ABSTRACT
The variability of the repetition of visual acuity measurements with a log MAR acuity chart with five optotypes in each row of acuity was studied in four groups of subjects. In three groups the threshold was calculated by probability of seeing curves, but the optotypes were read in different orders. For the fourth group the acuity was taken as the smallest row discriminated. Estimating the threshold by a probability of seeing curve did not improve the threshold's stability. Poorer acuity was detected when the optotypes were read vertically. It is suggested that clinical visual acuity charts are not suitable tools for generating data points to be fitted by probability of seeing curves.
Subject(s)
Vision Tests/methods , Visual Acuity , Adolescent , Adult , Humans , Mathematics , Middle Aged , Psychophysics , Sensory ThresholdsABSTRACT
Upper eyelid cicatricial entropion is commonly encountered as a sequela of inflammatory conditions. The surgical correction of this defect is often difficult and frequently unsuccessful. We have used the Barbera-Carre technique with good results in 20 patients with cicatricial entropion due to trachoma. We take this opportunity to present the surgical technique and our results.