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At least 289 records · Page 16Linked to original sources

[Antioxidant therapy of vision organ disorders in the Chernobyl accident liquidators].

Antioxidant complex including flacumine, glutamic acid, and sodium thiosulfate was used to treat pathological changes in the organ of vision in the liquidators of the Chernobyl accident. The treatment stabilized vision acuity and improved some hormonal and immunological parameters of the blood. Hence, this therapeutic complex can be used for the prevention and treatment of ocular abnormalities in subjects exposed to radionuclides.

Adult↗

Efficacy of interferon therapy on patients with HCV infection in dependence from the time of treatment.

Among 45 patients with chronic hepatitis C the efficiency of interferon alpha 2b treatment was evaluated. The efficiency of interferon therapy was determined after 6 months of treatment in the group of 28 patients (group I) treated for 6 months and 17 patients (group II) treated for 12 months. The side effects were investigated with respect to such a factor as time of treatment. 11 (39%) patients from group I had eliminated HCV RNA and 14 (50%) patients had normalized AlAT levels in the serum. Five (29%) patients from group II eliminated HCV RNA and 8 (47%) patients had normalized AlAT levels in the serum. The flu-like syndrome, thrombocytopenia, vision disorder, depression and somnolence were most often the side effects observed in treated patients. Proportionally to time of treatment vision disorder, depression and somnolence increased.

Adult↗

Use of interferometry in preschool children.

Any procedure that can help to predict the outcome of treatment for a vision disorder is a desired clinical goal. Interferometry has shown such an ability for predicting the post-treatment visual acuities in amblyopia and other vision disorders. In this study, we investigated the effectiveness of using interferometry with preschool children, aged 3-5 years. We determined that they can be reliably tested in 5-10 minutes using a non-verbal, forced choice technique. Due to developmental differences, the 3-year-olds needed slightly more time to test and were more variable in their responses than the 4-years-olds. Overall, the prognostic value of interferometer visual acuity measures should be considered for use in preschool children with visual acuity disorders, e.g., amblyopia.

Amblyopia↗

[Seeing in the dusk: physiological basis and investigation].

Dark adaptation and seeing in the dusk require a complex interaction of the cone and rod system. Whereas the former provides high temporal resolution and colour vision in daylight, temporal resolution of the latter is smaller but sensitivity higher by a factor of 100 to 1,000. The two operational ranges overlap by several decades. Characteristic symptoms of disease may be derived from the systems' physiological function and should be enquired about specifically. Problems due to opacity of the optic media or reduced visual acuity should be differentiated from night vision disorders in the more specific sense. Apart from a routine ophthalmological examination a set of other tests should be used: When rods function normally the second limb of the dark adaptation curve initiates at 5 - 12 min und reaches a normal absolute threshold after 30 - 40 min; dark adapted visual fields are unrestricted apart from a physiological central scotoma, and the dark adapted electroretinogram (ERG) shows normal amplitudes and latencies for low intensity flashes. The influence of glare on mesopic contrast sensitivity may be investigated with a mesoptometer. Night vision disorders may arise from cone system dysfunction, too. Intact cone vision provides high visual acuity, normal colour vision, normal photopic visual fields, a quick regeneration within minutes during the first limb of the dark adaptation curve and normal single flash and oscillatory potentials in the light-adapted ERG. Localised defects may be detected using the multifocal ERG. Interpretation of the results must account for the age-related decay of contrast sensitivity and speed of adaptation.

Age Factors↗

[Examination of central vision. Visual acuity, contrast sensitivity, color vision].

In the neurophysiological organization of the visual system, form, color, movement, and depth perception are processed separately. Therefore, sensorial examination methods should test each of these basic functions separately, since they may be affected individually or to different extents by pathologic processes. For diagnosis the limit of visual acuity, i.e., the capacity for discrimination must be searched for, using Paliaga's "limits method". Visual acuity can also be tested in infants by the preferential looking method. Contrast sensitivity is tested using sinusoidal grid patterns of varying contrast and spatial frequency. In routine practice, however, this is usually achieved more easily with acuity cards on which contrast is reduced in several stages. The "two-equation method" is a colorimetric test combining two metameric matches, red + green = yellow, and blue + green = cyan, for testing color vision. The test requires an anomaloscope or anomalometer with four light channels. With this method it is possible to test the "red", "green", and "blue" cones and the "red-green" and "blue-yellow" opponents. The test provides a qualitative and quantitative evaluation of color vision disorders. If no colorimeter is available, classic printed test can be used. However, they might never achieve the same qualitative and quantitative precision.

Color Perception Tests↗

Analysis of tonic and accommodative vergence disorders of binocular vision.

Tonic and accommodative vergence disorders of binocular vision are analyzed with separate methods. The center of symmetry and the associated phoria of forced duction fixation disparity curves are two criteria used for prismatic correction of tonic vergence disorders. The associated phoria is corrected physiologically when patients who have tonic disorders are able to develop prism adaptation with orthoptic exercises. Graphical methods are used to analyze accommodative disorders resulting from mutual interactions between accommodation and convergence. Graphic analysis illustrates that patients with high AC/A ratios have greater demands upon fusional divergence than other patients with similar ocular deviations who have normal or low AC/A ratios. Prism adaptation, which has no direct influence upon the open-loop accommodative response, replaces corrective fusional vergence innervation and thereby eliminates the main stimulus to convergence accommodation and its exaggeration of accommodative convergence. Because prism adaptation has a response time of 15 to 30 sec, abnormal accommodative convergence interactions exaggerated by convergence accommodation can be transient in patients with normal prism adaptation. Accommodative convergence disorders in patients who lack prism adaptation are classified as sustained. Orthoptic exercises which develop fast fusional vergence are recommended for the transient disorders and additional exercises to develop prism adaptation are recommended for the sustained disorders of accommodative vergence interactions.

Accommodation, Ocular↗

Prevalence of vision and ocular disease conditions in a clinical pediatric population.

BACKGROUND: The purpose of this study was to fill a significant void in the ophthalmic literature by performing a large scale, comprehensive, prospective study of the prevalence of vision disorders and ocular pathology in a clinical pediatric population using well-defined diagnostic criteria. METHODS: A prospective study was performed on 2,023 consecutive patients between the ages of 6 months and 18 years presenting for an initial comprehensive examination at the Eye Institute of The Pennsylvania College of Optometry. There were 373 subjects between 6 months and 5 years, 11 months of age, and 1,650 subjects between 6 years and 18 years of age. RESULTS: The most important finding from this study is that other than refractive anomalies, the most common conditions optometrists are likely to encounter in a pediatric population are binocular vision and accommodative disorders. The prevalence of accommodative and binocular (strabismic and non-strabismic) vision disorders is 9.7 times greater than the prevalence of ocular disease in children 6 months to 5 years of age, and 8.5 times greater than the prevalence of ocular disease in children 6 to 18 years of age. CONCLUSIONS: The data from this study has great significance for clinicians, optometric educational institutions, health care planners, and administrators. This data suggests that other than refractive anomalies, the most prevalent conditions in the clinical pediatric population are binocular and accommodative disorders. Clinicians should use a minimum data base that includes assessments of accommodation and binocular vision that will allow them to detect conditions with the highest prevalence.

Adolescent↗

Citation patterns in the optometric and ophthalmologic clinical binocular vision literature.

PURPOSE: The purpose of this study is to compare citation patterns in the clinical binocular vision literature of optometry and ophthalmology. METHODS: The author conducted citation analysis of two current clinical binocular vision textbooks from optometry and two from ophthalmology and of articles published in the years 2000 to 2004 in optometry and ophthalmology journals. Topical parameters for inclusion of sources were diagnosis and management of nonstrabismic binocular vision disorders, diagnosis and management of nonpresbyopic ocular accommodation disorders, and procedures for examining such conditions. These topical parameters were chosen because they are areas in which the diagnostic procedures and treatment options available to members of the two professions are not delineated by their respective scopes of practice. RESULTS: The most frequently cited journals in the optometric publications were optometry journals (63% of citations in the optometry textbooks and 58% in the optometry journal articles). The most frequently cited journals in the ophthalmology publications were ophthalmology journals (79% of citations in the ophthalmology textbooks and 49% in the ophthalmology journal articles). Each discipline also cited a greater variety of journals from within its own field than was cited by the other discipline. The journal with the highest total number of citations was Optometry and Vision Science (280) followed by Ophthalmic and Physiological Optics (73), American Journal of Ophthalmology (68), Investigative Ophthalmology and Visual Science (62), and Optometry (61). CONCLUSIONS: Optometry and ophthalmology sources show more citations to materials from their own discipline than from their fellow discipline in the area of nonstrabismic binocular vision disorders and nonpresbyopic accommodative disorders. Reasons may include lack of awareness of the literature of the other discipline, bias toward the literature of one's own discipline, or bias against the literature of another discipline. It is also likely that the diagnostic and management strategies of the two professions are significantly different, although scope of practice would not constrain the range of strategies for the conditions chosen as the topical matter for consideration in this study. The journals found to be most frequently cited in this study should help to identify the core journals in this area of clinical binocular vision.

Adolescent↗