Page 148 - July-August 2020

the apex of the lung (Pancoast
tumour), carotid artery aneurysm, TAKE HOME MESSAGE
dissection of the carotid artery,
lymphoproliferative disorders or  Familiarise yourself with the variations of normal
brachial plexus injury. In practice pupils and their reflexes.
it is near impossible to get hold of
cocaine so a handy alternative is the  Anisocoria of more than 1mm should always be
‘iopidine test’ using apraclonidine, questioned / investigated further.
a weak adrenergic agonist that
reverses the anisocoria caused  Have a low threshold for further testing
by Horner syndrome through and imaging.
1
denervation hypersensitivity .
ANTERIOR UVEITIS
synechiae. The following are a list of Any kind of trauma causing
A patient with a unilateral red, common topical medications:
painful eye with impaired vision and damage to the iris sphincter may
a small irregular pupil is most likely MYDRIATICS: result in traumatic mydriasis, which
suffering from anterior uveitis. The can be temporary or permanent –
diagnosis can be easily made on slit- – Cholinergic antagonists the pupil will react sluggishly or not
lamp examination: an acute episode  Atropine at all to light or accommodation but
will show ciliary injection, endothelial the consensual reflex in the other
dusting, aqueous cells, anterior  Cyclopentolate eye will be present. Iridodialysis is a
vitreous cells and in severe cases  Tropicamide dehiscence of the iris from the ciliary
hypopyon and posterior synechiae. – Adrenergic agonist body at its root. The resulting pupil
Recurrent episodes of anterior uveitis is typically D shaped and the dialysis
will result in a painless irregular  Phenylephrine is seen as a dark biconvex area near
mitotic pupil which does not dilate in MIOTICS: the limbus.
the dark. On slit-lamp examination,
pigment deposits on the lens, – Cholinergic CONCLUSION
keratoprecipitates can be seen and in  Pilocarpine
some cases iris nodules and atrophy Examination of the pupils and
will also be present. – Anticholinesterase pupillary reflexes are crucial in
obtaining an accurate diagnosis of
BILATERAL SMALL PUPILS  Physostigmine an ophthalmological problem and
 Neostigmine many other systemic conditions. It is
IATROGENIC
TRAUMA a relatively simple examination that
The use of eyedrops should can be performed at most patients’
always be considered when When taking a history from a bedsides and is a skill all doctors
presented with bilateral constricted patient with pupil abnormalities, should have.
or dilated pupils. For example, remember to specifically ask for any
miotics such as pilocarpine may be in history of trauma to the eye including REFERENCE
treatment of glaucoma. Short acting surgical trauma. A blunt force to 1. Morales J, Brown SM, Abdul-
mydriatics are used to enhance the eye can cause the anterior Rahim AS, Crosson CE. Ocular
examination of the lens, vitreous uvea to sustain structural and / or effects of apraclonidine in Horner
and fundus. Mydriatics are also used functional damage. The iris may be syndrome. Arch Ophthalmol
in the treatment of acute uveitis transiently compressed against the 2000;118:951-4.
especially iridocyclitis and severe anterior surface of the lens by severe
corneal epithelial defects to relieve anteroposterior force, with resultant ACKNOWLEDGEMENT: Reprinted
the spasm of the ciliary muscle imprinting of the pigment from the with kind permission from the original
and iris sphincter and breakdown / pupillary margin. Transient miosis publisher Eye News (www.eyenews.
prevent the formation of posterior accompanies the compression. uk.com)

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