Neovascularization of iris is frequently seen in all/except –
**Core Concept**
Neovascularization of the iris refers to the growth of new blood vessels on the surface of the iris, which is a common complication of various ocular and systemic diseases. This process is characterized by the formation of fragile, abnormal blood vessels that can lead to vision-threatening complications, including neovascular glaucoma. The underlying pathophysiology involves the release of angiogenic factors, such as vascular endothelial growth factor (VEGF), which stimulate the growth of new blood vessels.
**Why the Correct Answer is Right**
The correct answer is related to the pathophysiology of neovascularization of the iris. Neovascularization is a common feature of conditions that cause ischemia or hypoxia in the retina or iris, such as diabetic retinopathy, retinal vein occlusion, and central retinal artery occlusion. In these conditions, the release of angiogenic factors leads to the growth of new blood vessels on the surface of the iris, which can cause complications such as neovascular glaucoma.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because neovascularization of the iris is not typically seen in conditions that cause inflammation of the iris, such as iritis or uveitis. While inflammation can cause damage to the iris, it does not typically lead to the growth of new blood vessels.
* **Option B:** This option is incorrect because neovascularization of the iris is not typically seen in conditions that cause degeneration of the iris, such as Fuchs' heterochromic iridocyclitis. While this condition can cause changes in the appearance of the iris, it does not typically lead to the growth of new blood vessels.
* **Option C:** This option is incorrect because neovascularization of the iris is not typically seen in conditions that cause tumors of the iris, such as melanoma. While tumors can cause changes in the appearance of the iris, they do not typically lead to the growth of new blood vessels.
**Clinical Pearl / High-Yield Fact**
Neovascularization of the iris is a common complication of conditions that cause ischemia or hypoxia in the retina or iris. It is characterized by the growth of fragile, abnormal blood vessels on the surface of the iris, which can lead to vision-threatening complications. The release of angiogenic factors, such as VEGF, is a key factor in the pathophysiology of neovascularization.
**Correct Answer: C.**