Persistent hyperplastic primary vitreus (PHPV) is a congenital and hereditary eye disease. The disease is caused by an embryonic developmental disorder that causes the embryonic vitreous body to remain and become hyperplastic. The treatment options are usually operations.
What is persistent hyperplastic primary vitreus?
The corpus vitreum is also called the vitreous body. It is a gelatinous and translucent structure between the lens and the retina. With its flexible shape, the vitreous maintains its pressure on the surrounding structures. The anatomical structure encompasses a fine fiber network that serves as a storage location for humor vitreus.
The vitreous body can be affected by various diseases. One is PHPV, persistent hyperplastic primary vitreus. This congenital malformation is a disease from the group of rare congenital disorders. Two variants of the disease exist: an anterior variant and a posterior variant. See AbbreviationFinder for abbreviations related to PHPV.
The front variant is more common. Persistent hyperplastic primary vitreus (PHPV) is also sometimes referred to by the synonymous term persistent fetal vascular structures (PFVS). Another synonym used in the clinical literature is the term PHPV syndrome. The congenital disorder already manifests itself in the newborn period. The prevalence of the disease is not known in detail.
Causes
The primary vitreous body develops during the embryonic period. In addition to the tunica vasculosa lentis, this structure also includes the hyaloid artery system. The primary vitreous does not remain, but regresses. In patients with persistent hyperplastic primary vitreous, there is no regression of the embryonic primary vitreous body.
PHPV is an embryonic developmental disorder. In the anterior variant, the remaining part develops into a plate of connective tissue. This variant is therefore associated with hyperplasia. During the embryonic period, the retina of the eyes forms from the neural tube. The lens epithelium is formed from the surface ectoderm.
The connective tissue of the eyes, for example, is formed from the mesoderm. Embryonic development disorders of the eyes can be favored by chemical noxae, ionizing radiation or infections. In persistent hyperplastic primary vitreus, the primary cause is genetic.
Inheritance is X-linked, autosomal dominant or autosomal recessive. Affected males pass the disorder on to all their daughters, with daughters being carriers and having a 50 percent chance of passing on the condition.
Symptoms, Ailments & Signs
The first symptoms of persistent hyperplastic primary vitreous (PHPV) appear in early childhood at the latest. A connective tissue plate has formed during embryonic development. The whitish plate lies just behind the pupil. This causes the patient’s pupil to appear whitish, also known as leukocoria or amaurotic cat’s eye.
The changes in the area of the pupil result in changes in the lens. Adipose tissue is deposited and cartilage is formed in the area of the lens. Diverse scarring processes occur. The ciliary villi become distorted and appear in the area of the pupil. Since the retina is also affected, this anterior variant of the disease can result in uncharacteristic loss of vision, the severity of which depends on the extent of the retinal detachment.
Sometimes there is a cataracta membranacea, which turns the lens into a clouded membrane. All fatty tissue growths in the lens area are called pseudophakia lipomatosa. The eye lags behind in the further course of growth. Often there are additional outflow disorders of the aqueous humor, which can result in hydrophthalmos. Glaucoma with blindness can develop from hydrophthalmos.
Diagnosis & course of disease
Patients with persistent hyperplastic primary vitreus are usually diagnosed in infancy. In addition to history and family history, gold-standard ultrasonography has a role to play in verifying PHPV. In some cases, visual diagnostics can already suggest the disease, for example with a clearly recognizable plate of connective tissue in front of the lens.
In this case, however, other malformations and tumors such as retinoblastoma must be considered in the differential diagnosis. Prognosis for patients with PHPV depends on retinal involvement.
Complications
For the treatment of persistent hyperplastic primary vitreus (PHPV), there is currently no therapy that promises success. There is always a loss of vision, i.e. a reduction in visual acuity. In the event of complications, however, immediate surgical treatment should be carried out.
Complications that occur more frequently are retinal detachment and retinal dysplasia. Left untreated, retinal detachment can lead to blindness. In many cases, however, this occurs without symptoms, so that it is often not recognized immediately. However, sometimes dots, spots, colors or flashes of light are perceived.
If there is a so-called falling rain (soot rain), bleeding occurs in the vitreous body, which increases the risk of rapid blindness. In these cases, the entire glass body must be replaced. Other symptoms of a retinal detachment can be a loss of visual field or a distorted perception of the environment. Another complication of PHPV is the so-called retinal dysplasia.
The retina is malformed. Those affected see flashes of light and flickering dots. In the worst case, retinal dysplasia can also lead to retinal detachment. Microphthalmos is also present in PHPV. This is an eye that is too small. This fact can in turn impede the outflow of aqueous humor. A further complication of PHPV can be hydrophthalmos with increased intraocular pressure (glaucoma), which without treatment is often the cause of blindness.
When should you go to the doctor?
In any case, this disease must be treated by a doctor. There is no self-healing and no improvement in the symptoms. The symptoms can only be removed by surgery, so a visit to a doctor is always necessary. The doctor should be consulted if there are problems with the eyes, if the person concerned has severe visual impairment or if the retina is detached. The visual problems can also occur later in life. In the worst case, the patient suffers complete blindness. Therefore, if you suddenly experience visual problems without any particular reason that do not go away on their own, you should always consult a doctor.
As a rule, the disease can be diagnosed by an ophthalmologist, whereby the treatment itself is usually associated with an inpatient stay in a hospital. Life expectancy is usually not reduced by this disease.
Treatment & Therapy
Causal therapy is not available for patients with PHPV. The developmental disorder has already taken place and is also genetic. This means that causal therapies are excluded as long as the gene therapy treatment does not achieve approval. The patient’s visual loss cannot be successfully treated. Symptomatic treatment options are also limited.
Therapy focuses on preventing complications. Invasive steps such as surgery may be necessary to avoid complications. In addition, some scientists are in favor of surgical interventions possibly preserving the current state of vision. If this is the case, surgery would automatically prevent a complete loss of vision.
Operations are also indicated in other contexts. Even if there is already complete loss of vision in one eye, invasive procedures improve the patient’s situation. The surgical intervention can usually save the eye. This does not lead to any major impairments on the cosmetic side. Since the face takes on the role of a calling card in the interpersonal area, the preservation of an eye that has even become completely non-functional is always preferable to complete removal.
Aftercare
Because persistent hyperplastic primary vitreus (PHPV) cannot be treated in most cases, there is often no follow-up care for the patients. Patients must learn to cope with their reduced vision. There is an exception if an operation is performed on the vitreous body in order to at least partially preserve the ability to see.
After the surgical procedure, the patients are given appointments for a follow-up examination by the ophthalmologist. At the check-up appointments, the doctor checks how far the operated vitreous body has healed and whether there are any complications from the operation. In addition, the patients must take eye drops regularly so that the operated eye does not dry out.
Visual deterioration can become a psychological burden if PHPV develops very late in childhood. In such cases it is advisable for the parents to seek therapeutic help for their children. In therapy, the children can learn how they can cope with their everyday life even with their reduced vision. But parents and family members also learn how to support the child. An almost normal life is possible in many cases despite the malformation of the vitreous body.
Outlook & Forecast
Since the eye disease called “persistent hyperplastic primary vitreus” – PHPV for short – is hereditary and congenital, this embryonic developmental disorder can only be corrected later by surgery. In PHPV, the vitreous body of the eye is affected. True, this disorder is relatively rare. But it occurs in two different variants.
The anterior variant of the PHPV syndrome is the one that occurs more frequently. Its effects can already be seen in infancy or in the early years of childhood. The prognosis of PHV syndrome depends on the severity of the vitreous damage and the course or the treatment initiated. An important question regarding the prospects is also whether and to what extent the retina is involved.
The problem is that there are no other treatment options apart from surgical therapy. The operation is usually used as the treatment of choice for complications such as retinal detachment or retinal dysplasia . Such operations on the eye represent emergency measures against impending blindness. The eyesight of those affected can also be lost due to glaucoma. Preventing this is the aim of the surgery. If operational preventive measures are used, the current state can be maintained for a long time.
In the case of persistent hyperplastic primary Vitreus disease, medicine promises a possible treatment option through gene therapy. That could potentially improve the prognosis significantly.
Prevention
Persistent hyperplastic primary vitreus (PHPV) can only be prevented by genetic counseling during the family planning phase. Affected men in particular should at least be aware that they are passing the disease on to their children.
You can do that yourself
Persistent Hyperplastic Primary Vitreus (PHPV) is a condition that can only be cured with medical attention. In everyday life, PHPV manifests itself through symptoms in the eyes, such as poor eyesight or detachment of the retina. To avoid total blindness, it is important to look out for these signs. The medical examination shows whether it is actually the disease and what treatment options are available.
By following the doctor’s recommendations, difficulties can be prevented or at least postponed. Often the best solution is surgery.
PHPV is an inherited disease, so it’s a good idea to find out more about it when planning a family. Children are often affected by the disease, so parents should find out about the possible surgical measures at an early stage. For everyday use itself, there isn’t much advice on how to deal with PHPV. After a certain degree of the disease, those affected find it difficult to read or see other things. Then they can rest their eyes, but the breaks in everyday life are only for relief and do not improve the situation.