Background: The aims of this study were to evaluate visual function outcomes in idiopathic intracranial hypertension (IIH) patients who underwent ventriculoperitoneal (VP) shunt for visual loss and to determine a VP shunt survival curve over time.
Methods: A retrospective medical record review was performed of all new IIH patients first evaluated at our institution who underwent VP shunt placement over a 7-year period (2004-2010). There were 2 primary outcome measures: the first being visual acuity (VA) and the second being shunt survival. Patients who received VP shunt for visual loss were included in the visual outcome analysis, and all patients who received VP shunt for any reason were included in the shunt survival analysis.
Results: Of the 338 new patients with IIH, 19 patients (6%) met the inclusion criteria and 17 underwent VP shunt for visual loss and 2 for headaches. Average follow-up was 21.2 months (range, 5-1,342 days). Of the 17 patients who had VP shunt for visual loss, 5 patients had optic nerve sheath fenestration (ONSF) surgery before VP shunt, and 1 patient had bilateral ONSF surgery after VP shunt. Median VA before shunt was 20/200 in the worse eye (range, 20/20 to NLP) and 20/40 in the better eye (20/20 to HM). Median VA after shunt was 20/60 in the worse eye (20/20 to lumboperitoneal) and 20/30 in the better eye (20/20 to 20/800). The improvement in VA was statistically significant in both worse eyes (P = 0.002, Wilcoxon signed-rank test) and better eyes (P = 0.028). The mean automated visual field (AVF) mean deviation (MD) of available AVFs before shunt was 223.36 dB (range, 233.38 to 27.01 dB) for the worse eye (n = 11) and 219.66 dB (230.11 to 25.91 dB) for the better eye (n = 11). Mean AVF MD deviation of available AVFs after shunt was 220.68 dB (232.13 to 23.97 dB) for the worse eye (n = 11) and 216.35 dB (232.13 to 21.00 dB) for the better eye (n = 11): this improvement was not significant (P = 0.27, P = 0.26, respectively). Independent masked record reviews by 3 neuro-ophthalmologists showed that 9 (53%) patients improved, 5 (29%) unchanged, 1 (6%) worsened, and 2 (12%) were indeterminate. Kaplan-Meier analysis showed a persistent steady decrease of functioning VP shunts over the entire period of 36 months with 80%, 65%, and 48% of VP shunts functioning without replacement, removal, or revision at 12, 24, and 36 months, respectively.
Conclusion: VP shunts improve or stabilize most IIH patients presenting with severe progressive visual loss or those with visual loss refractive to medical treatment and ONSF. Survival analysis shows persistent decrease of functioning shunts over time.