Ischemic Optic Neuropathies
Vivek Lal in A Clinical Approach to Neuro-Ophthalmic Disorders, 2023
Pupil reactions:2 Pupil reactions are one of the most critical clinical examinations for patients with optic neuropathies. Pupil reactions are checked in a semi-dark room, patient looking into the distance, a bright pen torch light is shone into the eye from slightly below or temporal away from the visual axis for a duration of 3 seconds and quickly moved to the other eye. The procedure is repeated several times until the examiner is sure of the pupil response. This is known as the swinging flashlight test. Normally as the light is shone into each eye by turn the pupils in both eyes shrink. However, if there is a conduction defect in one of the eyes or there is asymmetric optic nerve involvement, as the light is shone into the abnormal/or more abnormal eye, pupils start dilating in both eyes. The eye is then recorded as having a relative afferent pupillary defect (RAPD).
Examination of the Nervous System
John W. Scadding, Nicholas A. Losseff in Clinical Neurology, 2011
The ‘swinging light test’ employs the principle that there is a difference in the direct and consensual pupillary reactions to light when there is a fault in the afferent visual pathway, the optic nerve or a severe degree of retinal damage. If a light is flashed from one eye to the other, the direct response on the side of the affected optic nerve will be less powerful than the consensual response evoked from the normal eye. As a result, when the light is shone in the affected eye, the pupil will dilate. In normal subjects, the response is symmetrical. When there is an asymmetry in the response this is called the afferent pupillary defect or Marcus Gunn phenomenon.
Management of Ophthalmic Injuries by the Forward Surgical Team
Mansoor Khan, David Nott in Fundamentals of Frontline Surgery, 2021
If one pupil is immobile when testing direct and consensual reflexes, the swinging flashlight test should still be performed. Because direct and consensual pupil reactions are symmetrical, the swinging flashlight test may be performed whilst examining the pupil size of only the eye with the mobile pupil but still swinging the light between both eyes.
Combined neurosurgical and orbital intervention for spheno-orbital meningiomas - the Manchester experience
Published in Orbit, 2020
J. Young, F. Mdanat, A. Dharmasena, P. Cannon, B. Leatherbarrow, C. Hammerbeck-Ward, S. Rutherford, S. Ataullah
Snellen charts were used to record visual acuity. A change in visual acuity of two or more lines was used to determine either an improvement or a deterioration of visual acuity. The Humphrey visual field analyser (Humphrey Systems, Carl Zeiss Meditec Inc, Dublin, CA, USA) or a Goldmann visual field machine was used to record the visual fields, unless visual acuity was too reduced to allow their use. Ishihara plates were used to measure colour vision. Any reduction in colour vision was noted and considered to represent a significant impairment of visual function. Proptosis of the affected eye was measured using a Hertel exophthalmometer. Proptosis was defined as a difference of 2 mm or more compared to the fellow eye. The pupillary assessment was performed via the swinging light test. This uses a bright torch to compare the afferent arms of the light reflex pathway, a discrepancy between these demonstrates a relative afferent pupillary defect (RAPD).14
Static and dynamic pupil characteristics in pseudoexfoliation syndrome and glaucoma
Published in Clinical and Experimental Optometry, 2020
Kemal Tekin, Hasan Kiziltoprak, Mehmet Ali Sekeroglu, Esat Yetkin, Serdar Bayraktar, Pelin Yilmazbas
All participants underwent a full ophthalmic assessment including best‐corrected visual acuity using the Snellen chart, gonioscopy with a Goldman three‐mirror lens, intraocular pressure measurement using a Goldmann applanation tonometer, slitlamp biomicroscopy, and dilated fundus examination. The refraction measurements were performed using the same automatic refractor‐keratometer device (RF‐K2 Full Auto Ref‐Keratometer; Canon, Tokyo, Japan) for each participant. The spherical equivalent (spherical component +1/2 cylinder component) was used to calculate the refractive error. In addition, eye movements were evaluated in all aspects of view and the clinical swinging flashlight test was performed to determine the afferent pupillary defects.
COVID-19: The Role of the Ophthalmologist in ICU
Published in Seminars in Ophthalmology, 2020
Minak Bhalla, Rohit Jolly, Saurabh Jain
Relative afferent pupillary defects (RAPD) indicate a defect in the retinal ganglion nerve pathway to the optic nerve or the subsequent optic nerve pathway towards the midbrain. This can be assessed by the swinging light test, where the impacted eye fails to constrict upon exposure to the torchlight. The commonest cause of RAPD is due to optic nerve pathology from ischaemia, inflammation or compression. However, the Ophthalmologist should also examine the patient’s retina for ischaemia, infection (CMV) or haemorrhagic causes. Although ophthalmic intervention for some of these conditions will be difficult in the ICU department, the diagnostic confirmation could help with systemic treatment and visual prognosis.
Related Knowledge Centers
- Cataract
- Physical Examination
- Relative Afferent Pupillary Defect
- Eye Examination