Comparison of Lang test, Randot test & TNO test in the assessment of stereo-acuity of normal population .

Comparison of Lang test, Randot test & TNO test in the assessment of stereo-acuity of normal population. Authors : ShalakaParalkar, Mihir Kothari, Khushbu Shah E-Poster No. FP289 E-Poster Serial No.: 268

Disclaimer • We have no Financial interest in any of the products mentioned in this poster • We have not received any financial assistance to carry out this study

Introduction Appropriate therapeutic measures can improve the stereoacuity in such patients. 1 - Czepita D, Goslawski W, Mojsa A. Occurrence of anisometropia among students ranging from 6 to 18 years of age. Klin Oczna. 2005;107(4-6):297-9. 2 - Weber, JL; Wood, Joanne : Amblyopia: Prevalence, Natural History, Functional Effects and Treatment. Clinical and Experimental Optometry 88 (6)

Aim

Methods and materials • Measured Stereoacuity • Using Lang test(Lang type 1 test), • Randot test and • TNO test: • with appropriate refractive correction • With appropriate environmental lighting • at reading distance ( 40 cm)

Results • 46 consecutive patients • aged 19.3 years ± 7.2 (5-36) • 26 were females. All the patients had measurable stereopsis on these tests. Mean Stereoacuity: • Lang test = 550” • Randot test = 50” ± 36.8” (20-250) • TNO test = 60” ± 63” (15-240)

Correlation of Randot and TNO test The correlation coefficient (Pearson’s r) for Randot test and TNO test = 0.66 – positive correlation

Discussion stereo – solid opsis – view or sight • Performance on motor skills of a person is related to stereoacuity* • Various methods have been used to assess stereoacuity in children. • Some tests have made use of global stereopsis (TNO test,Frisby test, Lang test etc.) and some are based on local stereopsis (Titmus test, Randot test) Stereopsis *O’Connor AR et al : The functional significance of stereopsis. Invest Ophthalmol Vis Sci. 2010 Apr;51(4):2019-23. Epub 2009 Nov 20.

LANG TEST • Demerits: • Only gross stereopsis with • Lang 1 • Lang 2 required for finer stereopsis Merits: • Useful for screening in children. • No glasses necessary • OUR EXPERIENCE: • Easy to perform in children • Gives a general idea about presence of gross stereopsis • More convenient to use in unco-operative children as there is no requirement for glasses

RANDOT TEST • Demerits • Mono-ocular clues are present Merits • Can detect stereoacuity over a range of 20 to 500 seconds of arc • OUR EXPERIENCE • Children could easily view the animal figures • Effectively gave an idea of the fine stereopsis

TNO TEST • Demerits • Crowding phenomenon may be seen • Dissociation may be present Merits • Can measure stereoacuity over a range of 15 to 480 seconds of arc • No mono-ocular clues • OUR EXPERIENCE • Easier to perform in children as compared to Randot test

Conclusion • Lang test, Randot test and TNO test are useful to assess stereopsis in patients. • The Lang test was the easiest test. • Randot and TNO test can assess much finer acuity over a large range of disparities. Both have a good correlation. THANK YOU FOR YOUR ATTENTION

Comparison of Lang test, Randot test & TNO test in the assessment of stereo-acuity of normal population .