![]() ![]() ![]() The new rules outlined clear for not only which visual field testing method was to be used, but also how the results should be interpreted and assessed, and guidelines for doctors to report drivers not fulfilling the requirements. Disadvantages of this technique are that it is not possible to judge whether the defect is absolute or relative, and there is no way to control fixation stability since the binocular testing conditions eliminate naturally occurring blind spots which are used for fixation control in other tests.īeginning September 1, 2010, new regulations for medical requirements for drivers’ licenses in Sweden went into effect. During binocular viewing, each location in the right monocular field has a corresponding point in the left monocular field and vice versa. An advantage of this method is that it allows for naturally-occurring binocular enhancement, in which two seeing eyes compensate for defects in the fellow eyes. This binocular method is useful in glaucoma patients with later stage bilateral visual field defects, and is used to assess the remaining visual ability or disability. The test consists of 120 white test points shown with equal, non-adjustable suprathreshold light intensity of 10 dB and examines more than 130° of the field. Esterman visual field perimetry is a binocular testing method which is also available on the HFA. The HFA offers several different testing programs, each with specialized testing strategies, including threshold programs which are appropriate for drivers’ license testing. The Humphrey Field Analyzer (HFA) is an automated, static threshold perimeter, using stimuli of varying luminance in order to find the minimum luminance which can be detected in each test point. Until now, there has not been a specific testing method required by the Swedish Transport Agency, and the requirement that was specified was stated simply that the applicant’s binocular visual field must be at least equivalent to a normal visual field of one eye. Studies have shown that drivers with limited fields of vision have significantly poorer driving capabilities with regard to speed adjustment with lane changes, maintaining lane positions in a curve, as well as anticipatory skills. The visual field is of great importance while driving a limited field of vision hinders the driver’s capability of not only detecting objects in the periphery, but also judging distances and speed. Glaucoma causes damage to the optic disc, which leads to visual field defects. Glaucoma is defined as ”a disease causing damage to the optic nerve with resulting visual field defects, characterized by slow progression”. There is a long list of eye diseases and conditions affecting the field of vision, among them glaucoma. The binocular visual field test (HEVF) seems not be as efficient as the HVF in finding visual field defects in glaucoma subjects, and is therefore doubtful in evaluating visual capabilities in traffic situations. The monocular visual field test (HVF) gave more specific information about the location and depth of the defects, and therefore is the overwhelming method of choice for use in diagnostics. There were no subjects who passed the HVF, but failed the HEVF. There was a significant difference between HEVF and HVF (χ 2, p = 0.004). Eight subjects passed the HEFV but failed the HVF. Sixteen subjects passed both tests, and sixteen subjects failed both tests. Resultsįorty subjects were recruited and participated in the study. Assessment of results was constituted as either “pass” or “fail”, according to the new medical requirements put into effect Septemby the Swedish Transport Agency. HVF SITA Fast 24–2 full threshold (monocularly) and HEVF (binocularly) were performed consecutively on the same day on 40 subjects with glaucomatous damage of varying degrees in both eyes. Visual field Digest 6th Edition 2016, Haag-Streit AG, Koniz Switzerland (ISBN 978-1-2).The purpose of this study was to compare the monocular Humphrey Visual Field (HVF) with the binocular Humphrey Esterman Visual Field (HEVF) for determining whether subjects suffering from glaucoma fulfilled the new medical requirements for possession of a Swedish driver’s license. The cumulative defect curve: separation of local and diffuse components of visual field damage. In: International Perimetric Society (IPS) Meeting. Realization of semi-automated kinetic perimetry (SKP) with the Interzeag 101 Instrument. Flicker-TOP perimetry in Normals and Patients with ocular hypertension and early Glaucoma Perimetry Update 1998/1999. ![]() González de la Rosa M, Rodríguez J, Rodríguez M. Test time and efficiency of the dynamic strategy in glaucoma perimetry. ![]()
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