Background:Many clinical techniques exist to quantify the magnitude of heterophoria in free space. In this article, we determine the agreement between the modified Thorington test and three different tests for dissociated heterophoria at near distance in free space. Methods:The modified Thorington, Maddox rod, von Graefe and alternate cover tests were performed on 49 university students at near distance in free space. The 95% limits of agreement between the modified Thorington and other tests were compared in pairs by using the Bland-Altman statistical test. Results: While the Maddox rod-modified Thorington pair showed narrow 95% limit range (2.5 to -3.34 Conclusion:The modified Thorington test cannot be interchanged with the other three near tests for heterophoria in free space. The accuracy in the measurement and the different methods of dissociation may play a crucial role in comparisons of the different tests for heterophoria.

Tele (remotely controlled) visual acuity measurement is as reliable as that measured with the physical presence of an optometrist.

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Purpose:To compare visual acuity with two visual acuity charts in preschool children.Materials and Methods:Visual acuity measurement with Lea symbols and Bailey-Lovie tumbling E chart was performed on children between 3 and 6 years of age. Visual acuity data from the two charts were analyzed with Bland-Altman plot to determine the limits of agreement. The Wilcoxon signed test was performed in children aged 3-4 years and in children aged 5-6 years separately to evaluate the influence of age. The inter-eye difference between the two charts were further analyzed with the paired t-test. A p value > 0.05 was considered statistically significant.Results:A total of 47 children were enrolled for the study. The average logarithm of the Minimum Angle of Resolution (LogMAR) monocular visual acuity with Lea symbols (0.17 ± 0.13) was better than the Bailey-Lovie tumbling E chart (0.22 ± 0.14). The mean difference between Bailey-Lovie tumbling E chart and Lea symbol chart was 0.05 ± 0.12 in logMAR units. A second analysis eliminating outliers showed the same result but lower differences (n = 43, 0.05 ± 0.05 logMAR units). Visual acuity results between the two charts in children aged 3-4 years showed a significant difference (p = 0.000), but not for children aged 5-6 years (p = 0.059). Inter-eye differences between the two charts was not statistically significant (p = 0.77).Conclusion:Bailey-Lovie tumbling E chart is comparable to the Lea symbols chart in pre-school children. But preference should be given to Lea symbols for children aged 3-4 years as the symbols are more familiar than a directional test for this age group.

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