In late 2006, a 55-year-old white female presented to the Kresge Eye Institute in Detroit with a complaint of decreasing vision and pain in her right eye during the past week. She had no significant past medical, surgical, or ocular history. Her BCVA was 20/100 OD and 20/25 OS, and her IOPs measured 56 mm Hg OD and 17 mm Hg OS by Goldmann applanation tonometry.
Her right pupil was dilated to midsize and reacted sluggishly to light. A slit-lamp examination of her right eye showed microcystic edema and a “hammered silver” appearance of the endothelium as well as mild shallowing of the anterior chamber, iridal atrophy, peripheral iridal transillumination defects, glaukomflecken, and temporal pupillary peaking (Figure 1). Her left eye was normal except for a mild cataract.
Figure 1. The slit-lamp examination of the patient's right eye showed corneal changes, mild corectopia, and glaukomflecken.
Both eyes had pink optic discs, 0.6 cup-to-disc ratios, and healthy rims. Gonioscopy of the right eye was hazy but showed a nearly 360º angle closure that did not open with goniocompression. The patient's left eye had an occludable angle that opened with goniocompression.
We treated the patient in the office with maximal topical therapy and oral acetazolamide. Her IOP responded well to the treatment, and her cornea cleared moderately through the day. We performed a prophylactic laser peripheral iridotomy to her left eye and sent her home on maximal topical therapy and oral acetazolamide. The next day, her IOPs were markedly reduced to 16 mm Hg OD and 13 mm Hg OS.
Our differential diagnosis at this time included iridocorneal endothelial (ICE) syndrome, primary acute angle closure, posterior polymorphous dystrophy, and Axenfeld-Reiger syndrome. We ordered specular microscopy to further evaluate the right eye's corneal endothelium, which showed significant pleomorphism in the cells' size and shape as well as a loss of clear hexagonal margins. These findings rule out a diagnosis of primary acute angle closure. We were also able to dismiss posterior polymorphous dystrophy and Axenfeld-Reiger syndromes due to the unilateral occurrence of the patients' ocular symptoms and a lack of family history. We therefore diagnosed the patient with ICE syndrome.
When the patient returned 1 week later, the IOP in her right eye was 40 mm Hg despite maximal topical therapy and oral acetazolamide.
How would you proceed?
1. Would you perform a trabeculectomy with mitomycin C?
2. Would you place a glaucoma drainage device?
3. If you placed a drainage device, which would you choose?
Surgical Course
We decided to perform surgery on the patient's right eye. After a lengthy discussion with her and her family, we decided to implant an Ex-Press R-50 mini shunt (Optonol Ltd., Zug, Switzerland) under a scleral flap with adjunctive mitomycin C.
The patient's surgery was uncomplicated, and her postoperative IOPs ranged from 7 mm Hg (day 1) to 12 mm Hg (day 10). Her anterior chamber was well formed with a diffuse posterior bleb.
Outcome
Three weeks postoperatively, the patient returned for a follow-up examination with a complaint of pain in her right eye. Her IOP measured 43 mm Hg OD, which decreased to 12 mm Hg with massage and suture release. At this time, we performed a prophylactic laser iridotomy on her right eye to resolve a mild pupillary block. The second releasable suture was removed from her eye during her 1-month postoperative evaluation.
By 6 weeks postoperatively, the patient's BCVA measured 20/50 OD. The IOP was 12 mm Hg, the bleb was well formed and functional, and the anterior chamber was formed and quiet (Figure 2). She was using only one topical medication (prednisolone acetate 1%) four times per day.
Figure 2. The patient developed a shallow, diffuse bleb in her right eye after receiving an Ex-Press R-50 mini shunt.
Discussion
The Ex-Press mini shunt was first developed in 1998. The device showed early promise for reducing IOP, but it quickly fell out of favor due to an unacceptably high rate of complications with its subconjunctival implantation.1 Investigators who placed the mini shunt under a scleral flap, however, found that the device's IOP-lowering efficacy was similar to that of trabeculectomy but caused fewer postoperative complications.2,3 These findings have led to a resurgence in the device's implantation.
The Ex-Press R-50 mini shunt is a 3-mm long stainless steel device with a 50-µm lumen that facilitates aqueous' egress from the anterior chamber into the subconjunctival space.4 In our practice, we place the implant under a partial-thickness scleral flap and use the same surgical algorithm (including the application of antifibrotic agents, the placement of releasable sutures, and patient selection) for both the Ex-Press mini shunt's implantation and the trabeculectomy procedure.
Because managing glaucoma surgically in patients with ICE syndrome can be challenging, the first-line treatment should include topical aqueous suppressants and oral carbonic anhydrase inhibitors. If the patient does not respond to this regimen or the medications lose their efficacy, surgery may be warranted.
Different surgical approaches for ICE syndrome have yielded mixed results. The current literature shows that these patients have a lower initial success rate with filtering surgery than those with other types of glaucoma.5,6 Trabeculectomy with antifibrotic agents and the implantation of glaucoma drainage devices are very successful (73% and 71%, respectively) in patients with ICE syndrome at 1 year postoperatively, but the efficacy of these approaches declines significantly (29% and 53%, respectively) by 5 years postoperatively.7
Surgical treatments for ICE syndrome can fail for several reasons. The complications commonly associated with glaucoma drainage devices include the migration or obstruction of the implant. Trabeculectomy can fail due to the closure of the sclerectomy site by an endothelial cell membrane. Aqueous shunts are also prone to failure in these patients. One study showed that 30% of these devices implanted in patients with ICE syndrome required revision due to the complications described earlier.8
Our preferred initial surgery for glaucoma patients with ICE syndrome is trabeculectomy with an antifibrotic agent, but we have encountered failures like those described in the literature in this population. The next step for patients with failed trabeculectomies is the implantation of a glaucoma drainage device. In our practice, we use the polypropylene Ahmed glaucoma implant (New World Medical, Inc., Rancho Cucamonga, CA), because its valves allow an immediate reduction in IOP with a minimal risk of early postoperative hypotony.
We feel that the Ex-Press shunt combines the advantages of trabeculectomy and aqueous drainage devices such as the Ahmed valve. Its steel construction and multiple drainage ports may make it to more resistant to migration and occlusion by endothelial cell membranes than other surgical treatments for ICE syndrome. The Ex-Press shunt also eliminates the risk of motility deficits and diplopia compared to aqueous drainage devices, because it does not impinge on the function of the extraocular muscles. In our experience, the Ex-Press mini shunt also appears to cause less postoperative inflammation than other drainage devices because patients do not have to undergo iridectomy or sclerotomy to improve the device's function. Further experience may show that this device is a viable alternative for treating patients with ICE syndrome.
Jason M. Yonker, MD, is a glaucoma fellow at Wayne State University, Kresge Eye Institute, Detroit. He acknowledged no financial interest in the products or companies mentioned herein.
Dr. Yonker may be reached at yonker@comcast.net.
Mark S. Juzych, MD, MHSA, is Professor of Ophthalmology at Wayne State University, Kresge Eye Institute, Detroit. He acknowledged no financial interest in the products or companies mentioned herein. Dr. Juzych may be reached at (313) 577-7614; mjuzych@med.wayne.edu.
1. Wamsley S, Moster M, Rai S, et al. Results of the use of the Ex-PRESS miniature glaucoma implant in technically challenging, advanced glaucoma cases: a clinical pilot study. Am J Ophthalmol. 2004;138:1049-1051.
2. Dahan E, Carmichael TR. Implantation of a miniature glaucoma device under a scleral flap. J Glaucoma. 2005;14:98-102.
3. Maris PJ Jr, Ishida K, Netland PA. Comparison of trabeculectomy with Ex-Press miniature glaucoma device under a scleral flap. J Glaucoma. 2007;16:14-19.
4. Nyska ADVM, Abraham DVM, Glovinsky Y, et al. Biocompatibility of the Ex-Press miniature glaucoma drainage implant. J Glaucoma. 2003;12:275-280.
5. Laganowski HC, Kerr Muir MG, Hitchings RA. Glaucoma and the iridocorneal endothelial syndrome. Arch Ophthalmol. 1992;110:346-350.
6. Kidd M, Hetherington J, Magee S. Surgical results in iridocorneal endothelial syndrome. Arch Ophthalmol. 1988;106:199-201.
7. Doe EA, Budenz DL, Gedde SG, Imami NR. Long-term surgical outcomes of patients with glaucoma secondary to iridocorneal endothelial syndrome. Ophthalmology. 2001;108:1789-1795.
8. Kim DK, Aslanides IM, Schmidt CM Jr, et al. Long-term outcome of aqueous shunt surgery in ten patients with iridocorneal endothelial syndrome. Ophthalmology. 1999;106:1030-1034.
