Coloboma of optic nerve: Difference between revisions

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Coloboma of the Optic Nerve

Coloboma of the optic nerve is a congenital malformation of the eye, specifically affecting the optic nerve. It is characterized by a defect in the structure of the optic nerve, which can lead to various visual impairments. This condition is part of a broader group of ocular colobomas, which can affect different parts of the eye.

Pathophysiology

Coloboma of the optic nerve occurs due to incomplete closure of the embryonic fissure during eye development. This results in a gap or defect in the optic nerve head. The defect can vary in size and shape, and its impact on vision depends on the extent and location of the coloboma.

Clinical Presentation

Patients with coloboma of the optic nerve may present with:

Reduced visual acuity
Visual field defects
Nystagmus
Strabismus

The severity of symptoms can vary widely among individuals. Some may have significant visual impairment, while others may have minimal symptoms.

Diagnosis

Diagnosis of coloboma of the optic nerve is typically made through a comprehensive eye examination, which may include:

Genetic Aspects

Coloboma of the optic nerve can occur sporadically or as part of a genetic syndrome. It may be inherited in an autosomal dominant pattern, as illustrated in the diagram. Genetic counseling may be recommended for affected families.

Management

There is no cure for coloboma of the optic nerve, but management focuses on optimizing visual function and addressing any associated conditions. This may include:

Corrective lenses
Low vision aids
Regular monitoring by an ophthalmologist

Related Pages

Template:Congenital disorders of eyes

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-{{More medical citations needed|date=September 2017}}
+== Coloboma of the Optic Nerve ==
-{{Infobox medical condition (new)
-| name            = Coloboma of optic nerve
-| synonyms        =
-| image           = Autosomal dominant - en.svg
-| alt             =
-| caption         = This condition is inherited in an autosomal dominant manner
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-}}
-'''Coloboma of optic nerve''', is a rare defect of the [[optic nerve]] that causes moderate to severe [[Visual field#Visual field loss|visual field defects]].
-Coloboma of the optic nerve is a [[Congenital disorder|congenital anomaly]] of the [[optic disc]] in which there is a defect of the inferior aspect of the optic nerve. The issue stems from incomplete closure of the embryonic fissure while in utero. A varying amount of glial tissue typically fills the defect, manifests as a white mass.
+[[File:Autosomal_dominant_-_en.svg|thumb|right|Diagram illustrating autosomal dominant inheritance.]]
-==Signs and symptoms==
+'''Coloboma of the optic nerve''' is a congenital malformation of the eye, specifically affecting the optic nerve. It is characterized by a defect in the structure of the optic nerve, which can lead to various visual impairments. This condition is part of a broader group of ocular colobomas, which can affect different parts of the eye.
-Vision in the affected eye is impaired, the degree of which depends on the size of the defect, and typically affects the [[visual field]] more than [[visual acuity]]. Additionally, there is an increased risk of serous retinal detachment, manifesting in 1/3 of patients. If retinal detachment does occur, it is usually not correctable and all sight is lost in the affected area of the eye, which may or may not involve the [[macula]].
-==Diagnosis==
+== Pathophysiology ==
-The first noticeable signs of the syndrome usually do not appear until after the first twelve months of the child’s life. The child usually has severe [[Balance (ability)|balance]] issues as he or she learns to sit or walk, often leaning or tilting the head toward the good eye to correct the brain’s skewed [[perception]] of the world. Often the child will fall in the same direction while walking or run into objects that are placed on his or her blind side. Additionally, family members may notice a white reflex in the pupil of an affected child instead of the normal [[red reflex]] when taking photographs. The presence of this phenomenon is dependent on the degree of the coloboma, with larger colobomas more likely to manifest this particular phenomenon.
+Coloboma of the optic nerve occurs due to incomplete closure of the embryonic fissure during eye development. This results in a gap or defect in the optic nerve head. The defect can vary in size and shape, and its impact on vision depends on the extent and location of the coloboma.
-This anomaly must be confirmed through [[pupillary dilation]] and examination of the optic disc, as the symptoms alone do not constitute a diagnosis.
+== Clinical Presentation ==
+Patients with coloboma of the optic nerve may present with:
+* Reduced visual acuity
+* Visual field defects
+* Nystagmus
+* Strabismus
-People with optic nerve colobomas live relatively normal lives. Although non-prescription glasses should be worn for eye protection, this syndrome does not usually prevent the individual from living a normal life, driving cars, playing sports, reading, etc. Certain activities, however, may be more difficult for patients with optic nerve colobomas due to a compromised view of the world. Like most other eye conditions, a diagnosis of optic nerve coloboma precludes a person from certain occupations.
+The severity of symptoms can vary widely among individuals. Some may have significant visual impairment, while others may have minimal symptoms.
-===Comparison with morning glory disc anomaly===
+== Diagnosis ==
-Although both optic nerve colobomas and [[morning glory disc anomaly]] (MGDA) involve mutations of the [[PAX6]] gene, these two separate diseases represent two distinct causes. An optic nerve coloboma is easily differentiated from morning glory anomaly. Colobomas affect only the inferior aspect of the nerve as it represents an incomplete closure of the embryonic fissure, whereas MGDA encompasses all aspects of the nerve and represents more generally a [[Dysgenesis (embryology)|dysgenesis]] of the mesoderm.
+Diagnosis of coloboma of the optic nerve is typically made through a comprehensive eye examination, which may include:
+* [[Ophthalmoscopy]]
+* [[Visual field test]]
+* [[Optical coherence tomography]] (OCT)
-==Management==
+== Genetic Aspects ==
-{{Empty section|date=September 2017}}
+Coloboma of the optic nerve can occur sporadically or as part of a genetic syndrome. It may be inherited in an [[autosomal dominant]] pattern, as illustrated in the diagram. Genetic counseling may be recommended for affected families.
-==See also==
+== Management ==
-*[[Coloboma]]
+There is no cure for coloboma of the optic nerve, but management focuses on optimizing visual function and addressing any associated conditions. This may include:
-*[[Visual field#Visual field loss|Visual field defect]]
+* Corrective lenses
-*[[Blindness]]
+* Low vision aids
-*[[Cataract]]
+* Regular monitoring by an ophthalmologist
-==References==
+== Related Pages ==
+* [[Coloboma]]
+* [[Optic nerve]]
+* [[Congenital eye disorders]]
+{{Congenital disorders of eyes}}
-== External links ==
+[[Category:Congenital disorders of eyes]]
-{{Medical resources
+[[Category:Ophthalmology]]
-|  DiseasesDB      =
-|  ICD10           = {{ICD10|Q|14|2|q|14}}
-|  ICD9            = 377.23
-|  ICDO            =
-|  OMIM            = 120430
-|  MedlinePlus     =
-|  eMedicineSubj   =
-|  eMedicineTopic  =
-|  MeshID          =
-}}
-[[Category:Diseases of the eye and adnexa]]
-{{dictionary-stub1}}