The given image is related to following?
A. Marcus Gunn pupil
B. Optic neuritis
C. Robertson-Argyll pupil
D. Pin point pupil
Answer-A-Marcus gun pupil
- RELATIVE AFFERENT PATHWAY DEFECT (RAPD) OR MARCUS GUNN PUPIL It is the paradoxical response of a pupil to light in the presence of a relative afferent pathway defect (RAPD). Caused by an incomplete optic nerve lesion or a severe retinal disease. It is best tested by ‘swinging flashlight test’.
- Normally, both pupils constrict equally and the pupil to which light is transferred remains tightly constricted.
- In the presence of RAPD in one eye, the affected pupil will dilate (paradoxical response) when the flashlight is moved from the normal eye to the abnormal eye.
- This response is called Marcus Gunn Pupil.
- It is the earliest indication of optic nerve disease even in the presence of a normal visual acuity