Chorioretinitis Treatment & Management

Medical care in chorioretinitis (CR) focuses on the establishment of specific therapies for treatable etiologies and on the stabilization of the patient with chorioretinitis to prevent further loss of vision, especially in immunocompromised infants and children.

Care for individuals with chorioretinitis is complex and requires thorough consideration of short-term and long-term care and goals to maintain quality of life.

Available treatment options for specific causes of chorioretinitis are as follows:

• Antivirals: Four drugs have been licensed for the systemic treatment of cytomegalovirus (CMV) infection. These include ganciclovir, valganciclovir (oral prodrug of ganciclovir), foscarnet, and cidofovir. Fomivirsen is licensed for intravitreal administration to treat CMV retinitis in patients with acquired immunodeficiency syndrome (AIDS). Newer drugs such as maribavir, which has the potential to be useful in ganciclovir-resistant strains of CMV, are under clinical investigation. ^{[9, 27]}

• For children with human immunodeficiency virus (HIV) infection, the drug of choice for initial treatment for CMV retinitis is intravenous ganciclovir. Oral valganciclovir is an option primarily for older children who are able to receive the adult dose and tablet formulation of valganciclovir. An alternative to treat CMV disease or for use in ganciclovir-resistant CMV infections in children with HIV is foscarnet. Combination therapy with ganciclovir and foscarnet delays progression of retinitis in certain patients failing monotherapy and can be used as initial therapy among children with sight-threatening disease. Intravenous ganciclovir and foscarnet may also be considered in initial therapy of CMV CNS disease. However, combination therapy is associated with substantial rates of adverse effects.

• Several agents are used to treat toxoplasmosis. Treatment with antiparasitic drugs is effective for active infections but not for the encysted form. The classic treatment includes triple drug therapy with pyrimethamine (0.5-1 mg/kg/d), sulfadiazine (120-150 mg/kg/d), and prednisone. Concurrent folinic acid helps to minimize bone marrow toxicity produced by the pyrimethamine. High-performance liquid chromatography with ultraviolet and mass spectrometric detection has been developed for monitoring the plasma levels of pyrimethamine and sulfadiazine during treatment using a small amount of plasma (25 mcL). This may be helpful in determining the relationship between plasma concentrations and treatment efficacy. ^[28]

• Alternative antibiotic treatments include atovaquone (40 mg/kg/d has been used in adults, no dosage for children), azithromycin (5 mg/kg/d) and trimethoprim-sulfamethoxazole (40 mg/kg/d sulfamethoxazole, 8 mg/kg/d trimethoprim). Adjunctive clindamycin (20 mg/kg/d) is used for coverage against the encysted form. Treatment duration for congenital infection is typically 1 year.

• Prevention of fetal infection after maternal Toxoplasma seroconversion during pregnancy is attempted with spiramycin administration. A 60% decrease has been reported in the congenital infection rate in patients who received this treatment; however, it does not ameliorate the fate of infants who are infected.

• Catscratch disease is usually a self-limited disease in immunocompetent patients. B henselae is sensitive to many antibiotics in vitro, but only aminoglycosides have bactericidal activity. In immunocompetent patients, doxycycline at 200 mg/d is usually administered because of its property to cross the blood-brain and blood-ocular barrier. Caution should be used if administered to children because it may cause dental changes. Ciprofloxacin (1.5 g/d), gentamicin (3-5 mg/kg/d), erythromycin (20-50 mg divided into 3 doses; adults, 2 g/d), trimethoprim-sulfamethoxazole (40 mg/kg/d sulfamethoxazole, 8 mg/kg/d trimethoprim) are good alternatives and, like doxycycline, are usually given for 14-28 days. Immunodeficient patients need a more prolonged course of treatment, usually as long as 4 months. Steroids are also indicated for ocular disease. ^{[29, 30]}

• Treatment of chorioretinitis due to fungal infections can be difficult and prolonged. Intravitreous amphotericin B (5-10 mcg) has been used to treat serious fungal chorioretinitis.

  • Candida species infection: Fluconazole (6-12 mg/kg/d) and amphotericin B (0.75-1 mg/kg/d) has been recommended as preferred antifungals for treatment of Candida endophthalmitis. New-generation triazoles (eg, voriconazole, posaconazole, ravuconazole) are changing the conventional approach to fluconazole-resistant Candida strains, as well as the approach to fungal endophthalmitis. Caspofungin is the first echinocandin approved to treat fungal endophthalmitis. Concomitant systemic caspofungin and voriconazole therapy has successfully treated endophthalmitis due to Candida albicans. ^{[31, 32, 33, 34]} Experimental intraocular voriconazole (≤ 25 mcg/mL) has been used for azole-resistant Candida infection with some success.

  • Ocular histoplasmosis: Treatment is limited to photocoagulation of neovascular membranes, particularly when the macula is threatened. Antifungal therapy has no role in treatment of this disease because no actively replicating organisms are present. Amphotericin B is used to treat systemic disease (0.75-1 mg/kg/d). ^[35]

  • Cryptococcus species infection: Amphotericin B (0.75-1 mg/kg/d) is used.

• Antituberculosis drugs are administered in patients with M tuberculosis (MTB) and include isoniazid (10-30 mg/kg/d), rifampicin (10-20 mg/kg/d), pyrazinamide (30 mg/kg/d), and ethambutol (15 mg/kg/d). Other drugs, such as aminoglycosides and quinolones, may be used for treatment of drug-resistant organisms. Duration of therapy depends on the extent of the disease and on the immune status of the host.

• Anthelmintics, including diethylcarbamazine (6 mg/kg/d), albendazole (400 mg PO bid), and mebendazole (100-200 mg PO bid), are usually administered with corticosteroids in patients with toxocariasis or baylisascariasis.

• Etiologic treatments may not alter the clinical course of chorioretinitis because the pathologic changes may be due to an inflammatory and/or immunologic response instead of infection.

• Treatment of other infectious etiologies, such as syphilis, yersiniosis, neuroborreliosis, depends on extent of disease but is likely to be successful in most patients.

Eye symptoms can be treated as follows:

• Steroids may have a role in the acute management of many vasculitides, collagen vascular diseases, or sarcoidosis; in some infectious processes (eg, MTB); or in some cases infections caused by Toxoplasma species.

• Laser treatment of retinal lesions is used in certain conditions with good results.

Vitrectomy is usually not needed and is reserved for severe cases that are resistant to conservative medical treatment.

Ocular cytology used to detect the presence of eosinophils, ocular antibody, and immunoglobulin E (IgE) levels should always be performed to differentiate toxocaral ocular larva migrans from malignant retinoblastoma to prevent unnecessary enucleations.

Involvement of the following specialists is helpful in performing a diagnostic workup, determining the length of treatment, and planning the total management of a child with chorioretinitis:

• Ophthalmologist - For determination of eye damage, treatment, and long-term follow-up care

• Infectious disease specialist - For diagnostic workup, selection of therapeutic agents and options, investigation of potential drug toxicities, and determination of treatment length in consultation with the ophthalmologist

Other specialists include the following:

• Neurologist - For seizure control and long-term follow-up care of neurologic deficits

• Allergy and immunology/rheumatology specialist - To treat other associated conditions (ie, juvenile rheumatoid arthritis)

• Audiologist - For assessment and corrective measures to detect and treat deafness (if possible)

• Physical therapist - For maximization of functions and range of motions of muscles and joints and for referral to an orthopedist for surgical intervention if needed

Occasionally, genetic testing is required to investigate possible dysmorphic syndromes.