The swinging light test is positive in
Correct Answer: Retrobulbar neuritis
Description: Retrobulbar neuritis: a common cause of visual loss with normal fundus. Presence of a definite or relative afferent pupillary defect (RAPD) and VER are diagnostic. Swinging flashlight test: It is performed when relative afferent pathway defect is suspected in one eye (unilateral optic nerve lesion with good vision). Normally, both pupils constrict equally and the pupil to which light is transferred remains tightly constricted. In the presence of relative afferent pathway defect in one eye, the affected pupil will dilate when the flashlight is moved from the normal eye to the abnormal eye. This response is called 'Marcus Gunn pupil' or a relative afferent pupillary defect (RAPD). It is the earliest indication of optic nerve disease even in the presence of normal visual acuity. In the swinging flashlight test, a light is alternately shone into the left and right eyes.Thus, light shone in the affected eye will produce less pupillary constriction than light shone in the unaffected eye. Anisocoria is absent. A Marcus Gunn pupil is seen, among other conditions, in optic neuritis. Ref: Khurana; 4th edition; Pg.No. 307, 474
Category:
Ophthalmology
Get More
Subject Mock Tests
Practice with over 200,000 questions from various medical subjects and improve your knowledge.
Attempt a mock test nowMock Exam
Take an exam with 100 random questions selected from all subjects to test your knowledge.
Coming SoonGet More
Subject Mock Tests
Try practicing mock tests with over 200,000 questions from various medical subjects.
Attempt a mock test now