Exploration of Polycoria: A Visionary Expedition into the Realm of Multiple Pupils

Anuska Chakraborty, B. Optom

Student, NSHM Knowledge Campus – Kolkata, India

 

“Cinema is a canvas of dreams, painting inspiration on the screens of our imagination, fuelling the fire of curiosity within our hearts”

As a student of Optometry, the eyes always catch my interest, even while watching a film. The well-known character Ahmanet’s eyes have made me wonder if it is possible to have two pupils in one eye; the answer is yes (Figure 1). This blog enlightens  the negative impacts of having multiple pupils in the eye.

Figure 1:  Ahmnet’s eyes at the ‘The Mummy’ (2017) movie poster
How would you rewrite 2017’s The Mummy? : r/fixingmovies. (n.d.). https://www.reddit.com/r/fixingmovies/comments/v11pgx/how_would_you_rewrite_2017s_the_mummy/?rdt=40728

The presence of more than one pupil in the eye is termed as Polycoria.⁽¹⁾ In  certain literature, polycoria is classified into two types: True Polycoria,⁽²⁾  where lookalike pupils react separately in the presence of light & chemicals and Pseudo Polycoria,⁽³⁾ where the non-reactive lookalike pupils often occur because of post-surgical complications like iridectomy or iris biopsy.

Decoding its Association with Diseases

The exact aetiology behind Polycoria has not been properly discovered yet. It has been found to be associated with two rare eye conditions: Iridocorneal Endothelial Syndrome (ICE) ⁽⁴⁾ and Axenfeld Rieger Syndrome.⁽⁵⁾

In ICE syndrome, normal endothelial cells of the cornea are replaced with epithelial- like cells, which then start migrating posteriorly. Later, these cells move beyond the Schwalbe’s line and settle on the trabecular meshwork and peripheral iris. Within the angle, adhesion of these tissues creates peripheral anterior synechiae (PAS). During pupil contraction, this kind of synechiae can pull a part of the iris, creating holes in the iris (Polycoria), and various changes can occur in different parts of the anterior chamber. According to some studies, it has been suggested that the herpes simplex virus may influence such changes.

Abnormalities in the iris associated with Rieger anomaly are typically caused by genetic factors. One of the genes commonly associated with this anomaly is the PITX2 gene. Mutations in this gene can disrupt the normal development of structures in the anterior segment, including the iris. This can lead to various abnormalities such as a malformed or atypical iris, changes in pupil size and shape and the formation of additional openings, Polycoria. During gestation, malformation of neural crest cells in the anterior segment arrests the development of trabecular meshwork or Schlemm canal, that can generally be diagnosed during infancy.

Acting as a Major Indicator

A thorough eye exam can detect Polycoria, a key indicator of conditions like ICE and Axenfeld-Rieger syndrome. These conditions impact the anterior chamber and its angle. The angle of the anterior chamber is extremely crucial for regulating intraocular pressure (IOP) by controlling aqueous humour outflow. Blockage of this part of the eye can raise the IOP and ultimately result in irreversible eye disease, Glaucoma.

Essential Takeaway

Based on a patient’s requirement, an optometrist can advise for prosthetic contact lens, mydriatics and miotics eye drops, or Pupiloplasty. Mild to severe photophobia are the only symptoms in the case of Polycoria. However, as it is proven to be associated with Glaucoma, so early diagnosis and needful treatments are very necessary.⁽⁶⁾

 

References:

1. Amplify EyeCare. (2024, February 27). Is polycoria (2 pupils in one eye) real? Eye-Opening Facts! https://amplifyeye.care/article/is-polycoria-2-pupils-in-one-eye-real-eye-opening-facts/ [Last accessed – 07Aug2024 19:30AEST]
2. Bardak H, Ercalik NY, Gunay M, Bolac R, Bardak Y. Pupilloplasty in a patient with true polycoria: a case report. Arquivos Brasileiros de Oftalmologia. 2016 Nov;79:404-6.
3. Sherman SW, Canestraro J, Bogomolny D, Marr B. Relief of symptomatic pseudo-polycoria due to iris biopsy using a daily contact lens. American Journal of Ophthalmology Case Reports. 2021 Jun 1;22:101084.
4. Iridocorneal endothelial syndrome and secondary glaucoma – EyeWiki. (n.d.). https://eyewiki.aao.org/Iridocorneal_Endothelial_Syndrome_and_Secondary_Glaucoma [Last accessed – 07Aug2024 19:30AEST]
5. Axenfeld Rieger Syndrome – EyeWiki. (n.d.). https://eyewiki.aao.org/Axenfeld_Rieger_Syndrome [Last accessed – 07Aug2024 19:30AEST]
6. Sankeerthana, N., Chandrika, P. M. K., Bhanu, Y. D., Arunanjali, E. S., & Ramachandra, P. U. A Review on Polycoria. International Journal of Current Pharmaceutical Research, 2023;1–6.