ORIGINAL ARTICLE
Simultaneous placement of 2 glaucoma drainage devices for uncontrolled glaucoma Anna C. Momont, MD, Joshua D. Stein, MD, MS, Paul P. Lee, MD, JD, Jennifer S. Weizer, MD ABSTRACT ● RÉSUMÉ Objective: To report baseline characteristics and surgical outcomes of placement of simultaneous glaucoma drainage devices (GDDs) in eyes with considerably elevated intraocular pressure (IOP) despite maximal medical therapy. Design: Retrospective case series. Participants: Twelve eyes of 12 patients underwent simultaneous placement of a Baerveldt 350 GDD and an Ahmed S3 GDD in the same eye. Methods: The medical records were reviewed of consecutive patients who underwent simultaneous placement of a Baerveldt 350 GDD and an Ahmed S3 GDD in the same eye at the University of Michigan Kellogg Eye Center from 2006 to 2009. Baseline characteristics, preoperative and postoperative IOP, number of glaucoma medications, visual acuity, and complications were recorded. Results: Mean follow-up time was 28.6 ⫾ 22.8 months. The mean baseline cup/disc ratio was recorded at 0.94 ⫾ 0.07 horizontally and 0.92 ⫾ 0.09 vertically. The mean baseline IOP of 38.8 ⫾ 6.2 mm Hg was significantly reduced at all time points postoperatively, and the mean IOP at last follow-up was 15.1 ⫾ 4.9 mm Hg (p r 0.0001). Mean number of glaucoma medications was significantly lower at last follow-up than preoperatively (1.4 ⫾ 1.3 vs 3.2 ⫾ 0.8; p ¼ 0.001). There was no difference in mean logMAR visual acuity from before surgery to last follow-up (1.14 vs 1.12; p ¼ 0.933). Conclusions: Simultaneous placement of 2 GDDs effectively reduces IOP in the immediate postoperative period and long-term, and may be useful in glaucomatous eyes with advanced disease and considerably elevated preoperative IOP. Objet : Compte-rendu des caractéristiques de base et des résultats chirurgicaux de la mise en place de dispositifs de drainage de glaucome (DDG) dans les yeux avec une pression intraoculaire (PIO) considérablement élevée malgré une thérapie médicale maximale. Nature : Rétrospective d'une série de cas. Participants : Douze yeux de 12 patients qui avaient subi une mise en place simultanée de DDG 350 Baervelt et DDG S3 Ahmed (?) dans le même œil. Méthodes : Révision des dossiers médicaux de patients consécutifs qui avaient reçu une mise en place simultanée de DDG 350 Baervelt et DDG S3 Ahmed (?) dans le même œil au Kellogg Eye Center de l'Université du Michigan, entre 2006 et 2009. L'on a relevé les caractéristiques de base, les PIO préopératoires et postopératoires, le nombre de médications du glaucome, l'acuité visuelle et les complications. Résultats : La moyenne des suivis a été de 28,6 ± 22,8 mois. La moyenne de base du rapport coupe à disque a été notée 0,94 ± 0,07 horizontalement et 0,92 ± 0,09 verticalement. La moyenne de pression de base de la PIO, 38,8 ± 6,2 mm Hg, a été significativement réduite à tous les moments postopératoires; au dernier suivi, elle était de 15,1 ± 4,9 mm Hg (p ≤ 0,0001). La moyenne du nombre de médications du glaucome était significativement plus inférieure au dernier suivi qu'avant l'opération (1,4 ± 1,3 vs. 3,2 ± 0,8; p ¼ 0,001). Il n'y avait pas de différence moyenne d'acuité visuelle logMar entre l'avant chirurgie et le dernier suivi (1.14 vs. 1.12; p ¼ 0.933). Conclusion : La mise en place simultanée des deux DDG a effectivement réduit la PIO dans les périodes postopératoires immédiate et à long terme; elle peut aussi être utile pour les yeux glaucomateux qui ont une maladie avancée et une PIO.
Glaucoma drainage devices (GDDs) are useful tools in achieving intraocular pressure (IOP) control in patients with refractory glaucoma.1 Several GDDs are available for clinical use and vary in shape, construction material, size, and presence of a “valve” or flow restrictor. It has been suggested that GDDs that have a larger explant surface area provide better long-term IOP control relative to GDDs with smaller plates.1,2 The Baerveldt GDD is available with a surface area of 350 mm² and requires temporary flow restriction to avoid early postoperative hypotony. Unlike the Baerveldt GDD, flow restrictive
devices such as the Ahmed implant do not require a temporizing ligation to avoid early postoperative hypotony and are capable of lowering IOP immediately after implantation. Ahmed GDDs have a unidirectional flow restrictive element designed to limit flow through the tube when the IOP declines to less than 8 mm Hg, although Moss and Trope3 note that the closing pressure of this valve is variable in certain Ahmed GDD models. This, in turn, reduces the risk for postoperative hypotony. In both the Ahmed Baerveldt Comparison Study and the Ahmed versus Baerveldt Study, the Ahmed GDD achieved
From the Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Mich
Can J Ophthalmol 2014;49:205–209 0008-4182/14/$-see front matter & 2014 Canadian Ophthalmological Society. Published by Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.jcjo.2013.09.024
Originally received June 19, 2013. Final revision Sep. 24, 2013. Accepted Oct. 2, 2013 Correspondence to Jennifer S. Weizer, MD, Department of Ophthalmology and Visual Sciences, University of Michigan, 1000 Wall Street, Ann Arbor, MI 48105; [email protected]
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Simultaneous placement of 2 glaucoma drainage devices—Momont et al. significantly lower IOP in the immediate postoperative period, although the Ahmed GDDs had a lower 1-year survival rate than the Baerveldt GDDs.4,5 Although the Ahmed GDD has the advantage of immediate IOP lowering after implantation while reducing the risk for postoperative hypotony, often there is an associated hypertensive phase associated with elevated IOP a few weeks after implantation of this device.6 The mean survival of the Ahmed S3 GDD was limited to 15 months in children in the 1 published study (to our knowledge) of this model.7 In patients with glaucoma with dangerously elevated IOPs despite maximum tolerated medical therapy and who are at risk for glaucoma progression in the immediate postoperative period, simultaneous placement of a Baerveldt 350 GDD and Ahmed S3 GDD may provide immediate, as well as long-term, IOP control (a technique pioneered at Duke University Eye Center). Although previous studies have described placement of sequential GDDs in patients who did not achieve adequate IOP control after placement of a single GDD,8–12 to our knowledge, there are currently no published studies that evaluate the simultaneous placement of 2 GDDs to achieve both short- and long-term IOP control in patients with advanced glaucoma. In our study, we report outcomes from a series of patients who underwent simultaneous placement of 2 GDDs.
METHODS The study was approved by the University of Michigan Institutional Review Board and followed the tenets of the Declaration of Helsinki. We retrospectively reviewed the records of 12 consecutive patients who underwent simultaneous placement of 2 GDDs at the University of Michigan Kellogg Eye Center between January 2006 and January 2010. Four surgeons were involved in the implantation of the devices. Patients were selected based on surgeon judgment. All patients underwent simultaneous placement of a Baerveldt 350-mm² GDD (Abbott Medical Optics, Abbott Park, Ill.) beneath the superior and lateral rectus muscles in the superotemporal quadrant and placement of an Ahmed S3 GDD (New World Medical Inc, Rancho Cucamonga, Calif.) in the superonasal quadrant. The Baerveldt GDDs had a nylon ripcord placed in the lumen of the tube and were occluded with a dissolvable 7–0 Vicryl suture before implantation; no fenestrations were placed in the tube. A scleral patch graft was placed over each GDD from the plate to the sclerostomy where it was inserted into the anterior chamber or pars plana. Data collected from the medical record included patient demographics, type of glaucoma, past procedures, best corrected visual acuity, number and class of glaucoma medications, length of follow-up, and intraoperative and postoperative complications. The last recorded IOP measurement before surgery was reported as the preoperative
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Table 1—Baseline demographics and clinical characteristics of patients with simultaneous placement of Baerveldt 350 and Ahmed S3 glaucoma drainage devices Age, y Mean Range Sex, n (%) Male Female Race, n (%) White Black Asian Glaucoma diagnosis, n (%) Neovascular glaucoma Glaucoma associated with trauma Primary open-angle glaucoma Aniridic Aphakic Lens status, n (%) Phakic Pseudophakic Aphakic
53.3 ⫾ 19.4 20–80 7 (58.3%) 5 (41.7%) 9 (75%) 2 (16.7%) 1 (8.3%) 5 3 2 1 1
(41.7%) (25%) (16.7%) (7.1%) (7.1%)
8 (66.7%) 2 (16.7%) 2 (16.7%)
IOP. Postoperative IOP, measured by Goldmann applanation tonometry, was recorded at 1 day, 1 week, 2 to 3 weeks, 1 month, 3 to 4 months, 6 months, 1 year, every year after surgery, and at the last documented visit. The paired Student t test was used to compare preoperative and postoperative levels of IOP. A p value r0.05 was considered statistically significant. Failure was defined prospectively as IOP greater than 21 mm Hg or less than a 20% reduction from baseline on 2 consecutive study visits after 3 months, IOP r5 mm Hg on 2 consecutive study visits after 3 months, reoperation for glaucoma, loss of light perception vision, or removal of the implant for any reason. Eyes that were not failures were defined as complete successes if they did not require any IOP-lowering medication by 6 months or later postoperatively, and qualified successes otherwise. Reoperation for glaucoma was defined as additional glaucoma surgery requiring a return to the operating room, such as for tube revision, placement of an additional aqueous shunt, or cyclodestruction. Interventions performed at the slit lamp, such as needling procedures, removal of ripcords, or laser suture lysis, were not considered glaucoma reoperations.4
RESULTS Fourteen eyes of 14 consecutive patients underwent simultaneous placement of 2 GDDs between January 1, 2006, and January 1, 2010. Two patients were lost to follow-up after 1 month and thus were not included in this analysis. Glaucoma types were diverse and included neovascular, primary open-angle, traumatic, chronic angleclosure, aniridic, and aphakic glaucoma. Patient characteristics are summarized in Table 1. The mean follow-up was 28.6 ⫾ 22.8 months (range 3–67 months). The mean age was 53.3 ⫾ 19.4 years (range 20–80 years). The mean baseline cup/disc ratio was recorded at 0.94 ⫾ 0.07
Simultaneous placement of 2 glaucoma drainage devices—Momont et al. Table 2—Mean intraocular pressure (mm Hg) after simultaneous glaucoma drainage device implantation IOP (mm Hg) n Preoperative Day 1 Week 1 Month 1 Months 3–4 Month 6 Year 1
12 12 12 12 10 9 8
Mean
Range
p
⫾ ⫾ ⫾ ⫾ ⫾ ⫾ ⫾
29.0–48.0 2.0–20.0 8.0–35.5 11.0–40.0 11.0–20.0 8.0–16.0 6.0–24.0
o0.0001 o0.0001 0.0025 o0.0001 o0.0001 o0.0001
38.8 12.3 13.8 25.0 15.2 10.3 13.6
6.0 6.5 7.3 9.2 3.4 3.19 6.23
The p value was derived from paired t test comparison between mean preoperative intraocular pressure (IOP) and mean postoperative IOP.
horizontally and 0.92 ⫾ 0.09 vertically. The mean number of previous incisional surgeries was 0.7 ⫾ 0.7 and included clear cornea cataract extraction in 4 (33.3%) eyes, pars plana vitrectomy in 2 (16.7%) eyes, and trabeculectomy in 2 (16.7%) eyes. Three patients (25.0%) had a prior history of laser trabeculoplasty. No patients had a history of previous GDD implantation in the study eye. Both tubes were placed in the anterior chamber in 9 (75.0%) eyes and through the pars plana in 3 (25.0%) eyes. Concomitant cataract surgery was performed in 1 (8.3%) eye and pars plana vitrectomy was performed in 2 (16.7%) eyes. Mean preoperative IOP was 38.8 ⫾ 6.2 mm Hg (range 29.0–48.0 mm Hg). The mean IOP was significantly reduced at all postoperative time points compared with preoperatively (Table 2). The mean preoperative IOP of 38.8 ⫾ 5.7 mm Hg was decreased to 12.3 ⫾ 6.5 mm Hg at 1 day and 13.8 ⫾ 7.3 mm Hg at 1 week. After the initial reduction in IOP at 1 day and 1 week, there was an increase in mean IOP that peaked at 25.0 ⫾ 9.2 mm Hg at the 2- to 3-week time point and then decreased again after the 1-month time point (Fig. 1). The Baerveldt ripcord suture was pulled in 10 (83.3%) eyes at an average of 30.2 ⫾ 7.9 days postoperatively and in the other
Fig. 1 — Mean intraocular pressure preoperatively and postoperatively after simultaneous glaucoma drainage device implantation.
Fig. 2 — Kaplan–Meier curves showing the cumulative probability of success (complete and qualified) in the first 12 months after simultaneous glaucoma drainage device implantation.
2 cases, the polygalactin suture dissolved spontaneously. The mean IOP at 1 month reflects the IOP before pulling the ripcord in those 10 patients. The mean IOP immediately after ripcord removal was 8.8 ⫾ 8.7 mm Hg (range 2.0–32.0 mm Hg), and no shallowing of the anterior chamber was noted in any eye. The mean IOP at last follow-up was 15.1 ⫾ 4.9 mm Hg (p r 0.0001), and mean percentage reduction in IOP at last follow-up was 60.5% ⫾ 13.6% (range 37.5%–77.1%). Four eyes (36%) were classified as achieving complete success, whereas 7 eyes (64%) were classified as achieving qualified success. Preoperatively, the mean number of topical glaucoma medications prescribed was 3.2 ⫾ 0.8 (range 2–5), and 6 (50%) patients were prescribed systemic carbonic anhydrase inhibitors. At last follow-up, the mean number of glaucoma medications prescribed was 1.4 ⫾ 1.3 (range 0–4), which was significantly less than preoperatively (p ¼ 0.001). No patients required systemic carbonic anhydrase inhibitors at last follow-up. There was no difference in mean preoperative and most recent postoperative logMAR visual acuity (1.14 ⫾ 0.97 vs 1.12 ⫾ 0.83; p ¼ 0.933), Snellen equivalent of 20/276 versus 20/264. Visual acuity remained unchanged or within 2 lines on the Snellen scale in 5 (41.7%) eyes, improved more than 2 lines in 4 (41.7%) eyes, and worsened more than 2 lines in 3 (25%) eyes. Of these last 3 eyes, 2 had worsening of visual acuity despite wellcontrolled IOP; both of these had aniridia as a comorbidity. The third eye had worsening of visual acuity when the Baerveldt tube became occluded with iris tissue and the IOP increased. Despite tube repositioning and resolution of the IOP elevation, the visual acuity did not recover. Kaplan– Meier survival analysis is shown in Figure 2; the single failure that occurred within the first postoperative year was 1 eye with both tubes placed in the vitreous cavity that required repeat pars plana vitrectomy when the IOP did not decline after release of the Baerveldt ripcord suture. CAN J OPHTHALMOL — VOL. 49, NO. 2, APRIL 2014
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Simultaneous placement of 2 glaucoma drainage devices—Momont et al. No major intraoperative complications occurred. Serous choroidal effusions were documented in 2 (16.7%) eyes. One case occurred immediately postoperatively, whereas the second case occurred after removal of the Baerveldt ripcord suture. In both cases, the serous choroidal effusions resolved spontaneously with no permanent deterioration in visual acuity. Vitreous hemorrhage occurred postoperatively in 2 (16.7%) eyes, both with a documented history of posterior segment neovascularization. Unintentional obstruction of the Baerveldt tube tip was encountered in 2 (16.7%) eyes. One eye with both tubes placed in the vitreous cavity was treated with repeat pars plana vitrectomy when the IOP failed to decline after release of the Baerveldt ripcord suture (also mentioned in the previous paragraph). In this eye, the IOP decreased from 32 to 10 mm Hg after the repeat vitrectomy. As discussed in the previous paragraph, a second eye had iris occluding the Baerveldt tube tip at 2 years postoperatively and was successfully treated with surgical tube repositioning in the anterior chamber and iris diathermy. One (8.7%) eye had mild late corneal edema at 2 years postoperatively without evidence of tube–cornea touch. No patients had postoperative diplopia.
DISCUSSION Management of refractory glaucoma can present a challenge to the clinician. Placement of a smaller valved GDD and a larger nonvalved GDD during the same surgery is a novel approach. The theoretical advantage is to achieve immediate IOP lowering in patients with dangerously elevated IOPs who are refractory to pressurelowering medications, whereas avoiding hypotony through the function of the valved Ahmed S3 GDD, which fits comfortably in the superonasal quadrant, coupled with longer-term IOP control from the Baerveldt 350 GDD a few weeks later when the temporary occluding ligature is removed. In our study, 12 consecutive eyes with a variety of underlying glaucoma diagnoses underwent simultaneous placement of a Baerveldt 350 GDD and an Ahmed S3 GDD. These eyes had extremely elevated preoperative Table 3—Intraocular pressure (mm Hg) at baseline and followup in our simultaneous glaucoma drainage device implantation compared with Baerveldt glaucoma drainage device implantation in the Tube Versus Trabeculectomy Study13,14 IOP (mm Hg) Baseline 1 day 1 week 1 month 3 months 6 months 1 year
Simultaneous GDDs 38.8 12.3 13.8 25.0 15.2 10.3 13.6
⫾ ⫾ ⫾ ⫾ ⫾ ⫾ ⫾
6.0 6.5 7.3 9.2 3.4 3.2 6.2
Baerveldt Group in the TVT 25.1 21.3 19.0 18.5 16.2 13.5 12.4
⫾ ⫾ ⫾ ⫾ ⫾ ⫾ ⫾
5.3 11.8 9.8 9.8 6.4 4.2 3.9
IOP, intraocular pressure; GDD, glaucoma drainage device; TVT, Tube Versus Trabeculectomy Study.
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IOP (mean 38.8 mm Hg) and were at risk for immediate progression of vision loss from glaucoma given their advanced disease, as demonstrated by the mean cup/disc ratio. There was significant lowering of IOP at all postoperative time points and a significant decrease in topical glaucoma medications. Decrease in visual acuity change of Z2 lines on the Snellen scale was seen in 3 patients. The Tube Versus Trabeculectomy Study (TVT) reported 1- and 3-year postoperative findings in 105 patients who underwent placement of a Baerveldt 350 GDD.13,14 In these patients, the mean IOP declined from a baseline of 25.1 mm Hg to 12.4 mm Hg at 1 year and 13.0 mm Hg at 3 years (a decrease of 50.6% and 48.2%, respectively). This is comparable with our 62.6% decrease in mean IOP from a baseline of 38.8 mm Hg to 14.5 mm Hg at last follow-up. In the TVT, the IOP in the Baerveldt group declined slowly over the first 2 months and only began to plateau at 6 months of follow-up. In contrast, the IOP decreased immediately postoperatively in our study (Table 3), which we suspect is likely attributed to the immediate functioning of the Ahmed S3 GDD. Previous authors have described a “hypertensive phase” after placement of the Ahmed GDD with an elevation in IOP peaking at 1 to 2 months and stabilizing over 3 to 6 months.6,15 Ayyala et al.6 found the incidence rate of a hypertensive phase to be as high as 82%, and one third of the patients in that study required revision of the first GDD or placement of a second GDD to control IOP during the hypertensive phase. In our study, after the initial postoperative decline in IOP, the mean IOP did increase somewhat between weeks 2 and 4, although not to preoperative levels. The subsequent decrease in mean IOP by postoperative month 2 corresponds to the patency and functioning of the Baerveldt GDDs after ripcord removal or spontaneous dissolution of the occluding Vicryl suture. The use of 2 sequential GDDs in the same eye to improve IOP control has been reported to have success rates ranging from 37% to 83%.8–11 The most common complications reported in these studies was new onset of or worsening of corneal edema or corneal graft failure in 16.3% to 45% of eyes. An additional concern when placing 2 glaucoma implants is overfiltration and resulting hypotony. Anand et al.8 reported 2 eyes with persistent hypotony after sequential GDD placement, whereas Shah et al.11 reported 2 eyes with phthisis and 1 eye with choroidal effusions requiring drainage. In our study, 1 eye had mild corneal edema at a 2-year follow-up, and there were no eyes with persistent hypotony. Alteration of the Baerveldt 350 GDD with tube fenestrations has also been proposed for immediate postoperative lowering of IOP. Kansal et al.16 found that placing 1 to 3 tube fenestrations just anterior to an occlusive ligature led to a 77% success rate defined as IOP control in the first 14 postoperative days without a need for surgical intervention or evidence of hypotony.
Simultaneous placement of 2 glaucoma drainage devices—Momont et al. Postoperative hypertension requiring surgical intervention or intraluminal suture removal occurred in 9% of patients, whereas postoperative hypotony occurred in 13.9% of patients. These findings highlight the unpredictable nature of tube fenestrations. The Ahmed valve is also offered in a double-plate design with a total surface area of 364 mm². In a review of 50 eyes treated with the double-plate Ahmed GDD, a 43.8% decline in IOP was observed at the most recent follow-up. However, in that study, postoperative disconnection of the 2 plates did occasionally occur.17 Our study is limited by a retrospective design, as well as a small number of patients and variable lengths of followup. Despite the limitations, our study does show that simultaneous GDD implantation can provide immediate and long-term IOP control with few complications in patients with refractory glaucoma. This strategy may benefit those eyes with very high preoperative IOP refractory to medical therapy with concomitant advanced glaucomatous damage that are at risk for blindness in the immediate postoperative period by providing both shortterm and long-term IOP control.
3. 4. 5. 6. 7. 8. 9. 10.
11. 12. 13.
Disclosure: The authors have no proprietary or commercial interest in any materials discussed in this article. 14.
Acknowledgements: Statistical support was provided by David Musch, PhD, MPH, and Leslie Niziol, MS. REFERENCES 1. Minckler DS, Francis BA, Hodapp EA, et al. Aqueous shunts in glaucoma: a report by the American Academy of Ophthalmology. Ophthalmology. 2008;115:1089-98. 2. Heuer DK, Lloyd MA, Abrams DA, et al. Which is better? One or two? A randomized clinical trial of single-plate versus double-plate
15. 16.
17.
Molteno implantation for glaucomas in aphakia and pseudophakia. Ophthalmology. 1992;99:1512-9. Moss EB, Trope GE. Assessment of closing pressure in silicone Ahmed FP7 glaucoma valves. J Glaucoma. 2008;17:489-93. Budenz DL, Barton K, Feuer WJ, et al. Treatment outcomes in the Ahmed Baerveldt Comparison Study after 1 year of follow-up. Ophthalmology. 2011;118:443-52. Christakis PG, Kalenak JW, Zurakowski D, et al. The Ahmed Versus Baerveldt study: one-year treatment outcomes. Ophthalmology. 2011;118:2180-9. Ayyala RS, Zurakowski D, Smith JA, et al. A clinical study of the Ahmed glaucoma valve implant in advanced glaucoma. Ophthalmology. 1998;105:1968-76. Djodeyre MR, Peralta Calvo J, Abelairas Gomez J. Clinical evaluation and risk factors of time to failure of Ahmed glaucoma valve implant in pediatric patients. Ophthalmology. 2001;108:614-20. Anand A, Tello C, Sidoti PA, Ritch R, Liebmann JM. Sequential glaucoma implants in refractory glaucoma. Am J Ophthalmol. 2010;149:95-101. Burgoyne JK, WuDunn D, Lakhani V, Cantor LB. Outcomes of sequential tube shunts in complicated glaucoma. Ophthalmology. 2000;107:309-14. Godfrey DG, Krishna R, Greenfield DS, Budenz DL, Gedde SJ, Scott IU. Implantation of second glaucoma drainage devices after failure of primary devices. Ophthalmic Surg Lasers. 2002;33: 37-43. Shah AA, WuDunn D, Cantor LB. Shunt revision versus additional tube shunt implantation after failed tube shunt surgery in refractory glaucoma. Am J Ophthalmol. 2000;129:455-60. Smith M, Buys YM, Trope GE. Second Ahmed valve insertion in the same eye. J Glaucoma. 2009;18:336-40. Gedde SJ, Schiffman JC, Feuer WJ, et al. Tube Versus Trabeculectomy Study Group. The Tube Versus Trabeculectomy Study: design and baseline characteristics of study patients. Am J Ophthalmol. 2005;140:275-87. Gedde SJ, Schiffman JC, Feuer WJ, et al. Tube Versus Trabeculectomy Study Group. Three-year follow-up of the Tube Versus Trabeculectomy Study. Am J Ophthalmol. 2009;148:670-84. Huang MC, Netland PA, Coleman AL, Siegner SW, Moster MR, Hill RA. Intermediate-term clinical experience with the Ahmed glaucoma valve implant. Am J Ophthalmol. 1999;127:27-33. Kansal S, Moster MR, Kim D, Schmidt CM Jr, Wilson RP, Katz LJ. Effectiveness of nonocclusive ligature and fenestration used in Baerveldt aqueous shunts for early postoperative intraocular pressure control. J Glaucoma. 2002;11:65-70. Al-Aswad LA, Netland PA, Bellows AR, et al. Clinical experience with the double-plate Ahmed glaucoma valve. Am J Ophthalmol. 2006;141:390-1.
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Simultaneous placement of 2 glaucoma drainage devices for uncontrolled glaucoma Anna C. Momont, MD, Joshua D. Stein, MD, MS, Paul P. Lee, MD, JD, Jennifer S. Weizer, MD ABSTRACT ● RÉSUMÉ Objective: To report baseline characteristics and surgical outcomes of placement of simultaneous glaucoma drainage devices (GDDs) in eyes with considerably elevated intraocular pressure (IOP) despite maximal medical therapy. Design: Retrospective case series. Participants: Twelve eyes of 12 patients underwent simultaneous placement of a Baerveldt 350 GDD and an Ahmed S3 GDD in the same eye. Methods: The medical records were reviewed of consecutive patients who underwent simultaneous placement of a Baerveldt 350 GDD and an Ahmed S3 GDD in the same eye at the University of Michigan Kellogg Eye Center from 2006 to 2009. Baseline characteristics, preoperative and postoperative IOP, number of glaucoma medications, visual acuity, and complications were recorded. Results: Mean follow-up time was 28.6 ⫾ 22.8 months. The mean baseline cup/disc ratio was recorded at 0.94 ⫾ 0.07 horizontally and 0.92 ⫾ 0.09 vertically. The mean baseline IOP of 38.8 ⫾ 6.2 mm Hg was significantly reduced at all time points postoperatively, and the mean IOP at last follow-up was 15.1 ⫾ 4.9 mm Hg (p r 0.0001). Mean number of glaucoma medications was significantly lower at last follow-up than preoperatively (1.4 ⫾ 1.3 vs 3.2 ⫾ 0.8; p ¼ 0.001). There was no difference in mean logMAR visual acuity from before surgery to last follow-up (1.14 vs 1.12; p ¼ 0.933). Conclusions: Simultaneous placement of 2 GDDs effectively reduces IOP in the immediate postoperative period and long-term, and may be useful in glaucomatous eyes with advanced disease and considerably elevated preoperative IOP. Objet : Compte-rendu des caractéristiques de base et des résultats chirurgicaux de la mise en place de dispositifs de drainage de glaucome (DDG) dans les yeux avec une pression intraoculaire (PIO) considérablement élevée malgré une thérapie médicale maximale. Nature : Rétrospective d'une série de cas. Participants : Douze yeux de 12 patients qui avaient subi une mise en place simultanée de DDG 350 Baervelt et DDG S3 Ahmed (?) dans le même œil. Méthodes : Révision des dossiers médicaux de patients consécutifs qui avaient reçu une mise en place simultanée de DDG 350 Baervelt et DDG S3 Ahmed (?) dans le même œil au Kellogg Eye Center de l'Université du Michigan, entre 2006 et 2009. L'on a relevé les caractéristiques de base, les PIO préopératoires et postopératoires, le nombre de médications du glaucome, l'acuité visuelle et les complications. Résultats : La moyenne des suivis a été de 28,6 ± 22,8 mois. La moyenne de base du rapport coupe à disque a été notée 0,94 ± 0,07 horizontalement et 0,92 ± 0,09 verticalement. La moyenne de pression de base de la PIO, 38,8 ± 6,2 mm Hg, a été significativement réduite à tous les moments postopératoires; au dernier suivi, elle était de 15,1 ± 4,9 mm Hg (p ≤ 0,0001). La moyenne du nombre de médications du glaucome était significativement plus inférieure au dernier suivi qu'avant l'opération (1,4 ± 1,3 vs. 3,2 ± 0,8; p ¼ 0,001). Il n'y avait pas de différence moyenne d'acuité visuelle logMar entre l'avant chirurgie et le dernier suivi (1.14 vs. 1.12; p ¼ 0.933). Conclusion : La mise en place simultanée des deux DDG a effectivement réduit la PIO dans les périodes postopératoires immédiate et à long terme; elle peut aussi être utile pour les yeux glaucomateux qui ont une maladie avancée et une PIO.
Glaucoma drainage devices (GDDs) are useful tools in achieving intraocular pressure (IOP) control in patients with refractory glaucoma.1 Several GDDs are available for clinical use and vary in shape, construction material, size, and presence of a “valve” or flow restrictor. It has been suggested that GDDs that have a larger explant surface area provide better long-term IOP control relative to GDDs with smaller plates.1,2 The Baerveldt GDD is available with a surface area of 350 mm² and requires temporary flow restriction to avoid early postoperative hypotony. Unlike the Baerveldt GDD, flow restrictive
devices such as the Ahmed implant do not require a temporizing ligation to avoid early postoperative hypotony and are capable of lowering IOP immediately after implantation. Ahmed GDDs have a unidirectional flow restrictive element designed to limit flow through the tube when the IOP declines to less than 8 mm Hg, although Moss and Trope3 note that the closing pressure of this valve is variable in certain Ahmed GDD models. This, in turn, reduces the risk for postoperative hypotony. In both the Ahmed Baerveldt Comparison Study and the Ahmed versus Baerveldt Study, the Ahmed GDD achieved
From the Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Mich
Can J Ophthalmol 2014;49:205–209 0008-4182/14/$-see front matter & 2014 Canadian Ophthalmological Society. Published by Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.jcjo.2013.09.024
Originally received June 19, 2013. Final revision Sep. 24, 2013. Accepted Oct. 2, 2013 Correspondence to Jennifer S. Weizer, MD, Department of Ophthalmology and Visual Sciences, University of Michigan, 1000 Wall Street, Ann Arbor, MI 48105; [email protected]
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Simultaneous placement of 2 glaucoma drainage devices—Momont et al. significantly lower IOP in the immediate postoperative period, although the Ahmed GDDs had a lower 1-year survival rate than the Baerveldt GDDs.4,5 Although the Ahmed GDD has the advantage of immediate IOP lowering after implantation while reducing the risk for postoperative hypotony, often there is an associated hypertensive phase associated with elevated IOP a few weeks after implantation of this device.6 The mean survival of the Ahmed S3 GDD was limited to 15 months in children in the 1 published study (to our knowledge) of this model.7 In patients with glaucoma with dangerously elevated IOPs despite maximum tolerated medical therapy and who are at risk for glaucoma progression in the immediate postoperative period, simultaneous placement of a Baerveldt 350 GDD and Ahmed S3 GDD may provide immediate, as well as long-term, IOP control (a technique pioneered at Duke University Eye Center). Although previous studies have described placement of sequential GDDs in patients who did not achieve adequate IOP control after placement of a single GDD,8–12 to our knowledge, there are currently no published studies that evaluate the simultaneous placement of 2 GDDs to achieve both short- and long-term IOP control in patients with advanced glaucoma. In our study, we report outcomes from a series of patients who underwent simultaneous placement of 2 GDDs.
METHODS The study was approved by the University of Michigan Institutional Review Board and followed the tenets of the Declaration of Helsinki. We retrospectively reviewed the records of 12 consecutive patients who underwent simultaneous placement of 2 GDDs at the University of Michigan Kellogg Eye Center between January 2006 and January 2010. Four surgeons were involved in the implantation of the devices. Patients were selected based on surgeon judgment. All patients underwent simultaneous placement of a Baerveldt 350-mm² GDD (Abbott Medical Optics, Abbott Park, Ill.) beneath the superior and lateral rectus muscles in the superotemporal quadrant and placement of an Ahmed S3 GDD (New World Medical Inc, Rancho Cucamonga, Calif.) in the superonasal quadrant. The Baerveldt GDDs had a nylon ripcord placed in the lumen of the tube and were occluded with a dissolvable 7–0 Vicryl suture before implantation; no fenestrations were placed in the tube. A scleral patch graft was placed over each GDD from the plate to the sclerostomy where it was inserted into the anterior chamber or pars plana. Data collected from the medical record included patient demographics, type of glaucoma, past procedures, best corrected visual acuity, number and class of glaucoma medications, length of follow-up, and intraoperative and postoperative complications. The last recorded IOP measurement before surgery was reported as the preoperative
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Table 1—Baseline demographics and clinical characteristics of patients with simultaneous placement of Baerveldt 350 and Ahmed S3 glaucoma drainage devices Age, y Mean Range Sex, n (%) Male Female Race, n (%) White Black Asian Glaucoma diagnosis, n (%) Neovascular glaucoma Glaucoma associated with trauma Primary open-angle glaucoma Aniridic Aphakic Lens status, n (%) Phakic Pseudophakic Aphakic
53.3 ⫾ 19.4 20–80 7 (58.3%) 5 (41.7%) 9 (75%) 2 (16.7%) 1 (8.3%) 5 3 2 1 1
(41.7%) (25%) (16.7%) (7.1%) (7.1%)
8 (66.7%) 2 (16.7%) 2 (16.7%)
IOP. Postoperative IOP, measured by Goldmann applanation tonometry, was recorded at 1 day, 1 week, 2 to 3 weeks, 1 month, 3 to 4 months, 6 months, 1 year, every year after surgery, and at the last documented visit. The paired Student t test was used to compare preoperative and postoperative levels of IOP. A p value r0.05 was considered statistically significant. Failure was defined prospectively as IOP greater than 21 mm Hg or less than a 20% reduction from baseline on 2 consecutive study visits after 3 months, IOP r5 mm Hg on 2 consecutive study visits after 3 months, reoperation for glaucoma, loss of light perception vision, or removal of the implant for any reason. Eyes that were not failures were defined as complete successes if they did not require any IOP-lowering medication by 6 months or later postoperatively, and qualified successes otherwise. Reoperation for glaucoma was defined as additional glaucoma surgery requiring a return to the operating room, such as for tube revision, placement of an additional aqueous shunt, or cyclodestruction. Interventions performed at the slit lamp, such as needling procedures, removal of ripcords, or laser suture lysis, were not considered glaucoma reoperations.4
RESULTS Fourteen eyes of 14 consecutive patients underwent simultaneous placement of 2 GDDs between January 1, 2006, and January 1, 2010. Two patients were lost to follow-up after 1 month and thus were not included in this analysis. Glaucoma types were diverse and included neovascular, primary open-angle, traumatic, chronic angleclosure, aniridic, and aphakic glaucoma. Patient characteristics are summarized in Table 1. The mean follow-up was 28.6 ⫾ 22.8 months (range 3–67 months). The mean age was 53.3 ⫾ 19.4 years (range 20–80 years). The mean baseline cup/disc ratio was recorded at 0.94 ⫾ 0.07
Simultaneous placement of 2 glaucoma drainage devices—Momont et al. Table 2—Mean intraocular pressure (mm Hg) after simultaneous glaucoma drainage device implantation IOP (mm Hg) n Preoperative Day 1 Week 1 Month 1 Months 3–4 Month 6 Year 1
12 12 12 12 10 9 8
Mean
Range
p
⫾ ⫾ ⫾ ⫾ ⫾ ⫾ ⫾
29.0–48.0 2.0–20.0 8.0–35.5 11.0–40.0 11.0–20.0 8.0–16.0 6.0–24.0
o0.0001 o0.0001 0.0025 o0.0001 o0.0001 o0.0001
38.8 12.3 13.8 25.0 15.2 10.3 13.6
6.0 6.5 7.3 9.2 3.4 3.19 6.23
The p value was derived from paired t test comparison between mean preoperative intraocular pressure (IOP) and mean postoperative IOP.
horizontally and 0.92 ⫾ 0.09 vertically. The mean number of previous incisional surgeries was 0.7 ⫾ 0.7 and included clear cornea cataract extraction in 4 (33.3%) eyes, pars plana vitrectomy in 2 (16.7%) eyes, and trabeculectomy in 2 (16.7%) eyes. Three patients (25.0%) had a prior history of laser trabeculoplasty. No patients had a history of previous GDD implantation in the study eye. Both tubes were placed in the anterior chamber in 9 (75.0%) eyes and through the pars plana in 3 (25.0%) eyes. Concomitant cataract surgery was performed in 1 (8.3%) eye and pars plana vitrectomy was performed in 2 (16.7%) eyes. Mean preoperative IOP was 38.8 ⫾ 6.2 mm Hg (range 29.0–48.0 mm Hg). The mean IOP was significantly reduced at all postoperative time points compared with preoperatively (Table 2). The mean preoperative IOP of 38.8 ⫾ 5.7 mm Hg was decreased to 12.3 ⫾ 6.5 mm Hg at 1 day and 13.8 ⫾ 7.3 mm Hg at 1 week. After the initial reduction in IOP at 1 day and 1 week, there was an increase in mean IOP that peaked at 25.0 ⫾ 9.2 mm Hg at the 2- to 3-week time point and then decreased again after the 1-month time point (Fig. 1). The Baerveldt ripcord suture was pulled in 10 (83.3%) eyes at an average of 30.2 ⫾ 7.9 days postoperatively and in the other
Fig. 1 — Mean intraocular pressure preoperatively and postoperatively after simultaneous glaucoma drainage device implantation.
Fig. 2 — Kaplan–Meier curves showing the cumulative probability of success (complete and qualified) in the first 12 months after simultaneous glaucoma drainage device implantation.
2 cases, the polygalactin suture dissolved spontaneously. The mean IOP at 1 month reflects the IOP before pulling the ripcord in those 10 patients. The mean IOP immediately after ripcord removal was 8.8 ⫾ 8.7 mm Hg (range 2.0–32.0 mm Hg), and no shallowing of the anterior chamber was noted in any eye. The mean IOP at last follow-up was 15.1 ⫾ 4.9 mm Hg (p r 0.0001), and mean percentage reduction in IOP at last follow-up was 60.5% ⫾ 13.6% (range 37.5%–77.1%). Four eyes (36%) were classified as achieving complete success, whereas 7 eyes (64%) were classified as achieving qualified success. Preoperatively, the mean number of topical glaucoma medications prescribed was 3.2 ⫾ 0.8 (range 2–5), and 6 (50%) patients were prescribed systemic carbonic anhydrase inhibitors. At last follow-up, the mean number of glaucoma medications prescribed was 1.4 ⫾ 1.3 (range 0–4), which was significantly less than preoperatively (p ¼ 0.001). No patients required systemic carbonic anhydrase inhibitors at last follow-up. There was no difference in mean preoperative and most recent postoperative logMAR visual acuity (1.14 ⫾ 0.97 vs 1.12 ⫾ 0.83; p ¼ 0.933), Snellen equivalent of 20/276 versus 20/264. Visual acuity remained unchanged or within 2 lines on the Snellen scale in 5 (41.7%) eyes, improved more than 2 lines in 4 (41.7%) eyes, and worsened more than 2 lines in 3 (25%) eyes. Of these last 3 eyes, 2 had worsening of visual acuity despite wellcontrolled IOP; both of these had aniridia as a comorbidity. The third eye had worsening of visual acuity when the Baerveldt tube became occluded with iris tissue and the IOP increased. Despite tube repositioning and resolution of the IOP elevation, the visual acuity did not recover. Kaplan– Meier survival analysis is shown in Figure 2; the single failure that occurred within the first postoperative year was 1 eye with both tubes placed in the vitreous cavity that required repeat pars plana vitrectomy when the IOP did not decline after release of the Baerveldt ripcord suture. CAN J OPHTHALMOL — VOL. 49, NO. 2, APRIL 2014
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Simultaneous placement of 2 glaucoma drainage devices—Momont et al. No major intraoperative complications occurred. Serous choroidal effusions were documented in 2 (16.7%) eyes. One case occurred immediately postoperatively, whereas the second case occurred after removal of the Baerveldt ripcord suture. In both cases, the serous choroidal effusions resolved spontaneously with no permanent deterioration in visual acuity. Vitreous hemorrhage occurred postoperatively in 2 (16.7%) eyes, both with a documented history of posterior segment neovascularization. Unintentional obstruction of the Baerveldt tube tip was encountered in 2 (16.7%) eyes. One eye with both tubes placed in the vitreous cavity was treated with repeat pars plana vitrectomy when the IOP failed to decline after release of the Baerveldt ripcord suture (also mentioned in the previous paragraph). In this eye, the IOP decreased from 32 to 10 mm Hg after the repeat vitrectomy. As discussed in the previous paragraph, a second eye had iris occluding the Baerveldt tube tip at 2 years postoperatively and was successfully treated with surgical tube repositioning in the anterior chamber and iris diathermy. One (8.7%) eye had mild late corneal edema at 2 years postoperatively without evidence of tube–cornea touch. No patients had postoperative diplopia.
DISCUSSION Management of refractory glaucoma can present a challenge to the clinician. Placement of a smaller valved GDD and a larger nonvalved GDD during the same surgery is a novel approach. The theoretical advantage is to achieve immediate IOP lowering in patients with dangerously elevated IOPs who are refractory to pressurelowering medications, whereas avoiding hypotony through the function of the valved Ahmed S3 GDD, which fits comfortably in the superonasal quadrant, coupled with longer-term IOP control from the Baerveldt 350 GDD a few weeks later when the temporary occluding ligature is removed. In our study, 12 consecutive eyes with a variety of underlying glaucoma diagnoses underwent simultaneous placement of a Baerveldt 350 GDD and an Ahmed S3 GDD. These eyes had extremely elevated preoperative Table 3—Intraocular pressure (mm Hg) at baseline and followup in our simultaneous glaucoma drainage device implantation compared with Baerveldt glaucoma drainage device implantation in the Tube Versus Trabeculectomy Study13,14 IOP (mm Hg) Baseline 1 day 1 week 1 month 3 months 6 months 1 year
Simultaneous GDDs 38.8 12.3 13.8 25.0 15.2 10.3 13.6
⫾ ⫾ ⫾ ⫾ ⫾ ⫾ ⫾
6.0 6.5 7.3 9.2 3.4 3.2 6.2
Baerveldt Group in the TVT 25.1 21.3 19.0 18.5 16.2 13.5 12.4
⫾ ⫾ ⫾ ⫾ ⫾ ⫾ ⫾
5.3 11.8 9.8 9.8 6.4 4.2 3.9
IOP, intraocular pressure; GDD, glaucoma drainage device; TVT, Tube Versus Trabeculectomy Study.
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IOP (mean 38.8 mm Hg) and were at risk for immediate progression of vision loss from glaucoma given their advanced disease, as demonstrated by the mean cup/disc ratio. There was significant lowering of IOP at all postoperative time points and a significant decrease in topical glaucoma medications. Decrease in visual acuity change of Z2 lines on the Snellen scale was seen in 3 patients. The Tube Versus Trabeculectomy Study (TVT) reported 1- and 3-year postoperative findings in 105 patients who underwent placement of a Baerveldt 350 GDD.13,14 In these patients, the mean IOP declined from a baseline of 25.1 mm Hg to 12.4 mm Hg at 1 year and 13.0 mm Hg at 3 years (a decrease of 50.6% and 48.2%, respectively). This is comparable with our 62.6% decrease in mean IOP from a baseline of 38.8 mm Hg to 14.5 mm Hg at last follow-up. In the TVT, the IOP in the Baerveldt group declined slowly over the first 2 months and only began to plateau at 6 months of follow-up. In contrast, the IOP decreased immediately postoperatively in our study (Table 3), which we suspect is likely attributed to the immediate functioning of the Ahmed S3 GDD. Previous authors have described a “hypertensive phase” after placement of the Ahmed GDD with an elevation in IOP peaking at 1 to 2 months and stabilizing over 3 to 6 months.6,15 Ayyala et al.6 found the incidence rate of a hypertensive phase to be as high as 82%, and one third of the patients in that study required revision of the first GDD or placement of a second GDD to control IOP during the hypertensive phase. In our study, after the initial postoperative decline in IOP, the mean IOP did increase somewhat between weeks 2 and 4, although not to preoperative levels. The subsequent decrease in mean IOP by postoperative month 2 corresponds to the patency and functioning of the Baerveldt GDDs after ripcord removal or spontaneous dissolution of the occluding Vicryl suture. The use of 2 sequential GDDs in the same eye to improve IOP control has been reported to have success rates ranging from 37% to 83%.8–11 The most common complications reported in these studies was new onset of or worsening of corneal edema or corneal graft failure in 16.3% to 45% of eyes. An additional concern when placing 2 glaucoma implants is overfiltration and resulting hypotony. Anand et al.8 reported 2 eyes with persistent hypotony after sequential GDD placement, whereas Shah et al.11 reported 2 eyes with phthisis and 1 eye with choroidal effusions requiring drainage. In our study, 1 eye had mild corneal edema at a 2-year follow-up, and there were no eyes with persistent hypotony. Alteration of the Baerveldt 350 GDD with tube fenestrations has also been proposed for immediate postoperative lowering of IOP. Kansal et al.16 found that placing 1 to 3 tube fenestrations just anterior to an occlusive ligature led to a 77% success rate defined as IOP control in the first 14 postoperative days without a need for surgical intervention or evidence of hypotony.
Simultaneous placement of 2 glaucoma drainage devices—Momont et al. Postoperative hypertension requiring surgical intervention or intraluminal suture removal occurred in 9% of patients, whereas postoperative hypotony occurred in 13.9% of patients. These findings highlight the unpredictable nature of tube fenestrations. The Ahmed valve is also offered in a double-plate design with a total surface area of 364 mm². In a review of 50 eyes treated with the double-plate Ahmed GDD, a 43.8% decline in IOP was observed at the most recent follow-up. However, in that study, postoperative disconnection of the 2 plates did occasionally occur.17 Our study is limited by a retrospective design, as well as a small number of patients and variable lengths of followup. Despite the limitations, our study does show that simultaneous GDD implantation can provide immediate and long-term IOP control with few complications in patients with refractory glaucoma. This strategy may benefit those eyes with very high preoperative IOP refractory to medical therapy with concomitant advanced glaucomatous damage that are at risk for blindness in the immediate postoperative period by providing both shortterm and long-term IOP control.
3. 4. 5. 6. 7. 8. 9. 10.
11. 12. 13.
Disclosure: The authors have no proprietary or commercial interest in any materials discussed in this article. 14.
Acknowledgements: Statistical support was provided by David Musch, PhD, MPH, and Leslie Niziol, MS. REFERENCES 1. Minckler DS, Francis BA, Hodapp EA, et al. Aqueous shunts in glaucoma: a report by the American Academy of Ophthalmology. Ophthalmology. 2008;115:1089-98. 2. Heuer DK, Lloyd MA, Abrams DA, et al. Which is better? One or two? A randomized clinical trial of single-plate versus double-plate
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