Abstract
Purpose: :
To evaluate the long term visual outcomes of subjects having undergone optic nerve sheath decompression for the treatment of idiopathic intracranial hypertension.
Methods: :
A retrospective chart review was performed on all patients who had undergone optic nerve sheath decompression between October 1994 and April 2006 at the University of Mississippi Medical Center and the University of Alabama-Birmingham Hospital. Surgeries performed for diagnoses other than IIH were excluded. Best-corrected visual acuity, color vision, optic disc appearance, and automated perimetry were recorded for the pre-operative period and each post-operative visit through January 2008.
Results: :
We reviewed 100 cases of optic nerve sheath decompression in 75 patients. We categoried our findings into 3 groups based on the level of pre-operative visual acuity: (1) VA ≥ 20/40 (2) VA = 20/50-20/200 (3) VA < 20/200. Of the 49 eyes in group 1, 43 eyes (88%) had a final visual acuity of 20/40 or better, 4 eyes (8%) had a final visual acuity of 20/50-20/200, and 2 eyes (4%) had a final visual acuity of less than 20/200. Of the 29 eyes in group 2, 10 eyes (34%) had a final visual acuity of 20/40 or better, 15 eyes (52%) had a final visual acuity of 20/50-20/200, and 4 eyes (14%) had a final visual acuity of less than 20/200. Of the 22 eyes in group 3, 2 eyes (9%) had a final visual acuity of 20/40 or better, 1 eyes (5%) had a final visual acuity of 20/50-20/200, and 19 eyes (86%) had a final visual acuity of less than 20/200. Of all cases taken together, 81 eyes (81%) showed improvement or stabilization of their visual acuity. Mean and pattern standard deviations on automated perimetry showed a trend toward improvement, color vision remained stable, and disc appearance evolved from edematous (96%) initially to pallor (58%) at final visit.
Conclusions: :
Optic nerve sheath decompression in the treatment of idiopathic intracranial hypertension tends to stabilize patients in the long term. Visual prognosis is better in patients with good visual acuities initially. Patients with poor visual acuities initially tended to retain poor visual acuities. Consideration should be given to earlier surgical intervention in IIH before visual acuity is signicantly affected.
Keywords: neuro-ophthalmology: optic nerve • optic nerve