Dalen fuch’s nodule is seen in –
**Core Concept**
Dalen-Fuchs nodules are a characteristic histopathological feature associated with uveitis, particularly in the context of sympathetic ophthalmia, a severe form of granulomatous uveitis that occurs after penetrating eye injury or surgery. These nodules represent aggregates of epithelioid cells and lymphocytes that accumulate in the outer retinal layers, adjacent to retinal pigment epithelial cells.
**Why the Correct Answer is Right**
The formation of Dalen-Fuchs nodules involves the infiltration of immune cells, specifically T lymphocytes and epithelioid cells, into the outer retinal layers. This process is thought to be mediated by the release of cytokines and chemokines that attract and activate these immune cells. The presence of these nodules is a hallmark of sympathetic ophthalmia and other forms of granulomatous uveitis, and is often seen in conjunction with retinal and choroidal inflammation.
**Why Each Wrong Option is Incorrect**
**Option A:**
This option is incorrect because Dalen-Fuchs nodules are not typically associated with non-granulomatous forms of uveitis, such as iritis or iridocyclitis.
**Option B:**
This option is incorrect because while retinal detachments can occur in association with uveitis, Dalen-Fuchs nodules are not a direct result of retinal detachment.
**Option C:**
This option is incorrect because choroidal melanoma is a type of primary intraocular malignancy, and Dalen-Fuchs nodules are a histopathological feature associated with granulomatous uveitis.
**Clinical Pearl / High-Yield Fact**
Dalen-Fuchs nodules are a key diagnostic feature of sympathetic ophthalmia, a severe and potentially vision-threatening form of granulomatous uveitis that requires prompt recognition and treatment.
**Correct Answer:** D.