[Ocular ultrasonography in pediatrics: persistence of hyperplastic primary vitreous]

To assess the diagnostic viability of ultrasound and color Doppler ultrasound in a particular segment of paediatric ophthalmology-persistent primary hyperplastic vitreous, in the presence of leucocoria, retrospectively evaluated in patients observed over the last two years.

We re-evaluated four patients (two new-born, one unweaned and one nine-years-old) who at ophthalmoscopic examination were suspected having persistent primitive hyperplastic vitreous. The follow-up included an ultrasound examination, basic color-Doppler ultrasound and re-evaluation during sedation both using an operative microscope and ultrasound. The examinations were performed with linear 7.5 Mhz probes and a Doppler frequency of 3.7 Mhz, while the sedation examination was performed with an anular 13 Mhz probe. The scans were sagittal and axial to correctly localize the lesion with respect to the lens, to ciliary bodies and to the optic nerve head.

In the first patient ultrasound revealed a hyperechogenic inhomogeneous structure bilaterally in the vitreous structure; this extended from the posterior wall of the lens to the optic nerve head and retina, and was found to be highly vascolarized at the subsequent color-Doppler ultrasound. In the second patient there was an echogenic band extending from the posterior wall of the lens to the optic nerve head and to the retina, as the fourth patient showed a series of echogenic bands extending from the temporal ciliar of bodies to the temporal retina; in both cases no significant vascolarization was found by color Doppler ultrasound. In the third patient ultrasound showed a lesion involving nearly all of the vitreous body, with inhomogeneous structure with small calcifications and intense vascolarization.

Ultrasound supplies essential information for the diagnosis of persistent hyperplastic primary vitreous as it determines the presence of the lesion, its extension and retinal and optic nerve head involvement. As confirmed by operative microscopy the first patient had bilateral lesions involving the optic nerve head, as well as the retina, the latter which appeared raised. The second and fourth patients had typically posterior lesions; the lesion of the third patient was difficult to interpret even by operative microscopy. To conclude,Ultrasound proved to have an optimal sensitivity and specificity for precisely locating the site and extension of the lesion. By contrast, the difficulties and need for sedation with color Doppler ultrasound unlikely to be useful with paediatric patients.