Glaucoma, a serious defect of eye which may lead to total blindness is caused due to

Options

A. blockage of canal of Schlem increasing the pressure of aqueous humor
B. blockage of canal of Schlem raising the pressure of vitreous humour
C. increased capillary perfusion raising the pressure of vitreous humor
D. blockage of intraocular arteries due to high B.P.

Answer

**Step-by-Step Solution:**

1. **Understanding Glaucoma**: Glaucoma is a serious eye condition that can lead to total blindness. It is primarily characterized by increased intraocular pressure.

2. **Identifying Causes**: The main cause of glaucoma is the blockage of the canal of Schlemm, which is responsible for draining aqueous humor from the eye.

3. **Analyzing the Options**:
- **Option 1**: "Blockage of the canal of Schlemm increases the pressure of aqueous humor."
- This statement is correct. When the canal is blocked, aqueous humor cannot drain properly, leading to increased pressure in the eye, which can damage the optic nerve and result in blindness.

- **Option 2**: "Blockage of the canal of Schlemm raising the pressure of vitreous humor."
- This statement is incorrect. The blockage affects the aqueous humor, not the vitreous humor.

- **Option 3**: "Increased capillary perfusion raising the pressure of the vitreous humor."
- This statement is also incorrect. Increased capillary perfusion does not directly relate to the mechanism of glaucoma.

- **Option 4**: "Blockage of the intraocular arteries due to high blood pressure."
- This statement is incorrect as well. While high blood pressure can affect the eye, it is not the primary cause of glaucoma.

4. **Conclusion**: The correct answer is the first option, which states that glaucoma is caused by the blockage of the canal of Schlemm, leading to increased pressure of aqueous humor.