True accessory pupil with its own sphincter (very rare); more commonly, non-sphincter iris holes (pseudopolycoria) from surgery, trauma, or iris atrophy (e.g., ICE syndrome)
Slit-lamp examination, pharmacologic testing of pupillary reactivity, anterior-segment imaging
Treatment
Tinted/prosthetic contact lens; surgical pupilloplasty in selected cases
Frequency
Extremely rare (mostly case reports)
Diplocoria is an ophthalmic term for the presence of two pupillary openings in a single iris ("double pupil"). In contemporary usage most reported "double pupils" represent pseudopolycoria: additional iris holes that lack their own sphincter muscle, whereas true diplocoria (a form of true polycoria) requires that each opening has a functional sphincter with synchronous constriction and dilation.[1][2] The term derives from Greek diplo- ("double") and korē ("pupil").[3]
People with diplocoria or pseudopolycoria may experience glare, photophobia, ghosting, or monocular diplopia, due to multiple apertures disrupting the eye's optical system; reducing the effective pupil size can improve optical quality ("pinhole" effect).[4][5] In children, small reactive pupils and multiple apertures have been associated with intense miosis and amblyopia in case reports.[6]
Classification
Ophthalmic literature distinguishes:
True diplocoria/true polycoria: each opening has a circumferential sphincter that reacts to light and pharmacologic agents; extremely rare.[1][7]
Pseudopolycoria (false diplocoria): additional iris holes without sphincter muscle; these do not constrict independently and account for most "double pupil" appearances.[2]
Causes
True diplocoria is generally congenital and exceptionally uncommon. Apparent diplocoria is more often acquired pseudopolycoria from:
iris procedures (e.g., surgical iridectomy/iridotomy, iris biopsy), trauma, or degeneration;[4]
Slit-lamp examination documents the number, position, and shape of openings. In true diplocoria, both pupils constrict and dilate together to light or pharmacologic stimuli, indicating separate sphincters; in pseudopolycoria, only the primary pupil reacts.[1][2] Anterior-segment imaging and careful pharmacologic testing of the pupillary light reflex help differentiate true from false accessory pupils.[10]
Management
Treatment depends on symptoms and the underlying cause. Visual symptoms from pseudopolycoria may be reduced with prosthetic or tinted contact lenses that limit stray light or create a single functional aperture.[4] Selected cases of true diplocoria (true polycoria) have been treated surgically (e.g., pupilloplasty) to reconstruct a single round pupil.[11]
Epidemiology
Diplocoria in the strict, "true" sense is very rare and mainly documented in isolated case reports; most "double pupil" appearances are pseudopolycoria rather than true accessory pupils.[1][2]
This page is based on this Wikipedia article Text is available under the CC BY-SA 4.0 license; additional terms may apply. Images, videos and audio are available under their respective licenses.
