Coloboma

Eye Deceases

Coloboma

Coloboma also called as colobomas or colobomata.

Coloboma is a Greek word that actually means mutilation. The condition involves missing of the typical tissue from the birth itself in and around the eye. In this condition is thereby a failure of the closing of the optic fissure which leaves a gap in more or less or all of the structures of the eye. This condition is unremarkably evident since the pupil shape is altered. It can frequently be a ‘cats eye’ or ‘keyhole’ shape. Coloboma also occurs in various forms according to the severity.

Complete coloboma condition exists when all of the structures of the eye are associated .These structures profoundly associated are the choroid, the retina, the optic disk, the ciliary body, the macular and the iris. Lens colobomas also exists but it is a very uncommon condition and the cause isn’t finely interpreted.

Symptoms Observed in Coloboma

  1. Blurred vision
  2. Low visual acuity
  3. Ghost image

What Causes Coloboma?

An eyelid coloboma may occur due to genetic inheritance or as a result of trauma during surgery or accidents. An eyelid coloboma is the most obvious symptom of Treacher Collins syndrome, which is autosomal dominant disorder with unpredictable severity.

Upper eyelid coloboma is mostly associated with cryptophthalmos and hence is observed in any genetic diseases that involve cryptophthalmos such as Fraser syndrome and Manitoba Oculotrichoanal (MOTA) syndrome.

Coloboma Treatment

Presently, no treatment for Coloboma is known. Continuous monitoring of the child during the initial years of development to study effect of the coloboma and eye health is necessary. Children having coloboma are more at risk of glaucoma and retinal detachment. Glaucoma and retinal detachment disorders can be treated by ophthalmologists.

Children with coloboma can wear glasses in some cases. Vision problems associated with coloboma cannot be treated with the use of glasses or contact lens. Nevertheless, glasses can help to correct short-sightedness or long-sightedness and help to use the parts of vision that are not affected by coloboma.

Occasionally cosmetic contact lenses can be used. These can maintain the appearance of the pupil to round instead of keyhole shaped.

Prescription sunglasses due to the photophobias may be suggested by the ophthalmologist as aids and equipments to help the child for vision.

Types of Coloboma

Normally, five types of coloboma are differentiated according to the part of the eye missing from birth. Coloboma can affect eyelids, lens, macula, optic nerve and uvea of the eye.

  1. Eyelid Coloboma - Missing of the upper or the lower eyelid from birth in the baby, it is called as Eyelid Coloboma. Eyelid coloboma can be caused due to genetic inheritance of the disorder or from the defects in development of the eyelid in the baby.
  2. Lens Coloboma - Lens focuses light on the retina. When some part of lens is missing from birth in the baby, it is called as Lens Coloboma.
  3. Macula Coloboma - Macula Coloboma is a condition when the macula present in the center of the retina does not develop normally. Any reason which under develops the macula of the eye or inflammation of retina of the eye can cause Macula Coloboma.
  4. Optic nerve Coloboma - Optic nerve coloboma is subdivided into optic nerve pit, in which there is abnormality in the optic nerve causing its excavation and uveal with optic nerve wherein the complete optical disk is involved.
  5. Uveal Coloboma - It is present as iris coloboma or chorioretinal coloboma. The iris coloboma is typical “cat-eye” or “keyhole” appearance of iris. Chorioretinal coloboma involves missing of the part of the retina on the lower inner side of the eye. Iris coloboma can occur due to eye surgery, genetic inheritance and trauma.