Digital contrast sensitivity chart with varying visual acuity: Development and validation

Abstract

BACKGROUND: Contrast sensitivity (CS) evaluation is very much necessary for the diagnosis and management of eye conditions. Several disadvantages seen in the traditionally used Pelli-Robson (PR) chart persuaded us to develop a novel digital device for the evaluation of CS at various levels of visual acuity (VA) for early detection of deteriorating vision. MATERIALS AND METHODS: The new chart was constructed on the Debian software. Letters were constructed at each level of VA from 6/60 to 6/6 with a contrast of 0–2.25 logCS. The newly constructed chart was validated against the PR chart. The data were analyzed on the SPSS software version 23. The Pearson's correlation test was used to find out the correlation between the digital CS chart (DCSC) and PR charts. RESULTS: On successful construction of a DCSC with varying VA, 56 participants were examined with a mean age of 20.43 ± 1.44 years. The mean CS with PR was 1.84 ± 0.13 logCS, whereas DCSC was 2.09 ± 0.14 logCS. The correlation between the two charts was moderate having r = 0.489 with P = 0 (confidence interval 95%). CONCLUSION: A newly developed CS chart is efficient in examining the CS in clinical practice and has good repeatability; it may help in the early detection and monitoring of ocular diseases.

Keywords

• contrast sensitivity
• digital contrast sensitivity chart
• pelli-robson chart
• visual acuity