Validation of Titmus vision screener V4 for diagnosing refractory errors and colour blindness: An analogy with quotidian.

ABSTRACT

Background: This study aims at evaluating the validity profile of Titmus vision screener V4 for gauging visual acuity and colour perception as a screening tool. Methods: Eleven hundred young adults attending eye OPD at a tertiary care center were included in the study. All individuals underwent distance visual acuity (DVA) measurement with Snellen chart and Titmus vision screener V4, at 6 m on the same day. Later, these individuals underwent colour vision testing with Ishihara pseudo isochromatic plates and Titmus vision screener V4. Results: The age distribution ranged from 19 to 53 years with mean age as 26.6 years. Males (87.4%) were more as compared to females. Mean DVA measured by Snellen's chart and Titmus vision screener V4 were 0.088 ± 0.15 and 0.110 ± 0.17, respectively (p = 0.000). Mean difference between DVA by Snellen's chart and Titmus screener V4 was -0.021 ± 0.82 with 95% CI (-0.026 to -0.016). For measuring visual acuity, Titmus vision screener V4 showed a sensitivity of 99.5% and specificity of 90.6%. Negative predictive value and positive predictive value were 99.6% and 85.6%, respectively. For diagnosing colour perception, the Titmus vision screener V4 showed a sensitivity of 100% and specificity of 99.8%. The negative predictive value and positive predictive value were 100% and 88.8% respectively. Area under the curve of receiver operating characteristic (ROC) curve was 0.960 with 95%CI (0.949-0.972). Conclusion: Our study supports use of Titmus vision screener V4 as an excellent screening tool for measurement of visual acuity as well as colour perception.