1 Authors : Shalaka Paralkar, Mihir Kothari, Khushbu Shah Comparison of Lang test, Randot test & TNO test in the assessment of stereo-acuity of normal population.E-Poster No. FP289E-Poster Serial No.: 268Authors : Shalaka Paralkar, Mihir Kothari, Khushbu Shah
2 DisclaimerWe have no Financial interest in any of the products mentioned in this posterWe have not received any financial assistance to carry out this study
3 IntroductionStereoacuity is reduced in:Global PrevalenceUncorrected ametropiaAnisometropia6%1Amblyopia1–5% 2StrabismusMonofixation syndrome1%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, FunctionalEffects and Treatment. Clinical and Experimental Optometry 88 (6)
4 Development of normative data for stereoacuity of normal population AimComparisonof testsDevelopment of normative data for stereoacuity of normal population
5 Methods and materials Inclusion criteria Best corrected visual acuity – 6/6OrthotropicNormal binocularityMeasured StereoacuityUsing Lang test(Lang type 1 test),Randot test andTNO test:with appropriate refractive correctionWith appropriate environmental lightingat reading distance ( 40 cm)
6 Results Mean Stereoacuity: Lang test = 550” 46 consecutive patientsaged 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)
7 Correlation of Randot and TNO test The correlation coefficient (Pearson’s r) for Randot test and TNO test = 0.66 – positive correlation
8 Discussion Stereopsis stereo – solidopsis – view or sightStereopsisPerformance 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 Apr;51(4): Epub 2009 Nov 20.
9 LANG TEST OUR EXPERIENCE: Merits: Demerits: Useful for screening in children.No glasses necessaryDemerits:Only gross stereopsis withLang 1Lang 2 required for finer stereopsisOUR EXPERIENCE:Easy to perform in childrenGives a general idea about presence of gross stereopsisMore convenient to use in unco-operative children as there is no requirement for glasses
10 RANDOT TEST OUR EXPERIENCE MeritsCan detect stereoacuity over a range of 20 to 500 seconds of arcDemeritsMono-ocular clues are presentOUR EXPERIENCEChildren could easily view the animal figuresEffectively gave an idea of the fine stereopsis
11 TNO TEST OUR EXPERIENCE Demerits Crowding phenomenon may be seen Can measure stereoacuity over a range of 15 to 480 seconds of arcNo mono-ocular cluesDemeritsCrowding phenomenon may be seenDissociation may be presentOUR EXPERIENCEEasier to perform in children as compared to Randot test
12 THANK YOU FOR YOUR ATTENTION ConclusionLang 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
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