Corectopia: Definition, Types, Symptoms, Causes, Associated Diseases, Diagnosis, Treatments and Studies

It is the displacement of the eye’s pupil from its normal central position.

Normally, the pupil is located about 0.5 mm inferonasally from the center of the iris.

Minor deviations of up to 1.0mm are generally cosmetically insignificant and should probably not be considered abnormal.

In this rare anomaly, visual acuity may be good, even with eccentric pupils , if it is not associated with other congenital anomalies or poor vision; you just need peace of mind.

Most cases do not require intervention or respond well to the simple fibrous chain lysis that is characteristic of the condition.

Idiopathic traction correctness

It is an isolated unilateral pupillary congenital anomaly. It is shown to respond well to the simple fibrous chain lysis typically seen in this condition.

Types of corectopia

When corectopia is present from birth (ie, “congenital”), the displacement of the pupil is usually toward the nose (medial).

When corectopia is acquired, due to trauma or scarring of the iris (accidental or surgical) or ocular causes such as high myopia, ectopia lentis, coloboma iridis, Axenfeld-Reiger anomaly, persistent pupillary membrane and hyperplastic pupillary membrane).

Symptoms of corectopia

Corectopia is identified by the displacement of the pupil from its center and is commonly deviated nasal. It is generally bilateral and symmetrical, the direction of travel is up and out.

Unilateral cases are rare. Ectopia lentis is a common accompaniment, and other uveal tissue abnormalities can coexist.

This condition has a hereditary tendency as a recessive characteristic. Some of the reported cases have shown evidence of intrauterine inflammation.

Causes of corectopia

A case series of five children with congenital corectopia without associated ocular cause, three had chromosomal abnormalities; one a probable prenatal diplegia, and a bilateral perisylvian dysplasia with vermian and midbrain hypoplasia.

The cause of corectopia can be congenital or acquired. The latter is usually associated with midbrain lesions and coma, and the poor prognosis is almost universal.

Bilateral congenital corectopia is an ophthalmic sign that deserves chromosomal analysis and neurodevelopmental evaluation.

Diseases associated with corectopia

It can be associated with high myopia or ectopia lentis, among other conditions. Hypoplasia of the sectoral iris or other colobomatous lesions can lead to corectopia, and an isolated noncolombotic autosomal dominant corectopia has also been reported.

More commonly, however, corectopia is associated with lens subluxation, and this combination is called ectopia lentis et pupillae. The condition is almost always bilateral, with the pupils and lenses displaced in opposite directions.

The pupils can be oval or slit-shaped, and they are often poorly dilated. Iris transillumination can occur and microspherophakia has been reported.

Progressive corectopia can be associated with the Axenfeld-Rieger spectrum and iridocorneal endothelial syndrome (ICE). Visual acuity can be good, even with eccentric pupils.

Lipoid proteinosis (Urbach-Wiethe disease) is a rare autosomal recessive disorder. Cases of association of bilateral corectopia with this condition have been reported.

Diagnosis of corectopia

If your child has a suspected unilateral pupillary abnormality, it is suggested that you consult an ophthalmologist, who will most likely rule out bilateral corectopia first.

And, of course, it will assess the general condition of the eyes. Only an ophthalmologist will be the best place to advise you on further administration of your child.

The differential diagnosis of corectopia includes iridocorneal endothelial syndrome, Axenfeld-Rieger syndrome, trauma, sectoral iris hypoplasia, or other colobomatous lesions.

Treatment for corectopia

Management depends on the cause. It can be medical, surgical, or both. Bilateral congenital corectopia is a sign that deserves chromosomal analysis and neurodevelopmental evaluation.

Medical or surgical intervention may be indicated for the treatment of corectopia in some cases.

Corectopia is an eccentric location of the pupil. The displacement follows an intracapsular cataract extraction.

Peripheral iridectomy at 12:30 o’clock does not prevent the occurrence of this rare but well-known complication of cataract surgery.

The peak of the distorted pupil points to the area of ​​angle pathology. Gonioscopy reveals anterior synechia in that position. Fortunately, despite incarceration at the healed limbal incision, a true prolapse of the iris does not develop.

Corectopy studies

Unilateral corectopia case

A 50-year-old laborer attended the outpatient department with a history and clinical features of upper respiratory infection.

There was no history of visual symptoms. There was no significant family history of congenital eye diseases. His vital signs, general and system examinations were normal.

However, examination of his left eye showed a small eccentrically placed pupil with a reduced papillary diameter. The right pupil was of normal size and reaction.

Extraocular movements were normal and complete bilaterally. His visual acuity and optic fundus were normal. An ophthalmic consultation was performed, which demonstrated a normal visual field and visual acuity. He was diagnosed with unilateral idiopathic tractional corectopia.

Congenital abnormalities of pupil position and shape are rare. Normal pupil sizes in adults range from 2 to 4 mm in diameter in bright light to 4-8 mm in the dark and are generally of equal size.

The pupils are normally located about 0.5 mm inferonasally from the center of the iris. Corectopia refers to the displacement of the pupil, which is normally around 0.5 mm inferonasally from the center of the iris.

Minor deviations of up to 1mm are generally cosmetically insignificant and probably should not be considered abnormal. In this case, the abnormal position of the pupil is caused by a fibrous structure that ties the pupillary margin of the iris to the peripheral cornea.

Idiopathic tractional corectopia is an isolated unilateral pupillary congenital anomaly with a highly characteristic appearance.

Case of bilateral corectopia

In a patient with a dural arteriovenous fistula resulting in a prominent basal vein of Rosenthal involving the midbrain.

A 37-year-old man presented to our neuro-ophthalmology clinic with complaints of light sensitivity and large pupils bilaterally for 6 months.

A year ago, he experienced pulsatile tinnitus and later began to misspell words on the computer.

On examination, the corrected visual acuity of the right and left eyes was 20/20 and 20/20, respectively. Color vision and sense of brightness were normal.

The pupils revealed anisocoria, more significant in the bright (outer diameter 5 mm, OS 7 mm) than in the dark (outer diameter 6 mm, OS 7 mm).

Pupillary reaction was slow. Relative afferent pupillary defect was absent.

Slit lamp examination revealed corectopia in both pupils, noting a peak observed at the 8 o’clock position of the right pupil and in the 4 and 8 o’clock region of the left pupil.

Slight vermiform movements of both pupils were present, worse in the left eye than in the right, and the patellar reflexes were moderately diminished bilaterally.

These characteristics were suggestive of Adie’s pupil, so the cholinergic supersensitivity test for Adie’s pupil was performed with dilute pilocarpine (0.1%).

No pupillary changes were observed even after the second application of 0.1% pilocarpine after 40 minutes. The presence of corectopia justified the exclusion of any midbrain lesion.

An MRI of the brain was requested and revealed some asymmetric prominence of the left basal vein of Rosenthal.

In addition, an increased flow artifact was observed medial to the left cavernous portion of the internal carotid artery, suggesting an indirect carotid cavernous fistula.

Subsequent study with diagnostic cerebral angiography and later computed tomography angiography of the brain confirmed a durable sphenoidal Cognard type 4 arteriovenous fistula of the left temporal pole located along the anterior aspect of the left middle cranial fossa.

Given the draining ectatic cortical veins, it was considered a dangerous injury with the potential to rupture and cause posterior intracerebral hemorrhage.

Endovascular embolization of the arteriovenous fistula was attempted and only partial embolization was achieved.

The patient was referred to the neurosurgery department and, after 2 months, underwent a craniotomy and successful ligation of the dural arteriovenous fistula, confirmed by diagnostic cerebral angiography the following day.

After 3 months, the corrected visual acuity was 20/25 and 20/20 in the right and left eyes, respectively.

The pupil size in bright surroundings was 5 mm in the right eye and 7 mm in the left eye, while it was 6 mm and 7 mm in the dark in the right and left eyes, respectively.

Despite treatment, her corectopia persisted, more pronounced in the right eye than the left.

The report demonstrates and corroborates previous cases that corectopia is associated with midbrain pathology. The basal vein of Rosenthal normally runs laterally along the techtal plate of the midbrain.

The patient had a prominent left basal vein of Rosenthal that would most likely result in a midbrain injury and posterior corectopia.

Furthermore, this patient had large pupils and sensitivity to light in both eyes with decreased deep tendon reflexes, consistent with the idiopathic Adie pupil, although pilocarpine supersensitivity suggested otherwise.

If your corectopia was not recognized, the diagnosis of AVM may not have been made.

A negative cholinergic supersensitivity test (as seen in this patient) does not exclude Adie’s pupil, because this test is demonstrated in only 80% of people with this condition.

The sensitivity of this test can be increased to more than 90% by a second round of 0.1% pilocarpine application.

Several factors can influence this test and these include intersubjective variability, differential corneal penetration, baseline pupil size (iris stroma), and reinnervation status.

Another explanation for the negative cholinergic supersensitivity test is an inverse relationship between the innervation of the iris sphincter segments and the response to dilute pilocarpine.

The possibility exists that the iris sphincter segments are less sensitive to dilute pilocarpine due to reinnervation of these segments.

Midbrain corectopia has previously been described in patients with clinically significant intracranial hypertension and decreased consciousness with a poor prognosis, especially in acute cerebrovascular disorders.

Initially described by Wilson, Selhorst et al. subsequently confirmed the observation of corectopia and its importance as a sign of rostral midbrain dysfunction.

Midbrain corectopy has also been seen in cases with transient midbrain dysfunction and is not considered a final sign.

The patient with posterior fossa intracranial pathology was alert, oriented, and without obvious cognitive impairment.

The case showed a minor involvement of the midbrain. Interestingly, the corectopia in our patient persisted despite treatment.

Different mechanisms of corectopy have been suggested; however, the general principle relates to the balance between the sympathetic and parasympathetic pupillary pathways.

Lesions in the midbrain (oculomotor nerve or nucleus) will non-uniformly paralyze the pupillary sphincter, and corectopia occurs with dilation of the pupils through the sympathetic pathway.

Lesions in the pupillary fibers of the midbrain, as seen in partially innervated Edinger-Westphal nuclei, produce uneven upward and inward movement of the pupil.

In patients with paralyzed dilator muscles, corectopia occurs from partial central inhibition of sphincter tone.

Also, various sections of the pupillary sphincter have different levels of parasympathetic tone.

This case reiterates the importance of obtaining neuroimaging in patients with acquired chorectopia in whom the cholinergic supersensitivity test is negative.