Persistent hyperplastic primary vitreous
Persistent hyperplastic primary vitreous (PHPV), also known as the persistent fetal vasculature, refers to a rare congenital developmental malformation of the eye.
Clinically, this condition usually manifests as unilateral or bilateral leucocoria. Patients may also have poor vision, small eye (microphthalmia) and strabismus.
It arises due to a failure of normal regression of the embryonic hyaloid vascular system. In the normal situation the primary vitreous forms around 7th week of gestation life and starts involuting around 20th week and nearly always disappears at the time of birth. Persistent fetal vasculature in PHPV can lead to fibrosis, resulting in elongation of the ciliary processes, retinal detachment, and spontaneous cataracts.
PHPV can be divided into either anterior (ventral) or posterior (dorsal) types, with most patients with PHPV having a combination of these 3.
PHPV can occur on its own or association with various other conditions notably when bilateral, these include 9:
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. On colour Doppler, arterial blood flow may be seen within this band.
The CT appearance can be quite variable 9 and the described spectrum of CT findings includes 1:
- soft-tissue replacement (infiltration) of the vitreous body
- retrolental soft tissue along the Cloquet canal: fine linear structure
extending from the head of the optic nerve to the posterior surface of the lens 3
- absence of abnormal calcification within the orbit
- retrohyaloid layered blood
- hypervascularity of the vitreous humor: after contrast administration, the vitreal abnormalities may enhance, which is believed to reflect a persistent hypervascular vitreous
- retinal detachments can be hyperdense on CT
On MRI the retrolenticular tissue characteristic of this condition has a triangular shape, like that of a martini glass appearing as low T2 low signal against the normal high T2 signal of the globe 10.
- 1. Mafee MF, Goldberg MF, Valvassori GE et-al. Computed tomography in the evaluation of patients with persistent hyperplastic primary vitreous (PHPV). Radiology. 1982;145 (3): 713-7. Radiology (citation) - Pubmed citation
- 2. Smirniotopoulos JG, Bargallo N, Mafee MF. Differential diagnosis of leukokoria: radiologic-pathologic correlation. Radiographics. 1994;14 (5): 1059-79. Radiographics (citation) - Pubmed citation
- 3. Castillo M, Wallace DK, Mukherji SK. Persistent hyperplastic primary vitreous involving the anterior eye. AJNR Am J Neuroradiol. 1997;18 (8): 1526-8. AJNR Am J Neuroradiol (citation) - Pubmed citation
- 4. Hunt A, Rowe N, Lam A et-al. Outcomes in persistent hyperplastic primary vitreous. Br J Ophthalmol. 2005;89 (7): 859-63. doi:10.1136/bjo.2004.053595 - Free text at pubmed - Pubmed citation
- 5. Küker W, Ramaekers V. Persistent hyperplastic primary vitreous: MRI. Neuroradiology. 1999;41 (7): 520-2. Neuroradiology (link) - Pubmed citation
- 6. Dass AB, Trese MT. Surgical results of persistent hyperplastic primary vitreous. Ophthalmology. 1999;106 (2): 280-4. doi:10.1016/S0161-6420(99)90066-0 - Pubmed citation
- 7. Sun MH, Kao LY, Kuo YH. Persistent hyperplastic primary vitreous: magnetic resonance imaging and clinical findings. Chang Gung Med J. 2003;26 (4): 269-76. - Pubmed citation
- 8. Kaste SC, Jenkins JJ, Meyer D et-al. Persistent hyperplastic primary vitreous of the eye: imaging findings with pathologic correlation. AJR Am J Roentgenol. 1994;162 (2): 437-40. AJR Am J Roentgenol (citation) - Pubmed citation
- 9. Edward DP, Mafee MF, Garcia-valenzuela E et-al. Coats' disease and persistent hyperplastic primary vitreous. Role of MR imaging and CT. Radiol. Clin. North Am. 1998;36 (6): 1119-31, x. - Pubmed citation
- 10. Koontz NA, Seltman TA, Kralik SF, Mosier KM, Harnsberger HR. Classic signs in head and neck imaging. Clinical radiology. 71 (12): 1211-1222. doi:10.1016/j.crad.2016.09.006 - Pubmed