Abstract
Purpose: :
The objective of the study was to determine how the visual acuity and visual fields of eyes affected by pseudotumor cerebri change after optic nerve sheath decompression surgery.
Methods: :
A retrospective chart review was conducted on 28 eyes (14 patients) with pseudotumor cerebri who underwent optic nerve sheath decompression at Kansas University Medical Center. Patients with other ocular disease such as orbital tumor, cerebral tumor, glaucoma, or ischemic optic neuropathy were excluded. All patients were using diamox and had a visual decline despite medical therapy. Surgery was performed using a Ferris Tang retractor, the optic nerve was isolated using Rhotons, and the pupil was used to assess excessive strain on the optic nerve. Acuity was assessed by using a Snellen chart 1 day prior to surgery and at 1, 3 to 6, and 12 months. Visual fields were assessed with a Humphrey visual field prior to surgery and at 1 month to 1 year after surgery. A statistically signficant change in acuity is identified as 3 Snellen lines. A statistically significant change in visual acuity is greater than 2 db. Complications were also identified.
Results: :
The age range was 18 to 53 and charts were reviewed from 2000 to the 2007. All patients except one were followed for at least 6 months. This patient moved out of state and had a statistically signficant improvement in vision prior to moving. 7 eyes (25%) had improvement, 18 eyes (64.3%) had no change, and 3 eyes (10.7%) had decline in acuity at 1 year (2 eyes had bilateral NAION and the other eye failed to seek medical assistance for 2 weeks because he thought that nothing could be done). Visual fields improved in 11 eyes (39.3%), remained unchanged in 9 eyes (32.1%), declined in 3 eyes (10.7%) (5 eyes were untested- 3 had acuity that impaired testing and 2 eyes moved). The following is a list of complications: 3 patients required a VP shunt, 1 patient had 6 prism diopters of exophoria, and one patient had proliferative diabetic retinopathy and fibrovascular macular traction.
Conclusions: :
Data from these patients indicate that optic nerve sheath decompression may have better success than currently accepted. This procedure improves or protects visual function in the majority of patients with pseudotumor cerebri who experience deterioration despite medical therapy. The patients who experienced visual decline had medical comorbidities or failed to seek medical assistance. There is potential for generous acuity recovery despite age and presenting acuity. Hand motion, 20/400 and 20/200 were corrected to 20/100, 20/80, and 20/40, respectively.
Keywords: neuro-ophthalmology: optic nerve • optic nerve • clinical (human) or epidemiologic studies: outcomes/complications