Antipsychotics learning module

3.9 Adverse effects on the eye

Antimuscarinic effects of antipsychotics may precipitate glaucoma, blurred vision and mydriasis.

Prolonged use of phenothiazines is associated with pigmentation of the cornea, conjunctiva and retina; lens opacities and potentially blinding condition of retinitis pigmentosa have been reported.

Factors which increase risk

The risk of harm from antimuscarinic effects is increased in patients with angle-closure (‘narrow-angle’) glaucoma.

The risk of pigmentation in the eye and lens opacities is likely to increase with higher doses of phenothiazines and the duration of use.

Risk-reduction measures

Initiating treatment with a low dose of an antipsychotic can help to avoid excessive antimuscarinic effects; the dose can be increased as tolerance develops.

Patients should be advised to report changes to eye coloration and any visual difficulty so as to identify any adverse effects as early as possible.

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Page last modified: 03 October 2018