Surgical Approach to Optic Nerve Decompression in Pediatric Osteopetrosis
Overview
A five-year-old girl with genetically confirmed Osteopetrosis type II underwent staged bilateral optic nerve decompression due to progressive vision loss. The surgical technique involved a pterional craniotomy with anterior clinoidectomy and optic canal decompression, resulting in stable postoperative visual function.
Background
Osteopetrosis type II can cause optic nerve compression within the narrowed optic canal, leading to progressive vision loss in pediatric patients. The optic nerve's intracanalicular segment is vulnerable due to bony hypertrophy and stenosis. Surgical decompression aims to relieve mechanical compression but carries risks due to complex anatomy and hypertrophic bone. Optimal timing for surgery remains unclear, with some evidence favoring early intervention to preserve vision.
Data Highlights
Parameter
Preoperative
Postoperative
Retinal Nerve Fiber Layer Thickness (Left Eye)
31 µm
58 µm
Retinal Nerve Fiber Layer Thickness (Right Eye)
38 µm
Unchanged
Key Findings
Preoperative assessment showed decreased visual acuity bilaterally, pale optic discs, and increased N70 latency on visual evoked potentials.
The optic canal roof and optic strut were drilled to achieve 180° decompression of the optic nerve.
Due to excessive bone hypertrophy, complete extradural clinoidectomy was unsafe; intradural durotomy facilitated early optic nerve identification.
Postoperative imaging confirmed complete or near-complete clinoidectomy and optic canal decompression bilaterally.
Visual function remained stable postoperatively, with improved retinal nerve fiber layer thickness in the left eye.
Staged surgery with a 6-week interval allowed monitoring and preserved vision in the less affected eye.
Clinical Implications
This case demonstrates that staged bilateral optic nerve decompression via a pterional approach with anterior clinoidectomy is feasible and safe in pediatric osteopetrosis with optic canal stenosis. Early identification and decompression of the optic nerve, including intradural exposure when extradural access is limited, may improve visual outcomes. Careful surgical planning and intraoperative navigation are essential due to hypertrophic bone and complex anatomy.
Conclusion
Optic nerve decompression through a combined extradural and intradural approach can effectively relieve compression in pediatric osteopetrosis, stabilizing vision. Early, staged intervention tailored to the severity of vision loss may optimize outcomes.
References
Surgical Approach to Optic Nerve Decompression in a Pediatric Case of Osteopetrosis
