What are the other Names for this Condition? (Also known as/Synonyms)

• Circumpapillary Dysgenesis of the Pigment Epithelium
• Helicoidal Peripapillary Degeneration
• Sveinsson Chorioretinal Atrophy (SCRA)

What is Helicoidal Peripapillary Chorioretinal Degeneration? (Definition/Background Information)

• Helicoidal Peripapillary Chorioretinal Degeneration is an extremely rare inherited disorder that affects the choroid and retina, which are parts of the eye. It is classified as a type of choroidal dystrophy
• Even though it is a congenital condition, the onset of signs and symptoms may occur during childhood or into adulthood
• The cause of Helicoidal Peripapillary Chorioretinal Degeneration is a genetic mutation that leads to atrophy of the eye parts. Since, the condition is inherited in an autosomal dominant manner; a positive family history is a key risk factor. It is occasionally associated with another genetic disorder abetalipoproteinemia
• Helicoidal Peripapillary Chorioretinal Degeneration results in signs and symptoms that include presence of blind spots and loss of central vision. The condition is progressive and can result in vision impairment
• A healthcare provider can use various physical (eye) exams, blood tests, and imaging studies to diagnose Helicoidal Peripapillary Chorioretinal Degeneration
• Currently, there is no specific treatment available to manage the condition. The prognosis of Helicoidal Peripapillary Chorioretinal Degeneration is typically guarded

Who gets Helicoidal Peripapillary Chorioretinal Degeneration? (Age and Sex Distribution)

• Helicoidal Peripapillary Chorioretinal Degeneration is a congenital condition that is manifested at birth. The onset of the signs and symptoms may occur during early childhood or into adulthood
• The condition affects both males and females
• Individuals of different racial and ethnic backgrounds can be affected
• The prevalence is approximately 1 in 1,000,000, making Helicoidal Peripapillary Chorioretinal Degeneration an extremely rare disorder in the world

What are the Risk Factors for Helicoidal Peripapillary Chorioretinal Degeneration? (Predisposing Factors)

• The main risk factor for Helicoidal Peripapillary Chorioretinal Degeneration is a positive family history
• Rare cases of the condition are known to be associated with abetalipoproteinemia (a rare genetic disorder, characterized by fat malabsorption from the intestines)

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one's chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Helicoidal Peripapillary Chorioretinal Degeneration? (Etiology)

• Helicoidal Peripapillary Chorioretinal Degeneration is a congenital disorder that is inherited in an autosomal dominant manner. It is classified as a type of choroidal dystrophy
• The gene causing the condition is not identified yet by the researchers. However, mutations are observed to occur on chromosome 11
• The disorder causes atrophy of the choroid and retina resulting in the signs and symptoms of the condition. On a fundoscopic examination, a characteristic shape of the lesion is observed, and hence, the name ‘Helicoidal Peripapillary Chorioretinal Degeneration’

Autosomal dominant: Autosomal dominant conditions are traits or disorders that are present when only one copy of the mutation is inherited on a non-sex chromosome. In these types of conditions, the individual has one normal copy and one mutant copy of the gene. The abnormal gene dominates, masking the effects of the correctly function gene. If an individual has an autosomal dominant condition, the chance of passing the abnormal gene on to their offspring is 50%. Children, who do not inherit the abnormal gene, will not develop the condition or pass it on to their offspring.

What are the Signs and Symptoms of Helicoidal Peripapillary Chorioretinal Degeneration?

The signs and symptoms of Helicoidal Peripapillary Chorioretinal Degeneration are observed in children and adults. The progression of the signs and symptoms may vary from one individual to another. Generally, children may have a rapid progression of the condition; adults may have a slower progression.

The signs and symptoms may include:

• Presence of blind spots or scotoma
• Loss of central vision
• Vision loss may occur early in children; or, there may be mild vision loss in elderly adults
• The condition affects both the eyes (bilateral presentation)
• The degree of vision loss varies from one individual to another (from mild to severe)

How is Helicoidal Peripapillary Chorioretinal Degeneration Diagnosed?

A healthcare professional may diagnose Helicoidal Peripapillary Chorioretinal Degeneration using the following tests and procedures:

• Physical examination and analysis of previous medical history
• Eye examination by an eye specialist
• Fundoscopic (ophthalmoscopic) examination by an eye specialist, who examines the back part of the eye (or the fundus): Eye changes can be seen in infancy through a fundoscope
• Visual acuity test using a special and standardized test chart (Snellen chart)
• Slit-lamp examination: Examination of the eye structure using a special instrument called a slit-lamp. In this procedure, the pupils are dilated and the internal eye structure is examined
• Tonometry: Measurement of intraocular pressure or eye fluid pressure, especially to detect conditions such as glaucoma
• Fundus fluorescein angiography (FFA): In this technique, the eye blood vessels are examined using a fluorescein dye
• Fundus autofluorescence (FAF) imaging: It is a diagnostic technique to examine the fundus of the eye using a fluorescent dye
• Indocyanine green (ICG) angiography: It is used to examine the blood vessels of the choroid using a dye, called indocyanine green, particularly to study the choroid
• B-scan ultrasonography: Special ultrasound scan of the eye through a non-invasive diagnostic tool, to assess health of the eye structures
• Electroretinogram (ERG): It is a technique to measure electrical activities in the retinal cells
• Optical coherence tomography (OCT) of eye: Radiological imaging technique to visualize the eye structure
• Blood tests that include:
  • Complete blood count (CBC) with differential
  • Erythrocyte sedimentation rate (ESR)

Note: The fundoscopic exam may not reveal too much inflammation, which is an important feature to arrive at an accurate diagnosis for the healthcare specialist.

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Helicoidal Peripapillary Chorioretinal Degeneration?

The complications of Helicoidal Peripapillary Chorioretinal Degeneration may include:

• Retinal detachment: An eye condition wherein the retina gets separated from the eye structures that holds the retinal layers together
• Cataracts: The type of cataracts that develop is termed as congenital anterior polar cataracts
• Total blindness due to progression of the condition

How is Helicoidal Peripapillary Chorioretinal Degeneration Treated?

• Currently, there is no definitive treatment modality available for Helicoidal Peripapillary Chorioretinal Degeneration
• Symptomatic treatment to address the signs and symptoms may be employed by the healthcare provider
• Rehabilitation, vocational, or occupational therapy may be provided to the affected individuals with vision loss

The healthcare provider may recommend the best treatment options based upon each individual’s specific circumstances.

How can Helicoidal Peripapillary Chorioretinal Degeneration be Prevented?

• Currently, there are no specific methods or guidelines to prevent Helicoidal Peripapillary Chorioretinal Degeneration, since it is a genetic condition
• Genetic testing of the expecting parents (and related family members) and prenatal diagnosis (molecular testing of the fetus during pregnancy) may help in understanding the risks better during pregnancy
• If there is a family history of the condition, then genetic counseling will help assess risks, before planning for a child
• Active research is currently being performed to explore the possibilities for treatment and prevention of inherited and acquired genetic disorders such as Helicoidal Peripapillary Chorioretinal Degeneration

What is the Prognosis of Helicoidal Peripapillary Chorioretinal Degeneration? (Outcomes/Resolutions)

• The prognosis of Helicoidal Peripapillary Chorioretinal Degeneration is guarded and depends on the severity of the signs and symptoms
• The progression is generally poorer in children who show a rapid progression of the signs and symptoms. The progression is comparatively better in adults, in whom the condition progresses more slowly

Additional and Relevant Useful Information for Helicoidal Peripapillary Chorioretinal Degeneration:

Please visit our Eye & Vision Health Center for more physician-approved health information:

http://www.dovemed.com/health-topics/vision-center/