What causes an afferent pupillary defect?
Retinal Causes of a Relative Afferent Pupillary Defect Ischemic retinal disease: Causes include ischemic central retinal vein occlusion, central retinal artery occlusion, severe ischemic branch retinal or arterial occlusions, severe ischemic diabetic or sickle-cell retinopathy.
What is a afferent pupillary defect?
A relative afferent pupillary defect (RAPD) is a critically important ophthalmological examination finding that defines a defect (lesion) in the pupil pathway on the afferent side. An RAPD is relative to the fellow eye and occurs because of the bilateral and equal innervation of the pupils in normal individuals.
What is Marcus Gunn pupil associated with?
Marcus Gunn pupil is indicative of a defect in the afferent pathway of the light reflex. To avoid the high morbidity associated with this condition, it must be promptly diagnosed and the cause should be treated.
Is RAPD the same as APD?
RAPD vs APD In literature, and clinical practice, RAPD, and APD, or afferent pupillary defect, may be used synonymously. However, RAPD is technically describing the relative response of one pupil so there is no such thing as bilateral RAPD and, for a RAPD to exist, the damage must be asymmetric between the eyes.
How do you test for afferent pupillary defect?
A relative afferent pupillary defect (RAPD), also known as a Marcus Gunn pupil, is a medical sign observed during the swinging-flashlight test whereupon the patient’s pupils dilate when a bright light is swung from the unaffected eye to the affected eye.
What is Argyll Robertson pupil?
The Argyll Robertson (AR) pupil has been defined as a pupil that is small and constricts poorly to direct light but briskly when a target within reading distance is viewed (“light-near dissociation”).
Can RAPD be treated?
If RAPD is caused by a tumor in the optic nerve, such as optic nerve glioma, your treatment plan may include radiation and surgery. The cause of the Marcus Gunn pupil will determine when or if it can be resolved.
What nerve dilates pupil?
The fibers enter the orbit with CNIII nerve fibers and ultimately synapse at the cilliary ganglion. Sympathetic innervation leads to pupillary dilation.
What happens when pupils dilate?
Pupil dilation occurs when the opening in the center of your iris grows bigger to let in more light. Under normal circumstances, pupils can dilate to let in more light or in response to a variety of stimuli. During an eye exam, a doctor will administer eye drops to increase the size of a patient’s pupils.
Why are my pupils so naturally large?
Pupils, or the black parts at the center of the eyes, change size to regulate the amount of light entering the eye. Pupils are large in the dark to let more light in and small in bright light. Usually, the pupils in each eye dilate or constrict at the same time.
What is APD in eye?
Marcus Gunn pupil which is also known as Afferent Pupillary Defect(APD) a condition of the eye where the pupil does not dilate appropriately to the level of light reaching it, resulting in one pupil appearing larger than the other. Causes of APD include Optic Neuritis , glaucoma and optic nerve tumour.
What causes an oval pupil?
Oval pupil may also be due to primary ocular diseases such as trauma, acute glaucoma, and eye surgery.
What is an afferent pupil defect?
An afferent defect of the pupil refers to an abnormal dilation instead of constriction when light hits the eye. It is due to major loss of total light input in the affected eye such as massive retinal loss, optic nerve disease, etc.