Eye Diseases

What is Coloboma? Types of Coloboma

There are various types of Coloboma, contingent upon which some portion of the eye is absent. Coloboma can be inherited or can occur spontaneously. This is a congenital defect that affects the normal structures of the eye, most commonly the eyelid or the iris.

This Disease involving the retina result in vision loss in specific parts of the visual field. Colobomas might be available in one or the two eyes and, contingent upon their size and area, can influence an individual’s vision.

Coloboma is an eye abnormality that occurs before birth. Colobomas involving the eyeball should be distinguished from gaps that occur in the eyelids.

How Many types of coloboma?

  1. Iris Coloboma
  2. Eyelid Coloboma
  3. Lens Coloboma
  4. Macular Coloboma
  5. Optic Nerve Coloboma
  6. Uveal Coloboma
  7. Chorioretinal Coloboma

Now, we are going to detail discuss about types of Coloboma.

Iris coloboma

Iris coloboma

The iris is the front most piece of the uvea (center layer of the eye). Coloboma can influence your iris, the tissue that gives you your eye shading. A coloboma is an opening in one of the structures of the eye, for example, the iris.

Clinical features of the iris coloboma are:

  • Glare
  • Blurry vision
  • Monocular diplopia
  • Signs:
  • Absence of sectoral iris tissue
  • Often associated with cataract

Iris coloboma is likely to cause light sensitivity in bright conditions. Light sensitivity and glare can cause discomfort and affect the quality of vision. Your pupil may look oval if the coloboma is partial, but if more of your lower iris is missing, your pupil will look more keyholes shaped.

The two kids and grown-ups with just iris coloboma will most likely have genuinely great vision. The iris has the characteristic “keyhole” shape. These normally leave the vision unchanged. Coloboma influences just the edge of the student, making it seem oval instead of round.

Eyelid Coloboma

Eyelid Coloboma

The most common position of Eylid Coloboma is at the junction of the medial and middle third of the upper lid. Eyelid coloboma is an unprecedented, one-sided or reciprocal, incomplete or full-thickness eyelid deformity. In eyelid coloboma a piece of either the upper or lower eyelid is missing.

Eyelid coloboma might be a piece of a hereditary disorder or occur because of a disturbance of eyelid advancement in an infant. An eyelid coloboma is a full-thickness imperfection of the eyelid. Eyelid coloboma can occur in many locations. It is brought about by disappointment of combination of the mesodermal top folds.

Treat Eyelid Coloboma:

Surgery in an eyelid coloboma is mainly for cosmesis and corneal protection. If small, then the cornea is protected with ocular lubricants till it is a little older. If large, immediate surgery is required to close the defect.

Lens Coloboma

In Lens coloboma, a piece of the lens is missing. The focal point, which enables spotlight to light on the retina, will normally show up with a score. On the off chance that the focal point of the eye is influenced by coloboma, vision is influenced in light of the adjustment fit as a fiddle brought about by a score or scratch.

There may also be some degree of cataract in the affected eye, that’s why the lens is cloudy instead of being clear. This cloudiness can cause symptoms such as blurred or misty vision, colors appearing dull and glare in your vision.

Treat Iris coloboma:

Contact lenses may be used to improve the cosmetic appearance of a coloboma, and to rid the patient of unwanted symptoms. If the patient is undergoing any intraocular surgery then repair of the iris may be done at the same time.

Macular Coloboma

Coloboma of Macula is a rare, non-syndromic developmental defect of the eye characterized by well-circumscribed. Macular coloboma is characterised by a sharply defined, rather large defect in the central area of the fundus that is oval or round, and coarsely pigmented. Macular coloboma might be caused when typical eye advancement is hindered or following an irritation of the retina during improvement of the infant.

Currently, no risk factors have been clearly identified for Macular Coloboma. This happens when the focal point of the retina, called the macula, does not grow regularly. Macular Coloboma may be seen in association with the Down syndrome and certain bone disorders and kidney disorders. The macula is responsible for daylight, fine and color vision. Macular colobomas, usually bilateral, are the major ocular feature of this oculoskeletal disorder.

Optic Nerve Coloboma

Colobomas of the optic nerve usually occur bilaterally. Coloboma of the optic nerve is an innate irregularity of the optic plate where there is a deformity of the second rate part of the optic nerve. The condition may occur in one or both eyes. Therefore, The optic nerve cups are frequently enormous and may have leftover glial tissue in them.

Optic nerve is burrowed out, diminishing vision. The optic nerve is the heap of nerve filaments that transfers the light flag from the eye to the mind. An uveal coloboma that is huge enough to include the optic nerve, either the sub-par divide or the whole optic plate.

Uveal ColobommUveal Coloboma

Uveal colobomas are a rare entity; they are present in our milieu. Uveal colobomas are a congenital malformation that is secondary to a failure in the closure of the embryonic optic fissure. The unea is the middle layer of the eye. This Disease can affect the iris, the colored part of the eye, giving it a distinct keyhole or cat-eye appearance. Uveal coloboma-cleft lip and palate-intellectual disability is characterize by coloboma of the iris, bilateral cleft lip and palate, and intellectual deficiency of varying degree.

It is believe that uveal coloboma is primarily genetic in origin. Patients with uveal coloboma ought to have yearly follow-up tests by an eye care proficient. There is at present no drug or medical procedure that can fix or turn around coloboma and make the eye entire once more.

Chorioretinal Coloboma

Chorioretinal Coloboma

Chorioretinal coloboma is an uncommon congenital anomaly of the posterior segment occurring as a consequence of incomplete closure of the embryonic fissure during fetal development. In the chorioretinal coloboma, part of the retina is missing. Chorioretinal colobomas are cause by failure of the embryonic fissure to close during development.

Clinical features of the Chorioretinal coloboma is Chorioretinal coloboma depend on the location of the coloboma and ocular structures involved. Chorioretinal coloboma typically located in inferotemporal area.

It can be unilateral or bilateral. It May extend and involve the macula. Chorioretinal coloboma Maybe associate with coloboma of other ocular structures along the embryonic fissure i.e. optic nerve, iris or lid.

Above all, 7 types of Coloboma disease.

Eye Diseases

Coloboma Signs and Symptoms, Causes, Treatment, Do and Don’ts

Coloboma Alternative Names

  • Congenital ocular coloboma
  • Microphthalmia, isolated, with coloboma
  • Ocular coloboma

Group of people

Baby boy, baby girl, Teen Boy, Teen Girl, Man, Women

General Information

Coloboma is an eye abnormality that occurs before birth. Most colobomas are present since birth (congenital). Colobomas are missing bits of tissue in structures that structure the eye. Coloboma can be inherited or can occur spontaneously. This is a congenital defect that affects the normal structures of the eye, most commonly the eyelid or the iris.

It can be inherited or can occur spontaneously. This is a congenital defect in the structure of either the eyelid or the eye. A coloboma depicts conditions where ordinary tissue in or around the eye is missing during childbirth. This Disease involving the retina result in vision loss in specific parts of the visual field. Colobomas might be available in one or the two eyes and, contingent upon their size and area, can influence an individual’s vision.

People with coloboma 

Colobomas involving the eyeball should be distinguished from gaps that occur in the eyelids. People with coloboma may also have other eye abnormalities, including cataract (clouding of the lens of the eye), glaucoma (increased pressure inside the eye) that can damage the optic nerve, myopia (vision problems such as nearsightedness), nystagmus (involuntary back-and-forth eye movements), or retinal detachment (separation of the retina from the back of the eye).

Frequency of Coloboma 

Coloboma is likely to cause light sensitivity in bright conditions. Coloboma occurs in approximately 1 in 10,000 people. Because coloboma does not always affect vision or the outward appearance of the eye, some people with this condition are likely undiagnosed.

Causes of Coloboma

Coloboma may be caused by changes in many genes involved in the early development of the eye, most of which have not been identified.

Coloboma can occur due to:

  • Trauma to the eye
  • Inherited conditions
  • Eye surgery
  • Certain drugs or infections during pregnancy.

Environmental causes

Factors may also be of significance in the development of this condition. Environmental components that influence early improvement, for example, the introduction to liquor and certain medications during pregnancy, may expand the danger of coloboma. Most sporadic cases of coloboma are unilateral and often due to environmental factors, leading to malformations in multiple systems of the body.

Environmental triggers (operating during pregnancy) include:

  • Vitamin A and vitamin E deficiency
  • Ionizing radiation exposure
  • Drugs used in pregnancy, such as thalidomide (4%) and alcohol
  • Hyperthermia
  • Infections with cytomegalovirus (CMV) and toxoplasmosis

Genetic causes

Coloboma may occur spontaneously or it may be inherited. People with disconnected coloboma can in any case pass the condition onto their kids. It might bunch in families as per the legacy design for that condition.

Symptoms of Coloboma

Persons with coloboma may have normal vision and no symptoms, or they may have mild to severe vision impairment. How vision is influenced relies upon where the hole or holes happen in the eye. Symptoms may include:

  • Keyhole-shaped pupil
  • Blurred vision
  • visual impairment and blindness or Vision that may not always be correctable
  • Ghost image
  • Light sensitivity or photophobia
  • Cataract formation, glaucoma and subluxation of the lens
  • Double vision
  • Decreased visual acuity

Risk Factors

There may be more than one gene involved in being at risk for coloboma, and environmental factors might play a role. The risk of coloboma may also be increased by environmental exposure to alcohol during pregnancy and other factors.

Sometimes a coloboma is part of a genetic syndrome. Not all babies born with a coloboma have a family history of this condition or a particular syndrome, suggesting that the disorder can appear by chance.

Treatments of Coloboma

There is no cure for a coloboma and treatment varies depending on the type. Symptoms manifest from early childhood, coloboma is diagnosed early in development. It is a birth defect affecting parts of the eye like the eyelid, iris, lens, retina or optic nerve. It is a feature of syndromes like CHARGE syndrome. Individuals with an iris coloboma may wear hued contact focal points to cause the iris to show up round.

Surgery can also correct the appearance of the iris. There are also a number of procedures to repair colobomas of the eyelid. Follow the healthcare provider’s instructions for ways to help your child’s vision. In the event that coloboma is just in one eye, the other eye might be treated with an eye fix or glasses to anticipate an issue called sluggish eye.

for Detail of Different Types of Coloboma.

Symptoms of Chorioretinal Colobomas

Chorioretinal colobomas occur in the posterior segment of the eye, behind the pupillary opening. These colobomas are brought about by disappointment of the back piece of the optic crevice. This disease do not cause any noticeable symptoms, but on examination, there are marked defects in the upper part of the visual field.

The defect could affect the retinal pigment epithelium, the choroid or the nervous part of the retina. On the off chance that the coloboma is enormous or includes the optic nerve, vision might be lost or poor and uncorrectable with focal points.

In many cases retinal detachment occurs. It then appears as a bare area of the sclera, uncovered by any other layers of the eye.

Prevention/ Do and Don’ts

Contact lenses used to improve the cosmetic appearance of a coloboma, and to rid the patient of unwanted symptoms. Contact focal points might be utilized to improve the corrective appearance of a coloboma. The youngster may require adjustment of strabismus (squint) or refractive mistakes sometimes.

Treatment of associated conditions like cataract and glaucoma will also require treatment.

  • High-contrast reading materials
  • Magnifiers
  • Glasses with special filters
  • Special computer software

Diagnosis of Coloboma

Colobomo Diagnose by below methods.

  • Direct and Indirect Ophthalmoscopy
  • Slit lamp examination
  • Optical Coherence Tomography (OCT)
  • CT Scan / MRI Brain

Other information

Coloboma can occur in conjunction with heart defects, choanal atresia, nervous system abnormalities, genital or urinary tract anomalies. This Disease can be inherited or can result from a random genetic mutation, as a stand-alone defect, or as part of a number of genetic disorders which affect other organs as well. Coloboma of the iris is a gap or deformity of the iris of the eye. Seek medical advice when Loss of vision, Eye that looks cloudy, Back-and-forth movement of the eye that your child can’t control, Eye pain, Other symptoms as noted by your child’s healthcare provider.