What are Colobomas?
Colobomas are congenital defects of either the eye or the eyelids. During development the eyes starts out as a cup shaped structure that than zips closed along the bottom. A disruption of this closure process can result in missing eye or eyelid tissue. The severity of the defects and their impact on visual functioning depend on which structures of the eye are affected and to what extent. Colobomas can occur either spontaneously or be inherited. Sometimes they are associated with other congenital anomalies, such as CHARGE syndrome or Goldenhar syndrome. Therefore, an infant with a coloboma should be carefully evaluated by their pediatrician for other congenital anomalies.
A coloboma of the eyelid appears as a vertical notch or missing portion of the center of an eyelid. It typically affects the upper eyelid. The eyelid defects can cause damage to the surface of the eye because of exposure and dryness. An eyelid coloboma can usually be repaired by your pediatric ophthalmologist or an oculoplastic surgeon.
An iris coloboma will have the appearance of a "key-hole" pupil with a notch at the lower edge. It usually has little to no affect on vision except for possible light sensitivity. However, an iris coloboma may be associated with other eye issues that can affect vision. A complete eye examination by a pediatric ophthalmologist is needed.
Fundus colobomas are defects that occur on the inside of the eye and affect the retina or optic nerve. Many retinal colobomas will be located at the bottom of the eye and do not affect vision. But larger colobomas or ones that involve the central retina or optic nerves may result in severe visual impairment. Fundus colobomas also need to be watched carefully over time by your pediatric ophthalmologist to observe for any sign of retinal detachment, one possible complication of the coloboma.