optotype method
نویسنده
چکیده
During routine work in the Orthoptic Department, we noticed that, in some children who were having their visual acuity tested by the Snellen method for the first time, the results proved worse than those recorded previously by the Sheridan Gardiner method. The majority of patients concerned had been having occlusion for amblyopia, which was either presumed or shown to exist by a test of the visual acuity. In this paper, we analyse the discrepancies which were apparent between the two tests in these amblyopic patients.
منابع مشابه
Optotype and grating visual acuity in preschool children.
PURPOSE To investigate the contribution of stimulus and response differences to the different developmental courses of grating and optotype visual acuity at the preschool age range. METHODS Binocular visual acuity at 228 cm was assessed in 205 children in 7 age groups between 2.5 and 6 years and in 12 adults. Acuities were obtained in three tasks: detection of a grating in one of two position...
متن کاملDetection of nonorganic visual loss with a new optotype chart in simulated malingerers.
BACKGROUND We tested a new distance and pocket optotype chart for detection of nonorganic symmetrically decreased vision in simulated malingerers. The new optotype used in the charts is based on a subjective contour formed by a misalignment of two line segments. The minimum angle of resolution of this optotype is independent of its size. Subjects claiming to see only the larger optotypes are su...
متن کاملThe pattern of visual deficits in amblyopia.
Amblyopia is usually defined as a deficit in optotype (Snellen) acuity with no detectable organic cause. We asked whether this visual abnormality is completely characterized by the deficit in optotype acuity, or whether it has distinct forms that are determined by the conditions associated with the acuity loss, such as strabismus or anisometropia. To decide this issue, we measured optotype acui...
متن کاملThe teller acuity cards are effective in detecting amblyopia.
PURPOSE Detection of amblyopia in infants and toddlers is difficult because the current clinical standard for this age group, fixation preference, is inaccurate. Although grating acuity represents an alternative, studies of preschoolers and schoolchildren report that it is not equivalent to the gold standard optotype acuity. Here, we examine whether the Teller Acuity Cards (TAC) can detect ambl...
متن کاملColour vision testing as an aid to diagnosis and management of age related maculopathy.
AIM To provide a simple test that detects the onset of age related maculopathy (ARM), and can be used to monitor its severity. METHODS Colour contrast sensitivity was measured using computer graphics techniques. Colour thresholds were measured along tritan and protan colour confusion axes in the presence of dynamic luminance noise. Thresholds were determined separately for two sizes of optoty...
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