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

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.