1. External ethmoidectomy is a method of choice for malignant lesions.

2. Objective To evaluate the effect of ethmoidectomy for the treatment of optic neuritis under nasal endoscope.

3. To provide objective data for the location of the ethmoidal artery in ethmoidectomy.

4. Objective:To provide objective data for the location of the ethmoidal artery in ethmoidectomy.

5. Result: The effect is marked by comparison with the traditional surgery such as middle turbinectomy, ethmoidectomy etc.

6. Conclusion:Endoscopic localization of the ethmoidal artery is of importance in ethmoidectomy.