Written by: Prof. Kent Kazlo, Professional Director of the Elia Association, Developmental Optometrist.
In the fourth week of pregnancy, the eyes begin to develop in stages. In the first stage, fibers from the fetal brain are drawn forward to form what will become the eyeball. This shape is reminiscent of a cup that, over time until the beginning of the last trimester, will close.
In the picture above you can see how the eyeball is formed: the "cup" closes from top to bottom. If there is no complete closure, a state of missing tissue called collobuma is formed. Lack of tissue, coloboma can be in several tissues of the eye – from the area of the back tissue (retina) to the anterior tissue area (iris/personality).
In this picture we see a normal retital:
A light circle centered on blood vessels (the optic nerve) and around an orange background is the retina. The smaller darker area is the area of central vision. Everything else, peripheral vision.
In the following image we see a retital with collobuma – the white area, as in most cases it is the area with the missing tissue, is below where the closure should have occurred.
If the coluluboma is in the back of the retina eye, we won't be able to see it looking at the eye. On the other hand, if the colobuma is located in the front of the iris eye (the colored part), we can understand it by looking at the eye. The colovoma can appear in one or both eyes.
Colobuma in one eye, Colobuma in two poor people.
The effect of collomoma on vision:
- If there is a colomoma of the iris, there may be good vision, but there will be hypersensitivity to light and blinding. This is because the aperture of the eye (pupil- circular opening in the icing) is incomplete and therefore too much light enters the eye.
- If there is also or only retital collomoma, there may be more significant effects on vision depending on the area of injury. If the missing area is in the peripheral retital, there will be almost no effect on vision. If the deficiency reaches the retina area responsible for central vision (macula and phobia) it is likely that there will be damage to central vision and difficulty in seeing colors. Whether the missing area also includes the optic nerve will have an impact on both central and peripheral vision.
There is no medical treatment for the retina collooma and there are only a few options to deal with iris collomoma. If the problem is lacking in iris tissue there is the possibility of a contact lens with a printed iris so that both improved vision and improved eye appearance and blinding lowering. Another therapeutic option is artificial iris transplant surgery, an operation that is still considered experimental.
The manner of work will be adjusted according to the eye injury.
Examples: difficulty in field of vision (peripheral vision)- to raise awareness of the missing field of vision. Present things in an existing field of view and help the child develop effective search and orientation methods.
If the damage is in the central vision then it is necessary to work with materials of suitable sizes, correct distances and high contrast. In addition, it is advisable not to emphasize color diagnosis even though it is possible to try to work on sorting objects by color– if there is a big difference between the colors and the colors are strong.