Teller acuity card

TELLER ACUITY CARD TEST

1. OPTOMETRY SUNIL PANJIYAR STUDENT B.OPTOMETRY(3'RD YEAR) SHARDA UNIVERSITY(SAHS)

2. CONTENTS TELLER ACUITY CARD INTRODUCTION 01 TESTING CONDITIONS 02 PROCEDURE 03 PROS AND CONS 02

3. PART 01 INTRODUCTION TELLER ACUITY CARD (TAC) TEST MEASUREMENT OF VISUAL ACUITY

4. TELLER ACUITY CARD TELLER ACUITY CARDS ARE USED TO TEST VISUAL ACUITY IN YOUNG CHILDREN AND THOSE WITH DISABILITIES WHO CAN NOT BE TESTED WITH STANDARD LETTER OR SYMBOL ACUITY TEST. RECOMMENDED TO TEST VISUAL ACUITY IN INFANTS FROM 1 MONTH TO 1 YEAR OF AGE. THIS TEST IS THE MODIFICATION OF PLT(PREFERENTIAL LO0KING TEST). THE STIMULUS ON THE TELLER ACUITY CARD IS HIGH CONTRAST BLACK AND WHITE PATTERN OF STRIPE CALLED A GRATING. THE GRATING RANGE FROM VERY COARSE TO VERY FINE, IN ORDER TO TEST VISUAL ACUITY FROM VERY LOW VISION TO NORMAL.

5. TELLER ACUITY CARD MOST RECTANGULAR CARD HAVE SINGLE GRATING PRINTED ON ONE SIDE OF CARD. THIS ALLOWS IT TO BE PRESENTED EITHER ON THE LEFT OR RIGHT . AN ADDITIONAL CARD HAS A GRATING NEARLY COVERING ONE HALF OF THE CARD. THIS CARD IS CALLED LOW VISION CARD.

6. TELLER ACUITY CARD THE FINAL CARD IS A BLANK GREY CARD WITHOUT GRATING. GRATING VALUES ARE SPECIFIED BY WIDTH OF THE BLACK AND WHITE BARS. A SINGLE BLACK AND WHITE BAR IS CALLED A CYCLE. THE METRIC CYCLES PER CENTIMETER IS CONVERTED TO VISUAL ACUITY BASED ON THE DISTANCE OF THE CARD GRATING FROM THE PATIENT AND IS SPECIFIED AS CYCLES PER DEGREE.

7. TELLER ACUITY CARD THE CYCLES PER DEGREE IS THE APPROPRIATE SPECIFICIATION FOR GRATING ACUITY. IF NECESSARY GRATING CAN BE CONVERTED TO CONVENTIONAL SNELLEN NOTATION WHICH MAY BE MORE APPROPRIATE FOR CERTAIN REPORTING.

8. TELLER ACUITY CARD EACH TELLER ACUITY CARD HAS LABELS ON THE BACK SHOWING THE GRATING SIZE IN CYCLES PER CM AND THE CONVERSION TO ACUITY BASED ON THREE TEST DISTANCES.

9. TELLER ACUITY CARD:PRINCIPLE THE PRIMARYY PRINCIPLE OF TELLER ACUITY CARD IS THAT IF A PATIENT SEES A GRATING ON THE GREY BACKGROUND HE/SHE WILL LOOK AT THE GRATING. IF THE GRATING BARS CANNOT BE RESOLVED OR SEEN BY A PATIENT THE GRATING SHOULD MATCH THE GREY BACKGROUND PERFECTLY MIMICKING THE BLANK CARD.

10. TELLER ACUITY CARD: CARD A COMPLETE SET OF TELLER ACUITY CARDS CONSISTS OF SEVENTEEN 25.5 x 55.5 CM CARDS, EACH OF WHICH HAS AN APPROXIMATELY 4-MM DIAMETER PEEPHOLE AT THE CENTER. FIFTEEN OF THE CARDS CONTAIN PATCHES OF SQUARE WAVE GRATINGS(VERTICAL BLACK AND WHITE STRIPES), APPROXIMATELY 12*12 CM IN SIZE, CENTERED ON ONHALF OF THE CARD. THE 16th(''LOW VISON'') CARD CAONTAIN A LARGER ,0.23CY/CM GRATING. THE 17th CARD IS BLANK GRAY SIMILAR TO THE GRAY OF THE OTHER CARDS IN THE SET.

11. PART 02 TESTING CONDITIONS TELLER ACUITY CARD(TAC)

12. TESTING CONDITIONS: LIGHTING : LUMINANCE OF THE TELLER ACUITY CARD SHOULD BE AT LEAST 10 CANDELAS/m2 DURING TESTING. TEST DISTANCE : THE TEST DISTANCE IS MEASURED FROM THE CHILD'S EYES TO THE PEEPHOLE IN THE CARDS. A KNOWN, FIXED DISTANCE MUST BE MAINTAINED, AS THE ACUITY VALUES IN CYCLES/DEG OR APPROMIXATE SNELLEN EQIVALENTS DEPEND UOPN THE DISTANCE.

13. TEST DISTANCES INANTS TO 6 MONTHS : 38 CM 7 MONTHS TO 3 YEARS : 55 CM OLDER THAN 3 YEARS : 84 CM CHILDREN WITH VERY POOR ACUITY MAY REQUIRE AN UNUSUALLY CLOSE TEST DISTANCE BETWEEN 19 CM AND 9.5 CM.

14. PART 03 PROCEDURE TELLER ACUITY CARD(TAC)

15. TESTING PROCEDURE: THE CHILD IS HELD IN FRONT OF A GREY CARDBORD SCREEN THAT SHILEDS HIS OR HER VIEW OF THE ROOM AT THE CORRECT DISTANCE. TO TEST THE ACUITY, THE EXAMINER DISPLAYS A SERIES OF CARDS, EACH CONTAINING A BLACK AND WHITE GRATING OF DIFFERENT SPATIAL FREQUENCY, LOCATED TO THE LEFT OR ROGHT OF THE CENTRAL PEEPHOLE. IT IS BEST TO BEGIN WITH STRIPE WIDTH THAT IS WIDER THAN THE THRESHOLD PREDICTED FOR THE AGE OF THE INFANTS. IF IT IS CLEAR THAT INFANTS SEE THE STRIPES, EXAMINEER PRESENTS THE CARDS WITH THE NEXT FINEST STRIPE WIDTH. TESTING CONTINUES UNTIL THE EXAMINER IS CONFIDENT ENOUGH ABOUT THE CHILD'S RESPONSE TO MAKE A JUDGEMENT CONCERNING THE FINEST GRATING THAT THE CHILD CAN DETECT.

16. TESTING PROCEDURE: THE SPATIAL FREQUENCY OF THIS GRATING IS TAKEN AS AN ESTIMATE OF THE CHILD'S VISUAL ACUITY. ESTIMATES OF VISUAL ACUITY, USING TAC GRATING TARGETS, SHOW A RAPID INCREASE IN ACUITY DURING THE FIRST 6 MONTHS OF LIFE FROM 1.0 CYCLES PER DEGREE AT 1 MONTH OF AGE TO FIVE CYCLES PER DEGREE BY 6 MONTHS OF AGE, THEN A GRADUAL INCREASE TO 40 CYCLES PER DEGREE. THE RESULTS ARE OBTAINED IN CYCLES WHICH CAN BE CONVERTED TO SNELLEN'S EQIVALENT. THE TESTING TIME RANGES FROM 6-10 MINUTE.

17. PART 04 PROS AND CONS

18. ADVANTAGES: SIMPLE TO PERFORM RELIABLE EFFICEINT DISADVANTAGES: RELATIVELY EXPENSIVE TIME CONSUMING IN UNCOPERATIVE PATIENT

19. 2020 THANK YOU ！ SUNIL PANJIYAR Date ： 2020-09-06