Three days after cataract surgery, an 70-year-old woman presents with a shallow central anterior chamber, a small quiet-looking pupil despite topical pilocarpine, and IOP of 42 mmHg with an intact patent iridectomy. Malignant glaucoma (ciliary block) is diagnosed. Why must miotic drops be stopped in this condition?

• A Miotics increase aqueous production and worsen the pressure rise
• B Miotics relax the zonules and allow forward lens displacement, aggravating aqueous misdirection
• C Miotics cause ciliary body contraction that further blocks aqueous access to the anterior chamber ✓
• D Miotics produce severe ciliary spasm that ruptures the hyaloid face

Explanation

In malignant glaucoma, aqueous is misdirected posteriorly behind the lens and vitreous cavity. Miotic-induced ciliary muscle contraction slackens the zonules and rotates the ciliary body forward, further blocking the flow of aqueous from the posterior chamber and worsening the attack. Treatment instead uses cycloplegics such as atropine to tighten zonules and pull the lens-iris diaphragm back, along with aqueous suppressants and hyperosmotics.

Reference: Parsons' Diseases of the Eye, 23rd ed.

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Written and medically reviewed by the StethoPrep medical team.