Posterior uveitis describes inflammation affecting the back of the eye, specifically the retina and choroid. This condition can lead to permanent vision loss if not addressed. Early medical intervention is important to manage posterior uveitis.
Corticosteroid Therapy
Corticosteroids are a primary treatment for posterior uveitis due to their anti-inflammatory properties. These medications work by inhibiting inflammatory mediators, such as cytokines and chemokines, and by suppressing the activation and proliferation of immune cells. This helps reduce swelling and irritation in the eye.
Corticosteroids can be administered through various routes. Oral medications, such as prednisone or prednisolone, are prescribed for systemic effect. Short-term intravenous corticosteroids may also be used for rapid resolution of acute flares.
Periocular injections deliver corticosteroids directly to the affected area. Intravitreal injections are also used for posterior segment inflammation. These injections offer direct action but their effects are short-lived.
Sustained-release intraocular implants provide a continuous, low dose of medication long-term. These implants can reduce the frequency of injections and deliver targeted drug levels to the eye. However, they carry a risk of ocular side effects, including elevated intraocular pressure and cataract formation.
Patients receiving corticosteroid therapy require close monitoring for side effects. Ocular complications can include cataracts and an increase in intraocular pressure. Systemic side effects from oral corticosteroids may include weight gain, elevated blood sugar levels, increased risk of infection, and bone thinning, especially with long-term use.
Immunosuppressive Medications
Immunosuppressive medications are used when corticosteroids alone are insufficient to control posterior uveitis, when high doses are needed long-term, or when patients experience significant corticosteroid-related side effects. These medications work by suppressing the overactive immune response that causes inflammation in the eye. They interfere with the proliferation and activation of immune cells, such as T and B lymphocytes.
Common immunosuppressive agents include antimetabolites like methotrexate, azathioprine, and mycophenolate mofetil. These have shown efficacy in controlling inflammation and reducing the need for corticosteroids. Another class includes T-cell inhibitors like cyclosporine, which suppress T-cell activation.
These medications are administered orally, and their effects may take weeks or months to become noticeable. Initial therapy often includes high-dose systemic steroids, with immunosuppressants started during the steroid tapering period. The choice of immunosuppressant is tailored to the patient’s needs.
Close medical supervision is necessary for patients on immunosuppressive medications due to their broad impact on the immune system. Regular blood tests monitor for side effects such as bone marrow suppression, liver, or kidney problems. Patients may also experience gastrointestinal disturbances like nausea and abdominal pain.
Biologic Agents
Biologic agents represent a newer class of treatment for posterior uveitis, typically reserved for severe, persistent cases that have not responded adequately to conventional immunosuppressants. These targeted therapies block certain molecules or pathways within the immune system that contribute to inflammation. This targeted approach can lead to a more precise anti-inflammatory effect.
Examples of biologic agents used in uveitis include adalimumab, infliximab, and rituximab. Adalimumab and infliximab are tumor necrosis factor-alpha (TNF-α) inhibitors, meaning they block a specific inflammatory protein. Rituximab targets B cells, another type of immune cell involved in inflammation.
These agents are administered through injections, either subcutaneously (under the skin) for adalimumab, or intravenously (into a vein) for infliximab and rituximab. The frequency of administration varies by agent, such as adalimumab typically given every two weeks. While biologics offer a targeted approach, they are associated with their own set of considerations.
Careful patient selection and ongoing monitoring are important when using biologic agents. Potential side effects include injection site reactions, headaches, and an increased risk of infections due to their immune-modulating effects. Although generally well-tolerated, serious adverse events can occur, and patients are monitored for any signs of infection or other complications.
Surgical Interventions and Adjunctive Therapies
Surgical interventions play a role in managing complications of posterior uveitis, rather than being primary anti-inflammatory treatments. One such procedure is vitrectomy, which involves removing the vitreous gel from the eye. This surgery is performed when vitreous hemorrhage, persistent vitreous opacities, or retinal detachment impair vision or prevent adequate examination of the back of the eye.
Vitrectomy can also be used to remove epiretinal membranes or address macular holes that develop as complications of chronic inflammation. While effective in restoring anatomical structure and improving vision in select cases, surgery in uveitic eyes can be complex due to potential vitreous adherence to the retina and a risk of post-operative inflammation. Aggressive control of inflammation before and after surgery is necessary to minimize complications.
Other adjunctive therapies, such as laser photocoagulation, are used for specific inflammatory lesions or complications. Laser photocoagulation can be applied to seal and destroy leaking blood vessels, for instance, in cases of retinal neovascularization caused by inflammation. It may also be used to create a barrier around areas of retinal schisis or to reduce inflammation in specific types of intermediate uveitis.
Cryotherapy, which involves freezing specific areas, can be used for peripheral retinal lesions or persistent vitreous inflammation, particularly in certain forms of intermediate uveitis. This treatment aims to decrease inflammation and improve visual outcomes, and in some cases, can help in the resolution of macular edema. These surgical and adjunctive therapies are often part of a comprehensive management plan, working alongside medical treatments to preserve vision and address disease complications.