, Vestibulo-Ocular ; Saccades ; Strabismus ; Vision Disorders

OBJECTIVE: To study the changes of visual nystagmography(VNG) in patients with vertebrobasilar transient ischemic vertigo(VBTIV), explore their clinical value in diagnosis of the patients with VBTIV. METHOD: Thirty-eight patients who complained vertigo and imbalance with VBTIV were selected as experimental group for testing of visual nystagmography (VNG). Twenty normal persons were chosen as control group. The result was analyzed. RESULT: In the experimental group, there was one case that had spontaneous nystagmus and 29 cases (76.3%) with positional nystagmus. The positional nystagmus intension in those patients was (4.08+/-3.18) degrees/s, which was much higher as compared with the control group( P <0.01). The incidence was 39.5% for positioning test. One or more abnormal findings for visual-oculomotor system examination were shown in 28 patients (73.7%). These abnormal findings included saccade test in 26 cases (68.4%), eye tracking test type III in 13 cases and type IV in 3 cases in all 16 cases (42.1%), optokinetic nystagmus in 17 cases (44.7%). There was none with gaze nystagmus. Caloric test showed canal paresis in 19 cases (50.0%) and directional preponderance in 6 cases (15.9%). In Amount distributing of the general slow phase velocity there is a difference between test group and control group. CONCLUSION Not only vestibular centrum but also peripheral system was involved in patients with VBTIV. These results suggest that VNG be used as important diagnostic test for patients with VBTIV and might be helpful for the location diagnosis of VBTIV.
Adult ; Case-Control Studies ; Electronystagmography ; Female ; Humans ; Male ; Middle Aged ; Nystagmus, Optokinetic ; Nystagmus, Pathologic ; complications ; diagnosis ; Vertebrobasilar Insufficiency ; complications ; physiopathology ; Vertigo ; etiology ; physiopathology ; Vestibular Function Tests

PURPOSE: The purpose of this paper was to determine the correlation between optokinetic nytagmus and grating and Snellen visual acuity charts and the validity of this correlation as an index. METHODS: Diffusion blur was used to cause visual decrease in 24 patients with normal eyes. Vision was measured using 3 different methods. To compare the central and peripheral vision, visiual acuity was measured using a macula occluder. RESULTS: Twenty four patients had an average uncorrected vision of 1.0 and showed regular visual acuity decrease using diffusion blur. Grating visual acuity showed correlation with the Snellen visual acuity but OKN visual acuity showed low correlation (p<0.05, ANOVA with repeated measure trend). OKN visual acuity showed low correlation with grating acuity when central visual acuity was occluded and only peripheral acuity was taken into consideration. CONCLUSIONS: Visual acuity measured using Snellen or grating acuity had little correlation with OKN visual acuity, and visual acuity measured using OKN was unable to indicate visual acuity in a quantitative manner.
Diffusion ; Humans ; Nystagmus, Optokinetic* ; Visual Acuity*