Persistent Fetal Vasculature (syndrome) or PFV (S)
What is PFV(S)?
Persistent fetal vasculature and persistent fetal vasculature syndrome are names that identify a condition that used to be called persistent hyperplasia of the primary vitreous or PHPV. It is a condition that has to do with the way the eyes developed before the baby was born.
Unborn babies are called "fetuses." That is where the word "fetal" comes from. The typical fetus has food called nutrients flowing into its eyes before birth. The nutrients flow into the eyes so that they can grow. They move through the eyes in a system of tubes called the hyaloid system. Another word for tubes in the body is "vasculature." The hyaloid system can be called "fetal vasculature" because it is a series of tubes in an unborn baby or fetus.
The hyaloid system is located in the vitreous of the fetus's eyes. The vitreous is the gel inside the eye that keeps it round. The hyaloid system usually dissolves into the gel of the vitreous before the baby is born. In babies who have PFV, however, the hyaloid system does not dissolve. It stays in the eyes. Another word for stays is "persists." The hyaloid system or "fetal vasculature" is persistent after the babies who have PFV are born. This is why the condition is called persistent fetal vasculature.
What causes PFV?
Doctors do not know why some people have PFV. There are some families who have more than one person who has PFV, but that is unusual. PFV seems to be a mistake that just happens while some babies are growing inside their mothers.
People who have PFV may also have nystagmus, cataracts, retinal detachment, glaucoma or microphthalmia. You can look up these causes of visual impairment on this website. People usually have PFV in only one eye. That often causes their eyes to move in different directions from each other. That is called strabismus, which you can look it up here.
What kind of vision do people have who have PHPV?
People who have PFV have vision that is more blurry than people who are fully-sighted. When light comes into their eye, it does not go directly to the back of the eye to send a message to the brain. It moves through the hazy vitreous. Some of the light is blocked by the haziness. Some of the light is reflected into different directions. The image that gets to the brain is blurry and sometimes hard to understand. If PFV is in both eyes, people have a difficult time seeing clearly in the distance. They have a hard time reading print.
Sometimes the persistent vasculature pulls on the lens. The lens loses its shape. It no longer can give a clear focus to light passing through it. Sometimes the persistent vasculature pulls on the retinal. It can pull the retina away from the back of the eye. This causes blind spots. It can cause total blindness if the retina is detached (see retinal detachment).
What will help you if you have PFV?
- Sometimes doctors will have ideas for surgery to help people who have PHPV. The surgeries probably will improve vision. They will not make it be like the vision of a fully-sighted person. The surgery may also prevent more vision loss. Surgery can help people avoid getting glaucoma or a totally detached retina, for example.
- If you notice a change in your vision, call your eye care specialist right away. Any change could be caused by another problem such as cataracts, retinal detachment or glaucoma. Any of these problems can be helped by a doctor.
- Use large print for learning. To read signs and papers you can look with a CCTV.
- Bright light that comes from behind you or next to you may help you see details more easily. Try to find lights that you can adjust yourself.
- You may want to learn braille to read books and to do school work. You may want to use real objects that you can touch to learn about things instead of using pictures.
- Use a white cane for travel. It will help you not bump into objects. It will help you find landmarks on your way. It will let other people know that you may not see them. They will get out of your way.
- Ask people to use bright colors when they want you to notice the differences between colors. Tell them that you may not be able to see the difference between light, pale or muddy colors.
- Wear sunglasses and maybe a hat with a dark brim when it is sunny or hazy out.
- If you have vision in one eye, wear protective glasses. You may not notice objects that are moving close to your eye with vision, and it may help to have glasses to protect that eye.
- Be sure to see an eye care doctor at least once a year to make sure your eyes stay healthy.