Comparison of

Lang test, Randot test & TNO test Lang test, Randot test & TNO test

in the assessment of stereo-acuity of normal population.

Authors : Shalaka Paralkar, Mihir Kothari, Authors : Shalaka Paralkar, Mihir Kothari, Khushbu ShahKhushbu Shah

E-Poster No.  FP289E-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

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)

Appropriate therapeutic measures can improve Appropriate therapeutic measures can improve the stereoacuity in such patients.the stereoacuity in such patients.

Aim

Methods and materials

Inclusion criteria

Best corrected visual acuity – 6/6

Orthotropic

Normal binocularity

Measured Stereoacuity•Using Lang test(Lang type 1 test), •Randot test and •TNO test:

with appropriate refractive correctionWith 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

0

100

200

300

400

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600

LANG

RANDOT

TNO

Discussion

• 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)

*O’Connor AR et al : The functional significance of stereopsis. Invest Ophthalmol Vis Sci. 2010 Apr;51(4):2019-23. Epub 2009 Nov 20.

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

Demerits:• Only gross stereopsis with Lang 1• Lang 2 required for finer stereopsis

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

Demerits•Mono-ocular clues are 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

Demerits• Crowding phenomenon may be seen• Dissociation may be present

Conclusion

THANK YOU FOR YOUR ATTENTION