Taking a closer look at persistent hyperplastic primary vitreous

Persistent hyperplastic primary vitreous, or PHPV, is a form of persistent fetal vasculature, first described by Reese in 1955. The exact etiology of PHPV remains unknown, but it characteristically presents as unilateral leukocoria. PHPV is divided into subtypes: anterior, posterior and combined. In anterior PHPV, the remnant vascular stalk is seen attached to the posterior surface of the lens capsule, but it does not extend back to the optic nerve. Posterior PHPV occurs when the remnant vascular stalk is seen arising off the optic nerve but does not reach the lens. Posterior PHPV may be associated with developmental abnormalities of the optic nerve and retina. In the combined type, features of both anterior and posterior PHPV are often detected, and they give a mixed presentation.Patients with PHPV present with varied clinical features depending on the extent of involvement of the ocular structure due to non-regression of fetal vasculature or a persistent hyaloid artery. They usually present with unilateral, rarely bilateral, leukocoria. Leukocoria is often the presenting feature, and it can result due to persistence of fibrovascular structure behind the lens; cataract; persistent dense pupillary membrane; or cloudy cornea secondary to raised IOP.