Related Experiment Video
Updated: Aug 11, 2026
09:53
Role of Diffusion MRI Tractography in Endoscopic Endonasal Skull Base Surgery
Published on: July 5, 2021
Surgical consideration to optic nerve protrusion according to sinus computed tomography
Ying-Lin Chen1, Li-Ang Lee, Kun-Eng Lim
1Department of Otolaryngology, Chang Gung Memorial Hospital, Taipei, Taiwan, Republic of China.
Summary
Optic nerve protrusion (ONP) is common in chronic sinus disease, found in 28% of patients. Sinus CT scans help identify ONP, crucial for preventing optic nerve damage during surgery.
Area of Science:
- Ophthalmology
- Radiology
- Otolaryngology
Background:
- Optic nerve protrusion (ONP) is an anatomical variation that can increase the risk of optic nerve damage during sinonasal surgery.
- Chronic inflammatory sinus disease can alter sinonasal anatomy, potentially affecting the optic nerve.
Purpose of the Study:
- To determine the prevalence of optic nerve protrusion (ONP) in patients with chronic inflammatory sinus disease.
- To identify clinical indicators of ONP using sinus computed tomography (CT) scans.
Main Methods:
- Retrospective review of sinus CT scans from 260 consecutive patients with chronic inflammatory sinus disease.
- Analysis of ONP prevalence, including protrusion into the sphenoid sinus, indentation, and coursing through the sinus.
- Statistical analysis to identify indicators associated with ONP.
Main Results:
- The prevalence of ONP was 28% in the study population.
- Nineteen percent of optic nerves protruded into the sphenoid sinus, with 12% showing sinus wall indentation and 8% coursing through the sinus.
- Contralateral ONP and ipsilateral anterior clinoid process pneumatization were significant indicators of ONP (P < 0.01).
Conclusions:
- Optic nerve protrusion is a common anatomical variation in patients with chronic inflammatory sinus disease.
- Sinus CT scans are valuable for detecting ONP.
- Careful evaluation of ONP via sinus CT and intraoperative findings is essential to minimize optic nerve damage during sinonasal surgeries.
Related Concept Videos
01:25Glaucoma: Overview
Glaucoma is an eye condition characterized by increased intraocular pressure that damages the retina and optic nerve, leading to irreversible blindness if left untreated. The human eye has various components, including the cornea, iris, pupil, lens, and optic nerve. Aqueous humor is secreted by the epithelium of the ciliary body in the posterior chamber and flows through the trabecular meshwork and canal of Schlemm, maintaining normal intraocular pressure. The trabecular meshwork and the canal...
01:28Angle Closure Glaucoma: Treatment
Angle-closure glaucoma, or closed-angle glaucoma, is an eye condition where the iris bulges out and blocks the iridocorneal angle, resulting in a buildup of aqueous humor and increased intraocular pressure. Immediate medical attention is necessary due to the sudden onset of symptoms. The treatment for angle-closure glaucoma includes short-term and long-term approaches. Short-term treatment involves using eye drops like pilocarpine to lower intraocular pressure by increasing aqueous humor...