Dalen-Fuchs Nodules: Clues to Granulomatous Uveitis

Dalen-Fuchs nodules are small yellow-white lesions at the level of the retinal pigment epithelium in eyes with granulomatous uveitis.

They are classic in sympathetic ophthalmia and Vogt-Koyanagi-Harada disease, and they also occur in sarcoidosis.

Their presence points to a diffuse inflammatory process of the uvea and guides the workup.

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What Dalen-Fuchs Nodules Are

Histology shows collections of epithelioid cells, lymphocytes, and proliferating RPE cells between the RPE and Bruch membrane.

Clinically they appear as multiple small, round, cream-colored spots in the mid-periphery.

Chan and colleagues described the immunopathology of sympathetic ophthalmia, including these lesions (see sympathetic ophthalmia).

They do not cause symptoms by themselves, but they reflect active choroidal inflammation.

Dalen-Fuchs Nodules in Sympathetic Ophthalmia

Sympathetic ophthalmia is a bilateral granulomatous panuveitis after penetrating injury or surgery to one eye.

The nodules are common in the fellow eye, and they appear along with vitritis and choroidal thickening.

Damico and colleagues reviewed the disease and stressed the importance of early immunosuppression.

Dalen-Fuchs Nodules in VKH Disease

In VKH disease, the nodules may appear in the late stage, along with sunset glow fundus and depigmentation.

Read and colleagues reported that recurrent disease and complications correlate with chronic stages.

Their presence helps to distinguish VKH from other causes of exudative detachment (see VKH disease and imaging).

Other Causes of Dalen-Fuchs Nodules

• Sarcoidosis and tuberculosis
• Lens-induced and other granulomatous uveitis
• Birdshot and other choroidopathies, in occasional reports

Look for systemic clues, such as hilar adenopathy or skin findings (see ocular sarcoidosis).

Imaging of Dalen-Fuchs Nodules

OCT shows small dome-shaped elevations of the RPE with a hyperreflective core.

Fluorescein angiography shows hypofluorescence early and hyperfluorescence later, or a pinpoint leak.

Indocyanine green angiography shows hypofluorescent spots that reflect choroidal granulomas.

Autofluorescence shows spots with increased or decreased signal.

Management

Treat the underlying disease with high-dose corticosteroids and immunosuppressive agents.

Sympathetic ophthalmia and VKH require early and sustained therapy to prevent recurrences.

Evaluate for systemic causes, and monitor for complications such as glaucoma, cataract, and neovascularization.

An Example Case

A 38-year-old man had a penetrating injury to his right eye six weeks ago, and the left eye now shows photophobia and blurred vision.

Examination shows mutton-fat keratic precipitates, vitritis, and multiple small yellow-white nodules in the mid-periphery.

OCT shows choroidal thickening and subretinal fluid, and angiography shows multiple pinpoint leaks.

The diagnosis is sympathetic ophthalmia, and he receives high-dose corticosteroids and an immunosuppressive agent.

The nodules fade over months, and his vision returns to 20/25.

Questions Patients Ask

Patients ask whether the nodules will go away, and they usually fade with treatment.

They also ask whether the disease will return, and recurrences are possible without long-term control.

Because the disease affects both eyes, explain the need for lasting treatment.

Pitfalls to Avoid

• Mistaking the nodules for drusen or drusenoid deposits
• Stopping steroids too early in sympathetic ophthalmia or VKH
• Missing a history of ocular trauma or surgery
• Overlooking systemic causes such as sarcoidosis and tuberculosis

Looking Ahead

Wide-field imaging and OCT angiography may reveal nodules and choroidal inflammation more clearly.

Also, biologic drugs may improve control with fewer steroid effects.

Therefore, outcomes may continue to improve.

Practical Points

Ask about trauma, surgery, and systemic symptoms in every patient with granulomatous uveitis.

Then image the choroid, and order tests for sarcoidosis and tuberculosis when needed.

Also coordinate with a uveitis specialist early.

Distinguishing Nodules From Drusen

Drusen sit in older patients, and they have smooth, round shapes with no inflammation.

Dalen-Fuchs nodules appear with active uveitis and in younger patients.

Because the treatment differs, review the clinical context carefully.

Histology in Brief

Biopsy is rarely needed, but pathology reveals clusters of epithelioid cells and pigmented cells under the RPE.

Therefore, the nodules reflect a granulomatous process.

Also, T-cell responses against retinal antigens drive the disease in sympathetic ophthalmia and VKH.

Course and Prognosis

With early and sustained treatment, most patients keep good vision.

However, delayed treatment leads to cataract, glaucoma, and depigmentation.

Because relapses may occur, follow patients for years.

Counselling

Explain that the nodules themselves are not dangerous, but they signal active inflammation.

Then discuss the plan for steroid tapering and drug monitoring.

Differential Diagnosis of Dalen-Fuchs Nodules

Drusen, multifocal choroiditis, and birdshot lesions may look similar.

However, the history, the age, and the signs of inflammation separate them.

Also use indocyanine green angiography to find choroidal granulomas.

Therefore, a careful workup prevents a missed diagnosis.

Because the diagnosis changes treatment, document the findings in detail.

For the latest studies, see the PubMed results for Dalen-Fuchs nodules.

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References

1. Chan CC, Nussenblatt RB, Fujikawa LS, et al. Sympathetic ophthalmia: immunopathological findings. Ophthalmology. 1986;93:690-695.
2. Damico FM, Kiss S, Young LH. Sympathetic ophthalmia. Semin Ophthalmol. 2005;20:191-197.
3. Read RW, Rechodouni A, Butani N, et al. Complications and prognostic factors in Vogt-Koyanagi-Harada disease. Am J Ophthalmol. 2001;131:599-606.
4. American Academy of Ophthalmology. Basic and Clinical Science Course, Section 9: Intraocular Inflammation and Uveitis. AAO; current edition.