Glaucoma associated with intraocular tumours is due to
**Core Concept**
Glaucoma associated with intraocular tumours is a rare condition where increased intraocular pressure is caused by a mass effect in the eye. This is often due to a tumour obstructing the drainage of aqueous humor from the eye, leading to elevated intraocular pressure and subsequent glaucoma.
**Why the Correct Answer is Right**
The correct answer is related to the pathophysiology of glaucoma secondary to intraocular tumours. In such cases, the tumour can physically obstruct the trabecular meshwork, the main drainage site of the eye, leading to increased intraocular pressure. This can be due to a variety of tumours, including melanoma, retinoblastoma, or medulloepithelioma. The obstruction can also lead to secondary angle closure glaucoma, where the iris is pushed forward, blocking the trabecular meshwork.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not address the pathophysiology of glaucoma associated with intraocular tumours. While inflammation can cause secondary glaucoma, it is not the primary mechanism in this specific scenario.
**Option B:** This option is incorrect because it is unrelated to the pathophysiology of glaucoma associated with intraocular tumours. Metabolic disorders can cause secondary glaucoma, but they are not directly related to intraocular tumours.
**Option C:** This option is incorrect because it is a type of glaucoma, but it does not address the underlying cause of glaucoma associated with intraocular tumours. Neovascular glaucoma is a type of glaucoma caused by new blood vessel growth, which is not directly related to intraocular tumours.
**Clinical Pearl / High-Yield Fact**
A key point to remember is that any new or rapidly growing intraocular mass should be evaluated for potential glaucoma secondary to tumour obstruction. Early detection and management of these tumours can help prevent vision loss.
**Correct Answer: C. Neovascular glaucoma is not the direct cause of glaucoma associated with intraocular tumours.**