Treatment of Proliferative Vitreoretinopathy With Intravitreal Infliximab

Proliferative vitreoretinopathy (PVR) is the most common cause for failure of rhegmatogenous retinal detachment repair and is characterized by the growth and contraction of cellular membranes within the vitreous cavity on both sides of the retinal surface as well as intraretinal fibrosis.

The incidence of PVR in all cases of retinal detachment is estimated to be 5- 10%. The incidence of PVR has largely remained unchanged in prospective studies despite the evolution of vitreoretinal techniques over the past 25 years, including valved trocars and smaller gauge instrumentation.

Numerous risk factors for the development of PVR have been identified. Almost all risk factors for PVR are associated with intravitreal dispersion of retinal pigment epithelial cells or breakdown of the blood-ocular barrier. Following a retinal break, the retinal pigment epithelial (RPE) cells are exposed to the vitreous cavity to react to growth factors and cytokines in the vitreous, resulting in a forward feedback to secret more growth factors and cytokines to further stimulate cellular responses.

Multiple therapeutic agents have been tried as an adjunctive to retinal detachment surgery for PVR with no consistent efficacy. Tumor necrosis factor-α (TNF-α), which is a prominent inflammatory cytokine, is secreted in response to trauma, infection, and inflammation. It is a key mediator of ocular inflammation and its interactions with RPE cells contribute to the initiation of PVR. This is because TNF-α was found to act on the RPE cells consequently inducing changes in cellular morphologies leading to the formation of fibroblastic cells. Additionally, if TNF-α is combined with other growth factors, a strong synergistic effect can be induced to form epithelial-mesenchymal transition (EMT)-associated fibrotic focus.

Infliximab (Remicade; Janssen Biotech, Horsham, PA, USA) is a mouse-human chimeric antibody that neutralizes the biological activity of TNF-α by high-affinity binding to the soluble and transmembrane forms of TNF-α, therefore preventing the effective binding of TNF-α with its receptors. Infliximab is used in the treatment of various ocular and systemic inflammatory conditions. Furthermore, intravitreal infliximab has been used for the treatment of various ocular diseases and has proven to be generally safe for the short term in inflammatory ocular conditions. A recent study showed that intravitreal infliximab can inhibit the development of PVR and reduce levels of cytokines in an experimental dispase-induced PVR model.