Funduscopy: to dilate or not?: Other drugs can cause partial pupil dilatation

doi:10.1136/bmj.332.7534.179-a

BMJ 2006;332:179 (21 January), doi:10.1136/bmj.332.7534.179-a

Letter

Funduscopy: to dilate or not?

Other drugs can cause partial pupil dilatation

The first 150 words of the full text of this article appear below.

Editor—Liew et al highlight the very small risks associatedwith precipitating an attack of angle closure glaucoma whendilating a pupil for the purposes of funduscopy.¹

The initiating event in acute angle closure glaucoma is incompletemydriasis (pupil dilatation) resulting in pupil block and theprevention of aqueous drainage through the trabecular meshwork.This partial mydriasis is normally caused by poor ambient lightingconditions, but drugs with adrenergic and anticholinergic propertieshave also been identified as causative agents. These drugs includeipratropium and tricyclic antidepressants.^{2 3} Serotonin selectivereuptake inhibitors (SSRIs) such as paroxetine and fluoxetinehave also been implicated through their anticholinergic properties.⁴

The British National Formulary advises caution with using thesedrugs in patients with a history of angle closure glaucoma.⁵This is, however, misleading, as patients who have had an attackof angle closure glaucoma will hopefully have been treated witheither iridotomies or trabeculectomies and will therefore . . . [Full text of this article]

Peter D Cackett, ophthalmology specialist registrar

Princess Alexandra Eye Pavilion, Edinburgh EH3 9HA pete@pdcackett.demon.co.uk