TRAUMATIC PROLIFERATIVE VITREORETINOPATHY: Clinical and Histopathological Observations.

PURPOSE: To determine the phases of traumatic proliferative vitreoretinopathy after open globe injury by assessing cellular components, extracellular matrix constituents of proliferative vitreoretinopathy membranes, and intraretinal changes over time.

METHODS: Twenty-one epiretinal and/or subretinal membrane specimens were obtained from 21 patients with open globe injuries. The patients were divided into Groups A (≤28 days), B (29-120 days), and C (>120 days) according to the interval between injury and vitrectomy. The staining intensity and percentage of positive cells in membranes were compared among the groups, and proliferative indices for Ki-67 and proliferating cell nuclear antigen were assessed. Intraretinal changes were evaluated through histology and immunohistochemistry. Fundus photography was performed during vitrectomy.

RESULTS: The proliferating cell nuclear antigen proliferative index was significantly higher in Group B (P = 0.002) than in Group A, and lower in Group C (P < 0.001) than in Group B. α-smooth muscle actin expression increased from day 29 to 120 after injury. Meanwhile, intraretinal gliosis and fibrosis developed.

CONCLUSION: Active proliferation and contraction in proliferative vitreoretinopathy membranes continue until 120 days after injury, and are accompanied by the initiation of intraretinal gliosis and fibrosis. These findings provide further insight into the optimal timing of vitrectomy after trauma.