Festooned Pupil
Ophthalmology High-Yield: Clinical Signs
1. Clinical Definition
A festooned pupil is a pupil that has an irregular, scalloped, or “wavy” appearance. This shape occurs because of multiple posterior synechiae (adhesions between the posterior iris and the anterior lens capsule).
2. Underlying Pathology
- Anterior Uveitis: The inflammatory exudates cause the iris to stick to the lens in various locations.
- Mechanism: When the pupil attempts to dilate (mydriasis), the areas not stuck to the lens expand, while the areas stuck remain fixed, resulting in the characteristic festooned or “cloverleaf” configuration.
3. High-Yield Pearls
- Diagnostic Significance: It is a hallmark sign of chronic or recurrent anterior uveitis.
- Clinical Danger: If synechiae occur 360 degrees around the pupil (seclusio pupillae), aqueous humor cannot flow from the posterior chamber to the anterior chamber, leading to iris bombe and subsequent secondary angle-closure glaucoma.
- Management: Requires aggressive use of topical cycloplegics (to break adhesions) and corticosteroids (to treat the underlying inflammation).