Developmental disorder of the eye due to abnormal persistence of fetal intraocular vessels in the anterior/posterior segments of the eye.
History:
Persistent hyperplastic primary vitreous was first described by Reese in 1955 in his Jackson Memorial Lecture. Representing a form of persistent fetal vasculature (PFV), Goldberg has suggested the terminology change to better reflect the pathology. The exact aetiology remains unknown.
Aetiology
Associated conditions:
- Patau syndrome (trisomy 13)
Pathophysiology
PHPV occurs due to incomplete regression of the embryonic vitreous and fetal intraocular vessels. The primary vitreous is formed during the 1st month of intrauterine life and starts regressing during the formation of secondary vitreous at 9th week. By the end of 3rd month, secondary vitreous fills most of the vitreous cavity and primary vitreous condenses into a narrow band (Cloquet’s canal) running from the optic nerve to posterior aspect of lens.
Subtypes:
- Anterior PHPV (best prognosis)
- Posterior PHPV
- Combined anterior and posterior variant PHPV (M/C type)
Clinical features
Characteristically PHPV presents as unilateral leucocoria with variably severe microcornea or microphthalmia.
- Leukocoria
- Microphthalmia
- Congenital cataract
- Strabismus
Complications
- Rupture of lens capsule
- Recurrent intraocular hemorrhage
- Secondary glaucoma
- Traction retinal fold
- Subsequent phthisis bulbi
Diagnosis
Ultrasound:
- Hyperechoic, inhomogenous structure bilaterally in the vitreous chamber extending from the posterior wall of the lens till the optic nerve head and retina and vascularized on color Doppler
Magnetic resonance imaging (MRI):
- PHPV appears as a triangular retrolental vascular soft tissue mass with a central stalk of hyaloid remnant connected to the optic disc like a “martini glass“
Differential diagnosis:
- Retinoblastoma
- Coat’s disease
- Vitreoretinal dysplasia
- Ocular toxocariasis
- Retinopathy of prematurity (ROP)