What Is a Coloboma?
A coloboma is a cleft or gap in some part of the eye, such as the iris, lens, optic nerve, or retina, caused by a defect in the development of the eyeball. The extent to which a coloboma affects a person’s vision depends on the size and location of the cleft and on whether it occurs in one or both eyes. A coloboma of the iris (colored portion of the eye that controls the amount of light entering the eye) will have less of a negative effect on vision than a coloboma of the retina (thin nerve tissue lining the back of the eye) or the optic nerve.
People with colobomas may have one or more of the following eye issues: nearsightedness, involuntary and repetitive movement of the eyes (“nystagmus”), retinal detachment, glaucoma, or cataracts.
While some are diagnosed with only colobomas or with a coloboma and accompanying eye issues, some are diagnosed with colobomas as one component of a syndrome (set of medical issues).
How Is a Coloboma Diagnosed?
A coloboma of the iris may be identified visually by parents or a pediatrician. It may be found during a preventative eye examination if there is a known family history of a visual impairment, or it may be found during an eye examination when another visual impairment has been previously identified. It may even go undetected until symptoms (such as apparent poor vision or strabismus) present in an otherwise healthy child. Regardless, an ophthalmologist will diagnose a coloboma during an eye exam.
Are There Treatments for a Coloboma?
There is no cure for a coloboma. A color contact lens or surgery may be an option to one day correct the appearance of a coloboma of the iris.
Young children with colobomas must be followed closely by their eye care specialists to ensure additional or secondary visual issues do not occur. If a child has a coloboma in one eye causing visual issues, patching the healthy eye may encourage the eye with the coloboma to continue functioning.
How Would You Describe the Eyesight of One with a Coloboma and How Will My Child Function with It?
A small coloboma or a coloboma of the iris may have little to no impact on a child’s vision.
The main visual impact of a coloboma of the iris is light sensitivity. Without the full ability to control the amount of light entering the eye, a child may have discomfort and poorer vision in bright light. Use of a hat and sunglasses would then be recommended for daytime travel, recreation, or work.
If a more significant coloboma (of the retina, lens, or optic nerve) is present in one eye and your child has good vision in the other, he or she will not technically have “low vision.” However, diminished or absent vision in one eye can affect how your child functions. Some children find it straining to read from a chalkboard or catch an oncoming ball, and many children struggle with depth perception.
If colobomas are present in both eyes, your child’s vision can range from good to poor. Your child’s teacher of students with visual impairments should perform a functional vision assessment to determine how your child uses remaining vision and a learning media assessment to determine which senses your child primarily uses to get information from the environment. These assessments, along with an orientation and mobility assessment conducted by a mobility specialist, will give the team information needed to make specific recommendations for your child to best access learning material and his or her environment.
You may learn your child has difficulty recognizing faces and facial expressions, accessing information from a distance, identifying small images or letters on paper, or travelling safely. If this is the case, your child may benefit from travel training from the mobility specialist, increased contrast of the environment, increased contrast of print by using a CCTV or screen-magnification software, and increased room and task lighting (assuming your child is not light sensitive). Your child may also benefit from assistive technology to more easily write, read, use the computer, and access information and from techniques and additional accommodations to perform activities with limited vision.
You may also learn your child has blind spots or field restrictions; perhaps he or she cannot see in the central field of vision or in the upper right quadrant. In this case, your child will be taught strategies for utilizing vision efficiently and utilizing assistive technology in order to access missing information.
Lastly, if your child has significant vision loss, he or she may be taught to complete tasks without the use of vision. Your child may be taught braille, use of screen-reading software to use the computer, and other techniques for performing life skills and academic tasks from the teacher of students with visual impairments.
Resources for Families of Children with Coloboma