Morphological Appearance of Type III Dalén-Fuchs Nodules by SD-OCT
A 62-year-old man presented with blurred vision in his left eye. He had a history of right-eye enucleation 4 years earlier, after a penetrating trauma. The best-corrected visual acuity was 20/40. Slit lamp examination showed an anterior chronic granulomatous uveitis in his left eye. Owing to inadequate funduscopic examination secondary to a severe asteroid hyalosis, spectral-domain optical coherence tomography (Heidelberg Spectralis, Heidelberg Engineering, Heidelberg, Germany) was performed. Spectral-domain optical coherence tomography revealed diffuse macular edema, located in the inner and outer nuclear layers, and multiple medium-reflectivity dome-shaped choroidal lesions extending up to the inner nuclear layer and interrupting both Bruch's membrane and RPE; as a consequence of RPE disruption, an increased transmission effect was seen in correspondence to these lesions. These findings coincided with hypocyanescent areas on indocyanine green angiography (Figure 1, A and B). These choroidal lesions were compatible with Type III Dalén-Fuchs nodules, which are histologically characterized by degeneration of the overlying RPE, disorganization of the nodules, and finally release of their contents into the subretinal space (Figure 2).3 As soon as tuberculosis, syphilis, and sarcoidosis were ruled out, sympathetic ophthalmia was diagnosed and treatment with topical and systemic steroids was initiated. After 8 weeks, the best-corrected visual acuity improved to 20/25 and the lesions partially disappeared, leading, however, to atrophic changes of the inner retinal layers, RPE, and choriocapillaris (Figure 1, C and D).
Spectral-domain optical coherence tomography findings report the morphologic appearance of Dalén-Fuchs nodules similar to histological sectioning, suggesting the diagnosis and the duration of the disease and its response to treatment.