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Show Ventriculoperitoneal Shunt as a Treatment of Visual Loss in Idiopathic Intracranial Hypertension Laura C. Huang, BA, Timothy W. Winter, DO, Angela M. Herro, MD, Potyra R. Rosa, MD, Joyce C. Schiffman, MS, Joshua Pasol, MD, Ryan S. Trombly, MD, Mike Tawfik, MRCOphth, Byron L. Lam, MD 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 per-formed 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, Wil-coxon 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. Journal of Neuro-Ophthalmology 2014;34:223-228 doi: 10.1097/WNO.0000000000000106 © 2014 by North American Neuro-Ophthalmology Society Idiopathic intracranial hypertension (IIH), also known as pseudotumor cerebri, is a disorder caused by increased intracranial pressure (ICP) of unknown cause. (1,2) The condition affects overweight women of childbearing age, and its incidence is rising in the United States paralleling the obesity epidemic. (3) Severe visual loss from papilledema occurs in 10% of IIH patients (2). Surgical interventions including optic nerve sheath fenestration (ONSF) and cere-brospinal fluid (CSF) shunting procedures are aimed to decrease papilledema and/or lower the ICP. The efficacy of these treatments is not established in clinical trials and are usually considered when visual loss is refractory to medical treatment. High rates of complications from lumboperitoneal (LP) and ventriculoperitoneal (VP) shunting are well docu-mented even with stereotactic placement (4-8). Outcome studies evaluating shunt procedures often include alleviation of headaches and generalized descriptions of visual function. Quantitative visual acuity (VA) and visual field measures often are not provided (Table 1) (5-7,13-15). At our institution, VP shunt for IIH-associated visual loss typically is reserved for cases refractory to medical Bascom Palmer Eye Institute (LCH, TWW, AMH, PRR, JCS, JP, MT, BLL) and Department of Neurological Surgery (RST), University of Miami, Miller School of Medicine; Miami, Florida. The authors report no conflicts of interest. Supported by National Institute of Health Center Grant P30- EY014801 and an unrestricted grant from Research to Prevent Blindness. Address correspondence to Byron L. Lam, MD, 900 NW 17th Street, Miami, FL 33136; E-mail: blam@med.miami.edu Huang et al: J Neuro-Ophthalmol 2014; 34: 223-228 223 Original Contribution Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. TABLE 1. Ventriculoperitoneal shunting for idiopathic intracranial hypertension: visual outcomes and shunt survival Study n Sex (F) Age Design Shunt Mechanism Revision/Fail Rate Follow-up (Mean) Ophthalmic Exam Prior Surgical Treatment Vision Improvement Kandasamy et al (6) 17 70% 24.2 Retro Stereotactic 29% 22 mo Pap, VFD (not quantitative) LP shunt (23%) 100% of patients, symptoms, and findings Maher et al (7) 13 - - - Stereotactic 23% 15.1 mo Blurred vision (not quantitative) 54% (ONSF) 38%, subjective 69% (shunt) Tarnaris et al (9) 34 94% 35 - LP vs VP 35% 28.9 mo Pap, ON atrophy, VA 15% (ONSF) 41% "improved VA based on clinic letters" Abubaker et al (10) 25 - - - LP vs VP LP 60%, VP 30% - VA, VFD, Pap - Not reported Uretsky (11) - - - Literature review LP vs VP vs ONSF - - - - - Feldon (12) 344; 31 VP shunt 74% 32.4 Literature review LP vs VP vs stent vs ONSF - 48.3 mo - - 38.7% Abu-Serieh et al (13) 9 55% 26.4 - Stereotactic 50% at 12 mo 44.3 mo Pap, VA, VFD, ON atrophy (none quantitative) Not reported 33% 71% at 24 mo Woodworth et al (14) 21 - - Retro VP vs VA vs V-pleural; Stereotactic 10% at 3 mo 24 mo - - - 20% at 6 mo 50% at 12 mo 60% at 24 mo McGirt et al (5) 42 - - Retro LP vs VP 44% 36 mo - - - Bynke et al (15) 17 70% 34 - No guidance 41% (all within 1.9 yrs) 6.5 yrs Pap, VA, VFD (VFD not quantitative) - 18% (acuity in M units); 65% VFD (including enlarged blind spot) Groh and Jünemann (16) 1 100% 30 Case report VP shunt - 30 mo VA 20/500 OU, constricted fields No 100% Tulipan et al (17) 7 - - Retro Stereotactic VP 0% 9 mo Pap 28% (1 LP, 1 ONSF) Not reported Rosenberg et al (18) 37; 30 for visual deficit - - Retro LP vs VP, atrial, jugular 37% 30.9 mo VA, VFD (not quantitative) - 35% Age is mean age in years. F, female; LP, lumboperitoneal; ON, optic nerve; Pap, papilledema; Retro, retrospective study design; VA, visual acuity; VFD, visual field defect; VP, ventriculoperitoneal. 224 Huang et al: J Neuro-Ophthalmol 2014; 34: 223-228 Original Contribution Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. treatment and ONSF or for cases who present with fulminant progressive severe bilateral visual loss. The purpose of our study was to evaluate visual function including VA and field outcomes in IIH patients who underwent VP shunt for visual loss with a secondary goal of determining a VP shunt survival curve over time. METHODS After institutional review board approval, a retrospective medical record review was performed of all new patients who met modified Dandy criteria for the diagnosis of IIH and were initially evaluated at our eye institute from January 2004 to December 2010. Patients who underwent VP shunt at our medical center for IIH with or without ONSF were included. Patients were excluded if the medical/ surgical record was not available, VP shunt was performed elsewhere or performed for headache only, or if no post-VP shunt follow-up at our eye institute was available. The best-corrected Snellen VA and automated visual fields (AVF) of qualified patients were used. The visual fields that were selected as "visual field before shunt" were those with the shortest time interval before the shunt and were reliable (#25% fixation loss, false positives, and false negatives). Visual fields selected for "visual field after shunt" were those on the latest follow-up visit after the fields had stabilized. In one case, the follow-up was ,1 month, and in this patient, the last available visual field after shunt was selected. VAs recorded on the same day as the selected visual fields were designated as "visual acuities before shunt" and "visual acuities after shunt," respectively. If no visual fields were available, VA was selected from the examination clos-est before the shunt and nearest to 3 months after the shunt. Visual fields were performed using an automated perimeter (Humphrey) using the SITA standard algorithm with a 30- 2 program and a Size III target. One patient underwent 24- 2 visual field testing. In 4 subjects, poor VA levels warranted kinetic visual fields (Goldmann) (Table 2). Medical records were reviewed independently in a masked fashion by 3 neuro-ophthalmologists to determine whether the visual function improved, remained unchanged, wors-ened, or was indeterminate after VP shunt. VP shunt survival was monitored in all patients by a collaborative effort between the neuro-ophthalmology and neurosurgery services at our institution. Shunt failure was defined as shunt replacement, removal, or revision. Kaplan- Meier analysis was used to estimate the survival rate of VP shunts over time. A literature review was performed to compare visual outcomes and shunt survival rates of VP shunting for IIH (Table 1). A PubMed search was performed in September 2013 with the keywords "idiopathic intracranial hyperten-sion," "pseudotumor cerebri," and "ventriculoperitoneal shunt." This returned 103 results, and of these, 13 articles were selected that mentioned visual outcome and specifically evaluated the surgical outcome of VP shunts alone or in comparison with LP shunting. Articles concentrating exclu-sively on LP shunting were eliminated as were those focused on pediatric populations. RESULTS Of the 338 new patients with IIH evaluated during the study period, 19 (6%) patients met the inclusion criteria. The mean age was 29 ± 13 years, and only 1 (5%) patient was male. Of the 19 qualified patients, 17 patients had VP shunt for visual loss and 2 patients had VP shunt for head-aches. The 2 patients who had VP shunt for headaches were excluded from the visual function analysis but were included in the shunt survival analysis. Table 2 summarizes the visual function data for the 17 patients who had VP shunt for visual loss. Five patients had ONSF surgeries before VP shunt, and another patient had bilateral ONSF surgeries 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 LP) 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 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). The mean AVF MD 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). There were only 9 patients who had both pre- and post-shunt AVF MDs. The improvements of 2.1 dB in the worse eye and of 2.4 dB in the better eye were not statistically significant (P = 0.27, P = 0.26 paired t test, respectively). However, there was a trend toward visual field improvement. Figure 1 shows a plot of AVF MD before shunt against MD after compared with a 1:1 line, showing that most points fall above the line, demonstrating improvement in MD. The available AVFs were taken 7 ± 4 (mean ± SD: range, 3-15) days before shunt (N = 9), and the AVFs after shunt were taken 96 ± 118 (range, 5-341) days after shunt (N = 9). Independent review of the medical records by 3 neuro-ophthalmologists were in agreement and showed 9 (53%) patients improved (of which 2 required shunt revision or adjustment), 5 (29%) patients unchanged, 1 (6%) patient worsened, and 2 (12%) patients were indeterminate because of unavailable or fluctuating visual fields. The one patient who worsened required ONSF bilaterally approximately 1 year after shunt placement. With VA improvement defined as 1 eye improving by at least 1 line of Snellen VA and the fellow eye either stable or improved, 12/17 (71%) patients improved. With visual field improvement defined similarly as at least 1 eye showing improvement in Huang et al: J Neuro-Ophthalmol 2014; 34: 223-228 225 Original Contribution Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. TABLE 2. Patients with idiopathic intracranial hypertension and visual loss treated with ventriculoperitoneal shunt Patient Sex Age* ONSF (Months Before Shunt) Visual Acuity† Before Shunt Visual Acuity† After Shunt AVF 30-2 Before Shunt MD (dB)‡ AVF 30-2 After Shunt MD (dB)‡ Length Follow-up After Shunt (mo) Shunt Complications and Failure (Months After Shunt)§ Visual Outcome from Shunt Based on Record OD OS OD OS OD OS Reviewk Days Before Shunt OD OS Days After Shunt 1 F 34 None 20/20 20/20 20/25 20/20 29.93 211.57 11 21.00 23.97 5 0.2 Improved 2 F 12 None 20/40 20/40 20/30 20/30 212.85 219.62 3 220.26 217.11 13 6 Improved 3 F 46 None 20/40 20/400 20/40 20/200 229.72 NA 29 NA NA NA 13 Adjustment (0.25) Worsened Replaced (7) ONSF OS (11)¶ ONSF OD (13)¶ 4 F 14 None 2/200 LP 5/200 2/200 NA NA NA KVF NA (112) 16 Stable 5 F 42 None CF 19 20/40 4/200 20/40 230.11 233.38 54 NA KVF (100) 19 Improved 6 F 22 None CF 19 20/30 20/20 20/20 NA NA NA 220.71 212.69 119 20 Improved 7 F 18 None NLP HM 5/200 20/40 NA NA NA NA 232.13 159 22 Improved 8 F 48 None 20/40 NLP 20/40 LP 217.02 NA 15 224.15 NA 125 23 Adjustment (3) Stable Replacement (14) 9 F 27 None 4/200 6/200 20/400 20/400 NA NA NA KVF KVF (58) 30 Adjustment (3) Stable Reset (29) 10 F 40 None 20/60 20/100 20/50 20/60 227.19 229.69 6 228.83 224.92 235 31 Revision (1) Improved Revision (22) 11 F 31 None 20/20 20/20 20/25 20/20 NA NA NA NA NA NA 38 Removal due to meningitis and gangrenous small bowel (8) Indeterminable 12 F 20 None 20/40 20/40 20/30 20/25 221.73 213.78 3 211.38 25.48 28 38 Tap (36), Adjustment (37) Improved Replacement (38) 13 F 25 OS (0.25) 20/20 20/25 20/20 20/20 25.91 27.01 3 24.38 25.62 14 2 Improved 14 M 61 OD (1) 20/25 20/50 20/25 20/60 218.45 229.73 9 219.43 231.31 62 2 Indeterminable OS (1) 15 F 40 OD (0.25) 20/200 20/50 20/30 20/25 226.88 224.79 6 219.65 214.83 40 27 Improved OS (0.25) 16 F 32 OD (18) 20/30 20/60 20/25 20/60 226.52 230.67 7 223.73 229.47 341 34 Stable OS (18) 17 F 16 OD (1) 5/200 20/50 8/200 20/70 KVF KVF (14) KVF KVF (124) 44 Revision (27) Stable OS (1) Revision (28) *Age at VP shunt. †Visual acuity on same day as AVF or KVF, if no VF, acuity on date closest before shunt date and nearest to 3 month after shunt. Patient 11 with post-shunt VA at 3 years because was lost to follow-up. ‡All 30-2 Humphrey SITA standard size III visual fields except for 24-2 in subject 6, KVF days before and after shunt in parentheses for those without AVF. §Shunt failure = replacement, removal, or revision. kBased on independent review of records from 3 neuro-ophthalmologists. ¶Number of months following VP shunt. AVF, automated visual field; CF, count fingers; HM, hand motion; KVF, kinetic visual fields; NA, not applicable; NLP, no light perception; OD, right eye; ONSF, optic nerve sheath fenestration; OS, left eye; VP, ventriculoperitoneal. 226 Huang et al: J Neuro-Ophthalmol 2014; 34: 223-228 Original Contribution Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. MD whereas the fellow eye either stable or improved, 5/9 (55%) showed improvement (only 9 patients had pre- and post-shunt visual fields). All 19 patients had VP shunts placed between October 2006 to August 2011, with an average follow-up of 21 months (range, 5-1,342 days). Kaplan-Meier analysis showed a persistent steady decrease of functioning VP shunts. Figure 2 shows 80% of VP shunts were functioning without replacement, removal, or revision at 12 months, 65% at 18 and 24 months, and 48% at 36 months. During this period, 3 patients required revision (at 1, 18, and 27 months after shunt), 2 required replacement (at 7 and 14 months), and 1 required removal (at 8 months). Addition-ally, 1 patient required a replacement at 38 months. DISCUSSION We found that VP shunting improved or stabilized VA and visual field analysis in most of our IIH patients who either presented with rapidly worsening vision or who had progressive visual loss despite medical treatment and ONSF. One patient worsened after VP shunt and required ONSF in both eyes. This is consistent with previous reports of the potential benefit of ONSF for those who worsen after VP shunt (19,20). Five of our patients had ONSF before VP shunt, of which, 2 showed improvement after VP shunt, 2 were unchanged, and 1 was indeterminate. There are reports of IIH patients with visual loss after ONSF who benefited from subsequent VP shunt (6,7). Visual acuity changes for worse eye and best eye were both statistically significant demonstrating that patients with both mildly decreased and poor VA may improve after VP shunt. Visual field analysis was not statically significant, but there was a trend toward less field constriction after VP shunt (Fig. 1). The lack of significance may be due to the small sample size because only 9 patients had quantifiable fields before and after surgery. The second outcome of our study was shunt survival. For a variety of reasons, VP shunting is the preferred method of CSF diversion at our institution. Kaplan-Meier survival analysis of our patients showed a persistent steady decrease in functioning VP shunt over time. Our failure rates of 20% at 1 year, 35% at 2 years, and 52% at 3 years are in line with other series that report shunt complication/ revision rates between 23% and 64% in the first 1-4 years (Table 1) (6,13,15). In our literature search, the closest study to ours was conducted by Bynke et al (15). In evaluating 17 IIH pa-tients, they reported a shunt revision rate of 41%, an 18% improvement in VA and a 65% improvement in visual field defects, compared with the 70% in our study based on VA and 55% based on visual field MD. Bynke et al included enlarged blind spot in their descriptive nonquantitative visual field analysis, which may, in part, explain the high percentage of improvement reported. We recognized the limitations of our study. The first is the retrospective design, leading to gaps in data collection, variation in baseline clinical characteristics, and lack of standardization of visual field testing and follow-up. Another limitation is the sample size. Although our sample size is similar to other studies looking at shunting procedures for IIH, it is small which limits statistical significance, making it difficult to compare outcomes directly in a paired fashion. Of the 17 patients included in the visual outcome analysis, only 9 had both a pre- and post-surgical visual field results that were suitable for analysis. Of those, 4 had previous ONSF FIG. 1. Mean deviation (MD) of visual fields before and after shunt placement plotted with 1:1 line. Points above the line indicate improvement in MD after surgery. ONSF, optic nerve sheath fenestration. FIG. 2. Kaplan-Meier survival plot of the probability of ventriculoperitoneal shunt success, defined as no replace-ment, removal, or revision over time. 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