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CASE PRESENTATIONA 65-year-old white woman presented to the glaucoma service at the Illinois Eye & Ear Infirmary, Chicago, upon refer-

ral by her corneal specialist for increased IOP in each eye. The patient had an ocular history significant for autosomal domi-nant keratitis and had undergone successful bilateral 360° limbal stem cell transplantation 2 years earlier.

On presentation, she reported stable vision and stated she had no acute ocular complaints. Her ocular medications includ-ed a fixed combination of dorzolamide and timolol, latanoprost, prednisolone acetate, and cyclosporine in each eye. Her oral medication regimen included prednisone and sertraline. The patient had a documented local intolerance to topical brimoni-dine and pilocarpine.

She had a BCVA of 20/100 OU, and her IOP measured 29 mm Hg OD and 32 mm Hg OS. Central corneal thickness measured 604 µm OD and 503 µm OS. On gonioscopy, the anterior chamber angle in each eye was open. The slit-lamp examination demonstrated an intact limbal stem cell graft extending approximately 2 to 3 mm beyond the limbus in each

eye (Figure 1). A funduscopic examination revealed advanced optic nerve head cupping in each eye, and automated visual field testing showed a dense inferior scotoma in each eye (Figure 2). A trial of therapy with oral methazolamide caused the patient gastrointestinal distress, fatigue, and dizziness.

HOW WOULD YOU PROCEED?• Would you perform trabeculectomy surgery with an adjunc-

tive antifibrotic agent?• A microinvasive glaucoma surgical procedure?• Diode laser cyclophotocoagulation via an internal or external

approach?• Glaucoma drainage implant surgery?

SURGICAL COURSEGiven the presence of a healthy corneal limbal stem cell graft,

we were hesitant to perform trabeculectomy surgery with an adjunctive antifibrotic agent, which would have necessitated manipulation of the graft and might have increased the risk of irreversible corneal stem cell damage. We were also concerned that diode laser cyclophotocoagulation via either an internal or external approach would increase the risk of ocular inflamma-tion and subsequent failure of the corneal limbal stem cell graft. Given the advanced nature of the patient’s glaucomatous optic neuropathy, we thought it unlikely that a microinvasive glau-coma surgery would sufficiently lower the IOP.

GLAUCOMA AFTER CORNEAL LIMBAL STEM CELL TRANSPLANTATIONBY AHMAD A. AREF, MD; KAVITHA R. SIVARAMAN, MD; AND ALI R. DJALILIAN, MD

Figure 1. Preoperatively, the ocular surface transplant is

intact. A fornix-based incision would result in localized graft

destruction.

Figure 2. Automated visual field tests with a size V stimulus

demonstrating dense inferior field loss in each eye.

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We therefore elected to perform glaucoma drainage implant surgery using a limbus-based approach to avoid manipulation of the corneal limbal stem cell graft (Figure 3). We placed the tube portion of the device in the ciliary sulcus to decrease the risk of contact with the corneal endothelium.

OUTCOMEThe patient’s IOP measured below 15 mm Hg on all visits

after 2 years of follow-up. A slit-lamp examination demonstrat-ed well-positioned tube implants in the ciliary sulcus of each eye (Figure 4). Her visual field defects have remained stable with no evidence of progression. Fluorescein staining continues to show a healthy corneal surface (Figure 5), indicating viability of her ocular surface transplants.

DISCUSSIONPatients with a history of ocular surface transplantation often

have coexisting glaucomatous optic neuropathy. Tsai et al reported an overall prevalence of 65.7%, ranging from 42.9% to 88.4% according to ocular surface disease subgroup, in 108 eyes.1

Underlying mechanisms of glaucoma include congenital anomalies of the filtering angle associated with aniridia and inflammation/scarring of the ocular surface in patients with severe chemical and thermal injuries. A new onset of glaucoma after limbal stem cell transplantation likely relates to the need for long-term topical steroidal therapy. Unfortunately, the occurrence of glaucomatous optic neuropathy may lead to irreversible visual field loss and a compromised visual outcome after otherwise successful ocular surface transplantation. The presence of glaucoma in this population requires a balanced approach to IOP lowering in order to decrease the risk of irre-versible glaucomatous visual field loss while also minimizing the risk of further iatrogenic limbal stem cell damage.

Initially, topical medication may be effective in lowering IOP in this patient population, but local toxicity or intolerance often precludes the agents’ long-term use.2 Oral carbonic anhydrase inhibitor therapy may be an option, but these agents are often associated with adverse effects, including gastrointestinal symp-toms, paresthesias, fatigue, electrolyte alterations, and nephro-lithiasis.3 Standard trabeculectomy surgery has been shown to cause iatrogenic stem cell damage.4 Laser cyclophotocoagula-tion may incite ocular inflammation and threaten long-term survival of the ocular surface transplant.5 Glaucoma drainage

implant surgery is a useful option, but anterior chamber place-ment of the tube increases the risk of corneal decompensa-tion from presumed endothelial cell contact. The technique described herein for glaucoma drainage implant surgery via a limbus-based conjunctival incision and tube placement in the ciliary sulcus may be an effective option for patients with a his-tory of ocular surface transplantation.6 n

1. Tsai JH, Derby E, Holland EJ, Khatana AK. Incidence and prevalence of glaucoma in severe ocular surface disease. Cornea. 2006;25:530-532.2. Holland EJ, Schwartz GS. The Paton lecture: ocular surface transplantation: 10 years’ experience. Cornea. 2004;23:425-431.3. Franfelder FT, Bagby GC. Monitoring patients taking oral carbonic anhydrase inhibitors. Am J Ophthalmol. 2000;130:221-223.4. Schwartz GS, Holland EJ. Iatrogenic limbal stem cell deficiency: when glaucoma management contributes to corneal disease. J Glaucoma. 2001;10:443-445.5. Oltra EZ, Djalilian AR, Wilensky JT. Diode laser transscleral cyclophotocoagulation for refractory glaucoma after limbal allograft transplantation. Poster presented at: American Academy of Ophthalmology Annual Meeting; October 22-25, 2011; Orlando, FL.6. Aref AA, Sivaraman KR, Djalilian AR. Glaucoma drainage implant surgery and ocular surface transplant graft preservation. Semin Ophthalmol. 2015;30:210-213.

Figure 3. The surgeon uses a limbus-based incision to place

a nonvalved glaucoma drainage device.

Figure 4. Postoperatively, the tubes implanted in the

ciliary sulcus space of the right (A) and left (B) eyes are well

positioned.

Figure 5. After surgery, a healthy fluorescein staining pattern

indicates viability of the ocular surface transplant graft.

Ahmad A. Aref, MDn assistant professor of ophthalmology, residency program director,

Illinois Eye & Ear Infirmary, University of Illinois at Chicago College of Medicine

n (312) 996-7030; aaref@uic.edu; Twitter @ahmadarefn financial interest: none acknowledged

Ali R. Djalilian, MDn associate professor of ophthalmology, Illinois Eye & Ear Infirmary,

University of Illinois at Chicago College of Medicinen adjalili@uic.edun financial interest: none acknowledged

Kavitha R. Sivaraman, MDn associate professor, Cincinnati Eye Institute, University of

Cincinnati Department of Ophthalmology n kavitha.sivaraman@gmail.comn financial interest: none acknowledged