Multifocal choroiditis (MFC) and panuveitis consist of vitreitis, anterior uveitis, and active choroidal lesions. (1) Punctate inner choroiditis (PIC) is similar, but the lesions are confined to the posterior pole.
• The exact cause remains unknown. Both MFC and PIC, as well as a third entity known as diffuse subretinal fibrosis (DSF) may be syndromic variations on a common disease spectrum.
• Exogenous viral pathogens that simulate antigens found within the eye may induce an autoimmune response resulting in inflammation within the eye.
• Patients with MFC are usually otherwise healthy. Some may experience systemic symptoms of viral illness just prior to the ocular manifestation. Women tend to be affected more than men, mostly in the third decade of life. PIC usually occurs in myopic eyes.
• Common complaints include decreased or blurred vision, peripheral field loss, and floaters that have an insidious onset. The disease may be noticed only in one eye, but both eyes are usually affected.
• PIC patients often have photopsias and scotomas.
Vitreitis is present in almost all cases. Anterior segment inflammation may also be found in about half of cases. Yellow–white subretinal lesions, often with pigmented borders, are the key finding and are seen throughout the fundus. Their size may vary between 50–300 microns in diameter and represent focal areas of inflammation within the choroid. Patients with PIC have similar lesions that are localized to the posterior pole. These patients may not have an associated vitreitis on presentation. Broad zones of coalesced lesions resulting in subretinal fibrosis typify DSF.
DIAGNOSTIC TESTS & INTERPRETATION
• May be necessary (as guided by history and exam) to rule out other treatable causes of posterior uveitis. (i.e., sarcoidosis, toxoplasmosis, syphilis, lyme disease, and tuberculosis)
• Complete blood counts as well as liver function and kidney function are needed when immune modulators are used for disease control.
• Fundus photography using color and red-free techniques is useful for documenting and following the course of the disease.
• Intravenous fluorescein angiography (IVFA) is helpful in these patients for several reasons. IVFA may reveal lesions that may not yet be visible clinically. Also, it is helpful in defining whether or not a particular lesion is active. Active lesions characteristically block fluorescein within the choroid, but as the study progresses these foci of inflammation will usually show hyperfluorescence due to staining. Older, inactive lesions typically show only a window defect (hyperfluorescence). In some cases lesions may show hypofluorescence due to complete loss of the choriocapillaris. IVFA also may demonstrate leakage from cystoid macular edema and abnormal hyperfluorescence from choroidal neovascular membranes that may complicate this disease.
• Optical coherence tomography (OCT) is useful for diagnosing the presence of cystoid macular edema, subretinal fluid, and choroidal neovascular membranes. Newer generation spectral-domain OCT may help in determining whether vision loss is from atrophy of photoreceptors or from a potentially treatable process such as cystoid macular edema or choroidal neovascular membrane. Serial OCT may be used to follow the course of disease and/or response to treatment.
• Visual field testing is sometimes useful for monitoring peripheral loss. These scotomas do not necessarily correspond to active choroiditis. Some patients also have an enlarged blind spot as demonstrated by formal visual field testing.
Follow-up & special considerations
• During the acute phase of inflammation, a patient may need to be seen at 1–4 week intervals depending on the severity of the disease.
• Patients should be followed to monitor for the development of choroidal neovascularization, which can occur under the macula or near the optic nerve (peripapillary). This can occur even after the acute phase of the disease is over. Self-monitoring with an Amsler grid may help the patient detect new scotomas, distortion, or blurriness that may herald the onset of new disease activity or the development of choroidal neovascularization.
• Self-monitoring with an Amsler grid may aid a patient in developing new disease activity or the development of choroidal neovascularization.
• Presumed ocular histoplasmosis
• Central serous chorioretinopathy
• Age-related macular degeneration
Topical steroid alone is generally inadequate for posterior uveitis. In general, these patients require systemic, and/or periocular steroid therapy (1). Intravitreal steroids may also be considered. Infectious causes of uveitis must be ruled out before instituting any immune- suppressing treatment.
Systemic immune modulating drugs may be considered when long-term therapy is required and/or a patient is not a good candidate for systemic steroid therapy (i.e., uncontrolled hypertension, diabetes, elderly, etc.) (2). Caution is required when dealing with these agents due to adverse effects ranging from organ damage to fetal insult. In general, their use should be avoided during pregnancy.
Issues for Referral
Posterior uveitis has many different causes and the potential for vision loss is high. In general, these cases should be promptly referred to someone who has considerable experience in the diagnosis and treatment of uveitis.
• Choroidal neovascular membranes may be treated with thermal laser, photodynamic therapy, anti-vascular endothelial growth factor agents, and/or intravitreal steroids.
• Cystoid macular edema may be treated with intravitreal steroids, periocular steroids, and/or anti-vascular endothelial growth factor.
• Surgical extraction of cataracts may be considered when the inflammation has been adequately controlled and remains in remission.
• Slow-release steroidal implants may be considered in some cases.
• Vitrectomy for therapeutic clearance of vitreous opacities and for diagnostic purposes may be considered when the diagnosis is unclear.
MFC, PIC, and DSF can often last months to years with frequent relapses resulting in a poor visual prognosis.
Patients with MFC/PIC are at risk for developing cystoid macular edema. Choroidal neovascularization can occur even after there is no active inflammation. Diffuse scarring as seen with DSF may occur resulting in poor visual potential. Cataracts and glaucoma can result from the disease process and as a side effect from steroid therapy. Lifetime periodic follow up is necessary to monitor for these complications.
1. Dreyer RF, Gass JDM. Multifocal choroiditis and panuveitis: A syndrome that mimics ocular histoplasmosis. Arch Ophthalmol 1984;102:1776–1784.
2. Michel SS, Ekong A, Baltatzis S, Foster CS. Multifocalchoroiditis and panuveitis: Immunomodulatory therapy. Ophthalmology 2002;109:378–383.