Clinical and pathological characterization of persistent fetal vasculature associated with vitreous hemorrhage

Purpose: To provide clinical and pathological features of posterior persistent fetal vasculature (PFV) presenting with vitreous hemorrhage. Observations: Case 1 was a one-year old male with PFV reaching up to the posterior lens capsule. Case 2 and 3 both had history of blunt trauma. B-scans in cases 2 and 3 revealed vitreous hemorrhage and an intravitreal tissue attached to the optic disc. Pre-operative visual acuity in cases 1, 2 and 3 was undetermined due to age, hand motion and light perception, respectively. During vitrectomy, a fibrotic stalk attached to the optic nerve was removed, which consisted of fibrovascular tissue enveloping pockets of hemorrhage histopathologically. The fibrovascular tissue contained smooth muscle actin (SMA) positive spindle-shaped myofibroblasts in one case and hemosiderin-laden macrophages in another case. Glial fibrillary acidic protein (GFAP) stain was focally positive in two specimens. The proliferation index was low using Ki-67 stain in all cases. Post-operative visual acuity in case 3 remained unchanged, while improved in case 2 from hand motion to 20/70. There was no recurrence of the vitreous hemorrhage. Conclusion and Importance: Vitreous hemorrhage may occur in cases of PFV with or without history of blunt trauma. Hemorrhage within the persistent fetal vasculature may become organized with reactive process in the hyaloid stalk. The fibrovascular stalk contained astrocytes and myelofibroblasts which contribute to the formation and contractile function of PFV, respectively. The outcomes following vitrectomy seemed to be satisfactory.