What is PHPV?
Disease. Persistent Fetal Vasculature (PFV), previously known as Persistent Hyperplastic Primary Vitreous (PHPV), is a failure of the regression of a component of fetal vessels within the eye. It is sometimes described as a “benign mimic of retinoblastoma,” being the second most common cause of infantile leukocoria.
How rare is PHPV?
Though the exact prevalence remains unknown, PHPV is considered to be not a very rare disease. The condition is usually unilateral and isolated (without associated systemic findings) in normal full-term infants.
What is dog PHPV?
PHPV stands for Persistent Hyperplastic Primary Vitreous and is a congenital (ie from birth) developmental problem of the eye. Puppies can be tested for PHPV from about 8-12 weeks of age and, if clear at that age, will be clear for life. Of the test results held by the Kennel Club, only 2% were affected.
How is PHPV diagnosed?
PHPV is also among the common causes of infantile leukocoria and is easily misdiagnosed as congenital cataract [3]. Diagnoses of PHPV are typically made based on the results of B-mode ultrasound, optical coherence tomography (OCT), or Doppler ultrasound [4, 5].
Is PHPV genetic?
Most cases of PHPV are sporadic, but it can be inherited as an autosomal dominant or recessive trait. Inherited PHPV also occurs in several breeds of dogs and cats. In a limited number of cases, Norrie disease and FZD4 genes are found to be mutated in unilateral and bilateral PHPV.
Is PHPV in dogs hereditary?
PHPV is typically unilateral and non-inherited with sporadic appearance. In a small percentage of cases (~10%), the condition is bilateral and inherited, thought to be the result of inbreeding. These cases have been reported in the Doberman pinscher8,9 and Staffordshire bull terrier breeds.
What is PHPV cataract?
Persistent hyperplastic primary vitreous (PHPV), also referred to as persistent fetal vasculature (PFV), is a congenital anomaly of the eye that results from failure of embryological primary vitreous and hyaloid vasculature to regress.
What is hyaloid artery?
The hyaloid artery is a branch of the ophthalmic artery, which is a branch of internal carotid artery. It is present in the optic canal and extends from the optic disc to the crystalline lens via the vitreous humour.
What does the hyaloid canal do?
It is formed by an invagination of the hyaloid membrane, which encloses the vitreous body. In the fetus, the hyaloid canal contains a prolongation of the central artery of the retina, the hyaloid artery, which supplies blood to the developing lens.
What happens to the hyaloid artery?
The hyaloid artery (a branch of the primitive dorsal ophthalmic artery) passes through the optic fissure into the optic cup and provides a transient intraocular circulatory system, which later regresses as mature retinal vascularization develops.
What causes babies to be born with cataracts?
What are the causes? Heredity is a common cause of congenital cataracts in babies. Other causes include infection, inflammation, drug reactions. When mothers come down with measels, ruebella, or other infections while they are pregnant, the child may also be born with cataracts in one or both eyes.
How is persistent hyperplastic primary vitreous (PHPV) characterized on MRI?
The presentation of PHPV at different stages was variable; the MRI features of PHPV along with clinical findings were able to facilitate the differential diagnosis from other intraocular abnormalities such as retinoblastoma and Coats’ disease. Persistent hyperplastic primary vitreous: magnetic resonance imaging and clinical findings
What does posterior PHPV look like?
In posterior PHPV, the globe is small and can contain retinal detachments. An echogenic band may be seen in the posterior segment of the globe, extending from the posterior surface of the lens to the optic nerve head. On color Doppler, arterial blood flow may be seen within this band.
Which MRI findings are characteristic of paroxysmal nocturnal hemoglobinuria (PHV)?
The MRI findings of the anterior type of PHPV included a shallow or collapsed anterior chamber, an anterior segment anomaly, and a retrolental vascular membrane which demonstrated hyperintensity after contrast enhancement.
What are the features of posterior paroxysmal glaucoma (PHPV)?
From an imaging standpoint, only the features of posterior PHPV are well known 3. In posterior PHPV, the globe is small and can contain retinal detachments. An echogenic band may be seen in the posterior segment of the globe, extending from the posterior surface of the lens to the optic nerve head.