What is an optic nerve pit?
An optic nerve pit is a small pocket or hole next to the optic nerve. A very small amount of the retina pushes backwards through that pocket. This pit is something that the child is born with and is a result of problems with growth of the eye in the womb during pregnancy. It usually occurs in one eye, however in 15% of children it may be seen in both eyes. See figure 1 where it shows a normal optic nerve with an orange pink circle and a yellow white center. See figure 2 which shows a nerve with a pit. There is an extra area of lighter color at the bottom of the orang pink circle.
Fig. 1: Normal optic nerve.
Fig. 2: Optic nerve pit. See how it is lighter in color at the bottom. This is where the hole or pocket in the nerve is.
How is optic pit diagnosed?
If the pit is not causing vision problems, the patient will not notice anything. An optic nerve pit is most often found during a routine eye exam. Most cases are diagnosed by an ophthalmologist examining the optic nerve and retina. If the optic nerve pit affects the vision, extra testing may be used like fluorescein angiography of the retina or OCT.
What is the effect of optic pit on vision?
The pit itself does not usually affect vision and most patients do not have any symptoms for many years if ever. About half of patients start having vision changes in their 20’s or 30’s. It is very uncommon for a child with an optic pit to have symptoms. Vision symptoms happen when there is a build up of fluid under the center part of the retina (the macula). The retina is the part of the eye that collects light and send that light to the brain to form a picture. If fluid builds up under the retina, the cells are not able to form a clear signal and vision can be blurry.
What is the treatment of optic pit?
There is no treatment required for the optic pit itself, and there is nothing that can be done to avoid the build up of fluid and the associated decrease in vision if it happens. Treatment is given after the fluid builds up. In some cases, the fluid goes away without doing anything. In such cases the doctor may ask the patient to limit activity for some time and to come for frequent follow up visits. In other cases, surgery (called vitrectomy, laser or scleral buckle) may be required to clear the fluid. Even with the right treatment, vision may not return to normal.
If you have more questions about an optic nerve pit, speak with your ophthalmologist.
For more scientific information on optic pits see: https://eyewiki.org/Optic_Pits