DUOCHROM TEST.pptx

what is Duochrome Test, Why do we take Red and Green color only,
What is the Principal of Duochrome Test, Why Hyperopic Pt sees green better than red and vice versa

1. DUOCHROME TEST KHULESH SAHU (Consultant Optometrist) Sai Baba Eye Hospital Raipur

2. INTRODUCTION Duo+ Chrome Also known as Bichrome test Used to refine final Spherical power

3. WHY DO WE TAKE RED AND GREEN COLOR ONLY ?

4. Both colors is same distance from yellow color Complementary color Means Red and Green are opposite to each other on the color wheel .when complementary color viewed together ,they enhance to each other with brightness and clarity

5. PRINCIPAL Chromatic Aberration Means the shorter wavelength of light (green) is refracted more by the eye optics Than the longer wavelength of light (red)

6. CAN THE DUOCHROM TEST BE USED PRIOR TO CORRECTING THE REFRACTIVE COMPONENT ? https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4361575/#:~:text=The% 20Duochrome %20Test%20is%20based,light%20(i.e.%2C%20red).

7. PROCEDURE ARRANGEMENT History taking , Vision, Objective refraction, Fogging, JCC INSTRUCTION Sir I will show you letters on two background please tell me letters in which background more clearer darker and sharper RESPONSES

8. WHY HYPEROPIC PATIENT’S SEES G>R AND VICE VERSA ?

9. NOTE- BLACK RAY=YELLOW RAY

10. EMMETROPIA As we know that in Emmetropic Pt the green color light focus infront of retina, the yellow light on the retina and the red color light away from the retina HYPERMETROPIA In HMT Pt the plus power is deficient and we know that the property of plus power is converging the light rays and converging power is less in the HTM pt. So all the rays diverge So the green light diverge near the retina ,the yellow light away from the retina and red light is away to away from the retina that’s the reason green color is dominant

11. MYOPIA In the myopia the minus power is deficient and we know that the property of minus power is diverging the light rays and diverging power is less in the myopic Pt. So all the rays converge So the red light converge on the retina ,the yellow light infront of the retina and greenlight is infront of yellow light the retina that’s the reason green color is dominant

12. THUMB RULE FOR DUOCHROM RED ADD MINUS (RAM) Either over corrected hyperopia or under corrected myopia Need Minus lens Increased minus in 0.25 Ds steps until both are clear GREEN ADD PLUS (GAP) Either under corrected HTM or over corrected myopia Need Plus lens Increased Plus in 0.25 Ds steps until both clear

13. Q/A SESSION If pt has -2.00Ds and saying that R>G So ______ lens we will add and the find correction will be _____ Ds If pt has +4.75Ds and saying that G>R So _______lens we will add ,after that he is saying R>G ,what is the interpretation and final correction of the pt _______

14. Q. Can we perform Duochrome test in pt who has color blind ? Q. In the Duochrome test which eye should be tested first ? Q. Can we perform Duochrome test for near ? Q. Can a Duochrome test be used to diagnose specific eye condition such as Glaucoma or ARMD ?