אפליקציה למדידת קונטרסט

שם הסטודנטיות: דינה הרשקוביץ אזולאי ואראלה פיליפס
שם המנחה: גברת דיינה פריצקי

Introduction:

Contrast sensitivity (CS) refers to the ability to detect a difference in light intensities of two bordering areas (Goldstein, 2010). The Peek Contrast Sensitivity App (Peek Vision, App) uses modern technology to determine a person's CS. The aim of this study is to validate the App performance on AMOLED and LCD screens as compared to the Pelli-Robson (PR) gold standard for CS measurements (Khambhiphant et al., 2011). 

Methods:

Subjects with minimum 6/60 and 6/48 VA for distance and near, have participated in the study. The eye with the lower VA was used in the analysis. ND filters were randomly used to simulate low CS. CS was tested using the PR chart (50 cm, examiner a) and the Peek App (1 meter, examiner b) on both AMOLED and LCD screens in random order (three times for each method). The examiners were blind to each other's results. Correlation, Paired T-Test, and Bland and Altman (1986) analysis was performed. 

Results:

32 subjects (ages 21-61, mean age 27.63±9.30 years) participated in the study (2 subjects had no refractive correction, 14 subjects were tested with ND filters and 7 subjects had ocular pathologies). Mean differences between PR and both LCD (0.18±0.28 log) and AMOLED (-0.03±0.28 log) were small, however low correlations were shown (LCD: r=0.41, AM: r=0.25). Surprisingly, no correlation was found between both DVA (r=-0.10) and NVA (r=0.08) with the PR. 

Conclusion:

Neither the AMOLED nor the LCD are interchangeable with the PR. This might be due to a screen brightness (up to 900, Peek representative) higher than that of the PR (up to 377 lux, chart instructions) or the difference in optotypes between the methods (the letter E on the screens as opposed to numbers on the PR chart).

מרכזת המחקר לתואר ראשון: ד"ר עינת שניאור