Polycoria

Last updated

Polycoria is a pathological condition of the eye characterized by more than one pupillary opening in the iris. [1] It may be congenital or result from a disease affecting the iris. [1] It results in decreased function of the iris and pupil, affecting the physical eye and visualization.

Contents

In the early history of China, double pupils were seen as a sign that a child would become a great king or sage.[ citation needed ]

Epidemiology

Polycoria is extremely rare, and other conditions are frequently mistaken for it. [2] [3] Polycoria is often congenital, however not diagnosed until adulthood. [4] The general cause of polycoria is unknown, but there are some other eye conditions that are in association with polycoria. These include (although not often) polar cataracts, glaucoma, abnormally long eyelashes, abnormal eye development, and poor vision.[ citation needed ]

There have been cases diagnosed from age 3 to adulthood. The prevalence of true polycoria is minimal. [3] The two kinds of polycoria are true polycoria and false pseudopolycoria.

There are no known or proposed trends in the occurrences of polycoria based on geographical location, age, gender, or season.

True polycoria

In cases of true polycoria, there is an extra pupil that tends to be reactive to light and medication. [5] To be considered true polycoria the extra pupil and the principal pupil must dilate and contract simultaneously with triggers such as light and administered drugs. [6] The extraneous pupil is c. 2.5mm away from the principal pupil. In cases of true polycoria there is an intact sphincter muscle, which contracts and dilates the pupils. [5] In an eye without polycoria, the sphincter muscle is a part of the iris that functions to constrict and dilate the pupil. [7] [ better source needed ] A patient with true polycoria experiences handicapped vision as well as stimulation of the retina in response to bright lights. [5]

It is said that the term "true polycoria" is overused, and used correctly when addressing congenital deformations of the iris. [6] Often "true polycoria" is used when it in fact is a case of pseudopolycoria.

Pseudopolycoria

Although less rare than true polycoria, pseudopolycoria is still very uncommon. In cases of pseudopolycoria there is a "passive constriction" that differentiates the extra pupil from the true pupil during constriction and dilation. The extra pupil in pseudopolycoria is different than the extra pupil in true polycoria because it shows defects that are independent of the sphincter muscles.[ citation needed ] Pseudopolycoria is often associated with Seckel syndrome, posterior polymorphous dystrophy, and juvenile glaucoma. [5]

Pseudopolycoria consists of splitting of the iris that are not contingent with the sphincter muscles at the root of the iris. [6]

Symptoms and diagnosis

The signs and symptoms shown in a patient diagnosed with polycoria are associated with ocular and adnexal growth abnormalities. [8] The iris and the pupil become less effective. Signs can be present as a child; however, the patient may be diagnosed later in their life. This condition results in abnormal eye development affecting both eyes or just one.[ medical citation needed ]

Upon gross examination the patient will typically have excessively long eyelashes. [8] The iris becomes hypoplastic, making abnormally shaped pupils with prominent crypts. [8] The crypts are little squiggly lines that radiate out around the pupil; with this condition, thick round or oval openings can be seen. [8]

On diagnosis, signs lead to symptoms where there is more than one set of iris muscles, which controls the amount of light being brought into the eye. [8] When the iris becomes deformed, it will disarrange the control of light coming in leading to blurred vision and finding it hard to visually focus. Polar cataracts will also be present in this condition where a round, opaque malformation of distorted lens fibers is located in the central posterior part of the lens showing disformality. [9]

Treatment

Polycoria has been linked to hereditary genetics, [8] and also associated with polar cataracts, glaucoma, and retinal detachment. [5] Not all cases are treated for this iris abnormality, but when cases are treated the only treatment is surgical procedure and life-long ocular monitoring that is highly recommended. [10] Considerations for surgery are surgical correction, intraocular surgery, and/or reapproximation, as if it was being treated for glaucoma or retinal detachment. [10] Children under the age of 3, who do not seek surgery, have responded well with miotic drops that contained mydriatic/cycloplegic, allowing the separate eye sphincters to dilate and constrict together. This allows improved balance of uncorrected visual acuity. [11] A 1-mm limbal incisions would be made, a spatula is inserted through the side to elevate the two pupils (avoiding contact with the lens), and the iris tissue would be cut using viscoelastic material. Finally, the limbal incisions were closed with stromal hydration, and intracameral cefuroxime is applied. [5]

Surgical technique

There have been cases where there are various techniques for surgical procedures [11] and can be performed on children and adults. One of the techniques for repair is by using a double armed polypropylene suture, where the suture is left externally on the sclera with a knot buried in the scleral flap. [12] This technique allows posterior fixation of intraocular lens implants in the absence of capsular support. [13] Another technique for surgery is called pupilloplasty, [14] where the patient would be placed under retrobulbar anesthesia with the pupils being dilated with 1% tropicamide. [5]

Prognosis

Postoperative care

Hypertonic saline solution used as eye drops may be used to reduce the corneal edema, [15] [ unreliable medical source? ] the use of anti-glaucomatous topicals to help improve corneal edema, and aqueous suppressants that are accompanied by miotics, include topical beta blockers, alpha antagonists, and carbonic anhydrase inhibitors. [16] Antibiotics and steroid drops for 4 weeks post surgery. [5]

Complications and benefits

Complications of surgical procedures are:

Prevention

There are no known preventive measures for polycoria, however genetic testing may be able to reveal genetic patterns of the disorder.[ citation needed ] Conditions such as reduced corneal thickness, are observed in people with cases of polycoria, as well as keratoconus (keratoconus is a corneal disease has the possibility of leading to blindness and/or astigmatism). [17] [ citation needed ] However, there are some proposals that it is caused by a dissociation of the pupil margins, a partial coloboma which is a hole in the eye, or abnormal eye tissue composition. [5]

Causes

There are not any known direct mechanisms involved in the development of true polycoria or pseudopolycoria. There are some proposed ideas, one being that after the sphincter muscle is fully formed and developed in the eye there is a severing of the pupillary margins leading to the distinction of the extra pupil and the principal pupil. [6] Polycoria can also be caused any hole in one's iris to develop a sphincter muscle development. [6] Another proposed theory about the cause of polycoria is intrauterine trauma, or postpartum iris trauma. [6]

If the development of the iris is hindered, the ectoderm of the eye (which forms the lens and corneal epithelium) may split, which could lead to pseudopolycoria. [6]

Genetics

The gene that is the cause of this disorder is the PRDM5 gene. [10] The PRDM5 gene has also been linked to Brittle Cornea syndrome, which is a tissue disorder of the eye, as well as Axenfeld syndome. [10] PRDM5 plays crucial roles in the molecular composition of the eye, as well as the tissue thickness. [10] Axenfeld syndrome occurs in the patient in a case of the mutation of the FOXC1 gene, which is a heterozygous mutation. [10]

History

Since true polycoria and pseudopolycoria are so rare, there is not much history on the disorders in the tradition of modern western medicine. According to an article published in 2002, there have only been 2 cases of true polycoria since 1966. [3]

Early Chinese history names multiple legendary figures as having double pupils, which as a result was led to a beliefs that a child born two double pupils were destined to be a great king or sage.

Xiang Yu, Hegemon of Chu, blood brother and later arch nemesis of Liu Bang, the founding emperor of the Han dynasty, was given great esteem due to his prowess in combat and auspicious double pupil.

After overthrowing the Qin dynasty together, he was named Hegemon of the loose series of kingdoms he created in its wake, while he gave Liu Bang the remote province of Han.

The Civil War that followed called the Chu-Han contention, ending with a Han victory and a legendary last stand by the Hegemon.

Pliny the Elder describes a mythological race of people known as Bythiæ who "have a double pupil in one eye, and in the other the figure of a horse." [18]

See also

Related Research Articles

<span class="mw-page-title-main">Glaucoma</span> Group of eye diseases

Glaucoma is a group of eye diseases that lead to damage of the optic nerve, which transmits visual information from the eye to the brain. Glaucoma may cause vision loss if left untreated. It has been called the "silent thief of sight" because the loss of vision usually occurs slowly over a long period of time. A major risk factor for glaucoma is increased pressure within the eye, known as intraocular pressure (IOP). It is associated with old age, a family history of glaucoma, and certain medical conditions or medications. The word glaucoma comes from the Ancient Greek word γλαυκός, meaning 'gleaming, blue-green, gray'.

<span class="mw-page-title-main">Iris (anatomy)</span> Colored part of an eye

The iris is a thin, annular structure in the eye in most mammals and birds, responsible for controlling the diameter and size of the pupil, and thus the amount of light reaching the retina. In optical terms, the pupil is the eye's aperture, while the iris is the diaphragm. Eye color is defined by the iris.

<span class="mw-page-title-main">Mydriasis</span> Excessive dilation of the pupil

Mydriasis is the dilation of the pupil, usually having a non-physiological cause, or sometimes a physiological pupillary response. Non-physiological causes of mydriasis include disease, trauma, or the use of certain types of drug. It may also be of unknown cause.

<span class="mw-page-title-main">Keratoconus</span> Medical condition involving the eye

Keratoconus (KC) is a disorder of the eye that results in progressive thinning of the cornea. This may result in blurry vision, double vision, nearsightedness, irregular astigmatism, and light sensitivity leading to poor quality-of-life. Usually both eyes are affected. In more severe cases a scarring or a circle may be seen within the cornea.

Photophobia is a medical symptom of abnormal intolerance to visual perception of light. As a medical symptom, photophobia is not a morbid fear or phobia, but an experience of discomfort or pain to the eyes due to light exposure or by presence of actual physical sensitivity of the eyes, though the term is sometimes additionally applied to abnormal or irrational fear of light, such as heliophobia. The term photophobia comes from the Greek φῶς (phōs), meaning "light", and φόβος (phóbos), meaning "fear".

<span class="mw-page-title-main">Eye surgery</span> Surgery performed on the eye or its adnexa

Eye surgery, also known as ophthalmic surgery or ocular surgery, is surgery performed on the eye or its adnexa. Eye surgery is part of ophthalmology and is performed by an ophthalmologist or eye surgeon. The eye is a fragile organ, and requires due care before, during, and after a surgical procedure to minimize or prevent further damage. An eye surgeon is responsible for selecting the appropriate surgical procedure for the patient, and for taking the necessary safety precautions. Mentions of eye surgery can be found in several ancient texts dating back as early as 1800 BC, with cataract treatment starting in the fifth century BC. It continues to be a widely practiced class of surgery, with various techniques having been developed for treating eye problems.

<span class="mw-page-title-main">Phakic intraocular lens</span> Lens implanted in eye in addition to the natural lens

A phakic intraocular lens (PIOL) is an intraocular lens that is implanted surgically into the eye to correct refractive errors without removing the natural lens. Intraocular lenses that are implanted into eyes after the eye's natural lens has been removed during cataract surgery are known as pseudophakic.

<span class="mw-page-title-main">Cataract surgery</span> Removal of opacified lens from the eye

Cataract surgery, also called lens replacement surgery, is the removal of the natural lens of the eye that has developed a cataract, an opaque or cloudy area. The eye's natural lens is usually replaced with an artificial intraocular lens (IOL) implant.

<span class="mw-page-title-main">Red eye (medicine)</span> Eye that appears red due to illness or injury

A red eye is an eye that appears red due to illness or injury. It is usually injection and prominence of the superficial blood vessels of the conjunctiva, which may be caused by disorders of these or adjacent structures. Conjunctivitis and subconjunctival hemorrhage are two of the less serious but more common causes.

<span class="mw-page-title-main">Inferior rectus muscle</span>

The inferior rectus muscle is a muscle in the orbit near the eye. It is one of the four recti muscles in the group of extraocular muscles. It originates from the common tendinous ring, and inserts into the anteroinferior surface of the eye. It depresses the eye (downwards).

Aphakia is the absence of the lens of the eye, due to surgical removal, such as in cataract surgery, a perforating wound or ulcer, or congenital anomaly. It causes a loss of ability to maintain focus (accommodation), high degree of farsightedness (hyperopia), and a deep anterior chamber. Complications include detachment of the vitreous or retina, and glaucoma.

<span class="mw-page-title-main">Ciliary ganglion</span> Bundle of nerves, parasympathetic ganglion

The ciliary ganglion is a parasympathetic ganglion located just behind the eye in the posterior orbit. It is 1–2 mm in diameter and in humans contains approximately 2,500 neurons. The ganglion contains postganglionic parasympathetic neurons. These neurons supply the pupillary sphincter muscle, which constricts the pupil, and the ciliary muscle which contracts to make the lens more convex. Both of these muscles are involuntary since they are controlled by the parasympathetic division of the autonomic nervous system.

<span class="mw-page-title-main">Iris cyst</span>

Iris cysts are hollow cavities in the eye filled with secretion. They come in various sizes, numbers, shapes, pigments and can be free-floating, attached to the pupillary margin or within the posterior chamber. Most frequently iris cysts don't cause any issues, but they can cause problems like: "fly biting" behavior, corneal endothelial pigment, lens capsular pigmentation, altered iris movement, decreased aqueous outflow with subsequent glaucoma or block the vision when grown too big. They can be acquired or innate. Possible causes are inflammation, drug-induced, uveitis, a trauma, tumor-induced, parasitic or implantation. Most frequently iris cysts are benign and need no treatment. Sometimes iris cysts are causing problems and need to be deflated. Iris cysts can be treated with trans corneal diode laser treatment, fine-needle aspiration or surgical excision. For the treatment of iris cysts is a conservative approach favored.

<span class="mw-page-title-main">Iridectomy</span> Surgical removal of part of the iris

An iridectomy, also known as a surgical iridectomy or corectomy, is the surgical removal of part of the iris. These procedures are most frequently performed in the treatment of closed-angle glaucoma and iris melanoma.

<span class="mw-page-title-main">Dilated fundus examination</span>

Dilated fundus examination (DFE) is a diagnostic procedure that uses mydriatic eye drops to dilate or enlarge the pupil in order to obtain a better view of the fundus of the eye. Once the pupil is dilated, examiners use ophthalmoscopy to view the eye's interior, which makes it easier to assess the retina, optic nerve head, blood vessels, and other important features. DFE has been found to be a more effective method for evaluating eye health when compared to non-dilated examination, and is the best method of evaluating structures behind the iris. It is frequently performed by ophthalmologists and optometrists as part of an eye examination.

The red reflex refers to the reddish-orange reflection of light from the back of the eye, or fundus, observed when using an ophthalmoscope or retinoscope. The reflex relies on the transparency of optical media and reflects off the fundus back through media into the aperture of the ophthalmoscope. The red reflex is considered abnormal if there is any asymmetry between the eyes, dark spots, or white reflex (Leukocoria).

<span class="mw-page-title-main">Persistent fetal vasculature</span> Medical condition

Persistent fetal vasculature(PFV), also known as persistent fetal vasculature syndrome (PFVS), and until 1997 known primarily as persistent hyperplastic primary vitreous (PHPV), is a rare congenital anomaly which occurs when blood vessels within the developing eye, known as the embryonic hyaloid vasculature network, fail to regress as they normally would in-utero after the eye is fully developed. Defects which arise from this lack of vascular regression are diverse; as a result, the presentation, symptoms, and prognosis of affected patients vary widely, ranging from clinical insignificance to irreversible blindness. The underlying structural causes of PFV are considered to be relatively common, and the vast majority of cases do not warrant additional intervention. When symptoms do manifest, however, they are often significant, causing detrimental and irreversible visual impairment. Persistent fetal vasculature heightens the lifelong risk of glaucoma, cataracts, intraocular hemorrhages, and Retinal detachments, accounting for the visual loss of nearly 5% of the blind community in the developed world. In diagnosed cases of PFV, approximately 90% of patients with a unilateral disease have associated poor vision in the affected eye.

<span class="mw-page-title-main">Cornea plana 1</span> Medical condition

Cornea plana 1(CNA1) is a congenital disorder that causes the cornea to flatten and the angle between the sclera and cornea to shrink. This could result in the early development of arcus lipoides, hazy corneal limbus, and hyperopia. Cornea plana 1 is an autosomal dominant disorder.

The eye is made up of the sclera, the iris, and the pupil, a black hole located at the center of the eye with the main function of allowing light to pass to the retina. Due to certain muscle spasms in the eye, the pupil can resemble a tadpole, which consists of a circular body, no arms or legs, and a tail.

<span class="mw-page-title-main">Corneal opacity</span> Medical condition

Corneal opacification is a term used when the human cornea loses its transparency. The term corneal opacity is used particularly for the loss of transparency of cornea due to scarring. Transparency of the cornea is dependent on the uniform diameter and the regular spacing and arrangement of the collagen fibrils within the stroma. Alterations in the spacing of collagen fibrils in a variety of conditions including corneal edema, scars, and macular corneal dystrophy is clinically manifested as corneal opacity. The term corneal blindness is commonly used to describe blindness due to corneal opacity.

References

  1. 1 2 Cassin, B. and Solomon, S. Dictionary of Eye Terminology. Gainesville, Florida: Triad Publishing Company, 1990.
  2. ↑ Islam, N.; Mehta, J. S.; Plant, G. T. (2007). "True polycoria or pseudo-polycoria?". Acta Ophthalmologica Scandinavica. 85 (7): 805–806. doi: 10.1111/j.1600-0420.2007.00985.x . PMID   17711542.
  3. 1 2 3 Hofeldt, Gregory T.; Simon, John W. (2002-10-01). "Polycoria, miosis, and amblyopia". Journal of American Association for Pediatric Ophthalmology and Strabismus {JAAPOS}. 6 (5): 328–329. doi:10.1067/mpa.2002.124649. ISSN   1091-8531. PMID   12381993.
  4. ↑ Berradi, Soufiane; Lezrek, Mounir (2014-09-30). "Pseudo-hypopion inverse avec polycorie congénitale". The Pan African Medical Journal. 19: 108. doi:10.11604/pamj.2014.19.108.3960. ISSN   1937-8688. PMC   4337356 . PMID   25722781.
  5. 1 2 3 4 5 6 7 8 9 10 Bardak, Handan; Ercalik, Nimet Yesim; Gunay, Murat; Bolac, Ruveyde; Bardak, Yavuz; Bardak, Handan; Ercalik, Nimet Yesim; Gunay, Murat; Bolac, Ruveyde; Bardak, Yavuz (December 2016). "Pupilloplasty in a patient with true polycoria: a case report". Arquivos Brasileiros de Oftalmologia. 79 (6): 404–406. doi: 10.5935/0004-2749.20160114 . ISSN   0004-2749. PMID   28076571.
  6. 1 2 3 4 5 6 7 Jaffe, Norman S.; Knie, Paul (1952-02-01). "True Polycoria*". American Journal of Ophthalmology. 35 (2): 253–255. doi:10.1016/0002-9394(52)90856-8. ISSN   0002-9394. PMID   14903014.
  7. ↑ "Iris sphincter muscle", Wikipedia, 2019-11-19, retrieved 2019-11-22
  8. 1 2 3 4 5 6 7 Bhattacharjee, Harsha; Bhattacharjee, Kasturi; Tahiliani, Prerana (2013-12-01). "Congenital polycoria, trichomegaly, and hereditary congenital cataract". Journal of American Association for Pediatric Ophthalmology and Strabismus. 17 (6): 619–620. doi:10.1016/j.jaapos.2013.06.020. ISSN   1091-8531. PMID   24321426.
  9. ↑ "Posterior Polar Cataract: Background, History of the Procedure, Problem". 2019-11-09.{{cite journal}}: Cite journal requires |journal= (help)
  10. 1 2 3 4 5 6 "polycoria | Hereditary Ocular Diseases". disorders.eyes.arizona.edu. Retrieved 2019-11-22.
  11. 1 2 Hofeldt, Gregory T.; Simon, John W. (2002-10-01). "Polycoria, miosis, and amblyopia". Journal of American Association for Pediatric Ophthalmology and Strabismus. 6 (5): 328–329. doi:10.1067/mpa.2002.124649. ISSN   1091-8531. PMID   12381993.
  12. ↑ Inoue, Toshihiro; Matsumura, Riyo; Kuroda, Utako; Nakashima, Kei-Ichi; Kawaji, Takahiro; Tanihara, Hidenobu (December 1, 2012). "Precise Identification of Filtration Openings on the Scleral Flap by Three-Dimensional Anterior Segment Optical Coherence Tomography". Investigative Ophthalmology & Visual Science. 53 (13): 8288–8294. doi: 10.1167/iovs.12-10941 . PMID   23188727.
  13. 1 2 Brown, Sandra M. (1998-12-01). "A technique for repair of iridodialysis in children". Journal of American Association for Pediatric Ophthalmology and Strabismus. 2 (6): 380–382. doi:10.1016/S1091-8531(98)90041-6. ISSN   1091-8531. PMID   10532731.
  14. ↑ "Pupilloplasty – Webvision". 16 May 2012.
  15. ↑ "Corneal Edema – Products for temporary daytime and nighttime relief when you suffer from Corneal Edema : Bausch + Lomb". www.bausch.com.
  16. ↑ Sacchetti, Marta; Mantelli, Flavio; Marenco, Marco; Macchi, Ilaria; Ambrosio, Oriella; Rama, Paolo (2015). "Diagnosis and Management of Iridocorneal Endothelial Syndrome". BioMed Research International. 2015: 763093. doi: 10.1155/2015/763093 . ISSN   2314-6133. PMC   4588350 . PMID   26451377.
  17. ↑ Mohammadpour, Mehrdad; Heidari, Zahra; Hashemi, Hassan (2017-12-06). "Updates on Managements for Keratoconus". Journal of Current Ophthalmology. 30 (2): 110–124. doi:10.1016/j.joco.2017.11.002. ISSN   2452-2325. PMC   6034171 . PMID   29988906.
  18. ↑ Plinius, Naturalis Historia 7, 11.
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.